1 00:00:04,430 --> 00:00:02,330 I'll scope public lecture series it is 2 00:00:06,769 --> 00:00:04,440 my pleasure to be your host I'm dr. 3 00:00:08,839 --> 00:00:06,779 Frank summers of the office of public 4 00:00:12,259 --> 00:00:08,849 outreach here at the Space Telescope 5 00:00:14,839 --> 00:00:12,269 Science Institute and when you came in 6 00:00:18,200 --> 00:00:14,849 if you notice them we have pictures 7 00:00:20,359 --> 00:00:18,210 we call these lithographs this one is of 8 00:00:23,179 --> 00:00:20,369 a brand-new one Nevernever everything 9 00:00:25,790 --> 00:00:23,189 this is the multi-wavelength Crab Nebula 10 00:00:27,609 --> 00:00:25,800 what do we mean by multi-wavelength well 11 00:00:29,810 --> 00:00:27,619 if you turn over you can see that this 12 00:00:33,470 --> 00:00:29,820 individual image the different colors 13 00:00:36,080 --> 00:00:33,480 are composed of light from six different 14 00:00:39,260 --> 00:00:36,090 five different wavelengths okay from 15 00:00:41,299 --> 00:00:39,270 x-ray all the way to radio and we have 16 00:00:43,850 --> 00:00:41,309 some explanatory text you didn't grab 17 00:00:47,690 --> 00:00:43,860 one on the way in for have one now or on 18 00:00:55,160 --> 00:00:47,700 your way out our talk tonight is the 19 00:00:56,779 --> 00:00:55,170 plumes of Europa ice water life which 20 00:00:58,939 --> 00:00:56,789 Susannah thought would be a cool title 21 00:01:02,200 --> 00:00:58,949 to bring in an audience and it is 22 00:01:05,000 --> 00:01:02,210 alright next month we will have 23 00:01:07,700 --> 00:01:05,010 gravitational wave astronomy which is 24 00:01:09,679 --> 00:01:07,710 now a field something we'd been thinking 25 00:01:13,120 --> 00:01:09,689 about for decades and it's now become a 26 00:01:16,070 --> 00:01:13,130 field our local expert and the fructose 27 00:01:17,330 --> 00:01:16,080 the month after that will feature Fisher 28 00:01:19,910 --> 00:01:17,340 is going to talk about one of my 29 00:01:23,600 --> 00:01:19,920 favorite places in the universe star 30 00:01:25,280 --> 00:01:23,610 formation in the Orion Nebula we're 31 00:01:27,530 --> 00:01:25,290 looking forward to hearing that and then 32 00:01:30,440 --> 00:01:27,540 in July we have one of these really long 33 00:01:33,440 --> 00:01:30,450 titles to call with the Milky Way's 34 00:01:36,770 --> 00:01:33,450 bulge from a hypothesized blob to a 35 00:01:39,859 --> 00:01:36,780 remarkably detailed picture talking 36 00:01:42,260 --> 00:01:39,869 about the center of our galaxy and the 37 00:01:44,300 --> 00:01:42,270 stars that orbit around it out in our 38 00:01:46,700 --> 00:01:44,310 center called the Bulge of our galaxy 39 00:01:49,340 --> 00:01:46,710 okay if you want to learn more about 40 00:01:51,530 --> 00:01:49,350 those or remind yourself of them you can 41 00:01:53,899 --> 00:01:51,540 go to our web page if you go to your 42 00:01:55,520 --> 00:01:53,909 favorite search engine and type in Space 43 00:01:57,649 --> 00:01:55,530 Telescope or Hubble public talks you'll 44 00:02:00,230 --> 00:01:57,659 find this page where we have the list of 45 00:02:03,639 --> 00:02:00,240 the upcoming lectures oops there we go I 46 00:02:06,859 --> 00:02:03,649 think my my lasers it's going all right 47 00:02:10,010 --> 00:02:06,869 we have also on the left-hand side we 48 00:02:11,930 --> 00:02:10,020 have the links for the webcasting both 49 00:02:13,910 --> 00:02:11,940 the Space Telescope webcast II and our 50 00:02:15,949 --> 00:02:13,920 YouTube events the live ones 51 00:02:18,770 --> 00:02:15,959 are active now because it's we're going 52 00:02:23,120 --> 00:02:18,780 live now the archived ones go all the 53 00:02:26,479 --> 00:02:23,130 way back to 2014 on YouTube and 2005 on 54 00:02:28,880 --> 00:02:26,489 the STScI webcast site you can also sign 55 00:02:31,490 --> 00:02:28,890 up for our email list which gets you 56 00:02:36,440 --> 00:02:31,500 about two emails a month reminding you 57 00:02:38,300 --> 00:02:36,450 of the lectures upcoming that email is 58 00:02:40,520 --> 00:02:38,310 on here just sign up at the website and 59 00:02:42,620 --> 00:02:40,530 those of you who can't handle going to a 60 00:02:44,000 --> 00:02:42,630 website can write it down on a piece of 61 00:02:45,800 --> 00:02:44,010 paper and hand it to me at the end of 62 00:02:48,800 --> 00:02:45,810 the lecture and I can make sure you get 63 00:02:50,210 --> 00:02:48,810 on the email list if you have comments 64 00:02:52,759 --> 00:02:50,220 or questions you can send them to the 65 00:02:57,770 --> 00:02:52,769 email address public lecture at STScI 66 00:02:59,420 --> 00:02:57,780 dot edu we have social media for both 67 00:03:01,520 --> 00:02:59,430 the Hubble Space Telescope the Webb 68 00:03:04,400 --> 00:03:01,530 Space Telescope and the Space Telescope 69 00:03:08,420 --> 00:03:04,410 Science Institute on Facebook Twitter 70 00:03:11,240 --> 00:03:08,430 YouTube and Instagram I myself am on 71 00:03:13,520 --> 00:03:11,250 Facebook Google+ and Twitter but don't 72 00:03:17,780 --> 00:03:13,530 expect a lot from me ID I spend a lot of 73 00:03:19,039 --> 00:03:17,790 my time doing other a lot of different 74 00:03:20,590 --> 00:03:19,049 astronomy things that I don't have too 75 00:03:23,750 --> 00:03:20,600 much time to do social media 76 00:03:26,690 --> 00:03:23,760 the observatory across the street will 77 00:03:29,270 --> 00:03:26,700 not be open as you might guess from the 78 00:03:32,840 --> 00:03:29,280 weather outside it's cloudy and a little 79 00:03:34,789 --> 00:03:32,850 bit rainy but they also have open houses 80 00:03:38,449 --> 00:03:34,799 on Friday evenings if you go to their 81 00:03:40,940 --> 00:03:38,459 website MD dot space grant dot o-r-g you 82 00:03:43,190 --> 00:03:40,950 will find that page on the on the right 83 00:03:45,650 --> 00:03:43,200 hand side and in that box that says 84 00:03:48,170 --> 00:03:45,660 Observatory status each Friday evening 85 00:03:49,610 --> 00:03:48,180 by about like 5 or 6 p.m. they post 86 00:03:52,819 --> 00:03:49,620 whether or not they're going to be open 87 00:03:54,199 --> 00:03:52,829 for public observing so yet again we are 88 00:03:57,199 --> 00:03:54,209 unable to take you across the street 89 00:03:59,509 --> 00:03:57,209 after the lecture for that tonight to 90 00:04:02,199 --> 00:03:59,519 the public lecture but hopefully you can 91 00:04:04,819 --> 00:04:02,209 find it on one of the Friday nights and 92 00:04:10,629 --> 00:04:04,829 now our news from the universe for 93 00:04:13,789 --> 00:04:10,639 April 2018 our first story unfortunately 94 00:04:16,610 --> 00:04:13,799 is the James Webb Space Telescope had 95 00:04:18,979 --> 00:04:16,620 another launch delay all right and the 96 00:04:22,510 --> 00:04:18,989 NASA press this is the James Webb Space 97 00:04:26,240 --> 00:04:22,520 Telescope it is a six and a half meter 98 00:04:26,890 --> 00:04:26,250 infrared space telescope that was it's 99 00:04:30,550 --> 00:04:26,900 it's 100 00:04:33,610 --> 00:04:30,560 challenging things we've ever launched 101 00:04:35,590 --> 00:04:33,620 into space possibly the most technically 102 00:04:39,850 --> 00:04:35,600 challenging civilian thing we've ever 103 00:04:41,920 --> 00:04:39,860 launched into space and the NASA press 104 00:04:45,969 --> 00:04:41,930 release stated that the launch window is 105 00:04:48,749 --> 00:04:45,979 now targeted for approximately May 2020 106 00:04:52,260 --> 00:04:48,759 yes we have to wait another year for it 107 00:04:55,390 --> 00:04:52,270 all the observatory but I pulled out 108 00:04:57,610 --> 00:04:55,400 specific quotes all right first of all 109 00:05:00,969 --> 00:04:57,620 all the observatories flight hardware is 110 00:05:02,620 --> 00:05:00,979 now complete okay so if they've got the 111 00:05:04,930 --> 00:05:02,630 spacecraft element and they've got the 112 00:05:06,730 --> 00:05:04,940 telescope element the stuff is complete 113 00:05:09,580 --> 00:05:06,740 and it's all together for the first time 114 00:05:12,189 --> 00:05:09,590 in the Northrop Grumman facility all 115 00:05:13,870 --> 00:05:12,199 right it is undergoing final integration 116 00:05:16,930 --> 00:05:13,880 and test phases that will require more 117 00:05:18,430 --> 00:05:16,940 time to ensure a successful mission we 118 00:05:20,529 --> 00:05:18,440 all remember what happened with the 119 00:05:22,290 --> 00:05:20,539 Hubble Space Telescope having a problem 120 00:05:24,999 --> 00:05:22,300 that needed to be fixed 121 00:05:27,850 --> 00:05:25,009 j2 st is going to be a million miles 122 00:05:29,710 --> 00:05:27,860 from Earth it's not gonna be a low Earth 123 00:05:32,680 --> 00:05:29,720 orbit like Hubble was it cannot be fixed 124 00:05:34,480 --> 00:05:32,690 when it is out there so it is extremely 125 00:05:37,270 --> 00:05:34,490 important to get it right and get it 126 00:05:39,370 --> 00:05:37,280 right the first time as one of the 127 00:05:41,439 --> 00:05:39,380 juniors to engineers says we got to 128 00:05:43,839 --> 00:05:41,449 knock this out of the park a million 129 00:05:45,670 --> 00:05:43,849 miles out of the park all right so yeah 130 00:05:47,740 --> 00:05:45,680 we are taking the time until you to get 131 00:05:50,170 --> 00:05:47,750 it correct and then the other question 132 00:05:52,120 --> 00:05:50,180 people have is about the budget NASA 133 00:05:53,770 --> 00:05:52,130 will provide a new cost estimate that 134 00:05:55,990 --> 00:05:53,780 may exceed the projected 8 billion 135 00:05:58,270 --> 00:05:56,000 development cost to complete the final 136 00:06:00,250 --> 00:05:58,280 phase of testing and prepare for launch 137 00:06:03,250 --> 00:06:00,260 which means that they are currently 138 00:06:05,230 --> 00:06:03,260 evaluating what the delay will cost and 139 00:06:09,520 --> 00:06:05,240 they will provide it to the American 140 00:06:11,230 --> 00:06:09,530 public when they have that okay so it is 141 00:06:13,149 --> 00:06:11,240 still going to do the same great science 142 00:06:16,570 --> 00:06:13,159 we're just gonna have to wait a little 143 00:06:18,129 --> 00:06:16,580 bit longer for it but it is as I said 144 00:06:20,860 --> 00:06:18,139 really important that we get it right 145 00:06:22,740 --> 00:06:20,870 the first time so it's to me it's worth 146 00:06:25,270 --> 00:06:22,750 the extra time ok 147 00:06:29,350 --> 00:06:25,280 second story tonight 148 00:06:34,930 --> 00:06:29,360 planetary construction dust now this 149 00:06:38,080 --> 00:06:34,940 image is up ace of a a disk or actually 150 00:06:39,600 --> 00:06:38,090 a ring around a star that's called HR 47 151 00:06:42,899 --> 00:06:39,610 96 a 152 00:06:46,110 --> 00:06:42,909 okay and it came out in 1999 this is a 153 00:06:48,420 --> 00:06:46,120 Hubble image and I was really excited 154 00:06:50,189 --> 00:06:48,430 when I saw this because I wasn't here at 155 00:06:53,159 --> 00:06:50,199 the time I was up in New York City and 156 00:06:55,469 --> 00:06:53,169 we were discussing the new discoveries 157 00:06:59,270 --> 00:06:55,479 in our own solar system in particular 158 00:07:01,820 --> 00:06:59,280 the Kuiper belt okay this new region of 159 00:07:05,129 --> 00:07:01,830 objects out beyond the orbit of Neptune 160 00:07:07,499 --> 00:07:05,139 all right and this is where Pluto lives 161 00:07:10,860 --> 00:07:07,509 ok Pluto is now the largest member of 162 00:07:12,360 --> 00:07:10,870 the Kuiper belt and so when you look in 163 00:07:14,339 --> 00:07:12,370 the lower right and you see that the 164 00:07:17,700 --> 00:07:14,349 diameter of Neptune's orbit is that and 165 00:07:19,769 --> 00:07:17,710 this ring of material um is just larger 166 00:07:21,480 --> 00:07:19,779 it kind of got us excited because we 167 00:07:23,490 --> 00:07:21,490 were just discovering the Kuiper belt in 168 00:07:26,219 --> 00:07:23,500 our own system and here we were finding 169 00:07:27,809 --> 00:07:26,229 something of the same scale however this 170 00:07:31,830 --> 00:07:27,819 isn't the Kuiper belt okay it's not made 171 00:07:34,260 --> 00:07:31,840 of ice this is made of dust and it's you 172 00:07:35,490 --> 00:07:34,270 don't even expect it to be a fully 173 00:07:40,409 --> 00:07:35,500 formed Kuiper belt type thing because 174 00:07:45,029 --> 00:07:40,419 the star HR 47 96 a is only 8 million 175 00:07:47,760 --> 00:07:45,039 years old but at 8 million years that's 176 00:07:48,469 --> 00:07:47,770 the time scale on which giant planets 177 00:07:54,540 --> 00:07:48,479 form 178 00:07:57,079 --> 00:07:54,550 order 10 million years so seeing a dust 179 00:08:01,200 --> 00:07:57,089 ring that's so tightly correlated here 180 00:08:03,269 --> 00:08:01,210 could indicate that a giant planet had 181 00:08:05,670 --> 00:08:03,279 formed in this system has recently 182 00:08:09,029 --> 00:08:05,680 formed in this system and that makes is 183 00:08:11,730 --> 00:08:09,039 exciting now so we can take this image 184 00:08:14,129 --> 00:08:11,740 we're gonna shrink it and rotate it okay 185 00:08:17,670 --> 00:08:14,139 that's the exact same image okay and now 186 00:08:22,290 --> 00:08:17,680 we have a new image of HR 47 96 a that 187 00:08:25,079 --> 00:08:22,300 looks like that yeah more sensitive 188 00:08:27,990 --> 00:08:25,089 looking deeper and seeing dust not in 189 00:08:32,550 --> 00:08:28,000 just a tight ring but actually spread 190 00:08:35,819 --> 00:08:32,560 out across the system see 47 96 a is 191 00:08:39,060 --> 00:08:35,829 about 23 times more luminous than the 192 00:08:42,300 --> 00:08:39,070 Sun right so therefore it has a lot more 193 00:08:44,420 --> 00:08:42,310 radiation pressure and so while giant 194 00:08:47,760 --> 00:08:44,430 planets formed on order 10 million years 195 00:08:50,250 --> 00:08:47,770 planets like Earth form on timescales of 196 00:08:53,130 --> 00:08:50,260 a hundred million years and in the 197 00:08:55,530 --> 00:08:53,140 process of building up tourists 198 00:08:56,750 --> 00:08:55,540 planets you get a lot of things smashing 199 00:08:59,160 --> 00:08:56,760 together all right 200 00:09:01,230 --> 00:08:59,170 planetesimals accretion and that 201 00:09:03,870 --> 00:09:01,240 produces some dust right planetary 202 00:09:08,130 --> 00:09:03,880 construction dust and the radiation 203 00:09:10,259 --> 00:09:08,140 pressure from 47 96 a can actually blow 204 00:09:12,780 --> 00:09:10,269 some of that dust out of the system like 205 00:09:15,569 --> 00:09:12,790 this alright so the interpretation of 206 00:09:18,389 --> 00:09:15,579 this image is that some of this dust is 207 00:09:20,340 --> 00:09:18,399 coming from the form possibly coming or 208 00:09:22,410 --> 00:09:20,350 as a reasonable hypothesis is that it's 209 00:09:24,300 --> 00:09:22,420 coming from the formation of terrestrial 210 00:09:26,100 --> 00:09:24,310 planets that's kicking up dust and then 211 00:09:29,940 --> 00:09:26,110 being pushed out by the radiation 212 00:09:32,639 --> 00:09:29,950 pressure of this large star spreading it 213 00:09:35,220 --> 00:09:32,649 across the system so that's kind of cool 214 00:09:39,120 --> 00:09:35,230 and here is by the way all of the 215 00:09:40,740 --> 00:09:39,130 details of this so 47 96 a is in that 216 00:09:42,750 --> 00:09:40,750 dark spot there we block it out of 217 00:09:44,940 --> 00:09:42,760 course because if you have the star you 218 00:09:47,519 --> 00:09:44,950 can't see the dust around it you can see 219 00:09:49,800 --> 00:09:47,529 the the ring there's also you notice a 220 00:09:52,560 --> 00:09:49,810 bow shock that curved line because the 221 00:09:55,170 --> 00:09:52,570 star system is moving through medium so 222 00:09:57,180 --> 00:09:55,180 you get a thing and also in the lower 223 00:10:01,199 --> 00:09:57,190 right there's a dark circle there that 224 00:10:03,030 --> 00:10:01,209 is the companion star 47 96 B all right 225 00:10:04,380 --> 00:10:03,040 and actually I what I think is kind of 226 00:10:05,100 --> 00:10:04,390 cool which we didn't mark is in the 227 00:10:09,509 --> 00:10:05,110 lower left 228 00:10:11,130 --> 00:10:09,519 that's a background galaxy so we're 229 00:10:12,660 --> 00:10:11,140 looking at a star in our galaxy but 230 00:10:14,519 --> 00:10:12,670 we're also looking at a background 231 00:10:17,220 --> 00:10:14,529 galaxy in the same image here 232 00:10:19,560 --> 00:10:17,230 alright so we're this may be the dust 233 00:10:23,670 --> 00:10:19,570 kicked up by the construction of planets 234 00:10:27,660 --> 00:10:23,680 in another solar system final story a 235 00:10:29,460 --> 00:10:27,670 cosmology conundrum about a hundred 236 00:10:31,740 --> 00:10:29,470 years ago a little less than a hundred 237 00:10:34,680 --> 00:10:31,750 years ago Edwin Hubble made this diagram 238 00:10:37,650 --> 00:10:34,690 and on this diagram he's plotting galaxy 239 00:10:39,509 --> 00:10:37,660 distance against galaxy redshift and he 240 00:10:41,490 --> 00:10:39,519 found he got a straight line that 241 00:10:43,769 --> 00:10:41,500 galaxies that were further away had 242 00:10:46,620 --> 00:10:43,779 larger redshifts in a linear fashion and 243 00:10:49,230 --> 00:10:46,630 this is the primary motivating evidence 244 00:10:51,180 --> 00:10:49,240 for the expanding universe all right 245 00:10:53,130 --> 00:10:51,190 that space is expanding and therefore 246 00:10:56,069 --> 00:10:53,140 distant galaxies appear to be moving 247 00:10:59,639 --> 00:10:56,079 away faster in a linear fashion 248 00:11:01,050 --> 00:10:59,649 however the slope of it is the expansion 249 00:11:02,730 --> 00:11:01,060 rate of the universe the current 250 00:11:05,460 --> 00:11:02,740 expansion rate of the universe we call 251 00:11:06,600 --> 00:11:05,470 that the Hubble constant unfortunately 252 00:11:08,790 --> 00:11:06,610 he got the Hubble constant 253 00:11:10,920 --> 00:11:08,800 wrong because the way he was measuring 254 00:11:12,420 --> 00:11:10,930 distances depended him on Cepheid 255 00:11:14,190 --> 00:11:12,430 variables and he was using the wrong 256 00:11:16,769 --> 00:11:14,200 type of Cepheid variables so he got it 257 00:11:19,050 --> 00:11:16,779 wrong by about a factor of 10 but 258 00:11:23,100 --> 00:11:19,060 eventually we astronomers got it right 259 00:11:25,380 --> 00:11:23,110 so this plot shows a date on the x-axis 260 00:11:27,420 --> 00:11:25,390 and the value of H naught which is this 261 00:11:29,040 --> 00:11:27,430 Hubble constant starts out in the 262 00:11:31,110 --> 00:11:29,050 hundreds and then finally gets down to 263 00:11:33,900 --> 00:11:31,120 when I was in graduate school 264 00:11:37,019 --> 00:11:33,910 in the late 80s the values were between 265 00:11:38,550 --> 00:11:37,029 50 and 100 so yeah we went from being a 266 00:11:41,100 --> 00:11:38,560 factor of 10 off to being down to a 267 00:11:43,050 --> 00:11:41,110 factor of 2 and this is cosmology a 268 00:11:44,670 --> 00:11:43,060 factor of 2 is good all right I keep 269 00:11:46,730 --> 00:11:44,680 telling myself I'm an astronomer a 270 00:11:51,000 --> 00:11:46,740 factor of 2 is good enough for me right 271 00:11:52,560 --> 00:11:51,010 and so but that's still not good enough 272 00:11:55,620 --> 00:11:52,570 to do what we call precision cosmology 273 00:11:58,590 --> 00:11:55,630 so when the hubble space telescope came 274 00:12:00,720 --> 00:11:58,600 online one of its key projects was 275 00:12:03,750 --> 00:12:00,730 measuring the Hubble constant by getting 276 00:12:05,460 --> 00:12:03,760 accurate distances to near near galaxies 277 00:12:08,220 --> 00:12:05,470 so that we could really measure the 278 00:12:12,990 --> 00:12:08,230 Hubble constant carefully as an HST key 279 00:12:15,930 --> 00:12:13,000 project in the year 2000 that the data 280 00:12:19,079 --> 00:12:15,940 was released and this is a graphic of 281 00:12:21,389 --> 00:12:19,089 the diagram showing that here the points 282 00:12:25,590 --> 00:12:21,399 plotted and plausible values were 283 00:12:27,269 --> 00:12:25,600 between 63 and 77 so that's great we've 284 00:12:28,680 --> 00:12:27,279 you know it's gone from you know being a 285 00:12:33,210 --> 00:12:28,690 factor of 10 off to down to a factor of 286 00:12:36,060 --> 00:12:33,220 2 down to 10% okay we had a difference 287 00:12:38,340 --> 00:12:36,070 of 10% but can we leave that alone 288 00:12:40,500 --> 00:12:38,350 no we're scientists we really want to 289 00:12:42,780 --> 00:12:40,510 beat that down and beat that down so 290 00:12:44,699 --> 00:12:42,790 what they have done with Hubble recently 291 00:12:48,300 --> 00:12:44,709 is they went back and remeasure the 292 00:12:51,569 --> 00:12:48,310 Cepheid in our galaxy the calibration 293 00:12:53,970 --> 00:12:51,579 method as well as doing other things and 294 00:12:57,870 --> 00:12:53,980 we are able in this new paper that just 295 00:13:02,189 --> 00:12:57,880 came out get it down to a range of 72 to 296 00:13:07,270 --> 00:13:02,199 75 success we finally have this Hubble 297 00:13:10,390 --> 00:13:07,280 constant measured except 298 00:13:13,450 --> 00:13:10,400 in the meantime we have developed other 299 00:13:15,940 --> 00:13:13,460 ways estimating the Hubble constant one 300 00:13:18,040 --> 00:13:15,950 of them depends upon measuring the 301 00:13:20,140 --> 00:13:18,050 Cosmic Microwave Background this is the 302 00:13:22,030 --> 00:13:20,150 Coby satellite the first measurement of 303 00:13:24,310 --> 00:13:22,040 the cosmic wave background which then 304 00:13:25,930 --> 00:13:24,320 got refined with the W map satellite and 305 00:13:28,300 --> 00:13:25,940 then got improved as to still a little 306 00:13:31,030 --> 00:13:28,310 bit more with the Planck satellite and 307 00:13:33,190 --> 00:13:31,040 this is measuring the temperature 308 00:13:34,510 --> 00:13:33,200 differences which is basically the 309 00:13:37,390 --> 00:13:34,520 density differences in the early 310 00:13:38,800 --> 00:13:37,400 universe and from that what we really 311 00:13:39,760 --> 00:13:38,810 measure out of the the COTS microwave 312 00:13:42,550 --> 00:13:39,770 background is something we call the 313 00:13:45,100 --> 00:13:42,560 power spectrum which is how much density 314 00:13:47,980 --> 00:13:45,110 is on different scales in the early 315 00:13:49,630 --> 00:13:47,990 universe and from that you know we can 316 00:13:51,040 --> 00:13:49,640 extrapolate through to the rest of the 317 00:13:54,460 --> 00:13:51,050 universe and start figuring out the 318 00:13:57,400 --> 00:13:54,470 expansion rate in particular the second 319 00:14:00,010 --> 00:13:57,410 peak of this power spectrum is sensitive 320 00:14:03,100 --> 00:14:00,020 to the hubble value the expansion rate 321 00:14:05,500 --> 00:14:03,110 of the universe okay and so its location 322 00:14:07,600 --> 00:14:05,510 and its its magnitude gives us a good 323 00:14:09,250 --> 00:14:07,610 estimate of the Hubble constant it 324 00:14:11,530 --> 00:14:09,260 doesn't give us a perfect estimate but 325 00:14:13,660 --> 00:14:11,540 it gives us a good estimate combine that 326 00:14:16,150 --> 00:14:13,670 with two other ways of measuring things 327 00:14:18,460 --> 00:14:16,160 one from supernovae and one from 328 00:14:21,970 --> 00:14:18,470 something called baryon acoustic 329 00:14:24,280 --> 00:14:21,980 oscillations it's labeled Bao I'm not 330 00:14:26,790 --> 00:14:24,290 gonna try and explain that in 30 seconds 331 00:14:29,320 --> 00:14:26,800 here it doesn't work but trust me 332 00:14:30,550 --> 00:14:29,330 combining the three of them the Cosmic 333 00:14:33,520 --> 00:14:30,560 Microwave Background baryon acoustic 334 00:14:35,860 --> 00:14:33,530 oscillations and the supernovae you can 335 00:14:38,650 --> 00:14:35,870 get another estimate of the Hubble 336 00:14:40,600 --> 00:14:38,660 constant independent of the Cepheid 337 00:14:46,810 --> 00:14:40,610 variables and all that and it comes out 338 00:14:49,240 --> 00:14:46,820 to 65 to 69 here's the problem both of 339 00:14:51,430 --> 00:14:49,250 these methods are tried-and-true both of 340 00:14:53,950 --> 00:14:51,440 these methods are we believe are 341 00:14:57,160 --> 00:14:53,960 estimating their errors well all right 342 00:15:00,370 --> 00:14:57,170 the local ones 72 to 75 the large-scale 343 00:15:01,780 --> 00:15:00,380 ones 65 to 69 and the quote from Adam 344 00:15:03,670 --> 00:15:01,790 riess the head of the researcher says 345 00:15:06,579 --> 00:15:03,680 both results have been tested multiple 346 00:15:09,310 --> 00:15:06,589 ways so barring a series of unrelated 347 00:15:11,920 --> 00:15:09,320 mistakes it is increasingly likely that 348 00:15:14,560 --> 00:15:11,930 this is not a bug but a feature of the 349 00:15:16,390 --> 00:15:14,570 universe that are local estimates of the 350 00:15:18,490 --> 00:15:16,400 Hubble value Hubble constant value 351 00:15:20,830 --> 00:15:18,500 differ from our large-scale measure 352 00:15:24,220 --> 00:15:20,840 estimates of the Hubble value 353 00:15:26,320 --> 00:15:24,230 what do we do okay well if you read the 354 00:15:29,230 --> 00:15:26,330 news bag news news about this 355 00:15:30,010 --> 00:15:29,240 astronomers are baffled no we're not 356 00:15:33,360 --> 00:15:30,020 baffled okay 357 00:15:35,500 --> 00:15:33,370 we're intrigued we're excited because 358 00:15:38,020 --> 00:15:35,510 frankly if we knew everything we'd be 359 00:15:39,790 --> 00:15:38,030 out of a job so this gives us something 360 00:15:42,610 --> 00:15:39,800 new there's something new in the 361 00:15:44,770 --> 00:15:42,620 universe it's either our problem which 362 00:15:46,210 --> 00:15:44,780 it's unlikely or there's some new 363 00:15:47,890 --> 00:15:46,220 feature in the universe okay 364 00:15:50,740 --> 00:15:47,900 so of course we can come up with new 365 00:15:52,570 --> 00:15:50,750 ideas and so some of the new ideas are 366 00:15:56,710 --> 00:15:52,580 perhaps there is an undiscovered 367 00:16:00,970 --> 00:15:56,720 subatomic particle such as a neutrino 368 00:16:02,440 --> 00:16:00,980 with mass that changes the measurements 369 00:16:03,670 --> 00:16:02,450 that we would get from one of the one of 370 00:16:07,150 --> 00:16:03,680 these values basically that would be a 371 00:16:09,280 --> 00:16:07,160 large scale or maybe dark matter doesn't 372 00:16:10,630 --> 00:16:09,290 behave exactly the way we think it is we 373 00:16:12,400 --> 00:16:10,640 think Dark Matter only behaves 374 00:16:14,710 --> 00:16:12,410 gravitationally maybe there's a little 375 00:16:17,740 --> 00:16:14,720 bit stronger interaction between dark 376 00:16:19,810 --> 00:16:17,750 matter and normal matter or the most 377 00:16:21,640 --> 00:16:19,820 popular one that you can written 378 00:16:23,410 --> 00:16:21,650 thinking today is what about dark energy 379 00:16:25,750 --> 00:16:23,420 we don't know much about dark energy 380 00:16:27,730 --> 00:16:25,760 we've got a lot of ignorance there maybe 381 00:16:30,160 --> 00:16:27,740 some of that ignorant effects one of 382 00:16:33,100 --> 00:16:30,170 these measures okay so we have a lot of 383 00:16:35,710 --> 00:16:33,110 hypotheses and ideas on what might 384 00:16:39,040 --> 00:16:35,720 resolve this but also I can really say 385 00:16:42,370 --> 00:16:39,050 is stay tuned because we have identified 386 00:16:44,080 --> 00:16:42,380 a discrepancy all right and the process 387 00:16:45,370 --> 00:16:44,090 of science is we're gonna hack at it and 388 00:16:47,290 --> 00:16:45,380 we're gonna hack at it we're gonna hack 389 00:16:49,870 --> 00:16:47,300 at it until either we figure out what's 390 00:16:51,670 --> 00:16:49,880 wrong with our observations or we come 391 00:16:53,830 --> 00:16:51,680 up with a really good idea that can 392 00:16:55,540 --> 00:16:53,840 explain this discrepancy and to me 393 00:16:57,730 --> 00:16:55,550 that's part of the joy and excitement of 394 00:16:58,830 --> 00:16:57,740 science when you find something that you 395 00:17:01,450 --> 00:16:58,840 can't explain 396 00:17:03,640 --> 00:17:01,460 then you're just like oh we got to 397 00:17:05,980 --> 00:17:03,650 figure this out unfortunately it'll take 398 00:17:08,080 --> 00:17:05,990 a decade or two that's actually find out 399 00:17:09,370 --> 00:17:08,090 so stay tuned and keep coming to the 400 00:17:11,770 --> 00:17:09,380 public lecture series I'll make sure 401 00:17:15,150 --> 00:17:11,780 that I have it for you all right okay 402 00:17:19,060 --> 00:17:15,160 and that's our news from the universe 403 00:17:22,150 --> 00:17:19,070 our featured speaker tonight is Susanna 404 00:17:25,090 --> 00:17:22,160 de use to ax she has been here for what 405 00:17:28,330 --> 00:17:25,100 10 years and she works in the AI NS 406 00:17:30,730 --> 00:17:28,340 division on the Hubble instrument Wide 407 00:17:34,240 --> 00:17:30,740 Field Camera 3 or we just call it with 408 00:17:35,890 --> 00:17:34,250 c3 and 409 00:17:37,810 --> 00:17:35,900 I asked her for some interesting things 410 00:17:42,270 --> 00:17:37,820 about her and she said that she fly 411 00:17:44,260 --> 00:17:42,280 Fitch's fly fishes from her kayak 412 00:17:48,310 --> 00:17:44,270 combining kayaking and fly fishing 413 00:17:50,950 --> 00:17:48,320 together and that once she did jump out 414 00:17:54,130 --> 00:17:50,960 of an airplane even as well as having 415 00:17:56,890 --> 00:17:54,140 never been on the Space Shuttle okay so 416 00:18:07,730 --> 00:17:56,900 here to tell us about Jupiter's moon 417 00:18:12,630 --> 00:18:07,740 Europa is Susanna Deus Troy thank you 418 00:18:29,260 --> 00:18:16,390 and I think I'm number one or three 419 00:18:31,270 --> 00:18:29,270 maybe I'm three okay all right so we're 420 00:18:48,490 --> 00:18:31,280 going to talk a little bit about the 421 00:19:07,130 --> 00:18:51,380 it recalibrated after I disconnected 422 00:19:07,140 --> 00:19:11,540 somebody needs to sing the jeopardy tune 423 00:19:15,300 --> 00:19:12,750 okay 424 00:19:19,590 --> 00:19:15,310 so with any luck I'll be able to tell 425 00:19:24,510 --> 00:19:19,600 you a little something about the plumes 426 00:19:26,190 --> 00:19:24,520 on Europa water ice life which is a 427 00:19:32,190 --> 00:19:26,200 little bit like our Baltimore winter 428 00:19:34,890 --> 00:19:32,200 this year let's see which way does this 429 00:19:39,780 --> 00:19:34,900 go so this is the abstract that I put 430 00:19:43,730 --> 00:19:39,790 together but more importantly is there 431 00:19:45,690 --> 00:19:43,740 are lots of people working on 432 00:19:49,080 --> 00:19:45,700 understanding what's going on with 433 00:19:52,890 --> 00:19:49,090 Europa in advance of perhaps actually 434 00:19:54,210 --> 00:19:52,900 sending a dedicated mission and I was 435 00:19:56,580 --> 00:19:54,220 trying to play around to figure but this 436 00:19:58,110 --> 00:19:56,590 was team a or team B or the raw team or 437 00:20:00,030 --> 00:19:58,120 the sparks team and I gave up on that 438 00:20:03,510 --> 00:20:00,040 because people go back and forth and 439 00:20:05,400 --> 00:20:03,520 people talk to each other so there I'm 440 00:20:08,480 --> 00:20:05,410 sure that I laughs I inadvertently might 441 00:20:11,820 --> 00:20:08,490 have left off some people but I 442 00:20:15,480 --> 00:20:11,830 apologize if I did that so more 443 00:20:18,240 --> 00:20:15,490 importantly is as an observer probably 444 00:20:20,310 --> 00:20:18,250 not tonight but maybe when it's clear if 445 00:20:22,650 --> 00:20:20,320 you go out and they look in the 446 00:20:26,280 --> 00:20:22,660 southeast kind of find where the moon is 447 00:20:28,620 --> 00:20:26,290 and you will see Jupiter and so 448 00:20:31,430 --> 00:20:28,630 Jupiter's a planet as you all know that 449 00:20:34,590 --> 00:20:31,440 we've known since antiquity when our 450 00:20:36,750 --> 00:20:34,600 ancestors first became Homo sapiens I am 451 00:20:45,080 --> 00:20:36,760 sure they looked up and saw Jupiter and 452 00:20:49,920 --> 00:20:45,090 named it something and 400 years ago in 453 00:20:51,930 --> 00:20:49,930 1609 Galileo as we know in I wouldn't 454 00:20:54,440 --> 00:20:51,940 say he invented the telescope but he was 455 00:20:56,970 --> 00:20:54,450 one of the first to put it together and 456 00:20:59,760 --> 00:20:56,980 incidentally he was very ill he had like 457 00:21:01,200 --> 00:20:59,770 the flu or something when he was putting 458 00:21:03,870 --> 00:21:01,210 together at the telescope 459 00:21:07,470 --> 00:21:03,880 I guess he kept him from being too sick 460 00:21:11,910 --> 00:21:07,480 and later he turned that telescope and 461 00:21:13,590 --> 00:21:11,920 he was the first to point at a celestial 462 00:21:15,790 --> 00:21:13,600 object and in his case it was Jupiter 463 00:21:20,110 --> 00:21:15,800 and what he saw over 464 00:21:24,600 --> 00:21:20,120 a period of time were a series of moons 465 00:21:27,820 --> 00:21:24,610 or objects or little stars that were 466 00:21:29,650 --> 00:21:27,830 revolving or moving around Jupiter and 467 00:21:31,780 --> 00:21:29,660 this is just a blow-up of that letter 468 00:21:36,340 --> 00:21:31,790 that I showed which is a letter he wrote 469 00:21:39,070 --> 00:21:36,350 to the Doge a of Venice in 1610 and he 470 00:21:44,620 --> 00:21:39,080 in that letter he is describing his 471 00:21:50,890 --> 00:21:44,630 observations so 1609 first observations 472 00:21:52,930 --> 00:21:50,900 of Europa and if I can do this I will 473 00:21:58,720 --> 00:21:52,940 start the movie because this is kind of 474 00:22:02,110 --> 00:21:58,730 cute I love the Internet this is a movie 475 00:22:04,990 --> 00:22:02,120 that put together by a gentleman named I 476 00:22:07,720 --> 00:22:05,000 think somebody right he has a website 477 00:22:10,840 --> 00:22:07,730 he's a computer scientist by profession 478 00:22:13,870 --> 00:22:10,850 and what he did is he took all of the 479 00:22:17,620 --> 00:22:13,880 observations that Galileo had recorded 480 00:22:20,860 --> 00:22:17,630 and he's juxtaposed those on a on the 481 00:22:23,440 --> 00:22:20,870 ephemeris and so what you see now is the 482 00:22:25,450 --> 00:22:23,450 beautiful pictures on the top and then 483 00:22:26,890 --> 00:22:25,460 Galileo's observations on the bottom 484 00:22:31,990 --> 00:22:26,900 this is just sort of a fun little thing 485 00:22:36,190 --> 00:22:32,000 and it'll go through sort of the modern 486 00:22:39,250 --> 00:22:36,200 and the end the ancient ok so let's just 487 00:22:42,430 --> 00:22:39,260 put this in context a little bit when we 488 00:22:44,350 --> 00:22:42,440 talk about the moons it's you know it's 489 00:22:47,530 --> 00:22:44,360 natural to think of it as being like our 490 00:22:50,710 --> 00:22:47,540 moon so here's our moon here this is 491 00:22:53,320 --> 00:22:50,720 Europa and it's about the same size over 492 00:22:55,540 --> 00:22:53,330 here so that's kind of comforting Moon's 493 00:22:59,850 --> 00:22:55,550 can be the same size as our Moon this is 494 00:23:02,320 --> 00:22:59,860 Callisto Ganymede Europa and IO or IO 495 00:23:04,600 --> 00:23:02,330 the four Galilean moons of although 496 00:23:06,070 --> 00:23:04,610 Galileo called and the Medici moons as 497 00:23:10,270 --> 00:23:06,080 you remember because the Medici was 498 00:23:13,900 --> 00:23:10,280 where his patrons it's always good to 499 00:23:17,350 --> 00:23:13,910 keep your patrons happy anyway so here's 500 00:23:19,030 --> 00:23:17,360 Europa tis not the largest of Jupiter's 501 00:23:21,250 --> 00:23:19,040 moons but it is certainly one of the 502 00:23:23,020 --> 00:23:21,260 most interesting along with you and neo 503 00:23:25,840 --> 00:23:23,030 is known to have volcanic activity and 504 00:23:27,730 --> 00:23:25,850 just for fun and scale here's one of the 505 00:23:29,230 --> 00:23:27,740 bands on Jupiter so you get the sense 506 00:23:29,620 --> 00:23:29,240 that these are actually relatively small 507 00:23:34,720 --> 00:23:29,630 and 508 00:23:36,490 --> 00:23:34,730 jupiter is very very big so we will skip 509 00:23:39,400 --> 00:23:36,500 forward a few hundred years to the 510 00:23:43,150 --> 00:23:39,410 Voyager missions and the Voyager I think 511 00:23:46,470 --> 00:23:43,160 are the most successful missions in my 512 00:23:50,320 --> 00:23:46,480 view that NASA has put together they 513 00:23:52,900 --> 00:23:50,330 have been going through the solar system 514 00:23:55,180 --> 00:23:52,910 for over 30 approaching 40 years 515 00:23:58,030 --> 00:23:55,190 returning good data ever since and it 516 00:24:00,910 --> 00:23:58,040 this was one of the first images that we 517 00:24:03,820 --> 00:24:00,920 had close-up images that we had of 518 00:24:06,450 --> 00:24:03,830 Jupiter and its moons this over here is 519 00:24:08,680 --> 00:24:06,460 a o and this is Europa down here 520 00:24:10,990 --> 00:24:08,690 question and these little dots are just 521 00:24:14,260 --> 00:24:11,000 some fiducial marks on the imaging 522 00:24:16,450 --> 00:24:14,270 system of Voyager about 20 years later 523 00:24:18,460 --> 00:24:16,460 there was another mission this time 524 00:24:22,150 --> 00:24:18,470 called the Galileo mission which also 525 00:24:24,040 --> 00:24:22,160 went to Jupiter and what I think is 526 00:24:27,580 --> 00:24:24,050 remarkable and a lot of people have as 527 00:24:30,160 --> 00:24:27,590 well is that we see Europa this was 528 00:24:34,240 --> 00:24:30,170 taken about I don't know almost six 529 00:24:36,130 --> 00:24:34,250 sixty thousand miles away is that Europe 530 00:24:37,780 --> 00:24:36,140 is relatively smooth it doesn't have big 531 00:24:39,360 --> 00:24:37,790 huge craters it doesn't have big huge 532 00:24:42,220 --> 00:24:39,370 mountains and it's got all these little 533 00:24:45,570 --> 00:24:42,230 striations all over it and some dark 534 00:24:47,980 --> 00:24:45,580 spots so it's a very interesting moon 535 00:24:50,740 --> 00:24:47,990 it's an interesting object in and of 536 00:24:53,920 --> 00:24:50,750 itself and this is a beautiful image 537 00:24:58,770 --> 00:24:53,930 that got reprocessed in the imaging 538 00:25:03,250 --> 00:24:58,780 department by somebody so to highlight 539 00:25:05,710 --> 00:25:03,260 the striations and sort of false color 540 00:25:09,520 --> 00:25:05,720 images and what you see is that these 541 00:25:13,360 --> 00:25:09,530 look like cracks in the ice fissures in 542 00:25:17,290 --> 00:25:13,370 the ice which tells you something about 543 00:25:19,720 --> 00:25:17,300 what is going on in on the moon and this 544 00:25:22,720 --> 00:25:19,730 is a blow-up also from the Galileo 545 00:25:25,270 --> 00:25:22,730 spacecraft where you can see these 546 00:25:27,790 --> 00:25:25,280 cracks and fissures and apparently some 547 00:25:28,990 --> 00:25:27,800 deposits of material because it's not 548 00:25:33,430 --> 00:25:29,000 all white and icy 549 00:25:35,560 --> 00:25:33,440 so this points to and there been a lot 550 00:25:38,590 --> 00:25:35,570 of papers and people got really busy and 551 00:25:42,740 --> 00:25:38,600 said this this looks a lot like cracking 552 00:25:44,660 --> 00:25:42,750 of ice and maybe it looks like looks 553 00:25:48,050 --> 00:25:44,670 like plate tectonics like we have on 554 00:25:50,240 --> 00:25:48,060 earth the the continental crusts and our 555 00:25:53,120 --> 00:25:50,250 shifting around in subducting and 556 00:25:57,110 --> 00:25:53,130 separating in this case this is on the 557 00:26:00,890 --> 00:25:57,120 icy surface so it's a very very 558 00:26:02,990 --> 00:26:00,900 intriguing but in addition one of the 559 00:26:05,300 --> 00:26:03,000 things that the Galileo spacecraft had 560 00:26:06,980 --> 00:26:05,310 with it was a magnetometer so it was 561 00:26:11,360 --> 00:26:06,990 measuring the magnetic field around 562 00:26:15,070 --> 00:26:11,370 Jupiter and an interesting thing is that 563 00:26:17,420 --> 00:26:15,080 if you have another source of 564 00:26:19,220 --> 00:26:17,430 electromagnetism it's sort of like 565 00:26:20,840 --> 00:26:19,230 having two magnets if you try to put the 566 00:26:24,110 --> 00:26:20,850 two South Poles together you get a 567 00:26:26,420 --> 00:26:24,120 little deflection have you ever tried 568 00:26:28,130 --> 00:26:26,430 that when you were kids so you'd see 569 00:26:29,630 --> 00:26:28,140 something similar if you had another 570 00:26:31,550 --> 00:26:29,640 source nearby you would see a little 571 00:26:34,330 --> 00:26:31,560 deflection in the magnetic field 572 00:26:36,320 --> 00:26:34,340 so when gyro PI was passing through 573 00:26:40,780 --> 00:26:36,330 Jupiter's magnetic field the 574 00:26:43,910 --> 00:26:40,790 magnetometer detected a deflection and 575 00:26:46,100 --> 00:26:43,920 that deflection was consistent with it 576 00:26:48,500 --> 00:26:46,110 another conductive or an inductive body 577 00:26:52,790 --> 00:26:48,510 and it probably had to be something like 578 00:26:55,100 --> 00:26:52,800 slushy salty water because it had to be 579 00:26:56,720 --> 00:26:55,110 something that was globally connected he 580 00:26:58,880 --> 00:26:56,730 couldn't just have one little pond it 581 00:27:00,440 --> 00:26:58,890 had to be all all around and about the 582 00:27:06,260 --> 00:27:00,450 only thing people could think of at the 583 00:27:08,180 --> 00:27:06,270 time was some slushy icy material which 584 00:27:11,750 --> 00:27:08,190 of course makes things really really 585 00:27:14,900 --> 00:27:11,760 interesting because now we have ice on 586 00:27:21,350 --> 00:27:14,910 this planet and potentially also water 587 00:27:23,150 --> 00:27:21,360 and so this is a sort of a model of what 588 00:27:25,340 --> 00:27:23,160 this might look like here's the the 589 00:27:28,010 --> 00:27:25,350 water down here some kind of a thick 590 00:27:31,580 --> 00:27:28,020 warm ice shelf and here you can see the 591 00:27:34,340 --> 00:27:31,590 cracks on the top subducting just like 592 00:27:36,650 --> 00:27:34,350 they would on on earth Stevie had plate 593 00:27:39,350 --> 00:27:36,660 tectonics and we're there little soft 594 00:27:41,120 --> 00:27:39,360 spots you might see sort of cryo lavas 595 00:27:45,110 --> 00:27:41,130 so instead of being molten lava I would 596 00:27:48,440 --> 00:27:45,120 be molten water otherwise known as 597 00:27:50,510 --> 00:27:48,450 liquid water and this would be something 598 00:27:52,430 --> 00:27:50,520 that would build up over time and the 599 00:27:54,530 --> 00:27:52,440 other clue to this is that was because 600 00:27:56,150 --> 00:27:54,540 the surface of Europe is so smooth it 601 00:27:58,370 --> 00:27:56,160 doesn't have a lot of cratering what 602 00:28:00,170 --> 00:27:58,380 also indicates it's a young surface and 603 00:28:02,210 --> 00:28:00,180 the only way you get a young surface is 604 00:28:04,490 --> 00:28:02,220 if you have some regeneration of 605 00:28:08,660 --> 00:28:04,500 material that covers the cracks and the 606 00:28:10,160 --> 00:28:08,670 in the craters so this is all pretty 607 00:28:14,210 --> 00:28:10,170 fascinating and people got really 608 00:28:15,890 --> 00:28:14,220 intrigued but this wasn't really enough 609 00:28:20,180 --> 00:28:15,900 to answer the question because you could 610 00:28:25,700 --> 00:28:20,190 still imagine having a rocky core in the 611 00:28:30,470 --> 00:28:25,710 planet ice warm ice and then cold ice on 612 00:28:34,880 --> 00:28:30,480 the surface or maybe you had a rocky 613 00:28:39,080 --> 00:28:34,890 interior and then a water layer down 614 00:28:41,660 --> 00:28:39,090 here and then ice and this was something 615 00:28:44,030 --> 00:28:41,670 in play if you have a lot of ice it's 616 00:28:47,210 --> 00:28:44,040 probably not so interesting or maybe it 617 00:28:49,610 --> 00:28:47,220 is but if you have water now you start 618 00:28:51,830 --> 00:28:49,620 thinking could you possibly have 619 00:28:56,510 --> 00:28:51,840 something really interesting going on if 620 00:28:57,980 --> 00:28:56,520 you have water and the answer of course 621 00:29:00,560 --> 00:28:57,990 and what we're working up to is if you 622 00:29:02,780 --> 00:29:00,570 have water then you have life or you 623 00:29:07,310 --> 00:29:02,790 have the possibility of life but the one 624 00:29:10,850 --> 00:29:07,320 question is Europa is far away it's very 625 00:29:13,570 --> 00:29:10,860 far from from the Sun it's and you have 626 00:29:17,750 --> 00:29:13,580 this icy cover so how would you get 627 00:29:21,320 --> 00:29:17,760 heating of the material to in order to 628 00:29:23,330 --> 00:29:21,330 have a liquid water ocean and so one 629 00:29:25,370 --> 00:29:23,340 potential answer and this is probably 630 00:29:28,760 --> 00:29:25,380 the right one is something called tidal 631 00:29:32,060 --> 00:29:28,770 heating and what that does is as as as 632 00:29:33,920 --> 00:29:32,070 Europa goes around Jupiter it's not in a 633 00:29:37,820 --> 00:29:33,930 perfectly circular orbit so you have 634 00:29:39,920 --> 00:29:37,830 gravitational forces acting on the moon 635 00:29:41,420 --> 00:29:39,930 itself sort of pushing and pulling it 636 00:29:43,490 --> 00:29:41,430 you can think of it as either you know 637 00:29:45,230 --> 00:29:43,500 and you bend a spoon you get a little 638 00:29:47,690 --> 00:29:45,240 heat or you're stretching a rubber band 639 00:29:49,730 --> 00:29:47,700 and you feel it it gets a little hot so 640 00:29:52,930 --> 00:29:49,740 sort of like friction and that is 641 00:30:01,790 --> 00:29:52,940 probably the source of the heat that 642 00:30:03,950 --> 00:30:01,800 keeps the water liquid then the Galileo 643 00:30:07,010 --> 00:30:03,960 mission I think has given planetary 644 00:30:09,810 --> 00:30:07,020 astronomers a lot to work on but I think 645 00:30:13,050 --> 00:30:09,820 it's it's been about 30 years and we're 646 00:30:17,490 --> 00:30:13,060 about you for NASA guys if you hear me 647 00:30:22,050 --> 00:30:17,500 were about you for another mission so 648 00:30:24,150 --> 00:30:22,060 this is a particular region on Europe 649 00:30:26,010 --> 00:30:24,160 and you can see the striations there 650 00:30:27,950 --> 00:30:26,020 this region is highlighted and this is 651 00:30:32,370 --> 00:30:27,960 now work that comes from a British 652 00:30:33,840 --> 00:30:32,380 Schmidt who's been working on this on 653 00:30:36,600 --> 00:30:33,850 Europa since she was I think in grad 654 00:30:39,450 --> 00:30:36,610 school and what this shows is a region 655 00:30:41,280 --> 00:30:39,460 that it looks very chaotic it looks sort 656 00:30:43,920 --> 00:30:41,290 of crumpled II like something happened 657 00:30:45,720 --> 00:30:43,930 there it's not a it's not a crater some 658 00:30:48,510 --> 00:30:45,730 typical crater has a little cone shape 659 00:30:50,340 --> 00:30:48,520 and you see the material inside but this 660 00:30:54,270 --> 00:30:50,350 seems to indicate that there might have 661 00:30:58,770 --> 00:30:54,280 been a region on the planet I mean on 662 00:31:03,720 --> 00:30:58,780 the moon that might be the source of 663 00:31:06,780 --> 00:31:03,730 some kind of flow of material a crack in 664 00:31:09,240 --> 00:31:06,790 the ice raises a material and so there 665 00:31:11,610 --> 00:31:09,250 was she developed a model that seemed to 666 00:31:15,950 --> 00:31:11,620 indicate that you had to have some kind 667 00:31:25,080 --> 00:31:15,960 of water driving this type of feature 668 00:31:29,340 --> 00:31:25,090 liquid and Galileo get to the rescue 669 00:31:32,160 --> 00:31:29,350 again and one of the John Spencer 670 00:31:34,260 --> 00:31:32,170 studied the thermal mapping of Europa 671 00:31:36,000 --> 00:31:34,270 and just because even you want to know 672 00:31:38,520 --> 00:31:36,010 what's going on what's the temperature 673 00:31:39,900 --> 00:31:38,530 on the surface is it all one the same 674 00:31:41,700 --> 00:31:39,910 temperature all around is there 675 00:31:43,320 --> 00:31:41,710 variation in the temperatures at hot 676 00:31:46,470 --> 00:31:43,330 cold is it like that the Earth's where 677 00:31:49,650 --> 00:31:46,480 the poles are colder etc and so he did 678 00:31:50,970 --> 00:31:49,660 this heat map if you will it measured 679 00:31:52,680 --> 00:31:50,980 the temperature in various locations 680 00:31:54,930 --> 00:31:52,690 this is sort of at the South Pole this 681 00:31:57,450 --> 00:31:54,940 is sort of hot you have regions where 682 00:32:01,010 --> 00:31:57,460 you go from warm relatively warm to cold 683 00:32:04,170 --> 00:32:01,020 and these are degrees um I think Kelvin 684 00:32:07,890 --> 00:32:04,180 so this also tells us that it's not as 685 00:32:12,020 --> 00:32:07,900 solidly single temperature situation 686 00:32:14,670 --> 00:32:12,030 which just adds to the to the intrigue 687 00:32:18,120 --> 00:32:14,680 so this is an a bit of an artist 688 00:32:20,550 --> 00:32:18,130 conception I think that between Galilean 689 00:32:22,710 --> 00:32:20,560 Voyager and a lot of heavy lifting by 690 00:32:23,040 --> 00:32:22,720 planetary scientists we sort of came up 691 00:32:25,050 --> 00:32:23,050 with 692 00:32:27,570 --> 00:32:25,060 the idea that we had a salty liquid 693 00:32:30,000 --> 00:32:27,580 ocean and that potentially you could 694 00:32:33,030 --> 00:32:30,010 have some kind of geyser activity if you 695 00:32:34,920 --> 00:32:33,040 had liquid water depositing here's sort 696 00:32:36,930 --> 00:32:34,930 of one of those little chaos terrains 697 00:32:38,490 --> 00:32:36,940 like the one I showed you earlier pool 698 00:32:40,620 --> 00:32:38,500 of water underneath this is probably 699 00:32:42,060 --> 00:32:40,630 some thin layer of ice about a hundred 700 00:32:43,860 --> 00:32:42,070 kilometers thick you get a little water 701 00:32:49,560 --> 00:32:43,870 pooling up and it comes up and maybe you 702 00:32:51,840 --> 00:32:49,570 could see geysers and so this seems to 703 00:32:54,870 --> 00:32:51,850 indicate all that it seems to indicate 704 00:32:58,290 --> 00:32:54,880 that this is really the right idea the 705 00:33:01,320 --> 00:32:58,300 right model for Europa so you do have a 706 00:33:03,870 --> 00:33:01,330 liquid ocean a salty liquid water ocean 707 00:33:11,330 --> 00:33:03,880 underneath ice and now things get really 708 00:33:14,820 --> 00:33:11,340 interesting because this is not Europa 709 00:33:20,580 --> 00:33:14,830 this is Enceladus which is a moon of 710 00:33:22,830 --> 00:33:20,590 Saturn and Cassini which was not did not 711 00:33:25,920 --> 00:33:22,840 go up 40 years ago more recently than 712 00:33:30,890 --> 00:33:25,930 that took a picture of Enceladus and 713 00:33:40,320 --> 00:33:30,900 noticed that there was water vapor on 714 00:33:43,730 --> 00:33:40,330 the South Pole hmm so if Cassini has 715 00:33:50,640 --> 00:33:43,740 this what about Europa 716 00:33:54,650 --> 00:33:50,650 so if Europa also has plumes of water 717 00:33:58,050 --> 00:33:54,660 vapor then maybe we can learn something 718 00:34:00,000 --> 00:33:58,060 about its ocean without necessarily 719 00:34:01,710 --> 00:34:00,010 having to go and send a mission and do 720 00:34:07,250 --> 00:34:01,720 ice cores and drill down a hundred 721 00:34:14,010 --> 00:34:12,030 so this is where Hubble comes in so and 722 00:34:19,080 --> 00:34:14,020 this is work that started roughly around 723 00:34:21,960 --> 00:34:19,090 2010 so this is Lorenz Roth it all came 724 00:34:26,210 --> 00:34:21,970 up with one technique and it's called 725 00:34:31,010 --> 00:34:28,800 which is not the same thing as direct 726 00:34:34,590 --> 00:34:31,020 imaging so we think of a spectrum as 727 00:34:36,790 --> 00:34:34,600 white light coming through a prism or a 728 00:34:38,740 --> 00:34:36,800 dispersing piece of glass and then 729 00:34:41,380 --> 00:34:38,750 getting broken up into its constituent 730 00:34:44,140 --> 00:34:41,390 colors we've all seen that or a drop of 731 00:34:47,440 --> 00:34:44,150 water or your hose or the rainbows they 732 00:34:51,070 --> 00:34:47,450 all work the same way and if you 733 00:34:52,660 --> 00:34:51,080 remember from your physics class whether 734 00:34:54,610 --> 00:34:52,670 it was high school or college or a 735 00:34:58,150 --> 00:34:54,620 graduate school or maybe even last week 736 00:35:00,280 --> 00:34:58,160 and you're analyzing some data typically 737 00:35:02,440 --> 00:35:00,290 when we do spectroscopy we talk about 738 00:35:04,210 --> 00:35:02,450 having a slit and then you have the 739 00:35:07,570 --> 00:35:04,220 disperser in this case it's a prism and 740 00:35:09,670 --> 00:35:07,580 this is just a model it gets sent off 741 00:35:13,270 --> 00:35:09,680 collimated and what you see then is a 742 00:35:17,580 --> 00:35:13,280 bunch of lines either absorption lines 743 00:35:20,230 --> 00:35:17,590 in this case or emission lines and 744 00:35:23,230 --> 00:35:20,240 that's a normal way of doing things but 745 00:35:29,560 --> 00:35:23,240 in actuality what these little lines are 746 00:35:34,720 --> 00:35:29,570 are actually an image of the slit so 747 00:35:38,260 --> 00:35:34,730 what happens if you take a moon and you 748 00:35:40,750 --> 00:35:38,270 use your traditional small slit well you 749 00:35:43,480 --> 00:35:40,760 can't see the whole moon but if you make 750 00:35:48,100 --> 00:35:43,490 the slit bigger and fortunately Hubble 751 00:35:50,560 --> 00:35:48,110 is one of Hubble's instruments the Space 752 00:35:52,990 --> 00:35:50,570 Telescope imaging spectrograph has a 753 00:35:56,740 --> 00:35:53,000 slit that's about two arc seconds wide 754 00:36:00,700 --> 00:35:56,750 and Europa extends an angle of about one 755 00:36:03,340 --> 00:36:00,710 in a bit so you open up the slit and you 756 00:36:05,320 --> 00:36:03,350 go through your same system so this is 757 00:36:08,410 --> 00:36:05,330 now standing in for the entire set of 758 00:36:11,710 --> 00:36:08,420 optics that are complicated and what you 759 00:36:13,840 --> 00:36:11,720 get is an image that's no longer those 760 00:36:16,000 --> 00:36:13,850 straight lines but rather an image of 761 00:36:22,360 --> 00:36:16,010 the source because you've made the slit 762 00:36:24,880 --> 00:36:22,370 large enough and then the idea then is 763 00:36:27,300 --> 00:36:24,890 that we know that if there is a plume of 764 00:36:31,060 --> 00:36:27,310 water when water hits the atmosphere 765 00:36:33,220 --> 00:36:31,070 water's hydrogen h2o two hydrogen's and 766 00:36:35,470 --> 00:36:33,230 an oxygen when it reaches the atmosphere 767 00:36:37,960 --> 00:36:35,480 will dissociate or exits the atmosphere 768 00:36:40,450 --> 00:36:37,970 it will dissociate break apart into 769 00:36:43,180 --> 00:36:40,460 hydrogen and oxygen so the logical thing 770 00:36:45,430 --> 00:36:43,190 to do would then be to look for the 771 00:36:48,280 --> 00:36:45,440 dissociation products of water which are 772 00:36:50,210 --> 00:36:48,290 hydrogen and oxygen and in the 773 00:36:53,360 --> 00:36:50,220 ultraviolet there are two 774 00:36:56,150 --> 00:36:53,370 of hydrogen and oxygen and this is what 775 00:37:00,950 --> 00:36:56,160 Lorenz Roth and his team took advantage 776 00:37:03,380 --> 00:37:00,960 of and so in 1999 this is the series of 777 00:37:06,800 --> 00:37:03,390 images this is this is the hydrogen 778 00:37:11,030 --> 00:37:06,810 lines these are the oxygen lines in 2012 779 00:37:13,640 --> 00:37:11,040 they took another series of images but 780 00:37:17,030 --> 00:37:13,650 in December of 2012 when they saw those 781 00:37:19,130 --> 00:37:17,040 images what they noticed is that unlike 782 00:37:22,670 --> 00:37:19,140 the earlier images there was a little 783 00:37:28,040 --> 00:37:22,680 excess of both hydrogen and oxygen down 784 00:37:31,060 --> 00:37:28,050 here and that indicates that there was a 785 00:37:35,270 --> 00:37:31,070 plume and they wrote a paper in science 786 00:37:38,410 --> 00:37:35,280 which is here came out in 2014 there 787 00:37:41,480 --> 00:37:38,420 were subsequent observations almost 17 788 00:37:43,700 --> 00:37:41,490 detection our orbits Lee and there were 789 00:37:47,260 --> 00:37:43,710 no additional plumes discovered so now 790 00:37:49,220 --> 00:37:47,270 that Lucknow just like with the 791 00:37:51,140 --> 00:37:49,230 presentation earlier is this the data 792 00:37:53,510 --> 00:37:51,150 did we use you know everybody thinks did 793 00:37:55,640 --> 00:37:53,520 we screw something up what's going on 794 00:37:58,220 --> 00:37:55,650 that we don't see it again get really 795 00:38:00,140 --> 00:37:58,230 panicky you think you've done something 796 00:38:02,450 --> 00:38:00,150 wrong in the analysis and you go back 797 00:38:07,880 --> 00:38:02,460 you do the reanalysis it's like no this 798 00:38:10,760 --> 00:38:07,890 was correct that really but because they 799 00:38:13,040 --> 00:38:10,770 didn't see the plumes again there was 800 00:38:14,690 --> 00:38:13,050 already hints that Europa could not be 801 00:38:20,660 --> 00:38:14,700 like Enceladus and so this is very 802 00:38:23,060 --> 00:38:20,670 regular cryovolcanism if you will so if 803 00:38:25,220 --> 00:38:23,070 you wanted to get a pretty picture and 804 00:38:30,460 --> 00:38:25,230 put it together so this is the location 805 00:38:34,370 --> 00:38:30,470 of the plumes and then here is um Europa 806 00:38:35,960 --> 00:38:34,380 okay the other thing about science is 807 00:38:39,530 --> 00:38:35,970 that you like people to repeat your 808 00:38:41,540 --> 00:38:39,540 experiment in some other way so that you 809 00:38:44,300 --> 00:38:41,550 have some confidence of what you're 810 00:38:47,060 --> 00:38:44,310 doing so the second method was to 811 00:38:48,620 --> 00:38:47,070 actually use direct imaging so no longer 812 00:38:49,880 --> 00:38:48,630 using spectrograph but just direct 813 00:38:51,860 --> 00:38:49,890 imaging just like you do with your 814 00:38:53,380 --> 00:38:51,870 camera and take a picture of somebody or 815 00:38:56,740 --> 00:38:53,390 the tree or the Pussycats 816 00:39:01,280 --> 00:38:56,750 okay that's direct imaging in this case 817 00:39:02,870 --> 00:39:01,290 there have been an example in 2000 John 818 00:39:05,120 --> 00:39:02,880 Spencer had looked at he 819 00:39:07,010 --> 00:39:05,130 in the ultraviolet so this is e oh and 820 00:39:08,180 --> 00:39:07,020 this is Jupiter in the background you 821 00:39:11,960 --> 00:39:08,190 can see there's a little plume here 822 00:39:15,910 --> 00:39:11,970 remember yo really is volcanic and so 823 00:39:19,240 --> 00:39:15,920 the idea was that look if this worked 824 00:39:23,890 --> 00:39:19,250 for IO where you can have Jupiter 825 00:39:26,150 --> 00:39:23,900 effectively back light so you're seeing 826 00:39:28,190 --> 00:39:26,160 Jupiter in the back back lighting the 827 00:39:29,960 --> 00:39:28,200 atmosphere of the of the of the of the 828 00:39:31,640 --> 00:39:29,970 moon the tenuous atmosphere if there's 829 00:39:37,160 --> 00:39:31,650 anything going on you should be able to 830 00:39:39,170 --> 00:39:37,170 detect it so the second idea then was to 831 00:39:42,140 --> 00:39:39,180 do direct imaging in the farl travaille 832 00:39:44,000 --> 00:39:42,150 ilat around 150 hundred and 60 833 00:39:47,590 --> 00:39:44,010 nanometers this is a region that is of 834 00:39:51,710 --> 00:39:47,600 course not accessible from the ground 835 00:39:55,220 --> 00:39:51,720 and we took images for almost three 836 00:39:57,920 --> 00:39:55,230 years well two years and we had 12 837 00:39:59,240 --> 00:39:57,930 images of Europa in transit and what we 838 00:40:02,800 --> 00:39:59,250 were doing then was measuring the 839 00:40:05,810 --> 00:40:02,810 atmosphere not necessarily looking for 840 00:40:07,970 --> 00:40:05,820 Jets but just changes in the in the in 841 00:40:09,950 --> 00:40:07,980 the thickness or the opacity of the 842 00:40:11,630 --> 00:40:09,960 atmosphere and we also just to 843 00:40:13,310 --> 00:40:11,640 double-check had images taken out of 844 00:40:18,200 --> 00:40:13,320 transit just in case I had something to 845 00:40:21,350 --> 00:40:18,210 do is being in front of Jupiter and the 846 00:40:23,090 --> 00:40:21,360 analysis of this data was is pretty 847 00:40:24,950 --> 00:40:23,100 straightforward here's the real image of 848 00:40:27,050 --> 00:40:24,960 Europa and this is Jupiter in the 849 00:40:28,400 --> 00:40:27,060 background and what you want to make 850 00:40:30,620 --> 00:40:28,410 sure is that that when you do the 851 00:40:32,090 --> 00:40:30,630 subtraction in R the analysis of the 852 00:40:32,780 --> 00:40:32,100 image that you're not doing anything 853 00:40:35,090 --> 00:40:32,790 crazy 854 00:40:38,030 --> 00:40:35,100 so the standard thing to do is to say 855 00:40:43,990 --> 00:40:38,040 assume a circle with a and you assume 856 00:40:46,550 --> 00:40:44,000 some kind of illumination pattern you 857 00:40:48,560 --> 00:40:46,560 figure out what Jupiter looks like in 858 00:40:52,160 --> 00:40:48,570 the background you make a model and then 859 00:40:53,870 --> 00:40:52,170 you subtract the model you actually also 860 00:40:55,250 --> 00:40:53,880 have to add you know the effects of the 861 00:40:57,680 --> 00:40:55,260 instrument on your model so you 862 00:40:59,210 --> 00:40:57,690 basically you're making a fake image so 863 00:41:03,460 --> 00:40:59,220 here's the fake image and here's the 864 00:41:05,780 --> 00:41:03,470 real image and they look okay they look 865 00:41:08,270 --> 00:41:05,790 plausible this is one that doesn't have 866 00:41:09,470 --> 00:41:08,280 plumes and this one in the model doesn't 867 00:41:11,750 --> 00:41:09,480 have it either so this tells you 868 00:41:14,060 --> 00:41:11,760 something about the gives you some 869 00:41:16,130 --> 00:41:14,070 confidence that your method is actually 870 00:41:18,590 --> 00:41:16,140 going to work 871 00:41:21,410 --> 00:41:18,600 and then just for fun you're just what 872 00:41:24,020 --> 00:41:21,420 these images look like here because 873 00:41:25,400 --> 00:41:24,030 Jupiter moves now here's the fun part of 874 00:41:27,200 --> 00:41:25,410 doing planetary science which I hadn't 875 00:41:29,290 --> 00:41:27,210 quite appreciated until I started doing 876 00:41:32,630 --> 00:41:29,300 it myself is that everything moves 877 00:41:34,780 --> 00:41:32,640 Jupiter moves Europa moves the satellite 878 00:41:36,800 --> 00:41:34,790 moves so everything has to somehow work 879 00:41:38,150 --> 00:41:36,810 together and you have to decide whether 880 00:41:41,270 --> 00:41:38,160 you're going to track on the moon or 881 00:41:44,570 --> 00:41:41,280 Jupiter or both so this is what it looks 882 00:41:47,270 --> 00:41:44,580 like if you assume that Jupiter isn't 883 00:41:49,390 --> 00:41:47,280 moving and then here if you assume 884 00:41:51,860 --> 00:41:49,400 Europa isn't moving so here's Europa and 885 00:41:56,930 --> 00:41:51,870 here's a shadow and that there's a no 886 00:41:59,930 --> 00:41:56,940 lovely Aurora and then I have to UM show 887 00:42:02,960 --> 00:41:59,940 this because this is kind of fun if you 888 00:42:04,490 --> 00:42:02,970 put all the images together and you D 889 00:42:08,270 --> 00:42:04,500 rotate everything then you could make 890 00:42:10,700 --> 00:42:08,280 fun images that show you here's Europa 891 00:42:12,050 --> 00:42:10,710 yours yo here's the Great Red Spot and 892 00:42:15,410 --> 00:42:12,060 obviously it's a partial them is because 893 00:42:20,000 --> 00:42:15,420 we're not imaging the whole of Jupiter's 894 00:42:21,680 --> 00:42:20,010 face so that's kind of fun and the 895 00:42:25,070 --> 00:42:21,690 reason we could do this is that one of 896 00:42:28,580 --> 00:42:25,080 the advantage of this disc spectrograph 897 00:42:31,700 --> 00:42:28,590 or imaging system is that you can 898 00:42:33,800 --> 00:42:31,710 actually take observations at what's 899 00:42:37,070 --> 00:42:33,810 called time tags so that the separation 900 00:42:39,560 --> 00:42:37,080 each each exposure is 0.125 seconds and 901 00:42:41,420 --> 00:42:39,570 you just can keep doing that so every 902 00:42:43,220 --> 00:42:41,430 tenth of a second you have a new image 903 00:42:45,710 --> 00:42:43,230 which is one of the things that lets you 904 00:42:47,450 --> 00:42:45,720 make these lovely movies but it also 905 00:42:52,160 --> 00:42:47,460 helps if you're trying to look for 906 00:42:54,620 --> 00:42:52,170 features and then you can also play some 907 00:42:57,680 --> 00:42:54,630 more with these images and this was made 908 00:43:01,010 --> 00:42:57,690 by Sean Lockwood who's also on the staff 909 00:43:03,050 --> 00:43:01,020 here and from the same data because the 910 00:43:04,190 --> 00:43:03,060 movies are kind of fun what's the point 911 00:43:06,110 --> 00:43:04,200 of doing this if you can't have fun so 912 00:43:09,130 --> 00:43:06,120 here you see the aurora which is kind of 913 00:43:12,380 --> 00:43:09,140 fun it changes with time and here is 914 00:43:15,200 --> 00:43:12,390 Europa so this is you know not not 915 00:43:17,900 --> 00:43:15,210 enhanced at all and then if you really 916 00:43:19,790 --> 00:43:17,910 want to see but again unenhanced so 917 00:43:21,920 --> 00:43:19,800 we'll just skip right right past this 918 00:43:24,200 --> 00:43:21,930 because the thing that's interesting is 919 00:43:26,030 --> 00:43:24,210 that what we're looking for is 3,000 920 00:43:28,580 --> 00:43:26,040 kilometers and this is Europa's north 921 00:43:30,490 --> 00:43:28,590 and then just to show you because you 922 00:43:32,930 --> 00:43:30,500 got to show the data 923 00:43:34,400 --> 00:43:32,940 I've talked a lot about it I've shown 924 00:43:38,110 --> 00:43:34,410 some pretty movies but I haven't shown 925 00:43:45,680 --> 00:43:38,120 you the data but you should always ask 926 00:43:48,350 --> 00:43:45,690 so these are the twelve ten of the 927 00:43:51,200 --> 00:43:48,360 twelve observations that we took and one 928 00:43:53,120 --> 00:43:51,210 two three four five actually one two and 929 00:43:55,670 --> 00:43:53,130 they're given in time so we started in 930 00:43:59,930 --> 00:43:55,680 twin December of 2013 through March of 931 00:44:01,820 --> 00:43:59,940 2015 and we did that whole careful 932 00:44:04,940 --> 00:44:01,830 analysis subtracting out the model 933 00:44:08,150 --> 00:44:04,950 making sure and you'll notice if you 934 00:44:10,490 --> 00:44:08,160 look carefully that there are only three 935 00:44:12,410 --> 00:44:10,500 of these images that should look that 936 00:44:18,200 --> 00:44:12,420 show something different three of these 937 00:44:26,300 --> 00:44:18,210 are not like the others and those are 938 00:44:28,310 --> 00:44:26,310 the plumes maybe okay and this is just a 939 00:44:30,080 --> 00:44:28,320 close-up and what these are done here is 940 00:44:34,370 --> 00:44:30,090 you subtract the model out and again you 941 00:44:35,870 --> 00:44:34,380 see the enhancement so I know that we 942 00:44:37,490 --> 00:44:35,880 had a lot of discussion because now we 943 00:44:39,860 --> 00:44:37,500 saw three-d-- we didn't see them 944 00:44:41,960 --> 00:44:39,870 sequentially and then we looked at the 945 00:44:44,930 --> 00:44:41,970 roth paper and it looked like they were 946 00:44:46,880 --> 00:44:44,940 in the same location and in addition we 947 00:44:48,860 --> 00:44:46,890 actually found a plume in a different 948 00:44:52,970 --> 00:44:48,870 location the other ones were down here 949 00:44:55,900 --> 00:44:52,980 in March of 2017 we actually found 950 00:44:59,150 --> 00:44:55,910 something a little Pucci thing over here 951 00:45:02,450 --> 00:44:59,160 that repeated again there so that that 952 00:45:09,050 --> 00:45:02,460 would be a second second plume that's 953 00:45:10,700 --> 00:45:09,060 really cool this is just more of the 954 00:45:12,170 --> 00:45:10,710 images and then just to prove that we 955 00:45:15,590 --> 00:45:12,180 weren't kidding ourselves we added 956 00:45:17,270 --> 00:45:15,600 subtracted and convinced ourselves that 957 00:45:24,170 --> 00:45:17,280 that was right so where are these plumes 958 00:45:26,810 --> 00:45:24,180 found so the ones that the eight the the 959 00:45:29,630 --> 00:45:26,820 direct method the direct imaging method 960 00:45:31,430 --> 00:45:29,640 found right just north of the South Pole 961 00:45:35,110 --> 00:45:31,440 and then right here near this crater 962 00:45:38,990 --> 00:45:35,120 called quill and we saw it twice 963 00:45:40,820 --> 00:45:39,000 so the plume at will be repeated we saw 964 00:45:42,980 --> 00:45:40,830 that twice this one we've only seen once 965 00:45:45,230 --> 00:45:42,990 and this is the location 966 00:45:49,190 --> 00:45:45,240 of the plume as seen it with the 967 00:45:49,970 --> 00:45:49,200 spectroscopic method so we have one two 968 00:45:53,960 --> 00:45:49,980 three 969 00:45:55,190 --> 00:45:53,970 plumes if you count them and one of the 970 00:45:56,990 --> 00:45:55,200 things that's really need you've seen 971 00:46:03,260 --> 00:45:57,000 this image before cuz I showed it to you 972 00:46:05,720 --> 00:46:03,270 earlier is that here's well this region 973 00:46:07,700 --> 00:46:05,730 here is like two degrees warmer than the 974 00:46:11,600 --> 00:46:07,710 surrounding region and that's coincident 975 00:46:14,450 --> 00:46:11,610 with what with that repeating plume so 976 00:46:17,030 --> 00:46:14,460 the question we're asking is are they 977 00:46:19,220 --> 00:46:17,040 related is it possible that you could 978 00:46:21,830 --> 00:46:19,230 have a slight warming of the ice would 979 00:46:24,140 --> 00:46:21,840 that be enough to allow some liquid 980 00:46:26,600 --> 00:46:24,150 water to come through to sort of break 981 00:46:32,450 --> 00:46:26,610 through that's a it's intriguing we we 982 00:46:35,450 --> 00:46:32,460 don't know but it's a possibility and so 983 00:46:38,570 --> 00:46:35,460 this might be what that looks like that 984 00:46:40,280 --> 00:46:38,580 plume 100 rising 125 miles above the 985 00:46:45,260 --> 00:46:40,290 surface and of course there's a Jupiter 986 00:46:53,270 --> 00:46:45,270 in the background so um looks like there 987 00:46:54,920 --> 00:46:53,280 it's probably water on on Europa and the 988 00:47:00,260 --> 00:46:54,930 observations continue we didn't just 989 00:47:02,000 --> 00:47:00,270 stop in 2017 both groups have has 990 00:47:03,740 --> 00:47:02,010 amorphous as they are have are 991 00:47:04,640 --> 00:47:03,750 continuing their observations using 992 00:47:08,390 --> 00:47:04,650 different techniques and different 993 00:47:12,170 --> 00:47:08,400 analysis methods so this is um from our 994 00:47:15,349 --> 00:47:12,180 most recent 2017-2018 data taken with 995 00:47:18,140 --> 00:47:15,359 the Hubble Space Telescope and again 996 00:47:20,690 --> 00:47:18,150 it's really kind of fun to see them and 997 00:47:23,750 --> 00:47:20,700 move around this is Ganymede up here by 998 00:47:26,120 --> 00:47:23,760 the way that isn't just a splash you can 999 00:47:29,540 --> 00:47:26,130 see you rope over there and you can see 1000 00:47:35,840 --> 00:47:29,550 that lovely I love the Aurora on the on 1001 00:47:40,070 --> 00:47:35,850 the poles of Jupiter okay so that's fun 1002 00:47:44,390 --> 00:47:40,080 there's a close-up of Ganymede so if you 1003 00:47:47,510 --> 00:47:44,400 have water we have ice we think we have 1004 00:47:50,150 --> 00:47:47,520 water the good thing is that both groups 1005 00:47:54,580 --> 00:47:50,160 got the same value when you do all your 1006 00:47:58,130 --> 00:47:56,630 coincident so that the sparks 1007 00:48:01,099 --> 00:47:58,140 diamond arrived found one plume 1008 00:48:04,370 --> 00:48:01,109 coincident or near each other and we saw 1009 00:48:08,930 --> 00:48:04,380 one that repeated but we also determined 1010 00:48:10,700 --> 00:48:08,940 the amount of water based on the on the 1011 00:48:12,079 --> 00:48:10,710 images that the amount of water was 1012 00:48:14,029 --> 00:48:12,089 about the same so you don't get the same 1013 00:48:16,670 --> 00:48:14,039 numbers unless you're more or less on 1014 00:48:20,000 --> 00:48:16,680 the right track so now we have the 1015 00:48:21,710 --> 00:48:20,010 ingredients for life so we have so what 1016 00:48:23,450 --> 00:48:21,720 do you need you need atoms you need 1017 00:48:27,400 --> 00:48:23,460 molecules you need the most important 1018 00:48:33,049 --> 00:48:27,410 molecule of all h2o and you need energy 1019 00:48:38,230 --> 00:48:33,059 now a nurse the energy that life as we 1020 00:48:41,980 --> 00:48:38,240 know it uses tens it comes from the Sun 1021 00:48:46,670 --> 00:48:41,990 plants the animals that eat the plants 1022 00:48:50,269 --> 00:48:46,680 algae slime mold bedbugs etc I'll derive 1023 00:48:53,829 --> 00:48:50,279 the energy required to synthesize these 1024 00:48:56,319 --> 00:48:53,839 elements into the amino acids along 1025 00:48:58,970 --> 00:48:56,329 biochemistry chain that happens 1026 00:49:01,039 --> 00:48:58,980 sometimes on earth we have hydrothermal 1027 00:49:03,680 --> 00:49:01,049 vents go to the bottom of the ocean 1028 00:49:06,259 --> 00:49:03,690 there are there's well volcanic activity 1029 00:49:08,029 --> 00:49:06,269 and that heats up the water and you get 1030 00:49:11,029 --> 00:49:08,039 these hydrothermal vents and we found 1031 00:49:14,779 --> 00:49:11,039 what we yeah and people have looked and 1032 00:49:19,670 --> 00:49:14,789 found at life bacteria and so forth 1033 00:49:21,829 --> 00:49:19,680 living there and this is a model sort of 1034 00:49:24,319 --> 00:49:21,839 indicating the tidal heating so if you 1035 00:49:27,079 --> 00:49:24,329 don't have direct energy from the Sun 1036 00:49:29,660 --> 00:49:27,089 and you may or may not have hydrothermal 1037 00:49:32,529 --> 00:49:29,670 vents you still need a source of energy 1038 00:49:37,279 --> 00:49:32,539 in order to be able to do the chemistry 1039 00:49:40,190 --> 00:49:37,289 that allows bio the biology to happen 1040 00:49:42,559 --> 00:49:40,200 and in Europa this is this would be due 1041 00:49:51,410 --> 00:49:42,569 to the tidal heating so there is an 1042 00:49:54,490 --> 00:49:51,420 energy source and many years of people 1043 00:49:59,210 --> 00:49:54,500 studying evolution so life on Earth is 1044 00:50:02,390 --> 00:49:59,220 divided into three clouds okay three 1045 00:50:05,420 --> 00:50:02,400 different groups we have what's what are 1046 00:50:06,800 --> 00:50:05,430 called the bacteria some of them we 1047 00:50:09,210 --> 00:50:06,810 don't like 1048 00:50:10,680 --> 00:50:09,220 these are single-celled generally 1049 00:50:12,620 --> 00:50:10,690 single-cell animals we have what's 1050 00:50:16,050 --> 00:50:12,630 called the archaea and those are 1051 00:50:20,040 --> 00:50:16,060 generally those those extremophiles 1052 00:50:22,530 --> 00:50:20,050 those organisms that like to live or 1053 00:50:24,870 --> 00:50:22,540 it's super salty super acidic super 1054 00:50:28,980 --> 00:50:24,880 alkaline super hot super cold super high 1055 00:50:32,070 --> 00:50:28,990 pressure super low pressure and then we 1056 00:50:32,700 --> 00:50:32,080 have the Eukarya and that's everything 1057 00:50:36,300 --> 00:50:32,710 else 1058 00:50:42,750 --> 00:50:36,310 this is slime molds bedbugs people cats 1059 00:50:44,790 --> 00:50:42,760 dogs your neighbor and I just put down 1060 00:50:46,890 --> 00:50:44,800 this last common ancestor because it's 1061 00:50:49,260 --> 00:50:46,900 kind of cool to see the quote unquote 1062 00:50:51,270 --> 00:50:49,270 Tree of Life if this one gets very messy 1063 00:50:56,060 --> 00:50:51,280 and so does this one so I just put 1064 00:50:59,850 --> 00:50:56,070 clouds but the main difference between 1065 00:51:03,450 --> 00:50:59,860 the left side and the right side is the 1066 00:51:05,880 --> 00:51:03,460 kind of cell that makes up the different 1067 00:51:08,010 --> 00:51:05,890 kinds of life and I have a question mark 1068 00:51:13,110 --> 00:51:08,020 for the viruses because I don't nobody 1069 00:51:15,600 --> 00:51:13,120 really knows where they fit in so these 1070 00:51:19,980 --> 00:51:15,610 guys have one particular kind of cell is 1071 00:51:22,830 --> 00:51:19,990 very simple and these organisms over 1072 00:51:28,910 --> 00:51:22,840 here do are all single-cell organisms 1073 00:51:31,770 --> 00:51:28,920 whereas as we know on this side whoa on 1074 00:51:33,570 --> 00:51:31,780 this side we have multicellular 1075 00:51:35,940 --> 00:51:33,580 organisms as well as single cellular 1076 00:51:38,880 --> 00:51:35,950 organisms and the cells are more 1077 00:51:40,200 --> 00:51:38,890 complicated how you know things like 1078 00:51:41,670 --> 00:51:40,210 that then you start getting into things 1079 00:51:45,300 --> 00:51:41,680 like how is the information for 1080 00:51:47,430 --> 00:51:45,310 replication or reproduction carried in 1081 00:51:50,220 --> 00:51:47,440 in the cells of different structures 1082 00:51:57,000 --> 00:51:50,230 that do that I think on this side the 1083 00:51:59,070 --> 00:51:57,010 eukaryotes over here on the right as you 1084 00:52:01,260 --> 00:51:59,080 can see these are real electronic 1085 00:52:04,200 --> 00:52:01,270 scanning electron images of these 1086 00:52:07,140 --> 00:52:04,210 critters so this cell has here's the 1087 00:52:08,730 --> 00:52:07,150 nucleus this is where the DNA lives all 1088 00:52:09,870 --> 00:52:08,740 the genetic information and you see they 1089 00:52:11,210 --> 00:52:09,880 have all these structures of 1090 00:52:13,920 --> 00:52:11,220 mitochondria furtive doing like 1091 00:52:16,710 --> 00:52:13,930 mitochondrial DNA analyses to see where 1092 00:52:18,710 --> 00:52:16,720 people came from that's what they're 1093 00:52:20,200 --> 00:52:18,720 looking for is the DNA that's in the 1094 00:52:21,550 --> 00:52:20,210 mitochondria you have the 1095 00:52:24,190 --> 00:52:21,560 plasma you have a whole bunch of 1096 00:52:29,310 --> 00:52:24,200 structures and this is where all the 1097 00:52:31,870 --> 00:52:29,320 biochemistry happens that that is life 1098 00:52:34,390 --> 00:52:31,880 whereas on this side these are the probe 1099 00:52:36,400 --> 00:52:34,400 the prokaryotes whether they're bacteria 1100 00:52:38,380 --> 00:52:36,410 or archaea they're really simple 1101 00:52:39,970 --> 00:52:38,390 they here's something that's called the 1102 00:52:43,510 --> 00:52:39,980 nucleoid 1103 00:52:45,190 --> 00:52:43,520 and all the DNA is is there and then you 1104 00:52:47,230 --> 00:52:45,200 can see there's just a couple of 1105 00:52:55,599 --> 00:52:47,240 structures in there so they're very 1106 00:52:57,820 --> 00:52:55,609 simple and of course on as we know from 1107 00:53:00,220 --> 00:52:57,830 you know everything that's the Eukarya 1108 00:53:03,730 --> 00:53:00,230 we have planned so they have solid cells 1109 00:53:05,980 --> 00:53:03,740 so the cells on this side ER are very 1110 00:53:10,540 --> 00:53:05,990 can be differentiated and have specific 1111 00:53:13,510 --> 00:53:10,550 purposes so here we go so life on Earth 1112 00:53:14,260 --> 00:53:13,520 the bacteria this is actually a picture 1113 00:53:19,930 --> 00:53:14,270 of e---coli 1114 00:53:21,940 --> 00:53:19,940 I had to find one that was a key this is 1115 00:53:25,000 --> 00:53:21,950 a meth an o-5 1116 00:53:28,230 --> 00:53:25,010 philic animal it loves methane and lives 1117 00:53:30,730 --> 00:53:28,240 where there's a lot of methane this is a 1118 00:53:33,250 --> 00:53:30,740 single-cell organisms rather than algae 1119 00:53:34,810 --> 00:53:33,260 and then here's the great white whale so 1120 00:53:36,339 --> 00:53:34,820 this side we have a lot of diversity 1121 00:53:39,670 --> 00:53:36,349 here we have a lot of diversity but 1122 00:53:41,170 --> 00:53:39,680 they're unicellular so then let's ask 1123 00:53:47,440 --> 00:53:41,180 the question of what would life on 1124 00:53:51,160 --> 00:53:47,450 Europa look like and it is probably not 1125 00:53:54,339 --> 00:53:51,170 going to be what we think of life it is 1126 00:53:56,050 --> 00:53:54,349 probably going to be something called 1127 00:53:58,599 --> 00:53:56,060 extremophiles now there are some 1128 00:54:02,859 --> 00:53:58,609 bacteria that are extremophiles and some 1129 00:54:05,230 --> 00:54:02,869 of these guys are extremophiles so these 1130 00:54:09,099 --> 00:54:05,240 are sort of the temperature ranges - 18 1131 00:54:11,650 --> 00:54:09,109 to 15 degrees Celsius 60 121 degrees 1132 00:54:17,470 --> 00:54:11,660 remember water at sea level boils at a 1133 00:54:22,270 --> 00:54:17,480 hundred degrees Celsius pressure is like 1134 00:54:24,940 --> 00:54:22,280 from 1/100 of an atmosphere to 1,300 1135 00:54:26,589 --> 00:54:24,950 times our nurse atmosphere so obviously 1136 00:54:29,680 --> 00:54:26,599 this would be at the bottom of the ocean 1137 00:54:32,380 --> 00:54:29,690 in the deep trenches this might be sort 1138 00:54:33,850 --> 00:54:32,390 of on the top of a mountain they can 1139 00:54:38,410 --> 00:54:33,860 live in places that are up to 1140 00:54:42,540 --> 00:54:38,420 38% salt and just as an example seawater 1141 00:54:46,080 --> 00:54:42,550 is only three percent salt whoops 1142 00:54:51,610 --> 00:54:46,090 some of them like to be really acid 1143 00:54:54,280 --> 00:54:51,620 sulfuric acid is about two and then we 1144 00:54:57,340 --> 00:54:54,290 have very basic eight to twelve most of 1145 00:54:59,320 --> 00:54:57,350 us love like seven and then some of them 1146 00:55:00,100 --> 00:54:59,330 can also withstand a lot of ionizing 1147 00:55:02,410 --> 00:55:00,110 radiation 1148 00:55:05,350 --> 00:55:02,420 so that would be x-rays gamma rays 1149 00:55:07,630 --> 00:55:05,360 ultraviolet even some of the products 1150 00:55:10,030 --> 00:55:07,640 from radioactive decay and they also 1151 00:55:11,680 --> 00:55:10,040 seem to be very resistant there are some 1152 00:55:13,630 --> 00:55:11,690 that are very resistant to cosmic rays 1153 00:55:15,610 --> 00:55:13,640 and you have to remember that for 1154 00:55:19,270 --> 00:55:15,620 example when people are talking about 1155 00:55:22,480 --> 00:55:19,280 traveling from Earth to Mars or to any 1156 00:55:25,750 --> 00:55:22,490 of the other planets humans one of the 1157 00:55:29,050 --> 00:55:25,760 things that people worry about in 1158 00:55:30,610 --> 00:55:29,060 transporting humans across space is the 1159 00:55:34,060 --> 00:55:30,620 effect of cosmic rays these are very 1160 00:55:37,630 --> 00:55:34,070 high-energy charged particles and they 1161 00:55:39,520 --> 00:55:37,640 damage cells and can lead to things like 1162 00:55:42,400 --> 00:55:39,530 like cancer and disease so that is 1163 00:55:46,350 --> 00:55:42,410 always a concern on say interplanetary 1164 00:55:48,880 --> 00:55:46,360 travel for humans is how to protect 1165 00:55:50,020 --> 00:55:48,890 living creatures from cosmic rays but it 1166 00:55:53,770 --> 00:55:50,030 turns out there are some of these 1167 00:56:01,150 --> 00:55:53,780 extremophiles that are happy to deal 1168 00:56:03,550 --> 00:56:01,160 with it so here I have two images here's 1169 00:56:07,900 --> 00:56:03,560 another bacterium this is actually a 1170 00:56:13,360 --> 00:56:07,910 hallow salt-loving bacterium and this is 1171 00:56:15,690 --> 00:56:13,370 a giant squid and Europa probably 1172 00:56:19,840 --> 00:56:15,700 doesn't have the giant squid so I think 1173 00:56:23,260 --> 00:56:19,850 we're going to see the bacteria and the 1174 00:56:28,090 --> 00:56:23,270 Archaea living in Europa and where would 1175 00:56:32,230 --> 00:56:28,100 they be found well here's a scale so 1176 00:56:34,570 --> 00:56:32,240 here's only some somebodies view the 1177 00:56:38,110 --> 00:56:34,580 view is that there is probably a 1178 00:56:45,100 --> 00:56:38,120 hypothermic vent or hyper thermal vents 1179 00:56:46,680 --> 00:56:45,110 in the deep ocean of Europa that heats 1180 00:56:50,130 --> 00:56:46,690 up the water 1181 00:56:53,700 --> 00:56:50,140 and then you sets up a convection which 1182 00:56:56,760 --> 00:56:53,710 allows the I want to call it the 1183 00:56:59,760 --> 00:56:56,770 nutritive 's but the basic elements that 1184 00:57:05,870 --> 00:56:59,770 are used by for biochemistry as we know 1185 00:57:11,370 --> 00:57:05,880 it carbon oxygen phosphorus etc and then 1186 00:57:14,190 --> 00:57:11,380 life bacteria archaea would end up 1187 00:57:18,630 --> 00:57:14,200 living at the bottom and sheets perhaps 1188 00:57:21,960 --> 00:57:18,640 or upside down mounds on the bottom of 1189 00:57:25,050 --> 00:57:21,970 the ice some of them might actually if 1190 00:57:26,910 --> 00:57:25,060 there were soft ice or a vent some of 1191 00:57:29,370 --> 00:57:26,920 these um living creatures might actually 1192 00:57:32,010 --> 00:57:29,380 end up working their way up to the 1193 00:57:34,770 --> 00:57:32,020 surface much the same way that rocks and 1194 00:57:36,540 --> 00:57:34,780 meteorites in the South Pole worked 1195 00:57:38,849 --> 00:57:36,550 their way up to the surface they just 1196 00:57:40,559 --> 00:57:38,859 get dredged up or I forget what the 1197 00:57:44,220 --> 00:57:40,569 actual word is for it 1198 00:57:47,579 --> 00:57:44,230 well dredged up by the physical forces 1199 00:57:49,589 --> 00:57:47,589 and from the surface of Europa you can 1200 00:57:53,040 --> 00:57:49,599 get some of the oxides 1201 00:57:55,470 --> 00:57:53,050 I think alum molecules with oxygen in 1202 00:57:57,870 --> 00:57:55,480 them might also make their way down sort 1203 00:58:00,750 --> 00:57:57,880 of in the same way through fissures in 1204 00:58:03,089 --> 00:58:00,760 the in the ice and so it is highly 1205 00:58:07,980 --> 00:58:03,099 likely that you would end up with life 1206 00:58:12,990 --> 00:58:07,990 on Europa living on the ice shelves and 1207 00:58:16,770 --> 00:58:13,000 so the next question is what comes next 1208 00:58:18,809 --> 00:58:16,780 and there are NASA has been looking at a 1209 00:58:22,280 --> 00:58:18,819 concept called the Europa clipper which 1210 00:58:25,380 --> 00:58:22,290 is a mission to go to Europa and 1211 00:58:28,050 --> 00:58:25,390 possibly fly through a plume and see if 1212 00:58:30,059 --> 00:58:28,060 any of these if there was any what's 1213 00:58:32,010 --> 00:58:30,069 what's in the plumes could there be some 1214 00:58:34,710 --> 00:58:32,020 biological material in the plumes 1215 00:58:37,230 --> 00:58:34,720 desiccated of course but would they be 1216 00:58:39,660 --> 00:58:37,240 there would it be possible to send some 1217 00:58:41,970 --> 00:58:39,670 type of a probe that would land on the 1218 00:58:45,809 --> 00:58:41,980 surface of Europa and perhaps be able to 1219 00:58:48,450 --> 00:58:45,819 either cozy up to one of those little 1220 00:58:51,540 --> 00:58:48,460 chaotic pieces of terrain or a soft spot 1221 00:58:56,940 --> 00:58:51,550 or near one of these plumes and actually 1222 00:58:58,740 --> 00:58:56,950 do some contact excavation and I I think 1223 00:59:00,330 --> 00:58:58,750 that would be really really cool so but 1224 00:59:02,550 --> 00:59:00,340 this is something that is being stai 1225 00:59:08,460 --> 00:59:02,560 very actively because this would be 1226 00:59:10,710 --> 00:59:08,470 perhaps Europa is after Earth's we were 1227 00:59:15,540 --> 00:59:10,720 we know there's life would is the next 1228 00:59:18,630 --> 00:59:15,550 most likely location suitable for liquid 1229 00:59:21,390 --> 00:59:18,640 carbon life as we know it in the solar 1230 00:59:24,030 --> 00:59:21,400 system and that would be super exciting 1231 00:59:25,740 --> 00:59:24,040 I think if something went there and we 1232 00:59:28,440 --> 00:59:25,750 discovered there was life there I think 1233 00:59:30,900 --> 00:59:28,450 it would also be super interesting if we 1234 00:59:32,820 --> 00:59:30,910 didn't find life there because then you 1235 00:59:34,890 --> 00:59:32,830 could ask the question was there ever 1236 00:59:37,890 --> 00:59:34,900 life how would you know would you be 1237 00:59:40,680 --> 00:59:37,900 able to find fossils on earth we do find 1238 00:59:44,100 --> 00:59:40,690 the people who look for them have found 1239 00:59:47,730 --> 00:59:44,110 fossilized bacteria so it's possible one 1240 00:59:50,520 --> 00:59:47,740 could find telltale signs of past life 1241 00:59:55,650 --> 00:59:50,530 or perhaps life hasn't actually started 1242 00:59:58,370 --> 00:59:55,660 yet these are all possibilities so I'm 1243 01:00:03,210 --> 00:59:58,380 just going to and here with one last 1244 01:00:06,390 --> 01:00:03,220 slide I don't know if it was Galileo's 1245 01:00:08,790 --> 01:00:06,400 dream to go to Europa or not in 400 1246 01:00:12,320 --> 01:00:08,800 years ago but I think he would certainly 1247 01:00:17,490 --> 01:00:12,330 be interested and would probably be a 1248 01:00:20,690 --> 01:00:17,500 promoter of exploring the icy moons this 1249 01:00:27,770 --> 01:00:20,700 also turns out to be a pretty good book 1250 01:00:42,080 --> 01:00:39,940 [Applause] 1251 01:00:43,900 --> 01:00:42,090 guess we have time for questions 1252 01:00:45,980 --> 01:00:43,910 oh we had plenty of time for questions 1253 01:00:48,490 --> 01:00:45,990 including a few that up here that 1254 01:00:50,500 --> 01:00:48,500 they're gonna come from online as well 1255 01:01:02,660 --> 01:00:50,510 [Laughter] 1256 01:01:04,580 --> 01:01:02,670 yes okay so I have to repeat the 1257 01:01:06,320 --> 01:01:04,590 question for the online audience can the 1258 01:01:07,550 --> 01:01:06,330 hub will be turned back on earth to look 1259 01:01:11,900 --> 01:01:07,560 for the same sort of things we might be 1260 01:01:15,620 --> 01:01:11,910 looking for on Europa the short answers 1261 01:01:21,650 --> 01:01:15,630 no Hubble is actually designed to avoid 1262 01:01:24,670 --> 01:01:21,660 looking down on Earth for logical 1263 01:01:28,000 --> 01:01:24,680 reasons but there are other satellites 1264 01:01:30,890 --> 01:01:28,010 whose missions are to look down on earth 1265 01:01:33,470 --> 01:01:30,900 so there are as a whole suite of Earth 1266 01:01:38,110 --> 01:01:33,480 observing satellites now I don't know 1267 01:01:48,350 --> 01:01:44,120 all of the sensing equipment to be able 1268 01:01:49,970 --> 01:01:48,360 to look for life but I did that is not 1269 01:01:51,890 --> 01:01:49,980 that is one of the few things Hubble 1270 01:02:13,280 --> 01:01:51,900 cannot do is turn turn around and look 1271 01:02:16,370 --> 01:02:13,290 at and look at hers we're here that's 1272 01:02:19,040 --> 01:02:16,380 actually some okay so the question is 1273 01:02:23,360 --> 01:02:19,050 does that is does the effect of the 1274 01:02:26,960 --> 01:02:23,370 tidal forcing of the or the tidal 1275 01:02:29,990 --> 01:02:26,970 heating of Europa coincide with where 1276 01:02:32,210 --> 01:02:30,000 you see the plumes and in fact I just 1277 01:02:36,500 --> 01:02:32,220 read a paper on that and I think the 1278 01:02:40,460 --> 01:02:36,510 answer is no that is that is what in 1279 01:02:41,870 --> 01:02:40,470 fact Enceladus is locked but Europe is 1280 01:02:43,280 --> 01:02:41,880 not so I think that's one of the other 1281 01:02:46,790 --> 01:02:43,290 pieces of evidence that you we're not 1282 01:02:49,890 --> 01:02:46,800 looking at exactly the same thing in the 1283 01:02:54,310 --> 01:02:49,900 green sweater there yes 1284 01:03:02,350 --> 01:02:54,320 when the bottom I think you said it was 1285 01:03:12,070 --> 01:03:02,360 100 degrees Celsius when it comes I 1286 01:03:13,360 --> 01:03:12,080 would be like a 94 degrees Kelvin no cuz 1287 01:03:15,610 --> 01:03:13,370 you only see it on you only have a 1288 01:03:17,820 --> 01:03:15,620 little bit of 100 degrees Celsius as it 1289 01:03:20,260 --> 01:03:17,830 comes out and then it'll cool and 1290 01:03:24,160 --> 01:03:20,270 remember the ice is a hundred meters is 1291 01:03:53,650 --> 01:03:24,170 a hundred kilometers thick so the the 1292 01:03:57,550 --> 01:03:53,660 surface of Europe is so the question is 1293 01:04:02,530 --> 01:03:57,560 is the temperature on the surface of 1294 01:04:05,920 --> 01:04:02,540 Europa fluid and the answer is I'm not 1295 01:04:07,750 --> 01:04:05,930 sure because it well you know sometimes 1296 01:04:11,050 --> 01:04:07,760 Europe is facing the Sun so it's gonna 1297 01:04:12,700 --> 01:04:11,060 have a little more insulation I think 1298 01:04:19,570 --> 01:04:12,710 overall if we go back and look at those 1299 01:04:23,230 --> 01:04:19,580 beautiful images let's go back and look 1300 01:04:25,930 --> 01:04:23,240 at the numbers let's do the numbers so 1301 01:04:29,310 --> 01:04:25,940 what you see here is that you see it's 1302 01:04:31,870 --> 01:04:29,320 roughly about eighty to ninety degrees 1303 01:04:35,230 --> 01:04:31,880 Kelvin with a little bit maybe getting 1304 01:04:37,900 --> 01:04:35,240 up 230 so I don't know if that means 1305 01:04:41,920 --> 01:04:37,910 it's constantly changing but I think 1306 01:04:43,060 --> 01:04:41,930 it's pretty constrained obviously when 1307 01:04:46,000 --> 01:04:43,070 it's facing the Sun it's gonna be a 1308 01:04:47,410 --> 01:04:46,010 little hotter right yeah your image on 1309 01:04:50,380 --> 01:04:47,420 the right is it says the marked is 1310 01:04:51,460 --> 01:04:50,390 daytime and this is daytime and this is 1311 01:04:53,860 --> 01:04:51,470 nighttime here 1312 01:04:56,530 --> 01:04:53,870 so night so that there's probably a 30 1313 01:04:58,630 --> 01:04:56,540 degree change between the daytime and 1314 01:05:02,680 --> 01:04:58,640 the nighttime I don't I don't know that 1315 01:05:03,069 --> 01:05:02,690 means fluid okay so over here in the 1316 01:05:05,079 --> 01:05:03,079 black do 1317 01:05:06,999 --> 01:05:05,089 sure so generally then what is the 1318 01:05:13,680 --> 01:05:07,009 theory behind why's there's a certain 1319 01:05:18,549 --> 01:05:16,359 so the question is what is our 1320 01:05:21,219 --> 01:05:18,559 understanding of why we only see the 1321 01:05:26,199 --> 01:05:21,229 plumes in one location yeah good 1322 01:05:29,140 --> 01:05:26,209 question that's what we're trying to 1323 01:05:30,849 --> 01:05:29,150 understand actually and isn't that what 1324 01:05:32,680 --> 01:05:30,859 one of the things your rope a clipper 1325 01:05:34,329 --> 01:05:32,690 would be able to Europa clipper we'll be 1326 01:05:37,690 --> 01:05:34,339 able to probe a little better so there 1327 01:05:39,880 --> 01:05:37,700 like there was a question earlier and so 1328 01:05:42,190 --> 01:05:39,890 doing the comparison between Europa and 1329 01:05:44,170 --> 01:05:42,200 say some of the other moons not quite 1330 01:05:47,410 --> 01:05:44,180 seeing a direct analog particularly with 1331 01:05:50,680 --> 01:05:47,420 Enceladus so it is a it is an open 1332 01:05:52,120 --> 01:05:50,690 question and yes having a mission 1333 01:05:54,089 --> 01:05:52,130 actually go there and get really close 1334 01:05:56,229 --> 01:05:54,099 and personal would be a wonderful thing 1335 01:05:57,459 --> 01:05:56,239 right so there was a question on line 1336 01:05:58,749 --> 01:05:57,469 let me just interrupt with that that was 1337 01:06:01,059 --> 01:05:58,759 sort of related to the Europa clipper 1338 01:06:03,729 --> 01:06:01,069 they were wondering what all right so 1339 01:06:05,709 --> 01:06:03,739 they they recognized that like that yes 1340 01:06:07,359 --> 01:06:05,719 you have to go survey what would be the 1341 01:06:09,279 --> 01:06:07,369 time scale for a lander mission is what 1342 01:06:12,099 --> 01:06:09,289 they were asking I mean like when would 1343 01:06:17,759 --> 01:06:12,109 that happen yes if Europa clipper went 1344 01:06:19,660 --> 01:06:17,769 up next next decade would there be the 1345 01:06:21,339 --> 01:06:19,670 several people online were very 1346 01:06:23,049 --> 01:06:21,349 concerned that we need to be able to 1347 01:06:29,229 --> 01:06:23,059 measure the water on Europa before they 1348 01:06:31,349 --> 01:06:29,239 died yeah how old are they and where do 1349 01:06:35,309 --> 01:06:31,359 they live 1350 01:06:39,150 --> 01:06:35,319 I think it's likely within my my my 1351 01:06:41,690 --> 01:06:39,160 lifetime okay and I would hope in 20 1352 01:06:46,200 --> 01:06:44,430 all right so we'll just call it decades 1353 01:06:48,359 --> 01:06:46,210 okay yeah yeah it's not it's not gonna 1354 01:07:04,220 --> 01:06:48,369 happen next decade but I think in the 1355 01:07:08,370 --> 01:07:04,230 thirties would be a reason possible yeah 1356 01:07:10,770 --> 01:07:08,380 there are there are people on the on the 1357 01:07:13,950 --> 01:07:10,780 team that not me because I'm sort of a 1358 01:07:16,140 --> 01:07:13,960 you know lower level type player in this 1359 01:07:20,030 --> 01:07:16,150 but there are people there who have been 1360 01:07:44,760 --> 01:07:20,040 who are very active in talking to NASA 1361 01:07:47,190 --> 01:07:44,770 about that okay that's you the question 1362 01:07:52,020 --> 01:07:47,200 is House Cassini flew through the plumes 1363 01:07:53,970 --> 01:07:52,030 of Enceladus and made some measurements 1364 01:07:56,130 --> 01:07:53,980 of the of the chemistry and so the 1365 01:07:57,539 --> 01:07:56,140 question is if you went through the 1366 01:08:04,079 --> 01:07:57,549 plumes of Europa what would that 1367 01:08:05,789 --> 01:08:04,089 chemistry look like I'm not actually 1368 01:08:08,730 --> 01:08:05,799 sure I know the answer to that I think 1369 01:08:11,990 --> 01:08:08,740 it would depend on well you'd want to 1370 01:08:14,910 --> 01:08:12,000 see some evidence for example like 1371 01:08:17,700 --> 01:08:14,920 hydrogen compounds sulfate compounds 1372 01:08:20,490 --> 01:08:17,710 maybe iron compounds but I don't know 1373 01:08:22,289 --> 01:08:20,500 the quantity of hand would it matter 1374 01:08:24,990 --> 01:08:22,299 that much that Enceladus is sort of a 1375 01:08:28,410 --> 01:08:25,000 medium sized moon whereas Europa is a 1376 01:08:31,530 --> 01:08:28,420 large moon your open one of the seven 1377 01:08:35,479 --> 01:08:31,540 large moons Enceladus is just one of the 1378 01:08:38,160 --> 01:08:35,489 medium one of the many in size moons so 1379 01:08:40,800 --> 01:08:38,170 that's one of the major differences I 1380 01:08:44,010 --> 01:08:40,810 think of those two and then in addition 1381 01:08:51,200 --> 01:08:44,020 the cool thing would be to find 1382 01:08:54,330 --> 01:08:51,210 tyria all right in the back up there we 1383 01:08:55,290 --> 01:08:54,340 knew that there were was like when 1384 01:08:58,370 --> 01:08:55,300 Europe 1385 01:09:01,040 --> 01:08:58,380 what would the implication be for 1386 01:09:13,050 --> 01:09:01,050 because there's life in the solar system 1387 01:09:17,720 --> 01:09:13,060 big deal I think it certainly opens up 1388 01:09:20,910 --> 01:09:17,730 the definition of the habitable zone so 1389 01:09:22,920 --> 01:09:20,920 so the question is what is what is the 1390 01:09:24,510 --> 01:09:22,930 implication if life were found on Europe 1391 01:09:27,210 --> 01:09:24,520 or what is the implication for life in 1392 01:09:28,950 --> 01:09:27,220 the universe in in general so I'm gonna 1393 01:09:32,520 --> 01:09:28,960 back that up a little bit which is that 1394 01:09:36,000 --> 01:09:32,530 on earth wherever there is the 1395 01:09:38,940 --> 01:09:36,010 possibility of life there is life so 1396 01:09:40,260 --> 01:09:38,950 life is very tenacious and you know just 1397 01:09:44,580 --> 01:09:40,270 but just take that you know the basic 1398 01:09:48,290 --> 01:09:44,590 definition of life organic an organism 1399 01:09:51,690 --> 01:09:48,300 that can replicate and eats and poops 1400 01:09:55,520 --> 01:09:51,700 that's the basic definition of life and 1401 01:09:59,720 --> 01:09:58,380 if there's life on Europa that tells you 1402 01:10:03,240 --> 01:09:59,730 that you don't need to have direct 1403 01:10:06,120 --> 01:10:03,250 starlight whether its sunlight or or 1404 01:10:07,440 --> 01:10:06,130 that to provide the energy and that's a 1405 01:10:09,570 --> 01:10:07,450 little different because that's one of 1406 01:10:11,670 --> 01:10:09,580 the difficulties is on earth is knowing 1407 01:10:12,960 --> 01:10:11,680 exactly when you know you're no longer 1408 01:10:15,510 --> 01:10:12,970 dependent on sunlight so if you're in 1409 01:10:17,730 --> 01:10:15,520 the bottom of the ocean with the in the 1410 01:10:19,650 --> 01:10:17,740 trenches is the hydrothermal vents and 1411 01:10:21,420 --> 01:10:19,660 so forth you know you're not getting a 1412 01:10:24,780 --> 01:10:21,430 lot of sunlight down there at all 1413 01:10:27,530 --> 01:10:24,790 so that's a possibility so then when 1414 01:10:29,940 --> 01:10:27,540 people talk about looking for 1415 01:10:31,230 --> 01:10:29,950 extraterrestrial planets and looking for 1416 01:10:32,490 --> 01:10:31,240 evidence of life there's a whole 1417 01:10:35,670 --> 01:10:32,500 discussion of what's considered the 1418 01:10:38,160 --> 01:10:35,680 habitable zone hours some people call it 1419 01:10:41,040 --> 01:10:38,170 the Goldilocks you may have heard of it 1420 01:10:43,410 --> 01:10:41,050 as the Goldilocks a factor which is 1421 01:10:45,360 --> 01:10:43,420 where now you're looking at but there 1422 01:10:48,930 --> 01:10:45,370 you're looking at things like what could 1423 01:10:51,090 --> 01:10:48,940 be an earth as we know as we know Earth 1424 01:10:54,630 --> 01:10:51,100 if there's life on Europa what that 1425 01:10:56,220 --> 01:10:54,640 tells us I think is that the definition 1426 01:10:57,900 --> 01:10:56,230 of a habitable zone you can have one 1427 01:11:00,000 --> 01:10:57,910 four planets but you might also 1428 01:11:02,250 --> 01:11:00,010 to sort of think about all the 1429 01:11:04,860 --> 01:11:02,260 conditions that are necessary going back 1430 01:11:08,100 --> 01:11:04,870 to the basics of energy and chemistry 1431 01:11:09,330 --> 01:11:08,110 that are necessary so I think it opens 1432 01:11:12,420 --> 01:11:09,340 it up I think it also makes it much 1433 01:11:13,920 --> 01:11:12,430 harder to Wow if you're looking for 1434 01:11:16,650 --> 01:11:13,930 moons around Jupiter z-- and extra 1435 01:11:18,990 --> 01:11:16,660 terrestrial planets you'd make an 1436 01:11:21,270 --> 01:11:19,000 exoplanets it's a more difficult to find 1437 01:11:23,610 --> 01:11:21,280 but I think it would imply that it's 1438 01:11:25,350 --> 01:11:23,620 probably more prevalent this is now my 1439 01:11:28,380 --> 01:11:25,360 personal opinion it's more prevalent 1440 01:11:30,360 --> 01:11:28,390 than we might otherwise have expected 1441 01:11:34,110 --> 01:11:30,370 it's a long-winded answer to a short 1442 01:11:38,940 --> 01:11:34,120 question all right other questions 1443 01:11:44,160 --> 01:11:38,950 Peter another source of heat for Europa 1444 01:11:45,980 --> 01:11:44,170 like radioactivity so the question is 1445 01:11:49,970 --> 01:11:45,990 could there be another source of heat 1446 01:11:54,390 --> 01:11:49,980 like radioactivity from the core 1447 01:11:56,730 --> 01:11:54,400 probably but you know these let's say 1448 01:12:00,000 --> 01:11:56,740 these formed four-and-a-half billion 1449 01:12:03,210 --> 01:12:00,010 years ago four billion years ago I don't 1450 01:12:04,740 --> 01:12:03,220 think it would be enough I think you 1451 01:12:18,540 --> 01:12:04,750 would definitely need the title heating 1452 01:12:20,550 --> 01:12:18,550 to to keep that ocean liquid some of the 1453 01:12:23,010 --> 01:12:20,560 numbers I've seen like six to ten times 1454 01:12:27,330 --> 01:12:23,020 the amount of water on earth it's a huge 1455 01:13:01,250 --> 01:12:27,340 amount of water hey was there a question 1456 01:13:04,770 --> 01:13:01,260 in the back there other questions no I I 1457 01:13:08,280 --> 01:13:04,780 think it's possible it's probably less 1458 01:13:10,380 --> 01:13:08,290 likely yes tardigrades are very 1459 01:13:15,600 --> 01:13:10,390 tenacious and they are very tough 1460 01:13:17,370 --> 01:13:15,610 they're really hard to to do away with I 1461 01:13:20,700 --> 01:13:17,380 mean they're used in school in school 1462 01:13:39,680 --> 01:13:20,710 labs all the time because of that so 1463 01:14:06,870 --> 01:13:55,590 survive cosmic radiation but they are 1464 01:14:08,370 --> 01:14:06,880 multicellular yeah you if you don't know 1465 01:14:11,690 --> 01:14:08,380 about tardigrades you might want to look 1466 01:14:14,430 --> 01:14:11,700 them up my son at one of the science 1467 01:14:16,020 --> 01:14:14,440 centers we went to spend about half an 1468 01:14:20,160 --> 01:14:16,030 hour reading about the tardigrades and 1469 01:14:23,370 --> 01:14:20,170 it's really cool tardigrades are used 1470 01:14:24,690 --> 01:14:23,380 for in a lot of astrobiology labs when 1471 01:14:25,830 --> 01:14:24,700 they when they teach astrobiology 1472 01:14:28,920 --> 01:14:25,840 because it's one of those life forms 1473 01:14:35,220 --> 01:14:28,930 that is very tough and it you can 1474 01:14:48,229 --> 01:14:40,009 [Laughter] 1475 01:14:49,759 --> 01:14:48,239 they're everywhere okay questions you've 1476 01:15:11,540 --> 01:14:49,769 had want to see if there's any other 1477 01:15:14,089 --> 01:15:11,550 okay back to you relationships so the so 1478 01:15:17,930 --> 01:15:14,099 the question is the fact that Jupiter is 1479 01:15:20,390 --> 01:15:17,940 a cat is a gaseous planet yeah because 1480 01:15:22,879 --> 01:15:20,400 that effect in the gravitational 1481 01:15:35,120 --> 01:15:22,889 relationship between the planet and its 1482 01:15:38,660 --> 01:15:35,130 moon because of the density yes yes it's 1483 01:15:42,169 --> 01:15:38,670 yes or no because if it's just gravity 1484 01:15:45,979 --> 01:15:42,179 then mass is more important than the 1485 01:15:48,229 --> 01:15:45,989 density so it's a total mass but the 1486 01:15:49,939 --> 01:15:48,239 fact that it has an atmosphere and has a 1487 01:15:52,669 --> 01:15:49,949 magnetic field so you start seeing 1488 01:15:56,899 --> 01:15:52,679 interactions of the magnetic field with 1489 01:15:59,709 --> 01:15:56,909 of Jupiter with its with its um plus the 1490 01:16:02,779 --> 01:15:59,719 the aurora which already you know it's a 1491 01:16:04,580 --> 01:16:02,789 it's a chemical reaction at a coming 1492 01:16:08,629 --> 01:16:04,590 it's a physical reaction so you you're 1493 01:16:10,100 --> 01:16:08,639 getting particles thrown into the 1494 01:16:12,890 --> 01:16:10,110 magnetic field so that will that will 1495 01:16:14,660 --> 01:16:12,900 affect so you could you can get 1496 01:16:17,029 --> 01:16:14,670 sputtering for example on the surface of 1497 01:16:18,890 --> 01:16:17,039 the of the moons that's when material 1498 01:16:22,040 --> 01:16:18,900 gets bombarded and then gets but gets 1499 01:16:28,729 --> 01:16:22,050 some sort of scraped off so the answer 1500 01:16:34,680 --> 01:16:28,739 is yes to both okay Herman okay 1501 01:16:44,259 --> 01:16:41,129 eating the course I don't think so no 1502 01:16:47,799 --> 01:16:44,269 all right so thank you all for coming on 1503 01:16:50,439 --> 01:16:47,809 next month may 1st gravitational wave 1504 01:16:56,590 --> 01:16:50,449 astronomy with Annie Fructis give