1 00:00:07,039 --> 00:00:03,830 welcome to the first of our astrobiology 2 00:00:10,370 --> 00:00:07,049 seminar series for this quarter as a bit 3 00:00:14,390 --> 00:00:10,380 of future advertising next week we'll be 4 00:00:17,840 --> 00:00:14,400 having Dave Chris from JPL talking about 5 00:00:20,480 --> 00:00:17,850 his new mission investigating new space 6 00:00:25,130 --> 00:00:20,490 mission investigating carbon dioxide 7 00:00:27,710 --> 00:00:25,140 levels and secret sources and sinks in 8 00:00:29,990 --> 00:00:27,720 the carbon cycle of the earth very 9 00:00:33,229 --> 00:00:30,000 relevant to astrobiology because carbon 10 00:00:37,729 --> 00:00:33,239 fluxes are all important for regulating 11 00:00:39,799 --> 00:00:37,739 planetary temperatures of course the 12 00:00:42,459 --> 00:00:39,809 other great volatile that's of vital 13 00:00:46,970 --> 00:00:42,469 importance to astrobiology is water and 14 00:00:50,180 --> 00:00:46,980 this week seminar will be on water and 15 00:00:54,319 --> 00:00:50,190 where it's where it's not why it's not 16 00:00:56,900 --> 00:00:54,329 on Mars being given to us by Erika honey 17 00:00:59,090 --> 00:00:56,910 of Earth and Space Sciences the space 18 00:01:02,240 --> 00:00:59,100 physics group in Earth and Space 19 00:01:03,590 --> 00:01:02,250 Sciences at University of Washington she 20 00:01:09,490 --> 00:01:03,600 comes to us from a physics background 21 00:01:15,170 --> 00:01:09,500 she did her PhD here with Robert winley 22 00:01:18,010 --> 00:01:15,180 investigating modeling of micro magneto 23 00:01:20,630 --> 00:01:18,020 spheres on the moon and was the first to 24 00:01:23,840 --> 00:01:20,640 demonstrate the potential for such 25 00:01:28,850 --> 00:01:23,850 things by modeling subsequently to that 26 00:01:30,830 --> 00:01:28,860 she was post-op of sorts in ESS in the 27 00:01:34,219 --> 00:01:30,840 space physics group and has recently 28 00:01:38,359 --> 00:01:34,229 been appointed research assistant 29 00:01:41,600 --> 00:01:38,369 professor in space physics and she's her 30 00:01:44,980 --> 00:01:41,610 interest generally in magnetospheric 31 00:01:47,389 --> 00:01:44,990 modeling and other suchlike processes 32 00:01:50,120 --> 00:01:47,399 she'll be talking about Mars where did 33 00:01:53,510 --> 00:01:50,130 all the water go very good thank you yes 34 00:01:55,999 --> 00:01:53,520 so I'm going to be discussing the sort 35 00:01:57,980 --> 00:01:56,009 of a space physicist take on where did 36 00:02:00,530 --> 00:01:57,990 all the water go at mars and i'll be 37 00:02:03,350 --> 00:02:00,540 presenting numerical simulations that 38 00:02:05,149 --> 00:02:03,360 will address what is that what is the 39 00:02:07,010 --> 00:02:05,159 sort of some of the things we have to 40 00:02:11,290 --> 00:02:07,020 consider when when 41 00:02:13,369 --> 00:02:11,300 looking at loss of water to space and 42 00:02:15,140 --> 00:02:13,379 trying to figure out how much of the 43 00:02:16,460 --> 00:02:15,150 water was lost to space and how much of 44 00:02:18,860 --> 00:02:16,470 the water that was present under an 45 00:02:21,830 --> 00:02:18,870 early Mother's is still residing at Mars 46 00:02:24,740 --> 00:02:21,840 possibly in what this picture hasn't 47 00:02:27,050 --> 00:02:24,750 been interpreted as icebergs does 48 00:02:28,550 --> 00:02:27,060 covered icebergs on Mars so it's most of 49 00:02:30,140 --> 00:02:28,560 the water in form of just being locked 50 00:02:31,610 --> 00:02:30,150 up in the surface and it's just not 51 00:02:36,890 --> 00:02:31,620 terribly visible or did a lot of it 52 00:02:38,420 --> 00:02:36,900 leave and get lost to space so I'm going 53 00:02:39,949 --> 00:02:38,430 to talk about my some of the simulations 54 00:02:41,870 --> 00:02:39,959 but first know that we're all on a the 55 00:02:43,850 --> 00:02:41,880 same background I want to give us sort 56 00:02:45,289 --> 00:02:43,860 of a short history of Mars and talk 57 00:02:47,300 --> 00:02:45,299 about some of the physical processes 58 00:02:50,539 --> 00:02:47,310 that could have contributed to loss of 59 00:02:52,370 --> 00:02:50,549 water to space remembering the geologic 60 00:02:54,800 --> 00:02:52,380 epoch SAT Mars is really easy because 61 00:02:57,559 --> 00:02:54,810 there's only three the first one is the 62 00:03:00,259 --> 00:02:57,569 nokia naira valent essentially the era 63 00:03:02,059 --> 00:03:00,269 begins with formation and the end of the 64 00:03:05,960 --> 00:03:02,069 area is associated with the end of heavy 65 00:03:07,640 --> 00:03:05,970 bombardment this time is associated when 66 00:03:10,580 --> 00:03:07,650 when water was thought to be fairly 67 00:03:12,949 --> 00:03:10,590 prevalent on Mars and there would have 68 00:03:15,920 --> 00:03:12,959 been active erosion there possibly even 69 00:03:18,470 --> 00:03:15,930 lakes and oceans present there would 70 00:03:20,629 --> 00:03:18,480 have an intense volcanic activity there 71 00:03:23,420 --> 00:03:20,639 was a dynamo generated magnetic field 72 00:03:25,220 --> 00:03:23,430 when exactly that shut off is a an area 73 00:03:28,370 --> 00:03:25,230 of active research and a big question 74 00:03:30,680 --> 00:03:28,380 and impacts associated with heavy 75 00:03:33,460 --> 00:03:30,690 bombardment would have driven eighty to 76 00:03:36,710 --> 00:03:33,470 ninety five percent of atmospheric loss 77 00:03:38,599 --> 00:03:36,720 the second era is the Hesperian era and 78 00:03:40,699 --> 00:03:38,609 this is essentially a trend the 79 00:03:42,949 --> 00:03:40,709 beginning of this area associated with 80 00:03:44,750 --> 00:03:42,959 the end of heavy bombardment and the end 81 00:03:46,879 --> 00:03:44,760 of it is a little fuzzy because its 82 00:03:49,370 --> 00:03:46,889 associated with people with when people 83 00:03:51,259 --> 00:03:49,380 think liquid water cease to become 84 00:03:53,449 --> 00:03:51,269 stable on the surface so we're not 85 00:03:56,030 --> 00:03:53,459 entirely sure when that's at it's sort 86 00:03:58,670 --> 00:03:56,040 of a general idea and this is sort of a 87 00:04:01,670 --> 00:03:58,680 transition time from Mars going from 88 00:04:04,430 --> 00:04:01,680 having in the early time of being having 89 00:04:06,349 --> 00:04:04,440 a lot of active erosion plenty of water 90 00:04:09,920 --> 00:04:06,359 to the more air in time that we know of 91 00:04:11,960 --> 00:04:09,930 today any sort of water bring prevalent 92 00:04:14,509 --> 00:04:11,970 on Mars would have been more episodic in 93 00:04:16,999 --> 00:04:14,519 nature then the water would have been 94 00:04:18,430 --> 00:04:17,009 migrating essentially my migrating to 95 00:04:20,380 --> 00:04:18,440 the polar caps and under 96 00:04:23,490 --> 00:04:20,390 held and there may have been transit a 97 00:04:25,930 --> 00:04:23,500 transitional or episodic river activity 98 00:04:28,090 --> 00:04:25,940 during this time there may have been a 99 00:04:31,930 --> 00:04:28,100 resurgence of the Dynamo magnetic field 100 00:04:33,190 --> 00:04:31,940 it's that's a question and most of the 101 00:04:34,720 --> 00:04:33,200 atmospheric loss that would have 102 00:04:36,100 --> 00:04:34,730 occurred during this time and water loss 103 00:04:38,800 --> 00:04:36,110 would have been thrown more sort of a 104 00:04:40,960 --> 00:04:38,810 mass selective method and sort of to 105 00:04:43,030 --> 00:04:40,970 sort of illustrate some of the episodic 106 00:04:45,040 --> 00:04:43,040 and breakout flooding you see here we 107 00:04:46,720 --> 00:04:45,050 this is a picture of a fluval fan that 108 00:04:50,230 --> 00:04:46,730 would have formed that formed during 109 00:04:52,330 --> 00:04:50,240 this hesperian area era and then the 110 00:04:54,760 --> 00:04:52,340 final era is the current era which is 111 00:04:57,490 --> 00:04:54,770 the amazonian era which goes from this 112 00:05:01,030 --> 00:04:57,500 fuzzy time of when water stopped being 113 00:05:03,160 --> 00:05:01,040 prevalent to present and this is this is 114 00:05:06,880 --> 00:05:03,170 an arid pit time there is there's 115 00:05:09,040 --> 00:05:06,890 occasional breakout activity but for the 116 00:05:11,350 --> 00:05:09,050 most part it's dry dusty conditions and 117 00:05:13,840 --> 00:05:11,360 there may have been occasional volcanic 118 00:05:15,220 --> 00:05:13,850 activity but we do know that there is 119 00:05:17,650 --> 00:05:15,230 something actually happening not just 120 00:05:19,210 --> 00:05:17,660 sort of in the the short geologic of 121 00:05:21,610 --> 00:05:19,220 time but even on the very short time 122 00:05:23,830 --> 00:05:21,620 scales this picture shows a crater wall 123 00:05:25,840 --> 00:05:23,840 an image of a crater wall taken by mars 124 00:05:28,420 --> 00:05:25,850 global surveyor and the two images are 125 00:05:30,790 --> 00:05:28,430 the exact same but spot six years apart 126 00:05:33,280 --> 00:05:30,800 and you can already sort of see just 127 00:05:34,930 --> 00:05:33,290 from looking at this inmates it looks 128 00:05:36,820 --> 00:05:34,940 like you see these crevasses associated 129 00:05:40,810 --> 00:05:36,830 with some sort of flowing possibly a 130 00:05:42,400 --> 00:05:40,820 aqueous fluid movement and but the real 131 00:05:45,400 --> 00:05:42,410 kicker is when you look at this the 132 00:05:47,350 --> 00:05:45,410 second image taken most recently is what 133 00:05:48,909 --> 00:05:47,360 looks like a new deposit so even though 134 00:05:50,740 --> 00:05:48,919 the concurrent conditions are not 135 00:05:52,990 --> 00:05:50,750 favorable for water there does appear to 136 00:05:57,670 --> 00:05:53,000 be some sort of occasional transitionary 137 00:05:59,740 --> 00:05:57,680 em activity so just how unfavourable are 138 00:06:02,460 --> 00:05:59,750 the current conditions for water on Mars 139 00:06:06,100 --> 00:06:02,470 this is the phase diagram for water and 140 00:06:07,930 --> 00:06:06,110 the yellow rectangle here indicates sort 141 00:06:10,000 --> 00:06:07,940 of the range of current conditions that 142 00:06:11,530 --> 00:06:10,010 can be found on Mars the highest 143 00:06:13,120 --> 00:06:11,540 pressure that are associated with the 144 00:06:14,530 --> 00:06:13,130 top of the rectangle are the conditions 145 00:06:17,200 --> 00:06:14,540 that would be found at the bottom of 146 00:06:19,170 --> 00:06:17,210 Valley Marineris during the summer the 147 00:06:21,210 --> 00:06:19,180 pub conditions that 148 00:06:22,650 --> 00:06:21,220 see at the bottom of the rectangle are 149 00:06:25,170 --> 00:06:22,660 the conditions if you're at the top of 150 00:06:29,219 --> 00:06:25,180 Olympus Mons and you can sorta see this 151 00:06:32,730 --> 00:06:29,229 little spot right here where possibly 152 00:06:35,100 --> 00:06:32,740 you may get liquid water forming that's 153 00:06:37,230 --> 00:06:35,110 why we do occasionally see it the other 154 00:06:39,180 --> 00:06:37,240 thing that this graph points out is that 155 00:06:41,969 --> 00:06:39,190 in the past if you wanted to have 156 00:06:43,680 --> 00:06:41,979 written stable liquid water just raising 157 00:06:45,540 --> 00:06:43,690 the surface temperature is not going to 158 00:06:47,100 --> 00:06:45,550 get to their all you'll do is the 159 00:06:49,080 --> 00:06:47,110 strands a shrimper somewhere around here 160 00:06:51,510 --> 00:06:49,090 over to here you're going to go straight 161 00:06:55,140 --> 00:06:51,520 from ice to vapor in order to have 162 00:06:56,520 --> 00:06:55,150 stable liquid water on Mars you needed 163 00:06:58,710 --> 00:06:56,530 to have what you need to have more 164 00:07:02,850 --> 00:06:58,720 pressure in the past which means poor 165 00:07:05,100 --> 00:07:02,860 atmosphere so what would that of 166 00:07:06,749 --> 00:07:05,110 atmosphere have been what was the past 167 00:07:08,969 --> 00:07:06,759 atmospheric condition composition 168 00:07:10,950 --> 00:07:08,979 possibly life so what I've got shown 169 00:07:13,200 --> 00:07:10,960 here are the are the atmospheric 170 00:07:14,939 --> 00:07:13,210 compositions for the three terrestrial 171 00:07:16,080 --> 00:07:14,949 planets that actually have a thick 172 00:07:18,330 --> 00:07:16,090 atmosphere I've left with Mercury 173 00:07:20,490 --> 00:07:18,340 Ralphie here and you'll notice but I'm 174 00:07:22,980 --> 00:07:20,500 sort of just doing the toppling person 175 00:07:25,170 --> 00:07:22,990 then our life build earth is actually 176 00:07:27,350 --> 00:07:25,180 the oddball out in this in this 177 00:07:31,110 --> 00:07:27,360 comparison that both of units and Mars 178 00:07:32,939 --> 00:07:31,120 primarily CO 2 atmospheres so if you 179 00:07:34,520 --> 00:07:32,949 think well okay maybe if we use Venus's 180 00:07:37,980 --> 00:07:34,530 not having lost much of its atmosphere 181 00:07:40,050 --> 00:07:37,990 then we could assume maybe that if Mars 182 00:07:44,040 --> 00:07:40,060 had a thicker atmosphere in the past it 183 00:07:45,570 --> 00:07:44,050 would have been primarily co2 but there 184 00:07:48,300 --> 00:07:45,580 was originally thought to be a problem 185 00:07:49,980 --> 00:07:48,310 with that entered that line of logic so 186 00:07:52,560 --> 00:07:49,990 if you use sort of a conservative 187 00:07:54,810 --> 00:07:52,570 estimate of what you might want to have 188 00:07:57,570 --> 00:07:54,820 for a thick a thick atmosphere to have 189 00:08:01,100 --> 00:07:57,580 water minimally stable us ooh maybe 190 00:08:03,689 --> 00:08:01,110 about 150 mil more just for reference 191 00:08:07,430 --> 00:08:03,699 conditions are about seven eight bars of 192 00:08:10,590 --> 00:08:07,440 co2 yo conventional wisdom with you 193 00:08:13,560 --> 00:08:10,600 to atmospheric you would get when I'm 194 00:08:15,900 --> 00:08:13,570 told were favorable position on the 195 00:08:17,550 --> 00:08:15,910 phase diagram first for water and you 196 00:08:20,100 --> 00:08:17,560 again in a greenhouse effect associated 197 00:08:21,750 --> 00:08:20,110 with the co2 but if there is a lot of 198 00:08:24,360 --> 00:08:21,760 water president you should be generating 199 00:08:26,280 --> 00:08:24,370 carbonate rock everywhere and there is 200 00:08:28,140 --> 00:08:26,290 very little carbonate rocks eating on 201 00:08:31,470 --> 00:08:28,150 the surface so this was thought to be 202 00:08:35,940 --> 00:08:31,480 evidence that the thicker atmosphere was 203 00:08:39,630 --> 00:08:35,950 not primarily co2 then Mars exploration 204 00:08:42,270 --> 00:08:39,640 Rovers landed specifically opportunity 205 00:08:44,430 --> 00:08:42,280 landed in Marathi meridiani planum and 206 00:08:47,100 --> 00:08:44,440 I'm sure we've all seen this absolutely 207 00:08:50,880 --> 00:08:47,110 beautiful picture of the layered outcrop 208 00:08:53,490 --> 00:08:50,890 at the top of Eagle crater and as Mars 209 00:08:56,370 --> 00:08:53,500 as murder got closer to the rock outcrop 210 00:08:58,350 --> 00:08:56,380 it's all these little round rocks that 211 00:09:00,390 --> 00:08:58,360 have been termed blueberries and just as 212 00:09:01,590 --> 00:09:00,400 a warning this picture is a false color 213 00:09:04,410 --> 00:09:01,600 image and the blueberries are not 214 00:09:06,870 --> 00:09:04,420 actually blue blue color can indicates 215 00:09:09,150 --> 00:09:06,880 composition specifically that their iron 216 00:09:11,280 --> 00:09:09,160 or hematite rich now is actually the 217 00:09:14,520 --> 00:09:11,290 reason why meridiani planum was chosen 218 00:09:15,900 --> 00:09:14,530 as a landing site from space it was 219 00:09:18,390 --> 00:09:15,910 indicated that there was a fair amount 220 00:09:20,400 --> 00:09:18,400 of grey hematite in that region and 221 00:09:22,470 --> 00:09:20,410 great imitator typically only farms in 222 00:09:25,170 --> 00:09:22,480 the presence of water so that's why this 223 00:09:28,320 --> 00:09:25,180 site was chosen and here it is in the 224 00:09:30,120 --> 00:09:28,330 form of blueberries when they look much 225 00:09:32,940 --> 00:09:30,130 camp got much closer this is a zoomed in 226 00:09:34,320 --> 00:09:32,950 picture of these blueberries that what 227 00:09:36,450 --> 00:09:34,330 these what these blueberries really are 228 00:09:40,130 --> 00:09:36,460 is something called concretions they 229 00:09:44,130 --> 00:09:40,140 form when iron precipitates out of rock 230 00:09:46,740 --> 00:09:44,140 when it when that rock is is saturated 231 00:09:49,110 --> 00:09:46,750 with water so there they indicate the 232 00:09:51,510 --> 00:09:49,120 presence of water and there in every 233 00:09:54,660 --> 00:09:51,520 single layer of the rock layer doubt 234 00:09:57,630 --> 00:09:54,670 crops that are the in Eagle crater but 235 00:09:59,700 --> 00:09:57,640 more importantly the surrounding rock 236 00:10:01,920 --> 00:09:59,710 around these blueberries is something 237 00:10:03,720 --> 00:10:01,930 called jira site Jerry site is a type of 238 00:10:07,020 --> 00:10:03,730 rock that only forms when the aqueous 239 00:10:08,520 --> 00:10:07,030 fluid has a pH of less than 5 and on 240 00:10:10,800 --> 00:10:08,530 earth that typically actually only forms 241 00:10:14,640 --> 00:10:10,810 and when the pH is a range of 123 so 242 00:10:16,710 --> 00:10:14,650 basically battery acid so that water 243 00:10:18,270 --> 00:10:16,720 that was that was present when these 244 00:10:20,440 --> 00:10:18,280 blueberries form well there may have 245 00:10:23,320 --> 00:10:20,450 been a lot of it at times 246 00:10:25,930 --> 00:10:23,330 it was very acidic water and if you have 247 00:10:27,970 --> 00:10:25,940 a very thick co2 atmosphere and very 248 00:10:30,040 --> 00:10:27,980 acidic water you will not cycle the co2 249 00:10:32,560 --> 00:10:30,050 through the water and create carbonate 250 00:10:35,050 --> 00:10:32,570 rocks so the thought that the atmosphere 251 00:10:36,880 --> 00:10:35,060 could not have been sickly a thick co2 252 00:10:39,400 --> 00:10:36,890 atmosphere is now that evidence is 253 00:10:41,320 --> 00:10:39,410 proven to be false and for way with 254 00:10:43,240 --> 00:10:41,330 regard to life one of the things this 255 00:10:45,940 --> 00:10:43,250 indicates is that if life was either 256 00:10:47,740 --> 00:10:45,950 developing at this time possibly or was 257 00:10:49,750 --> 00:10:47,750 already present it would have had to 258 00:10:52,780 --> 00:10:49,760 deal with it with the conditions that 259 00:10:58,690 --> 00:10:52,790 were not only very acidic but oxidizing 260 00:11:00,280 --> 00:10:58,700 saline and intermittently wet so with 261 00:11:02,860 --> 00:11:00,290 that sort of idea of where some of the 262 00:11:04,990 --> 00:11:02,870 past history of Mars now let us talk 263 00:11:06,250 --> 00:11:05,000 about that through Mars is history what 264 00:11:09,190 --> 00:11:06,260 are some of the loss or hiding 265 00:11:12,370 --> 00:11:09,200 mechanisms by which we can see water can 266 00:11:14,320 --> 00:11:12,380 sort of disappear from our view so the 267 00:11:16,570 --> 00:11:14,330 first and most obvious possible hiding 268 00:11:17,800 --> 00:11:16,580 mechanisms is in the polar caps and you 269 00:11:19,300 --> 00:11:17,810 can actually see from this picture I 270 00:11:20,950 --> 00:11:19,310 have up in the corner this is a picture 271 00:11:22,780 --> 00:11:20,960 taken during the salt the southern 272 00:11:27,100 --> 00:11:22,790 winter and we see a very prominent 273 00:11:29,620 --> 00:11:27,110 southern polar cap there's water ice in 274 00:11:32,380 --> 00:11:29,630 the caps with a co2 frost and both the 275 00:11:35,340 --> 00:11:32,390 north and south polar the the persistent 276 00:11:37,780 --> 00:11:35,350 caps are about three kilometers thick 277 00:11:39,190 --> 00:11:37,790 another possible hiding mechanism is 278 00:11:40,780 --> 00:11:39,200 relates to that picture I showed at the 279 00:11:42,970 --> 00:11:40,790 beginning which is what was have 280 00:11:45,160 --> 00:11:42,980 interpreted as does covered I Sparks is 281 00:11:47,290 --> 00:11:45,170 it could just be locked up in permafrost 282 00:11:49,690 --> 00:11:47,300 or in the soil and you can actually hide 283 00:11:54,730 --> 00:11:49,700 about ten you could hide tens of meters 284 00:11:57,640 --> 00:11:54,740 of water through that method or it could 285 00:11:59,860 --> 00:11:57,650 be lost to space and we know that that 286 00:12:01,480 --> 00:11:59,870 there has been lost to space because we 287 00:12:03,850 --> 00:12:01,490 have measured a significant amount of 288 00:12:05,320 --> 00:12:03,860 mass fraction ization mass fraction 289 00:12:07,270 --> 00:12:05,330 ization will only occur when you have 290 00:12:09,070 --> 00:12:07,280 something that's a mass selective method 291 00:12:10,930 --> 00:12:09,080 which is only occurs when you're losing 292 00:12:13,540 --> 00:12:10,940 it to space but with the caveat that you 293 00:12:17,350 --> 00:12:13,550 can modify it somewhat by the surface 294 00:12:19,840 --> 00:12:17,360 reservoirs so it's sort of different 295 00:12:22,270 --> 00:12:19,850 that said now I'm going to focus on 296 00:12:24,400 --> 00:12:22,280 different types of loss mechanisms that 297 00:12:26,470 --> 00:12:24,410 can occur and the first being a thermal 298 00:12:28,150 --> 00:12:26,480 mechanism thermal mechanisms so the 299 00:12:30,310 --> 00:12:28,160 first type of thermal mechanism is the 300 00:12:31,230 --> 00:12:30,320 one that was primary the primary lost 301 00:12:32,940 --> 00:12:31,240 mechanism not 302 00:12:34,410 --> 00:12:32,950 Elliot Mars but all of the early 303 00:12:36,180 --> 00:12:34,420 terrestrial planets right after 304 00:12:38,550 --> 00:12:36,190 formation and that's hydrodynamic 305 00:12:40,500 --> 00:12:38,560 outflow but early atmospheres would have 306 00:12:43,530 --> 00:12:40,510 been primarily light species 307 00:12:45,510 --> 00:12:43,540 specifically hydrogen and that species 308 00:12:47,760 --> 00:12:45,520 would have been hot and as it was 309 00:12:50,130 --> 00:12:47,770 escaping to the fact that it thermal 310 00:12:51,660 --> 00:12:50,140 velocity was korea had greater than this 311 00:12:53,610 --> 00:12:51,670 escape velocity and had enough energy 312 00:12:55,199 --> 00:12:53,620 due to the fact that the atmospheres 313 00:12:56,910 --> 00:12:55,209 were very thick it would have just 314 00:12:58,350 --> 00:12:56,920 removed the collision time scales would 315 00:13:00,090 --> 00:12:58,360 have been very short and it would have 316 00:13:03,900 --> 00:13:00,100 just drank all of the other heavier 317 00:13:06,480 --> 00:13:03,910 elements with it so this would been a 318 00:13:10,190 --> 00:13:06,490 non nuttin this is a non mass selective 319 00:13:12,060 --> 00:13:10,200 method another chief early source of 320 00:13:14,310 --> 00:13:12,070 mechanism for loss would have been 321 00:13:17,160 --> 00:13:14,320 impact to rosen impactors occurring 322 00:13:18,750 --> 00:13:17,170 during the era of heavy bombardment you 323 00:13:21,150 --> 00:13:18,760 get a vapor plume coming off of the 324 00:13:22,680 --> 00:13:21,160 impact vapor plume is essentially a 325 00:13:25,740 --> 00:13:22,690 small kiss scale version of hydrodynamic 326 00:13:27,960 --> 00:13:25,750 outflow the temperatures are high it's 327 00:13:30,150 --> 00:13:27,970 very thick very collisional that light 328 00:13:31,949 --> 00:13:30,160 species that are being there being lost 329 00:13:34,949 --> 00:13:31,959 will describe the heavier species out 330 00:13:39,510 --> 00:13:34,959 with it also it's a source of volatile 331 00:13:41,760 --> 00:13:39,520 so you get material back to a mass 332 00:13:43,500 --> 00:13:41,770 selective loss mechanism in thermal 333 00:13:45,389 --> 00:13:43,510 mechanisms thermal or jeans escape and 334 00:13:47,760 --> 00:13:45,399 this will incur went what's the 335 00:13:49,440 --> 00:13:47,770 atmosphere has become thinner and then 336 00:13:51,060 --> 00:13:49,450 you can in your diffusion time scales 337 00:13:53,370 --> 00:13:51,070 are short compared to your collision 338 00:13:57,090 --> 00:13:53,380 time scales in that case you have 339 00:13:59,160 --> 00:13:57,100 species where the thermal velocity is 340 00:14:01,350 --> 00:13:59,170 greater than the skate velocity such as 341 00:14:06,079 --> 00:14:01,360 hydrogen per snail mail escape whereas 342 00:14:08,730 --> 00:14:06,089 if oxygen it's gravitationally bound 343 00:14:11,550 --> 00:14:08,740 this is fiction from the hydrodynamic 344 00:14:14,430 --> 00:14:11,560 that I thought that that was also normal 345 00:14:16,860 --> 00:14:14,440 eating it is but the hydrodynamic escape 346 00:14:19,530 --> 00:14:16,870 that one you have collisions so the 347 00:14:21,600 --> 00:14:19,540 hydrogen the so boxes so oxygen or 348 00:14:23,370 --> 00:14:21,610 something heavy may have normally what 349 00:14:25,920 --> 00:14:23,380 under its under normal conditions have 350 00:14:27,329 --> 00:14:25,930 been it's dragging exactly would have 351 00:14:29,579 --> 00:14:27,339 been below escape velocity but the 352 00:14:32,400 --> 00:14:29,589 collisions will pull it out so it's a 353 00:14:34,230 --> 00:14:32,410 collisional effect whereas when jeans 354 00:14:36,690 --> 00:14:34,240 escape or thermal escape start taking 355 00:14:38,310 --> 00:14:36,700 over you the collision time scale is 356 00:14:40,980 --> 00:14:38,320 much longer so you don't you don't have 357 00:14:42,900 --> 00:14:40,990 hydrogen pulling the heavier zout so 358 00:14:46,610 --> 00:14:42,910 it's just leaving it's leaving and 359 00:14:51,720 --> 00:14:50,130 so nonthermal mechanisms include 360 00:14:53,160 --> 00:14:51,730 photochemical escape and this is 361 00:14:55,200 --> 00:14:53,170 actually a very important escape 362 00:14:57,720 --> 00:14:55,210 mechanism occurring in the current day 363 00:15:01,650 --> 00:14:57,730 atmosphere and what occurs is you have 364 00:15:04,790 --> 00:15:01,660 co2 will be ionized by ultraviolet rays 365 00:15:07,560 --> 00:15:04,800 from the Sun and in a very fairly quick 366 00:15:09,930 --> 00:15:07,570 process photog well through photolysis 367 00:15:13,320 --> 00:15:09,940 it will interact with an oxygen neutral 368 00:15:15,900 --> 00:15:13,330 creating 02 plus and a co neutral this 369 00:15:18,600 --> 00:15:15,910 is the reason why co2 is the dominant 370 00:15:22,140 --> 00:15:18,610 neutral at Mars but 0 2 plus is the 371 00:15:23,730 --> 00:15:22,150 dominant eye on it Mars o 2 plus can 372 00:15:26,280 --> 00:15:23,740 then interact with an electron and 373 00:15:28,650 --> 00:15:26,290 through dissociative recombination break 374 00:15:32,220 --> 00:15:28,660 apart the molecular bond and create two 375 00:15:33,360 --> 00:15:32,230 very energetic oxygens of atoms the star 376 00:15:35,340 --> 00:15:33,370 indicates that they're very energetic 377 00:15:37,800 --> 00:15:35,350 this will create what's called a hot 378 00:15:39,720 --> 00:15:37,810 oxygen Corona this is these are very 379 00:15:42,180 --> 00:15:39,730 energetic oxygen they escape very 380 00:15:44,610 --> 00:15:42,190 quickly and very easily from Mars and 381 00:15:46,500 --> 00:15:44,620 just make a corona of neutrals around 382 00:15:49,140 --> 00:15:46,510 the planet this Corona has been met 383 00:15:51,330 --> 00:15:49,150 definitely measured up to five planetary 384 00:15:52,950 --> 00:15:51,340 radii away from the planet and it's 385 00:15:54,930 --> 00:15:52,960 probably actually present up to ten 386 00:15:58,700 --> 00:15:54,940 radii away from the planet so this makes 387 00:16:01,620 --> 00:15:58,710 a very large Corona around the planet 388 00:16:03,330 --> 00:16:01,630 another mechanism which then temps up 389 00:16:06,420 --> 00:16:03,340 takes over is once you've got this 390 00:16:08,550 --> 00:16:06,430 neutral Corona around the planet there 391 00:16:09,990 --> 00:16:08,560 are I ons coming from the Sun in form of 392 00:16:12,020 --> 00:16:10,000 solar wind and there's magnetic field 393 00:16:14,130 --> 00:16:12,030 that's laced through that solar wind 394 00:16:15,960 --> 00:16:14,140 it's a ver still a very tenuous 395 00:16:17,400 --> 00:16:15,970 atmosphere so the Mutual's will not 396 00:16:19,830 --> 00:16:17,410 interact with the ions through 397 00:16:21,840 --> 00:16:19,840 pollutions and because they're neutral 398 00:16:24,630 --> 00:16:21,850 they will not feel the effect of the 399 00:16:27,720 --> 00:16:24,640 magnetic field but once they get ionized 400 00:16:29,910 --> 00:16:27,730 by solar ultraviolet radiation they will 401 00:16:31,380 --> 00:16:29,920 instantly be picked up by that magnetic 402 00:16:33,780 --> 00:16:31,390 field they will instantly feel it and 403 00:16:36,360 --> 00:16:33,790 then start being carried downstream and 404 00:16:38,250 --> 00:16:36,370 with the solar wind when they can either 405 00:16:40,980 --> 00:16:38,260 just be carried downstream and go flying 406 00:16:44,370 --> 00:16:40,990 past Mars and be completely lost or 407 00:16:46,920 --> 00:16:44,380 since it's a heavy element in the form 408 00:16:48,990 --> 00:16:46,930 of a plus they can react the atmosphere 409 00:16:51,330 --> 00:16:49,000 and they do so with much more momentum 410 00:16:53,790 --> 00:16:51,340 and energy then if it was a hydrogen ion 411 00:16:55,590 --> 00:16:53,800 and in doing so they can either break 412 00:16:57,220 --> 00:16:55,600 apart molecular bonds or they can 413 00:17:00,820 --> 00:16:57,230 actually just kick heavies 414 00:17:02,200 --> 00:17:00,830 out of the atmosphere if they kick the 415 00:17:04,540 --> 00:17:02,210 heavies out of the atmosphere that's a 416 00:17:06,010 --> 00:17:04,550 process called sputtering and this may 417 00:17:09,270 --> 00:17:06,020 be have may have been an important 418 00:17:11,170 --> 00:17:09,280 process in the early atmosphere and 419 00:17:14,050 --> 00:17:11,180 because we have ions that are 420 00:17:15,870 --> 00:17:14,060 interacting with the ionosphere near 421 00:17:17,920 --> 00:17:15,880 near the bound near the planet at 422 00:17:19,960 --> 00:17:17,930 boundaries that you'll get there will be 423 00:17:22,480 --> 00:17:19,970 waves plasma waves that will interact at 424 00:17:24,700 --> 00:17:22,490 that boundary there's both removal or 425 00:17:26,290 --> 00:17:24,710 associated with this this plasma waves 426 00:17:32,470 --> 00:17:26,300 and instead of instability can also lead 427 00:17:35,950 --> 00:17:32,480 to loss so just to recap it to recap of 428 00:17:37,930 --> 00:17:35,960 the lost history at Mars is that it that 429 00:17:40,000 --> 00:17:37,940 formation the original atmosphere was 430 00:17:42,550 --> 00:17:40,010 delivered by impactors and outgassing 431 00:17:44,620 --> 00:17:42,560 from the created material this 432 00:17:46,330 --> 00:17:44,630 hydrodynamic escape which was non mass 433 00:17:48,250 --> 00:17:46,340 selective would then take over and 434 00:17:50,770 --> 00:17:48,260 stripping most of the early atmosphere 435 00:17:52,480 --> 00:17:50,780 until it stripping when the early 436 00:17:55,060 --> 00:17:52,490 atmosphere until most of the hydrogen 437 00:17:56,620 --> 00:17:55,070 was gone that impact erosion would have 438 00:17:59,250 --> 00:17:56,630 would take over as the dominant lock 439 00:18:02,230 --> 00:17:59,260 myth lost mechanism until the end of 440 00:18:06,030 --> 00:18:02,240 heavy bombardment ended but it would 441 00:18:08,410 --> 00:18:06,040 also lead to a source of volatiles and 442 00:18:10,330 --> 00:18:08,420 then the wild cards come in that you 443 00:18:12,030 --> 00:18:10,340 have the secondary atmosphere that was 444 00:18:14,920 --> 00:18:12,040 there after the end of heavy bombardment 445 00:18:17,080 --> 00:18:14,930 may have possibly been predicted by a 446 00:18:18,520 --> 00:18:17,090 global magnetic field and may have also 447 00:18:21,190 --> 00:18:18,530 been supplemented by some additional 448 00:18:23,680 --> 00:18:21,200 volcanic activity and then jeans escape 449 00:18:26,170 --> 00:18:23,690 and photo chemical processes would then 450 00:18:28,300 --> 00:18:26,180 take over and be become the dominant 451 00:18:30,910 --> 00:18:28,310 lost mechanism for Mutual's and still be 452 00:18:32,950 --> 00:18:30,920 that today and solar wind will have 453 00:18:35,650 --> 00:18:32,960 become lost mechanisms will come the 454 00:18:39,070 --> 00:18:35,660 dominant loss mechanism for ions so what 455 00:18:40,780 --> 00:18:39,080 about this magnetic field at Mars up 456 00:18:43,960 --> 00:18:40,790 until the arrival of Mars Global 457 00:18:46,750 --> 00:18:43,970 Surveyor it was not entirely known what 458 00:18:49,090 --> 00:18:46,760 the nature of Mars's magnetic field was 459 00:18:50,920 --> 00:18:49,100 it was there was something measured and 460 00:18:53,620 --> 00:18:50,930 it was weak but nobody was quite sure if 461 00:18:54,970 --> 00:18:53,630 it was a weak global dynamo or I've even 462 00:18:56,800 --> 00:18:54,980 seen papers where people thought well 463 00:18:57,539 --> 00:18:56,810 maybe Phobos the moons Phobos was 464 00:18:59,489 --> 00:18:57,549 magnetized 465 00:19:00,899 --> 00:18:59,499 that's what they were picking up but 466 00:19:02,669 --> 00:19:00,909 with Mars levels are there they're all 467 00:19:03,869 --> 00:19:02,679 to prove without a doubt that the 468 00:19:06,239 --> 00:19:03,879 magnetic field that was being measured 469 00:19:08,609 --> 00:19:06,249 was actually in the form of magnetized 470 00:19:10,109 --> 00:19:08,619 rock on the surface the name that it 471 00:19:11,639 --> 00:19:10,119 goes by the name magnetic anomalies and 472 00:19:13,710 --> 00:19:11,649 this is the first sort of measurement of 473 00:19:16,729 --> 00:19:13,720 these magnetic anomalies the color 474 00:19:19,019 --> 00:19:16,739 indicates a magnetic field measured it 475 00:19:20,609 --> 00:19:19,029 felt to be at the surface that was 476 00:19:21,810 --> 00:19:20,619 measured it at a higher atmosphere so 477 00:19:24,779 --> 00:19:21,820 they don't know exactly what it is at 478 00:19:28,470 --> 00:19:24,789 the surface look shown on top of a 479 00:19:30,330 --> 00:19:28,480 topography map and because most people 480 00:19:32,279 --> 00:19:30,340 don't except for space businesses work 481 00:19:34,440 --> 00:19:32,289 in units of Nana Tesla just as a 482 00:19:36,899 --> 00:19:34,450 reference the Earth's global magnetic 483 00:19:39,509 --> 00:19:36,909 dynamo driven global magnetic field at 484 00:19:41,340 --> 00:19:39,519 the surface at the equator is 30,000 485 00:19:43,320 --> 00:19:41,350 Nana Tesla so only about ten times 486 00:19:45,419 --> 00:19:43,330 larger than this so these are very 487 00:19:47,399 --> 00:19:45,429 strong magnetic anomalies which is why 488 00:19:50,549 --> 00:19:47,409 they was ambiguous nobody thought they 489 00:19:52,739 --> 00:19:50,559 could be quite this strong here's 490 00:19:54,119 --> 00:19:52,749 another showing of them because you 491 00:19:56,099 --> 00:19:54,129 couldn't really get an idea where these 492 00:19:57,840 --> 00:19:56,109 magnetic anomalies work this is a 493 00:20:00,269 --> 00:19:57,850 picture of the color indicates the 494 00:20:01,979 --> 00:20:00,279 topography of Mars and the black and 495 00:20:04,739 --> 00:20:01,989 white contour is in to create the 496 00:20:06,419 --> 00:20:04,749 magnetic field strength both inward and 497 00:20:08,099 --> 00:20:06,429 outward and you'll see that the magnetic 498 00:20:10,289 --> 00:20:08,109 field is primarily in the southern 499 00:20:12,899 --> 00:20:10,299 hemisphere and associated with this 500 00:20:15,869 --> 00:20:12,909 heavily cratered older terrain of the 501 00:20:17,759 --> 00:20:15,879 southern highlands but there is some 502 00:20:19,970 --> 00:20:17,769 there are some magnetic anomalies in the 503 00:20:21,989 --> 00:20:19,980 northern lowlands in the newer train 504 00:20:23,340 --> 00:20:21,999 most of them don't show up on this 505 00:20:26,099 --> 00:20:23,350 resolution they tend to be much smaller 506 00:20:28,200 --> 00:20:26,109 and you also say that appears that the 507 00:20:31,320 --> 00:20:28,210 large impact basins of Hellas and our 508 00:20:32,849 --> 00:20:31,330 jar appeared to be unmagnetized the fact 509 00:20:34,799 --> 00:20:32,859 that Hellas and our jar appear to be 510 00:20:38,249 --> 00:20:34,809 unmagnetized has been used to suggest 511 00:20:40,970 --> 00:20:38,259 that the Mars Global dynamo turned off 512 00:20:44,220 --> 00:20:40,980 prior to the end of heavy bombardment 513 00:20:46,409 --> 00:20:44,230 but it's possible that hellas and our 514 00:20:48,330 --> 00:20:46,419 jar are actually magnetized but the 515 00:20:50,489 --> 00:20:48,340 signal is just so incoherent that you 516 00:20:51,989 --> 00:20:50,499 can't be measured at space so it's not 517 00:20:53,279 --> 00:20:51,999 until we actually get something on the 518 00:20:54,749 --> 00:20:53,289 surface that measures we couldn't know 519 00:20:57,239 --> 00:20:54,759 for sure and the fact that there are 520 00:20:59,279 --> 00:20:57,249 magnetic anomalies up in the more newer 521 00:21:01,979 --> 00:20:59,289 terrain of the northern highlands naw 522 00:21:04,979 --> 00:21:01,989 northern lowlands has suggested to some 523 00:21:09,659 --> 00:21:04,989 that maybe the dynamo restarted later on 524 00:21:11,220 --> 00:21:09,669 in the Hesperian era and then the other 525 00:21:13,860 --> 00:21:11,230 wild card that comes in 526 00:21:15,720 --> 00:21:13,870 this is the obliquity obliquity is their 527 00:21:17,760 --> 00:21:15,730 angle at which the rotation vector of a 528 00:21:20,909 --> 00:21:17,770 planet makes with the normal to the 529 00:21:23,220 --> 00:21:20,919 ecliptic plane currently Mars is rotated 530 00:21:25,500 --> 00:21:23,230 obliquity angles about 20 degrees but 531 00:21:27,510 --> 00:21:25,510 simulations have shown that due to the 532 00:21:29,220 --> 00:21:27,520 fact that Mars does not have only a few 533 00:21:31,409 --> 00:21:29,230 puny little moons babosa need us and 534 00:21:34,140 --> 00:21:31,419 does not have a large moon its obliquity 535 00:21:36,510 --> 00:21:34,150 won't have Brooke floated around and 536 00:21:38,760 --> 00:21:36,520 oscillated up to maybe even about 50 537 00:21:41,370 --> 00:21:38,770 degrees up to about 10 million years ago 538 00:21:44,159 --> 00:21:41,380 and possibly even more even earlier on 539 00:21:46,380 --> 00:21:44,169 the fact that the earth has a large moon 540 00:21:49,500 --> 00:21:46,390 has helped stabilize its rotation axis 541 00:21:52,049 --> 00:21:49,510 so it's liquid rotates just a little bit 542 00:21:54,720 --> 00:21:52,059 and as it is suggest about that's one of 543 00:22:00,960 --> 00:21:54,730 the actually helpers that make life on 544 00:22:04,650 --> 00:22:00,970 Earth a little more possible so some 545 00:22:07,500 --> 00:22:04,660 initial results are a research into what 546 00:22:10,560 --> 00:22:07,510 obliquity changes can do to Mars was by 547 00:22:13,289 --> 00:22:10,570 Manning's um McKay and zolani and 548 00:22:15,539 --> 00:22:13,299 they've looked at how obliquity changes 549 00:22:18,000 --> 00:22:15,549 would affect this variations in the 550 00:22:19,470 --> 00:22:18,010 atmospheric density and showing this 551 00:22:21,330 --> 00:22:19,480 plot is to showing for a thicker 552 00:22:23,640 --> 00:22:21,340 atmosphere which they claim is being 553 00:22:27,270 --> 00:22:23,650 five bars so much thicker than we 554 00:22:29,280 --> 00:22:27,280 assumed first earlier on or a thin model 555 00:22:31,320 --> 00:22:29,290 thin atmospheric models of something 556 00:22:34,620 --> 00:22:31,330 less than five bars of atmosphere how 557 00:22:37,860 --> 00:22:34,630 that how co2 would have moved from being 558 00:22:39,780 --> 00:22:37,870 trapped in regolith and co2 ice to being 559 00:22:41,430 --> 00:22:39,790 in the atmosphere and found that if they 560 00:22:43,590 --> 00:22:41,440 started with a very thick atmosphere 561 00:22:46,530 --> 00:22:43,600 obliquity the obliquity changes would 562 00:22:48,600 --> 00:22:46,540 charge would lead to large changes in 563 00:22:50,549 --> 00:22:48,610 global warming and large variations in 564 00:22:52,500 --> 00:22:50,559 the atmospheric temperatures but if they 565 00:22:53,610 --> 00:22:52,510 started with a thin atmosphere that 566 00:22:57,390 --> 00:22:53,620 there wouldn't be quite as much 567 00:22:59,310 --> 00:22:57,400 variation so with that background 568 00:23:02,340 --> 00:22:59,320 they'll know now talk about the solar 569 00:23:04,710 --> 00:23:02,350 wind interaction at Mars so this is a 570 00:23:06,690 --> 00:23:04,720 little cartoon of what happens so i can 571 00:23:10,890 --> 00:23:06,700 define some of the terms the solar wind 572 00:23:13,830 --> 00:23:10,900 is presidential ii the sun's atmosphere 573 00:23:15,780 --> 00:23:13,840 boiling off into space and it's charged 574 00:23:17,280 --> 00:23:15,790 particles so it's a plasma so it's ions 575 00:23:19,860 --> 00:23:17,290 and electrons there's no neutrals as 576 00:23:23,370 --> 00:23:19,870 it's a plasma is highly conductive and 577 00:23:24,340 --> 00:23:23,380 when it boils off into space it will 578 00:23:26,560 --> 00:23:24,350 drag the soul 579 00:23:28,659 --> 00:23:26,570 magnetic field with it into space and 580 00:23:32,380 --> 00:23:28,669 forming what's called the interplanetary 581 00:23:34,770 --> 00:23:32,390 magnetic field or IMF the current 582 00:23:37,600 --> 00:23:34,780 conditions are such that the solar wind 583 00:23:40,419 --> 00:23:37,610 what as its traveling out into space is 584 00:23:42,610 --> 00:23:40,429 moving with a speed that is faster than 585 00:23:45,039 --> 00:23:42,620 its inherent sales be so when it runs 586 00:23:48,250 --> 00:23:45,049 into an obstacle such as a planet like 587 00:23:50,860 --> 00:23:48,260 Mars or the earth and slows down it will 588 00:23:54,190 --> 00:23:50,870 form a bow shock and it's not well for 589 00:23:56,440 --> 00:23:54,200 shown in this picture as it sure as the 590 00:23:59,710 --> 00:23:56,450 the kinetic energy is converted into 591 00:24:01,630 --> 00:23:59,720 thermal energy it will that it will form 592 00:24:03,610 --> 00:24:01,640 a hot layer of plasma call to magneto 593 00:24:06,669 --> 00:24:03,620 sheath which is sort of shown in this 594 00:24:09,310 --> 00:24:06,679 region right here with whole lot of wavy 595 00:24:13,020 --> 00:24:09,320 mature waves on the magnetic field so 596 00:24:15,460 --> 00:24:13,030 this the white lines of magnetic IMF 597 00:24:17,740 --> 00:24:15,470 eventually the solar wind will enter it 598 00:24:19,899 --> 00:24:17,750 will come in contact with the highly 599 00:24:21,640 --> 00:24:19,909 conducting I atmosphere of a planet it's 600 00:24:23,799 --> 00:24:21,650 got an atmosphere or in the case of 601 00:24:25,720 --> 00:24:23,809 something like the moon does not have an 602 00:24:27,730 --> 00:24:25,730 atmosphere it will just keep plowing in 603 00:24:30,100 --> 00:24:27,740 if it comes in contact with a 604 00:24:32,169 --> 00:24:30,110 nightosphere old then it can because the 605 00:24:34,120 --> 00:24:32,179 magnetic field associated with the solar 606 00:24:36,310 --> 00:24:34,130 wind cannot transit through this 607 00:24:43,060 --> 00:24:36,320 conductor it will pile up and then 608 00:24:45,430 --> 00:24:43,070 eventually slide around the side so what 609 00:24:47,350 --> 00:24:45,440 are some of the solar wind possible 610 00:24:50,110 --> 00:24:47,360 possible solar wind conditions in the 611 00:24:54,010 --> 00:24:50,120 past from the Sun well we know 612 00:24:58,299 --> 00:24:54,020 essentially that a young son is an 613 00:24:59,950 --> 00:24:58,309 active son and that in the past the 614 00:25:03,310 --> 00:24:59,960 ultraviolet and x-ray flux would have 615 00:25:05,200 --> 00:25:03,320 been larger that will lead to more 616 00:25:07,120 --> 00:25:05,210 ionization of atmospheres would have led 617 00:25:09,520 --> 00:25:07,130 to more heating so an honest here would 618 00:25:11,830 --> 00:25:09,530 have been heated it expanded inflated 619 00:25:14,409 --> 00:25:11,840 and increasing scale heights in and 620 00:25:18,070 --> 00:25:14,419 extend expanding out this hot oxygen 621 00:25:19,659 --> 00:25:18,080 Corona that Mars possesses the solar 622 00:25:21,880 --> 00:25:19,669 wind would have been elevated by what 623 00:25:23,770 --> 00:25:21,890 elevated what I mean is that the dip the 624 00:25:25,779 --> 00:25:23,780 density of material flowing off of the 625 00:25:27,970 --> 00:25:25,789 Sun would have been higher or larger and 626 00:25:29,799 --> 00:25:27,980 the speeds at which they come off would 627 00:25:31,659 --> 00:25:29,809 have been larger as well that 628 00:25:33,460 --> 00:25:31,669 interplanetary magnetic field would have 629 00:25:36,010 --> 00:25:33,470 been stronger as well but it works out 630 00:25:36,230 --> 00:25:36,020 that the pick up a pick up of ions in 631 00:25:38,030 --> 00:25:36,240 this 632 00:25:42,799 --> 00:25:38,040 perona associated with that would have 633 00:25:45,230 --> 00:25:42,809 actually decreased though and then we 634 00:25:46,820 --> 00:25:45,240 have our wild cards of when did the 635 00:25:50,240 --> 00:25:46,830 planetary magnetic field certain with 636 00:25:53,840 --> 00:25:50,250 the global man dynamo turn off and how 637 00:25:55,280 --> 00:25:53,850 to obliquity changes figure into this so 638 00:25:57,049 --> 00:25:55,290 one of the problems is if you're going 639 00:25:59,030 --> 00:25:57,059 to be modeling something you want to 640 00:26:00,200 --> 00:25:59,040 have some data to validate your model 641 00:26:04,820 --> 00:26:00,210 against and prove that it's really 642 00:26:06,500 --> 00:26:04,830 correct um we don't know exactly what 643 00:26:08,960 --> 00:26:06,510 the solar wind conditions were in the 644 00:26:11,840 --> 00:26:08,970 early side we can only look at it at 645 00:26:14,120 --> 00:26:11,850 solar types cars in estimating and we 646 00:26:17,030 --> 00:26:14,130 definitely don't have any data from then 647 00:26:19,640 --> 00:26:17,040 either so the best thing we can do is 648 00:26:22,549 --> 00:26:19,650 use current date forms as analogues by 649 00:26:25,580 --> 00:26:22,559 which to test our models so how good of 650 00:26:27,290 --> 00:26:25,590 that of an approximation is that so I'm 651 00:26:28,940 --> 00:26:27,300 going to go through and the and talk 652 00:26:30,680 --> 00:26:28,950 about the sort of the four main 653 00:26:33,740 --> 00:26:30,690 characteristics of the Sun of the Sun 654 00:26:37,040 --> 00:26:33,750 for both storms current date storms and 655 00:26:39,860 --> 00:26:37,050 what we know for looking at solar-type 656 00:26:45,010 --> 00:26:39,870 stars that are at least a billion years 657 00:26:47,480 --> 00:26:45,020 younger than the Sun so we know that the 658 00:26:49,340 --> 00:26:47,490 ultraviolet to x-ray flux will it was 659 00:26:52,400 --> 00:26:49,350 probably between three to 50 times 660 00:26:54,610 --> 00:26:52,410 larger during a flare that's associated 661 00:26:57,110 --> 00:26:54,620 with a solar with a storm that 662 00:26:58,970 --> 00:26:57,120 ultraviolet and x-ray flux can increase 663 00:27:02,690 --> 00:26:58,980 from ten to a hundred times its nominal 664 00:27:04,010 --> 00:27:02,700 of range the solar wind speed in the 665 00:27:06,560 --> 00:27:04,020 past was probably about four times 666 00:27:08,660 --> 00:27:06,570 larger than current values during a 667 00:27:12,049 --> 00:27:08,670 storm the speed will increase by about 668 00:27:14,090 --> 00:27:12,059 two to five times solar wind density was 669 00:27:17,060 --> 00:27:14,100 probably somewhere between 15 to 40 670 00:27:19,190 --> 00:27:17,070 times larger in the past during storm 671 00:27:21,580 --> 00:27:19,200 conditions you can get dense increases 672 00:27:24,020 --> 00:27:21,590 in density there about five times larger 673 00:27:26,299 --> 00:27:24,030 IMS strength is probably about 10 times 674 00:27:30,320 --> 00:27:26,309 stronger at each given planet in the 675 00:27:31,700 --> 00:27:30,330 past and during storm conditions the IMF 676 00:27:35,210 --> 00:27:31,710 strength can increase by about five 677 00:27:36,680 --> 00:27:35,220 times interplanetary magnetic field this 678 00:27:39,350 --> 00:27:36,690 magnetic field that's laced throughout 679 00:27:42,470 --> 00:27:39,360 the solar wind uh now there's a caveat 680 00:27:43,500 --> 00:27:42,480 here in the past the soap both the solar 681 00:27:45,380 --> 00:27:43,510 wind speed and 682 00:27:47,880 --> 00:27:45,390 density would have been elevated 683 00:27:50,580 --> 00:27:47,890 typically not all of the time but 684 00:27:53,100 --> 00:27:50,590 typically during a solar storm during a 685 00:27:54,870 --> 00:27:53,110 solar storm when the speed increases the 686 00:27:57,480 --> 00:27:54,880 density decreases so they're usually 687 00:27:58,800 --> 00:27:57,490 inversely correlated it doesn't happen 688 00:28:01,620 --> 00:27:58,810 all the time so you have to be very 689 00:28:03,930 --> 00:28:01,630 careful with which storms you pick to 690 00:28:05,430 --> 00:28:03,940 use this doll as analogues because not 691 00:28:09,870 --> 00:28:05,440 all storms are created equal in that 692 00:28:12,090 --> 00:28:09,880 respect so how do we do this modeling we 693 00:28:15,390 --> 00:28:12,100 use something that we call a 3d multi 694 00:28:17,280 --> 00:28:15,400 fluid model the physical the formulas 695 00:28:18,930 --> 00:28:17,290 that govern the physics of solar wind 696 00:28:21,510 --> 00:28:18,940 interacting with ayanna spears and 697 00:28:23,730 --> 00:28:21,520 atmospheres of planets cannot be solved 698 00:28:27,720 --> 00:28:23,740 analytically so we have to solve the set 699 00:28:34,560 --> 00:28:27,730 of equations numerically and what we do 700 00:28:36,480 --> 00:28:34,570 is sorry um what we do is we solve we 701 00:28:38,850 --> 00:28:36,490 have this track several different ion 702 00:28:41,040 --> 00:28:38,860 species for the most part it's usually 703 00:28:43,350 --> 00:28:41,050 free once associated with the solar wind 704 00:28:46,230 --> 00:28:43,360 and one or two associated with in 705 00:28:48,630 --> 00:28:46,240 atmosphere of a planet or moon and for 706 00:28:51,480 --> 00:28:48,640 each ion species we solve conservation 707 00:28:53,820 --> 00:28:51,490 of mass momentum and energy equations 708 00:28:55,530 --> 00:28:53,830 numerically on a grid because we have 709 00:28:57,540 --> 00:28:55,540 this magnetic field that's both laced 710 00:28:59,670 --> 00:28:57,550 through the solar wind and may be 711 00:29:01,440 --> 00:28:59,680 associated with the planet itself we 712 00:29:05,160 --> 00:29:01,450 have to solve the induction equation and 713 00:29:07,800 --> 00:29:05,170 then on a sort of large scale we assume 714 00:29:11,640 --> 00:29:07,810 charge neutrality and a generalized 715 00:29:14,580 --> 00:29:11,650 Ohm's law as well so I to some of the 716 00:29:17,010 --> 00:29:14,590 simulation results look like so why is 717 00:29:19,650 --> 00:29:17,020 he here this sort of blue blob with some 718 00:29:22,170 --> 00:29:19,660 green spots on it is indicating Mars but 719 00:29:24,000 --> 00:29:22,180 the color variation is to indicate the 720 00:29:25,650 --> 00:29:24,010 fact that i have actually modeled the 721 00:29:27,330 --> 00:29:25,660 anomaly put that an ominous magnetic 722 00:29:29,730 --> 00:29:27,340 field into the model I'll talk about 723 00:29:31,380 --> 00:29:29,740 this a little bit more later is this is 724 00:29:33,780 --> 00:29:31,390 oriented such that this the North Pole 725 00:29:36,150 --> 00:29:33,790 is up here South Pole is here solar wind 726 00:29:38,730 --> 00:29:36,160 is coming in from the left hand side and 727 00:29:40,800 --> 00:29:38,740 the interplanetary magnetic field is 728 00:29:42,600 --> 00:29:40,810 arranged such that it's pointing into 729 00:29:45,990 --> 00:29:42,610 the board and these give sort of the 730 00:29:47,610 --> 00:29:46,000 these are nominal average quiet 731 00:29:48,480 --> 00:29:47,620 conditions solar wind conditions you 732 00:29:50,940 --> 00:29:48,490 don't have to worry about the numbers 733 00:29:54,270 --> 00:29:50,950 too much what's shown here is the color 734 00:29:55,690 --> 00:29:54,280 is a log of the ionospheric density in a 735 00:29:58,360 --> 00:29:55,700 plane going through them 736 00:30:00,490 --> 00:29:58,370 noon-midnight meridian so tactic North 737 00:30:03,730 --> 00:30:00,500 Col here so noon over here midnight over 738 00:30:05,620 --> 00:30:03,740 here the black contours indicate solar 739 00:30:07,990 --> 00:30:05,630 wind density so this is actually 740 00:30:09,879 --> 00:30:08,000 tracking out this bow shot how I picked 741 00:30:11,649 --> 00:30:09,889 value so they pick out this bow shop so 742 00:30:13,600 --> 00:30:11,659 this indicates where the solar wind 743 00:30:15,070 --> 00:30:13,610 comes in and then we out the inner edge 744 00:30:18,250 --> 00:30:15,080 is sort of where it's sort of petering 745 00:30:20,560 --> 00:30:18,260 out and one of the first things you sort 746 00:30:22,539 --> 00:30:20,570 of see is this is the tube that itís 747 00:30:23,680 --> 00:30:22,549 great density and bow shock sort of 748 00:30:25,120 --> 00:30:23,690 track each other in the northern 749 00:30:26,799 --> 00:30:25,130 hemisphere but in the southern 750 00:30:29,200 --> 00:30:26,809 hemisphere there's a significant portion 751 00:30:30,970 --> 00:30:29,210 of ionospheric material it's outside of 752 00:30:33,700 --> 00:30:30,980 the bow shock so this is basically in 753 00:30:35,620 --> 00:30:33,710 this unperturbed region where the solar 754 00:30:39,430 --> 00:30:35,630 wind is traveling it in is if there was 755 00:30:42,009 --> 00:30:39,440 nothing there so why is that occur it 756 00:30:43,299 --> 00:30:42,019 occurs because the fact that ions in the 757 00:30:46,149 --> 00:30:43,309 presence of the presence of a magnetic 758 00:30:48,490 --> 00:30:46,159 field will gyrate in a circle about that 759 00:30:50,259 --> 00:30:48,500 magnetic field and it will they dry rate 760 00:30:51,580 --> 00:30:50,269 gyrate and such that for this magnetic 761 00:30:56,200 --> 00:30:51,590 field they will go in a counterclockwise 762 00:30:57,940 --> 00:30:56,210 direction and if you were to launch they 763 00:30:59,950 --> 00:30:57,950 say launched an ion from the northern 764 00:31:04,240 --> 00:30:59,960 hemisphere it would gyrate around and 765 00:31:06,190 --> 00:31:04,250 then re impact the surface but if you 766 00:31:07,690 --> 00:31:06,200 were to launch that same ion from the 767 00:31:09,009 --> 00:31:07,700 southern hemisphere it would start 768 00:31:11,590 --> 00:31:09,019 gyrating among the magnetic field and 769 00:31:12,970 --> 00:31:11,600 then we're never run into nothing it 770 00:31:14,799 --> 00:31:12,980 would just go right out into the solar 771 00:31:17,379 --> 00:31:14,809 wind in which and where the conditions 772 00:31:19,810 --> 00:31:17,389 are different and then the this orbit 773 00:31:22,480 --> 00:31:19,820 about the size of the gyro motion would 774 00:31:24,850 --> 00:31:22,490 change so anything sort of launched from 775 00:31:26,320 --> 00:31:24,860 here can it or bleed out the southern 776 00:31:28,299 --> 00:31:26,330 hemisphere can bleed out into the solar 777 00:31:31,450 --> 00:31:28,309 wind and this is what's called pick up 778 00:31:33,399 --> 00:31:31,460 this is the pickup region now to 779 00:31:36,669 --> 00:31:33,409 righties I did a series of simulations 780 00:31:39,039 --> 00:31:36,679 where I kept a single parameter synthase 781 00:31:40,720 --> 00:31:39,049 I either kept the solar wind conditions 782 00:31:42,789 --> 00:31:40,730 the same and move the orientation of 783 00:31:45,399 --> 00:31:42,799 Mars or I kept the orientation of Mars 784 00:31:47,830 --> 00:31:45,409 the same and varied a single parameter 785 00:31:50,649 --> 00:31:47,840 in the solar ring just to figure out how 786 00:31:52,480 --> 00:31:50,659 solar wind well itís great loss and 787 00:31:54,190 --> 00:31:52,490 solar wind precipitation into Mars as 788 00:31:55,840 --> 00:31:54,200 ionosphere change with different 789 00:31:57,879 --> 00:31:55,850 parameters because it's not a given that 790 00:32:00,710 --> 00:31:57,889 they would that they would vary linearly 791 00:32:03,110 --> 00:32:00,720 and to highlight that I have sir 792 00:32:05,210 --> 00:32:03,120 series here this indicates essentially 793 00:32:07,190 --> 00:32:05,220 this is the same nearly the same 794 00:32:09,230 --> 00:32:07,200 conditions is that first lot so we have 795 00:32:11,840 --> 00:32:09,240 solar wind coming in from the slide here 796 00:32:15,020 --> 00:32:11,850 North Pole of Mars here South Pole here 797 00:32:16,730 --> 00:32:15,030 the color and the color is plane is 798 00:32:17,990 --> 00:32:16,740 running through them is the ina spheric 799 00:32:20,149 --> 00:32:18,000 density running through the 800 00:32:22,399 --> 00:32:20,159 noon-midnight Meridian the black contour 801 00:32:24,950 --> 00:32:22,409 lines indicate the bow shock and this 802 00:32:27,430 --> 00:32:24,960 this is sort of my nominal case normal 803 00:32:30,200 --> 00:32:27,440 solar wind conditions what we assume the 804 00:32:33,169 --> 00:32:30,210 primary ionospheric composition is of 0 805 00:32:35,539 --> 00:32:33,179 plus 0 2 plus in the I know skirt when I 806 00:32:39,110 --> 00:32:35,549 only change the mass of the ionosphere 807 00:32:41,390 --> 00:32:39,120 so I went from 0 to plus 20 plus the 808 00:32:44,060 --> 00:32:41,400 solar wind precipitation rate and the 809 00:32:47,149 --> 00:32:44,070 INA spheric loss rate deep both decrease 810 00:32:49,669 --> 00:32:47,159 by thirty percent name thing that might 811 00:32:52,220 --> 00:32:49,679 seem counterintuitive if you decrease 812 00:32:54,470 --> 00:32:52,230 the mass of the ionospheric component 813 00:32:55,940 --> 00:32:54,480 therefore its escape velocity should be 814 00:32:58,850 --> 00:32:55,950 lower so you would think well maybe that 815 00:33:01,279 --> 00:32:58,860 it should have large larger escape rate 816 00:33:03,740 --> 00:33:01,289 what but what turns out to be more 817 00:33:05,810 --> 00:33:03,750 important is the fact that it's mounted 818 00:33:07,279 --> 00:33:05,820 pick up actually decreases and you can 819 00:33:09,049 --> 00:33:07,289 see that by comparing the southern 820 00:33:11,450 --> 00:33:09,059 portion here that's outside the bow 821 00:33:13,940 --> 00:33:11,460 shock for this light ionospheric mass 822 00:33:15,980 --> 00:33:13,950 case the pickup region is smaller 823 00:33:18,890 --> 00:33:15,990 because the pickup region is smaller 824 00:33:20,600 --> 00:33:18,900 there is less loss this goes back to the 825 00:33:23,060 --> 00:33:20,610 discussion of what was the past 826 00:33:25,399 --> 00:33:23,070 ionospheric composition that was not 827 00:33:28,220 --> 00:33:25,409 just an interesting thought exercise it 828 00:33:30,409 --> 00:33:28,230 is an actual important parameter to try 829 00:33:33,590 --> 00:33:30,419 to figure out because it is crucial to 830 00:33:35,720 --> 00:33:33,600 get the the mass effects right in order 831 00:33:40,190 --> 00:33:35,730 to figure the mass right in order to 832 00:33:42,049 --> 00:33:40,200 figure out loss rates another men when I 833 00:33:44,750 --> 00:33:42,059 started from the north sort of nominal 834 00:33:47,029 --> 00:33:44,760 conditions and then merely doubled the 835 00:33:49,850 --> 00:33:47,039 solar wind speed we saw I saw that the 836 00:33:51,830 --> 00:33:49,860 finest very gloss rates increased by 837 00:33:54,560 --> 00:33:51,840 twice and again associated with this 838 00:33:58,010 --> 00:33:54,570 increased pick up so it's in the the 839 00:33:59,930 --> 00:33:58,020 solar wind speed seems to scale linearly 840 00:34:03,289 --> 00:33:59,940 with loss rates or the loss rate scale 841 00:34:04,940 --> 00:34:03,299 linearly with with solar wind speeds so 842 00:34:08,270 --> 00:34:04,950 it's talking about the the anomalous 843 00:34:10,010 --> 00:34:08,280 magnetic field this is a picture of how 844 00:34:11,899 --> 00:34:10,020 it what it looks like in the simulation 845 00:34:14,899 --> 00:34:11,909 so this is just purely magnitude 846 00:34:16,760 --> 00:34:14,909 it's a 400 kilometer so higher than the 847 00:34:19,250 --> 00:34:16,770 picture I was shown indicating before of 848 00:34:20,720 --> 00:34:19,260 the surface field you see primarily in 849 00:34:22,760 --> 00:34:20,730 the southern hemisphere although there's 850 00:34:26,930 --> 00:34:22,770 a little bit of a strong one of nerdy 851 00:34:29,419 --> 00:34:26,940 equator so this kind of comes now just 852 00:34:31,760 --> 00:34:29,429 do the ina straight loss rates vary as a 853 00:34:33,500 --> 00:34:31,770 function of how the anomalies are 854 00:34:34,849 --> 00:34:33,510 oriented if they're facing directly into 855 00:34:36,470 --> 00:34:34,859 the solar wind if they're pointed sort 856 00:34:38,020 --> 00:34:36,480 of off to the side this this is 857 00:34:40,940 --> 00:34:38,030 important with respect to obliquity 858 00:34:43,159 --> 00:34:40,950 because when the obliquity is around 50 859 00:34:46,279 --> 00:34:43,169 degrees these anomalies will never face 860 00:34:48,230 --> 00:34:46,289 directly into the solar wind what I'm 861 00:34:49,970 --> 00:34:48,240 showing here is 44 different happens to 862 00:34:52,220 --> 00:34:49,980 be 44 different cases for the solar wind 863 00:34:54,230 --> 00:34:52,230 and where I ran with this the anomalies 864 00:34:56,389 --> 00:34:54,240 pointed directly facing into the solar 865 00:34:58,760 --> 00:34:56,399 wind so they are all aligned along the 866 00:35:01,520 --> 00:34:58,770 new Meridian what i'm showing is solar 867 00:35:03,920 --> 00:35:01,530 wind density at 400 kilometers so what 868 00:35:06,140 --> 00:35:03,930 this means is when it's blue the region 869 00:35:08,420 --> 00:35:06,150 is sort of anomalous magnetic field 870 00:35:11,059 --> 00:35:08,430 protects the region from the solar wind 871 00:35:12,440 --> 00:35:11,069 and when it's red it means it has an 872 00:35:14,809 --> 00:35:12,450 increased amount of solar wind 873 00:35:17,559 --> 00:35:14,819 penetrating into that area and you can 874 00:35:19,760 --> 00:35:17,569 see that when I just merely rotated the 875 00:35:22,789 --> 00:35:19,770 interplanetary magnetic field by 90 876 00:35:24,380 --> 00:35:22,799 degrees the ridge protected regions sort 877 00:35:26,930 --> 00:35:24,390 of moved around a little bit and some of 878 00:35:29,000 --> 00:35:26,940 the enhanced regions moved around but 879 00:35:31,220 --> 00:35:29,010 there are also still regions where that 880 00:35:33,079 --> 00:35:31,230 that were protected from one IMF 881 00:35:35,140 --> 00:35:33,089 orientation remained protected from the 882 00:35:37,309 --> 00:35:35,150 solar wind and regions that were 883 00:35:39,470 --> 00:35:37,319 enhanced for one orientation remain 884 00:35:43,010 --> 00:35:39,480 enhanced so places you probably don't 885 00:35:45,559 --> 00:35:43,020 want to build a Martian base and then 886 00:35:49,730 --> 00:35:45,569 when I went to sort of more active storm 887 00:35:51,260 --> 00:35:49,740 as old son kite conditions everything's 888 00:35:53,380 --> 00:35:51,270 were to get smeared out but you still 889 00:35:57,769 --> 00:35:53,390 have regions that are a bit protected 890 00:35:59,750 --> 00:35:57,779 the main thing i found was that the loss 891 00:36:02,390 --> 00:35:59,760 rates do not seem to very much with 892 00:36:05,539 --> 00:36:02,400 anomaly orientation now that could be 893 00:36:07,849 --> 00:36:05,549 because whatever plasma it was deflected 894 00:36:09,289 --> 00:36:07,859 room say this region was just funneled 895 00:36:11,480 --> 00:36:09,299 to another region so when you calculate 896 00:36:12,500 --> 00:36:11,490 things globally you didn't see a net 897 00:36:16,460 --> 00:36:12,510 change because they were just moved 898 00:36:19,279 --> 00:36:16,470 around another possibility was the fact 899 00:36:22,190 --> 00:36:19,289 that the sort of grid site the sort of 900 00:36:23,370 --> 00:36:22,200 bar shaped pattern or a bar code type 901 00:36:26,400 --> 00:36:23,380 pattern associated with 902 00:36:28,829 --> 00:36:26,410 the anomalies what is at was actually on 903 00:36:30,720 --> 00:36:28,839 the order of the grid resolution in the 904 00:36:32,759 --> 00:36:30,730 numerical simulations we have to solve 905 00:36:35,940 --> 00:36:32,769 our about our numerical simulations on a 906 00:36:37,620 --> 00:36:35,950 grid and they were about comparable so 907 00:36:39,930 --> 00:36:37,630 it was possible that I may be just not 908 00:36:41,759 --> 00:36:39,940 resolving the anomalies so it didn't 909 00:36:43,559 --> 00:36:41,769 really so even though this made it look 910 00:36:44,609 --> 00:36:43,569 like they were there they really didn't 911 00:36:47,370 --> 00:36:44,619 look like they were there in the 912 00:36:49,170 --> 00:36:47,380 simulations so in order to resolve this 913 00:36:50,910 --> 00:36:49,180 issue whether it was just moving plasma 914 00:36:53,460 --> 00:36:50,920 round or this or this effect wasn't 915 00:36:56,819 --> 00:36:53,470 resolved I did higher resolution 916 00:37:00,210 --> 00:36:56,829 simulation of the solar wind interaction 917 00:37:02,460 --> 00:37:00,220 and so what we see here is the sort of 918 00:37:04,230 --> 00:37:02,470 sphere colored sphere is again Mars and 919 00:37:06,990 --> 00:37:04,240 the color indicates the magnetic field 920 00:37:09,509 --> 00:37:07,000 you can see up in the sort of close to 921 00:37:11,069 --> 00:37:09,519 the equator this sort of hot region of 922 00:37:13,680 --> 00:37:11,079 high magnetic field that I pointed out 923 00:37:15,359 --> 00:37:13,690 early earlier the really strong 924 00:37:17,099 --> 00:37:15,369 anomalies errs that are down here is 925 00:37:18,779 --> 00:37:17,109 closer to the southern hemisphere and 926 00:37:21,809 --> 00:37:18,789 you can't see them because they're off 927 00:37:24,299 --> 00:37:21,819 plane the plane the color material are 928 00:37:26,160 --> 00:37:24,309 the color planes here are either solar 929 00:37:28,529 --> 00:37:26,170 wind density ionospheric hydrogen 930 00:37:31,019 --> 00:37:28,539 density or is carrying oxygen density in 931 00:37:33,240 --> 00:37:31,029 the noon meridian and then also showing 932 00:37:34,589 --> 00:37:33,250 magnetic field lines and you can see 933 00:37:36,809 --> 00:37:34,599 that you can definitely see sort of 934 00:37:38,970 --> 00:37:36,819 features associated with anomalous 935 00:37:41,249 --> 00:37:38,980 magnetic field and you see sort of this 936 00:37:43,440 --> 00:37:41,259 loop like structure whereas this is pure 937 00:37:46,230 --> 00:37:43,450 anomalous magnetic field and is 938 00:37:48,089 --> 00:37:46,240 protected from solar winds so very low 939 00:37:50,039 --> 00:37:48,099 solar wind down sitting at higher itís 940 00:37:52,349 --> 00:37:50,049 great density in those regions and then 941 00:37:54,019 --> 00:37:52,359 there's this region down here where the 942 00:37:57,390 --> 00:37:54,029 interplanetary magnetic fields are 943 00:37:59,279 --> 00:37:57,400 connects to the anomalous magnetic field 944 00:38:01,109 --> 00:37:59,289 and almost sort of funnels solar wind 945 00:38:03,180 --> 00:38:01,119 into that region so you see higher 946 00:38:05,069 --> 00:38:03,190 densities here at solar wind and in that 947 00:38:07,380 --> 00:38:05,079 region you're a sitter essentially 948 00:38:09,690 --> 00:38:07,390 seeing where the ionosphere or the 949 00:38:12,150 --> 00:38:09,700 atmosphere of Mars has been eroded or 950 00:38:16,019 --> 00:38:12,160 eaten away by this increased solar win 951 00:38:17,819 --> 00:38:16,029 access so when I went through engine 952 00:38:20,099 --> 00:38:17,829 higher-resolution simulations i found 953 00:38:21,720 --> 00:38:20,109 this is these are itís very loss rates 954 00:38:23,880 --> 00:38:21,730 of the different components both o 2 955 00:38:26,039 --> 00:38:23,890 plus and hydrogen and then solar wind 956 00:38:28,769 --> 00:38:26,049 precipitation rates for nominal 957 00:38:31,499 --> 00:38:28,779 conditions but different orientations of 958 00:38:33,539 --> 00:38:31,509 the strongest anomalies ones where they 959 00:38:35,190 --> 00:38:33,549 were located on the dawn Terminator or 960 00:38:36,130 --> 00:38:35,200 if they were located on the dust 961 00:38:38,230 --> 00:38:36,140 Terminator or 962 00:38:41,170 --> 00:38:38,240 located at midnight and now you can see 963 00:38:43,930 --> 00:38:41,180 significant variation with anomaly 964 00:38:45,670 --> 00:38:43,940 located at orientation and these numbers 965 00:38:48,640 --> 00:38:45,680 work out too big for these for these 966 00:38:52,050 --> 00:38:48,650 nominal conditions of about two to three 967 00:38:55,480 --> 00:38:52,060 times ten to the 25 ions per second 968 00:38:57,760 --> 00:38:55,490 correspond to being over 1 billion years 969 00:39:00,910 --> 00:38:57,770 that would be equivalent to 10 970 00:39:03,190 --> 00:39:00,920 centimeters globally of water lost from 971 00:39:04,450 --> 00:39:03,200 Mars for more storm light conditions 972 00:39:07,060 --> 00:39:04,460 which I'm not showing the numbers here 973 00:39:09,220 --> 00:39:07,070 this increases up to about 10 to the 26 974 00:39:10,930 --> 00:39:09,230 ions per second and that will correspond 975 00:39:16,080 --> 00:39:10,940 to over a billion years being able to 976 00:39:21,670 --> 00:39:18,490 so what are these where the conclusions 977 00:39:23,860 --> 00:39:21,680 from my interactions is that that due to 978 00:39:27,240 --> 00:39:23,870 solar wind interactions alone you could 979 00:39:31,150 --> 00:39:27,250 possibly over the lifetime of Mars lost 980 00:39:32,770 --> 00:39:31,160 meters of water to space and it's 981 00:39:34,780 --> 00:39:32,780 important one of the things that's 982 00:39:36,880 --> 00:39:34,790 important for figuring this out is to 983 00:39:38,830 --> 00:39:36,890 try to get some limits on the 984 00:39:40,860 --> 00:39:38,840 composition of the early Martian 985 00:39:43,900 --> 00:39:40,870 atmosphere as we saw the loss rates 986 00:39:48,280 --> 00:39:43,910 correlated fairly heavily with the mass 987 00:39:49,960 --> 00:39:48,290 of that you assume for Mars another 988 00:39:52,270 --> 00:39:49,970 thing anyway so this so that the 989 00:39:54,820 --> 00:39:52,280 composition is quite important another 990 00:39:56,740 --> 00:39:54,830 thing I think is that that when you can 991 00:39:59,800 --> 00:39:56,750 resolve them when you're able to 992 00:40:02,200 --> 00:39:59,810 simulate properly there is a the loss 993 00:40:04,540 --> 00:40:02,210 rates do correlate with the orientation 994 00:40:06,220 --> 00:40:04,550 of the magnetic anomalies so this means 995 00:40:08,650 --> 00:40:06,230 it is really actually you have to pay 996 00:40:10,240 --> 00:40:08,660 attention to blick whaty changes because 997 00:40:11,830 --> 00:40:10,250 there are times when those anomalies may 998 00:40:14,350 --> 00:40:11,840 not face into the solar wind and 999 00:40:16,590 --> 00:40:14,360 therefore they may your loss rates 1000 00:40:28,680 --> 00:40:16,600 during those periods will have changed 1001 00:40:28,690 --> 00:40:34,410 what's what's the curve best estimates 1002 00:40:39,610 --> 00:40:37,840 it probably tens of meters so it's it's 1003 00:40:41,830 --> 00:40:39,620 in the tens of meters that it took them 1004 00:40:45,300 --> 00:40:41,840 lost but nobody knows how Mr probably 1005 00:40:48,580 --> 00:40:45,310 was because you know so the question is 1006 00:40:50,680 --> 00:40:48,590 was there enough to completely fill that 1007 00:40:52,600 --> 00:40:50,690 northern lowlands some people like James 1008 00:40:55,420 --> 00:40:52,610 head have looked at high resolution 1009 00:40:57,730 --> 00:40:55,430 images and have suggested that that sees 1010 00:41:00,370 --> 00:40:57,740 what he thinks is evidence for seizures 1011 00:41:02,860 --> 00:41:00,380 seashores in wave action around the edge 1012 00:41:04,930 --> 00:41:02,870 of that bull northern lowland so is his 1013 00:41:07,030 --> 00:41:04,940 suggestion is there were times when that 1014 00:41:10,210 --> 00:41:07,040 entire region was filled with a lake a 1015 00:41:12,010 --> 00:41:10,220 giant lake or an ocean but nobody knows 1016 00:41:19,900 --> 00:41:12,020 how much water what you've been moving 1017 00:41:22,600 --> 00:41:19,910 around at the time in a question from 1018 00:41:26,800 --> 00:41:22,610 Penn State for the exceptional school 1019 00:41:28,330 --> 00:41:26,810 yep higher co this Jim casting in the 1020 00:41:31,270 --> 00:41:28,340 beginning when you went through the list 1021 00:41:34,240 --> 00:41:31,280 of escape mechanisms you talked about 1022 00:41:37,180 --> 00:41:34,250 hydrodynamic escape and you mentioned 1023 00:41:39,220 --> 00:41:37,190 that it is non fractionating people who 1024 00:41:41,530 --> 00:41:39,230 suggested that maybe a lot of what we 1025 00:41:43,750 --> 00:41:41,540 associate with being water is actually 1026 00:41:47,050 --> 00:41:43,760 been due to wind or a alone aeolian 1027 00:41:49,570 --> 00:41:47,060 processes and I I don't know if that's 1028 00:41:52,420 --> 00:41:49,580 really how well resolved it is I mean we 1029 00:42:04,309 --> 00:41:52,430 do know that there's water there um so I 1030 00:42:12,150 --> 00:42:09,299 and bandwidth is hit by the evidence is 1031 00:42:14,430 --> 00:42:12,160 not water my teenage colleague at work 1032 00:42:17,279 --> 00:42:14,440 or large patient to visit they see those 1033 00:42:21,630 --> 00:42:17,289 nails over time with your client for 1034 00:42:24,539 --> 00:42:21,640 when I'm slide the spirit caller yeah 1035 00:42:25,829 --> 00:42:24,549 it's not shirring what they are zombie 1036 00:42:28,609 --> 00:42:25,839 I've suggested that there was some sort 1037 00:42:31,439 --> 00:42:28,619 of explosive process that may have 1038 00:42:35,069 --> 00:42:31,449 explosively ice or you know some 1039 00:42:37,650 --> 00:42:35,079 vaporization hey it's yeah it's still 1040 00:42:40,859 --> 00:42:37,660 open for today yeah thank you doing 1041 00:42:49,519 --> 00:42:40,869 something about water could conjure up 1042 00:42:55,049 --> 00:42:52,699 yeah it's not that a lot of the current 1043 00:43:00,209 --> 00:42:55,059 transition or events may be associated 1044 00:43:02,789 --> 00:43:00,219 with impacts of some sort a couple of 1045 00:43:08,099 --> 00:43:02,799 questions for me either so Penn State 1046 00:43:09,299 --> 00:43:08,109 has a question okay sorry Erica win in 1047 00:43:12,209 --> 00:43:09,309 the beginning when you were talking 1048 00:43:15,120 --> 00:43:12,219 about hydrodynamic escape you mentioned 1049 00:43:17,219 --> 00:43:15,130 that it was non fractionating there's 1050 00:43:20,160 --> 00:43:17,229 actually a couple different regimes in 1051 00:43:22,319 --> 00:43:20,170 there but mean what what we call nan 1052 00:43:25,709 --> 00:43:22,329 fractionating escape is often termed 1053 00:43:27,900 --> 00:43:25,719 blow off there's also a regime of 1054 00:43:30,539 --> 00:43:27,910 hydrodynamic escape that that is 1055 00:43:32,640 --> 00:43:30,549 fractionating and there's a long 1056 00:43:39,089 --> 00:43:32,650 literature Bob Pepin has written lots of 1057 00:43:41,430 --> 00:43:39,099 papers on this so so some some loss may 1058 00:43:43,709 --> 00:43:41,440 occur by that mechanism in fact that we 1059 00:43:48,120 --> 00:43:43,719 think that that would be very important 1060 00:43:50,819 --> 00:43:48,130 early on no I thank you for pointing out 1061 00:43:52,769 --> 00:43:50,829 that there are two set two types from 1062 00:43:55,199 --> 00:43:52,779 some of the stuff I've read it suggests 1063 00:43:58,349 --> 00:43:55,209 that also that that some of the early 1064 00:44:00,209 --> 00:43:58,359 mechanisms were more we're not quite as 1065 00:44:02,569 --> 00:44:00,219 mass selective as things that would take 1066 00:44:05,880 --> 00:44:02,579 come over that would have come later on 1067 00:44:08,939 --> 00:44:05,890 but in fact Bob Pepin has derived this 1068 00:44:11,750 --> 00:44:08,949 whole history of the solar system doing 1069 00:44:15,610 --> 00:44:11,760 the fractionation of noble gases and 1070 00:44:19,000 --> 00:44:15,620 gasps isotopes using hydrodynamic escape 1071 00:44:27,710 --> 00:44:19,010 so so that may be part of the picture 1072 00:44:31,760 --> 00:44:27,720 okay thank you any more questions from 1073 00:44:34,100 --> 00:44:31,770 Jim this is dalton can you talk a little 1074 00:44:35,930 --> 00:44:34,110 bit about why I guess certainly just in 1075 00:44:37,940 --> 00:44:35,940 white Venus so has really been 1076 00:44:39,430 --> 00:44:37,950 atmosphere of Mars doesn't if it can you 1077 00:44:44,240 --> 00:44:39,440 say much about the original atmosphere 1078 00:44:45,980 --> 00:44:44,250 Peters has kind of a finish there are a 1079 00:44:47,000 --> 00:44:45,990 couple of things that I don't know a lot 1080 00:44:48,650 --> 00:44:47,010 about Venus but I know there are a 1081 00:44:51,170 --> 00:44:48,660 couple mechanisms that mention Venus 1082 00:44:55,580 --> 00:44:51,180 doesn't have one of these hot oxygen 1083 00:44:57,950 --> 00:44:55,590 type coronas because even after it will 1084 00:45:00,110 --> 00:44:57,960 is the process of photolysis and 1085 00:45:02,630 --> 00:45:00,120 dissociative recombination can occur but 1086 00:45:04,430 --> 00:45:02,640 at Venus the the hot oxygen that is 1087 00:45:07,100 --> 00:45:04,440 created after the dissociative 1088 00:45:09,530 --> 00:45:07,110 recombination is still below escape 1089 00:45:11,810 --> 00:45:09,540 velocity so Venus doesn't have a hot 1090 00:45:13,250 --> 00:45:11,820 oxygen corona so it doesn't have this 1091 00:45:14,870 --> 00:45:13,260 large material it won't have therefore 1092 00:45:17,690 --> 00:45:14,880 it won't have the sputtering and some of 1093 00:45:20,810 --> 00:45:17,700 the pickup processes and so I think 1094 00:45:22,430 --> 00:45:20,820 that's one of the one of the reasons why 1095 00:45:25,280 --> 00:45:22,440 it may have held mine it's also more 1096 00:45:28,010 --> 00:45:25,290 massive so it's escape velocity is a lot 1097 00:45:30,740 --> 00:45:28,020 higher so if I mean you know Congress 1098 00:45:33,380 --> 00:45:30,750 Lee it's also closer to to the Sun but I 1099 00:45:36,230 --> 00:45:33,390 think that the more massive amount more 1100 00:45:42,890 --> 00:45:36,240 more mass does help retain more of the 1101 00:45:46,640 --> 00:45:42,900 atmosphere in that respect any more 1102 00:45:50,160 --> 00:45:46,650 questions comments it's not I'd like to