I
morning I'm Don savage and NASA public
affairs officer space science welcome
today to the beginning of day two of the
world's watching the comet impacting
Jupiter following a very successful
first night of observing we're here at
the Goddard Space Flight Center and
Maryland today and with us we will have
some panelists discuss the results of
last night's observing from around the
world and from the Hubble telescope I'd
like to introduce first of all Jean
shoemaker who was a astronomer with
Lowell Observatory and a professor with
the US Geological Survey to his left his
wife Carolyn shoemaker also an
astronomer with the US Geological Survey
and the Lowell Observatory to my
immediate left David Levy amateur
astronomer and author and co-discoverer
with the shoemaker's of this connor and
to his left we have Heidi Hammel from
massachusetts institute of technology
with the Space Telescope Science
Institute imaging team and I'd like to
start off with Jean shoemaker thanks Don
well many of you know we had an
absolutely incredible night last night
when we knew for the first time they
were we were really going to see some
exciting results the first tense came in
from Colorado Spain and from la SIA and
Chile and just about the time we were
giving our first announcement I'm not
Heidi came up from the bowels of the
Space Telescope Science Institute waving
a picture and showing that indeed Hubble
was producing fantastic images so how
he's going to tell you into some detail
now about that a little bit later to
bring you up to date fragments ABC and D
have now all hit the planet there are
observations on the first three of these
that will be able to report on D has
just come down this morning and we're
not quite ready to give you any up
on that we're going to have observations
on we'll show you an observation from
Sarah to low low in Chile the
inter-american Observatory in Chile and
we have reports that are coming up then
from the NASA infrared telescope
facility and from the Keck Observatory
on Mauna Kea in Hawaii but first Heidi
will tell you about all the excitement
that was happening at the Space
Telescope Science Institute last night
Heidi Thank You gene it was indeed very
exciting I think we were all incredibly
astonished at what we saw last night and
I'm not going to waste any time i'm
going to show you that first image again
this is a 4 10 nanometers that's four
thousand angstroms blue wavelengths you
can see jupiter on the right and what
you see on the left is a blow-up of the
impact site from fragment a this is the
first feature that went into the plant
the first large fragment that went into
the planet you can see the blue
wavelengths that it is very dark very
dark indeed we're speculating at this
point as to our that might be we think
that possibly what we're mostly seeing
is cometary material at this point
because comets are very dark too I
expected to see a bright future myself
so I was a little bit surprised to see
this lovely black splotch on Jupiter it
looks somewhat like a streak there in
the center we're beginning to think that
perhaps that's just a projection effect
we think when we do the measurements of
that outer Oriole perhaps that's the
wood we might use and measure the
latitudes and longitudes very carefully
it appears that that larger spreading is
circular and then it only looks like
like that your lips because it's down
near the edge of the planet at same for
that central streak we're not sure
exactly what the size of that is to give
you a scale that box the blow-up box is
to earth diameters so that feature is a
good good fraction of the size of the
earth we can be very good
add that this comment was heading for
Jupiter not the earth now the next way
image that I'll show you is that a very
different wavelength this is it's a red
wavelengths which showed the next image
m ec inverts this is a very strong
methane band nine thousand angstroms
methane is a molecule that absorbs
photons very efficiently and so Jupiter
is very dark the only place that jupiter
is bright at this wavelength is where
you have particles at high altitudes you
can see the Great Red Spot very clearly
it's a high altitude feature it's bright
the poles are bright now look at the
comet site it's right that was likely to
mean it's a high altitude feature so
that was very interesting to see at all
the other wavelengths that feature was
dark that would clarify that at all the
wavelengths that Hubble was observing
the visual the ultraviolet and even nine
thousand five hundred angstroms it was
dark it's bright in the methane band and
it's bright in the infrared observations
that will hear about later now I would
like to show you one of the most
exciting things that we saw last night
absolutely knocked our socks off and we
saw this this is a plume sequence and
you can see this is hot off the press
and we're just taking a picture of a
laser copy hold up it's a sequence from
top to bottom in the first image the
impact has not occurred at 2018 a has
gone in and sent out a fireball that
extends beyond the limb of the planet
you can see a clear separation between
that fireball and the Terminator of
Jupiter and we think at this point that
we're seeing the shadow of Jupiter on
the fireball and the third image you can
see that this fireball is spreading the
fourth image is spreading even more and
in the bottom image it's a flat little
pancake it's absolutely amazing I mean
there were theories about this but we
really didn't in our heart of hearts
expect to see it in the first impact we
are expected to see it at the
when we are very close to the limb this
is not particularly close to the limb
this is a massive thing we're talking a
thousand fifteen hundred kilometers
above the limb of Jupiter so that's
pretty astounding we are just
flabbergasted so I also have a video of
Hubble images that are taking pre impact
and I'm showing you this so that you can
see the kind of detail that's on Jupiter
already and also to set you up because
one week from now we're going to give
you another movie showing what Jupiter
looks like after the impacts and that
will be a very interesting comparison so
if we can run this video reminder this
is a pre impact video just to show you
the amazing quality of the images from
the Hubble Space Telescope after its
refurbishment mission this is the wide
field camera we will also be taking
close-up views of the impact sites in
the planetary camera which has a factor
of 2 greater resolution and I am really
looking forward to seeing those images
thank you ok that's great hiding maybe
Kelvin will tell us a little bit about
the excitement we were having last night
all right we have a reaction tape from
the OSS that talks about celebration I
think you know that we just all
literally hit the ceiling when we heard
the results it was too exciting to to
believe and it's something that will
always remember the reactions i think
from all over the world show that
excitement can we have that b roll so
it's you can usually see people looking
eagerly to
you're tidy examining the image to
select earnestly we all did every single
one of them just have us breathtaking
and you there's how we were hard all of
the tune universe' there does you can
see these people have worked extremely
hard get the results and they were all
filled and we all closes baby hiding is
still excited don't worry I didn't know
right there what a great time oh great
Alyssa Vita hasn't moved she's still
looking puzzled the infamous bottle of
champagne Lewis was martyred everyone
was ready to celebrate ok that's
wonderful killed well David let's let's
hear about some of the other early
reports ok yeah Heidi we have to work on
getting a little more enthusiastic well
I thought we would have to make stuff up
and i don't know if i'm going to say
everything that I need to say we started
observing getting observations from
Keller alto and Spain impact a was
observed with the 3.5 liter telescope
there the plume appeared now the the
observation of a plume is absolutely
amazing it was as Heidi said it was not
expected for this fragment this the
later ones especially w at the end is
going to be really quite close to the
limb and to get so much from this first
little impact I'm wondering if we could
take a look at that picture of the comet
behind us with a over there look look
how small rod is compared to what's
coming later on I mean look at G over
here I mean where this is just the the
Orchestra warming up
so from La Palma with the two point
meter telescope there were they the
impact site was visible sorry Mel the
impact site was visible in images
obtained with the one meter capoten
telescope from La Palma there is a
report that if concern confirmed is
really interesting of a visual sighting
of the meteors from the wise Observatory
that's as the flashes as the comet
started to go into Jupiter's upper
atmosphere and behaved as abnormal
meteor would on earth but the meteors on
earth that we see in the night sky are
objects the size of a pea or a grain of
sand this is the impact of something
that's at least one kilometer in
diameter coming into Jupiter possibly
seen the two independent observations
were made with small telescopes they
would pour in a possible sighting of a
brief sharp flash by brief we mean less
than one second duration near the limb
near the edge of Jupiter and it was at
the approximately correct location Jim
Scotti who was at the wise observatory
at the time has asked me to be really
careful with this report I don't want to
it needs to be mentioned because it's
out on all the electronic mail but I
don't want to put a whole lot of
credence into it just yet until if we
get other observations of other flashes
but because there are these two reports
it means that other flashes could be
visible with people using small
telescopes if this is true and I don't
know that it is I'd like to be be
conservative and say it probably isn't
but it means that people with small
telescopes who know exactly where to
look on the limb of Jupiter at the right
time do have a chance of seeing future
flashes amateur astronomers should
really this is a red alert for amateur
astronomers with small telescopes there
was an observation from the point four
meter that's a 16 inch telescope in
western Massachusetts
they saw a bright spot at the impact on
this is the impact site for fragment a
the South Pole infrared Explorer 60
centimeter telescope has detected the
plume from frag grenades being detected
all over the place fragmin be was also
detected from the Keck telescope and not
detected from a number of other sites
that would have expected to detect
fragment be if you look back at that
picture though take notice that fragment
B which is the second one there is not
exactly on the line of a vintage on the
line of comets there that's a good one B
is a little bit above it and we
interpret that as being that that
fragment split off from the main comment
after july seventh nineteen ninety-two
when the main comet split apart and if
this and and the fact that fragment see
which is right on the line was also
detected and detected so strongly I
think we can doing a little bit of arm
waving here suggests that the fragment
be and all of the other fragments that
are off the line might be weaker they
might be more loosely held together more
more of a rubble pile than a and the
other fragments that split up right at
the time of closest approach back in
1992 we have a lot of other observations
d just came down about an hour ago and
we don't have any any observations of
that yet they will be coming in very
soon I think I'll give a thank you note
G ok thanks well early this morning we
heard from James Graham at the
University of California reporting on
fragments a and C from the Keck
Observatory on Mauna Kea and I think
week if we can roll now those
observations and we should have a direct
audio before can't front lace
when the second impact was jus and we
thought distinct signature of the plume
of one of the only impacts and topical
images show very bright features on the
surface of Jupiter at the impact site
incredibly bright very clear very
spectacular event one of the things that
that surprises just how bright these
events are and so the thing that the
check the advantage the church has is
that can see much fainter things going
on in particular what I experiments that
we did this evening that will take some
more time to analyze was looking at
jupiters ring and that has the advantage
is that by looking at reflected light
off the rain we can sense view the
impact fight directly so hopefully when
we look at that data carefully we will
see the initial flash when the comet
fragment hit Jupiter let's go on then we
have an image now from fragment a impact
from Sarah to low low in la serena chile
this is this is an image now coming up
from John Spencer of Lowell Observatory
who's down at serif to low low and Louis
it doesn't look great they grant
imagenext for the gram images next we
just had Grail there it is oh here's his
image ok image that directly is a
picture from the Keck telescope did an
infrared picture at the wavelength of
3.3 microns which is but six times the
wavelength of visible light the features
that you see are the bright polar caps
which are always present and just the
equator is
the storm system of the red spot but
Pfeifer's about the minus 40 degrees
must roll out features which are the
aftermath of the comet impacts of the
curious evening the brightest part of
the very first impact the one the S on
the left-hand edge is the impact numbers
and test a fantastic I'm like I might
make just insert the comment there that
it's very clear that these impact sites
are going to remain visible we've seen
one now go through a complete rotation
we may see a whole string of these now
by the end of the week lighting up that
latitude band on Jupiter string of
pearls that's another string of four
Carolyn okay now I think we should have
the coming up next on the screen John
Spencer's image from Sarah to Lola and
there it is again a John is going to
give us a report tomorrow so we'll have
him an audio at that time but I think
you can see that we're getting good
images now from many telescopes around
the world that's that's the impact site
for a we also heard from Glenn Orton at
the at nasa's infrared telescope
facility at mauna kea who filed the
report now that we're going to see again
on fragment a very clearly had
introduced the new cloud which was quite
long oh when we observed the plume from
C was clearly at the same latitude but
at first very difficult to distinguish
from the holiday that is the final
and time passed the plume from sea
became very much brighter several times
brighter than that cloud the cloud from
the a fragment that turned out to be
about the same brightness as the north
and south polar caps I'm very ecstatic
about any of this witnessing this is
kind of amazing and what what's amazing
about both of these is the fact that
being see are both rather faint objects
certainly in the thermal improv in the
near infrared so fmg are known to be
much bigger I'm much brighter in there
for a specially mirror they're both much
baby spiders biggest objects than a and
so this is going to be a real show okay
I guess we're going to see Glen's actual
images tomorrow so we'll have an update
their from from glenarden I guess at
this point we turn it back to you don
okay yeah well then we'll turn it over
to reporters here at the Goddard Space
Flight Center for Q&A and then we'll
check with our other centers to see if
we have questions there let's start here
in the front and please wait for the
microphone is state your name and
affiliation I've cooked news day and you
had a chance to think about why it might
be dark in terms of chemical terms or
something like that I think we're going
to wait to answer that question until we
get some spectroscopy we actually have
been getting some reports a very
interesting chemistry going on some of
the telescopes in Hawaii have reported I
don't I don't know how much detail I can
go into at this point but I think I'll
leave it at saying that the the
chemistry appears to be very interesting
Miles O'Brien with CNN let's talk what
about the significance of seeing those
plumes
or fragment a not something you expected
just the significance of being able to
see that first of all and then what you
might think we might see on some of
these potentially larger fragments well
miles I showed a theoretical prediction
last night for the plumes as I look at
the plumes that Heidi showed us now in
that sequence it looks to me as though
the prediction is bang-on you in terms
of the timing you get a plume growing up
to a tall column it cools at the top and
then it collapses and flattens and flows
out and spreads out at the base and I
think you can see that whole sequence
and if I remember the times correctly
that I saw in Heidi's images we're
looking at a time interval of about
eight or nine minutes isn't it 18 27
minus 18 yeah nine minutes 9 minutes I'm
talked about and so we really expected
the plume to start to collapse after
about five minutes and flow out and
spread and I think that's exactly what
you're seeing it's a and I think that's
a beautiful testimony to the prediction
that was made by Paul hassock of Titan
research corporation who did that model
on and what it also is saying is to get
that size plume we are in fact dealing
with an object that had the energy of at
least a kilometer sized object maybe
even a little bit bigger there so that
means there's a lot of stuff even in
these smaller fragments the implication
is that the later fragments will
probably be even more extended and
larger yep Cathy oh ok we'll do a
follow-up
you said earlier many times gene that
all your career you'd hope to witness
something like this you've studied
craters the the residue of something
like this now having seen one run of
your thoughts love you sooo beyond the
fact that we feel enormously relieved
that they're really big objects there
that are going to give us a show it
gives me a very warm feeling that we can
affect you some of the most
sophisticated numerical models that have
been developed with intensive effort
over the last three decades and find
that they really work on this enormous
scale and that we really can gain a
close theoretical understanding of what
is happening with each one of these
impacts I think I feel very good about
that Kathy Kathy Sawyer the Washington
Post for gene can you tell me roughly
what altitude you think the dark splotch
is residing at currently if it's fixed
in a place and what's there what what
gases are at that level to the extent
that you know or could this be material
that's been exposed from the interior
possibly the model calculations would
indicate that the largest part of the
material in that dark splotch actually
consists of jovian atmosphere that's
been dredged up from beneath the ammonia
cloud tops but it will contain almost
all of the cometary material as well so
this is heidi said there's there's got
to be some wonderful chemistry going on
remember all of this stuff got very hot
we're talking about the initial fireball
temperatures in the range of 30,000
degrees Kelvin and then it cools off
from there and so there's some chemistry
that I think we don't really know how to
model just what those constituents are
that make it dark and bright at the
relative wavelengths is is something
that's still going to take a lot of work
the the altitude at which you're seeing
that reside later on I think you got a
hit from that
from the limb profile but it's probably
of the order most of it will be of the
order of a couple hundred kilometers I
think above the ammonia cloud top so
you'd like to comment on that honey I
think that that's where we're heading
right now to mostly based on the methane
band image where we saw this material
very bright similar brightness to the
Great Red Spot for example if we could
show the methane band image which is the
the second graphic by seeing this thing
fighting the methane bands and
particularly in all the infrared images
too we know that it's got to be
relatively high I think we're going to
have to wait for more detailed analysis
before we can give us a firm number on
that back here third round Debra's a
prank oh I work for Reuters what can you
tell us about what permanent effects
this might have on Jupiter these these
impacts seem to be brighter bigger you
know altogether more than them you were
predicting and now that these look like
they're gonna be lasting features of the
planet how's it going to change is there
anything you know at this point you
oughta try it yeah I'll give it a whirl
well we we don't we won't know for a few
days I think how long did these features
are it could be a very tenuous
deposition of material that splotch and
the zonal winds on Jupiter are pretty
strong so they could cheer it out and
spread it out based on what we've seen
however just from the the few that we've
seen it looks pretty clear that that
whole band of latitude is going to be
pockmarked with these impact sites and
heaven only knows what I'm going to show
you a week from now and I'll show you
that movie yeah except that we're not at
the moment expecting that these impact
sites and whatever is forming are going
to last permanently there they're very
brief we're expecting that they will
disappear within a matter of days or
weeks I don't think Bob West would agree
with that one no you've got a
program yeah absolutely we're dumping a
lot of material in the stratosphere and
you know as we see on in the earth when
Pinatubo erupted and you through all
that material in the stratosphere of the
earth it hung around for a long time we
were seeing beautiful sunsets for a very
long time so you know this stuff could
hang around in the stratosphere of
Jupiter for a while and we have programs
on the Hubble and many other
ground-based telescopes to look for that
for a week after a month after many
months after and we will be able to tell
you until we've done those observations
how long it's going to hang around this
may be one of the surprises we were
looking for yeah I'm going to stop being
conservative maybe what you were leading
to heidi is that you know as a higher
altitude of stuff spreads out there
there's going to be a haze band very
likely something that will be readily
observable even with a small telescope
on the ground that maybe have broad
enough feature that will be seen for
some time which i think is exciting for
all everybody it'll be interesting to
see if those features stay dark very
interesting to see a senior sky of an
educator who do to us a size of fragment
b c d e and what happened to those
fragment i heard that the Hubble Space
Telescope is taking a picture just 10
hour before the Corazon itself so what
happened to fragmented selex before the
collision is broke down are you still
keep this shape or something alright I
can try um I it looked as though in the
days preceding the impact of fragment a
there was a report that that the that
the fragment was becoming much more oval
and one report said that the nucleus it
meant the nucleus was splitting up but
how Weaver definitely wanted to stop
that idea saying that it was just the
dust coma around the nucleus that was
starting to to be pulled on by Jupiter's
gravity so that it would start getting
more elliptical all the evidence we have
right now indicates that fragment a must
have impact
pretty well intact and that elongation
we were seeing in the days before was
simply the coma of the that particular
comet that was starting to get pulled in
towards Jupiter but I think in partial
answer the quite the thing that you were
suggesting earlier David was that the
nuclei that are off the line may in fact
be essentially swarms of objects so a
maybe mostly a single object be maybe a
swarm see is again mostly a single
object and we come back and he sort of
sort of pick out the candidates for just
swarms and those are the things that
have less mass and less energy and will
produce less than of an effect when they
hit Jupiter front glenda chu San Jose
Mercury News I have two questions one
for David Lee V the the two reports that
you got of flashes possibly being seen
from small telescopes at rise
observatory could you tell us where that
Observatory is and that were those
observatory and Hezbollah and where were
those Observatory telescopes how big
were they or were they amateur
telescopes nearby and I have one other
question yeah thnkx the the wiser betray
is in southern Israel it's us south of
Beersheba and it's in it's in the Negev
desert beautiful beautiful conditions
although I understand from Jim Scotti at
the from the University of Arizona who's
actually observing their that they have
been having a lot of clouds and were
really lucky that it cleared up at
impact time were there abouts
surrounding the observatory the gym
Scotty was observing him were a lot of
the whole crowd of either amateur
advanced amateurs or professionals with
just small telescopes trying to see if
they could see the flashes to people
with I believe a four-inch diameter and
a 10 inch diameter telescope detected
seeing the impact flashes these are
small telescopes that you can just go
out and get in a store somewhere and so
I want to be very cautious about this
because they were not can no one else
has seen this no one else has reported
impact flashes however it does mean that
people with telescopes of that size
knowing exactly where to look at the
limb on the limb of Jupiter the edge of
Jupiter should be able to to at least
try to see if some of the later impacts
will display meteor flashes as the
initial media comes in I had I I'm kind
of confused about the term fireball to
keep people keep using as I understood
it there's no oxygen on Jupiter they
can't be any fire and people keep
talking about a fireball and a plume
what exactly is this thing burning or is
it simply very hot what what is it is it
just an expanding bubble of hot gas or
can you describe it yeah there are
number of different events the first we
call the meteor phase this is this
happens when the fragment is coming into
Jupiter it it enters Jupiter
stratosphere it starts to interact with
the atmosphere just like a meteor on
earth that we see any night of any night
of the year and next month on August
eleventh with the perseid shower that we
should be seeing a lot of them but
instead of a grain of sand producing the
bright meteor this is an object one
kilometer that's more than well more
than half a mile wide producing a very
very bright meteor lasting like the
meteors on earth a second or so then it
disappears it goes down into into
Jupiter's clouds explode somewhere well
below the clouds and then a huge
fireball cloud comes up we've all heard
of the sad but accurate term the nuclear
fireball after an atomic explosion where
a big huge cloud rumbles up and creates
a plume that lasts for several minutes
that we call the fireball and the plume
as a the plume of from that fireball has
apparently lasted a while and then it
collapsed just as jeans model its
chested it would yes absolutely it's
just a terminology that comes from
nuclear experiments where you simply
created tremendously hot
at atmospheric a mass that's shot the
the heating is actually due to the shock
and the temperatures go up to
temperatures that are way beyond
anything in our normal experience on the
earth the temperatures rise to tens of
thousands of degrees Kelvin and that's
what we mean by the fireball it doesn't
mean that something is burning it's just
extraordinarily hot by the heat is
coming from the shock wave not from
combustion it's it's incandescent
because it's so hot bubble of hot gas is
exactly the right way to think about it
very very hot gas Jim Jim slave ABC news
what do you have in radio emissions at
this point you have any seismic data I
don't think that we've heard any reports
radio emissions at the present time I'm
certainly from the impacts there was
that earlier one we heard we heard a
report from Japan this came over the
wire services yesterday that that
predates the impacts and we need to
learn more about that but in terms of
radio emission of time of impact I'm not
aware that we received any reports in at
the present time the second question was
prospect sighs me well you saw the
seismic wave there it is we're right
down there on your spot we were
primarily expecting to see the seismic
waves and the atmospheric waves in the
infrared data more so than in the
visible wavelength data that's where you
would directly detect the seismic waves
and in this visible wavelength data
you're seeing a secondary effect or the
temperature causes some kind of cloud to
condense in the atmosphere from what I
have heard and seen so far we have seen
the impact sites in the infrared but I
have not yet heard a report of seeing
wave phenomena in the infrared okay now
Heidi yes what's that ring around the
dark spot well that's a good question I
claim I claim that's just about the
distance at which this acoustic wave
should have around we all know when we
have another sequence of images where we
can see that expand outwards if we don't
see
moving outwards gene then it's not
likely to be an atmospheric wait this
isn't the best one we didn't expect to
see anything even we didn't plan a
sequence we do have images later on
where we're planning to take sequences
over several orbits so we can see this
wave move out and certainly as i said in
the infrared that's where we really
expect to see these seismic waves if you
see them here you should see them in the
infrared ok so we're going to have to
wait and see when we really look closely
at the end for that data you're going to
believe anything you want but you have
yet you have to explain why that is out
as far as it is and I think that's just
about the distance at which needs to
call you well ok I'll go out on the limb
here I thought that that was debris that
had fallen down I mean when we looked at
that plume image it's very extended and
I thought that that circular pattern was
the fallout from that plume ok we'll see
I'm betting it's the size of a Quaker
see you're seeing an effect in the
atmosphere member bhikkhus take way
we'll see ok this is marker o of the
Houston Chronicle could you go over the
witch of the fragments you think are the
largest and some estimate of what size
you think they might be and as a related
question the impact information you're
getting now what is it telling you about
what these fragments are actually made
of what let's look at let's look at the
panel in the back this is a wonderful
book there is the graphics coming up
again only they've got those horrible
numbers i think an ABC fe dollar all
numbers except for eggs except array all
right number 24 on there which is G that
big guy behind that's tomorrow G and H
are the biggies let's see what else is
in here that's re go Nadine fabulous
there we go all right all right now
we've got it H&K are
all goodies that was a little bit
smaller q1 is another biggie those are
the real big ones and if we engage now
from nucleus a and the effects we got
from that then I would say how Weaver's
estimates of the sizes that came out now
and were published in January are
probably very good and so we're talking
about three probably three
kilometer-sized objects for GH k and q q
one dick Kerr science magazine out in
the the Graham images we saw two spots
those were a and C was the B failed to
create one of those spots are with it
just not in that view and what would
that imply about mass or nature of that
object he would have been on the other
side and be would be would have been up
a few to i think but but be was detected
at kick attacked one more question here
and then we'll go to Kennedy Space
Center and come back after that baba
hagar with NBC did the new observations
tell you any more about the amount of
energy released during this event with a
and the amounts that you could expect
down the line as the others hit
well what we can say is that from what
we saw on a it was much more energetic
than we expected and so the kind of
energetics we were expecting were ten to
the twenty nine hundred million megatons
4G so it seems like we're seeing that
kind of energy for a it seems to be more
powerful than we expected well I'd say
about you know think we're off by a
factor of 10 all right yeah 10 million
megatons all right I'd like to go to
Kennedy Space Center we have some
questions there we will check the other
centers and come back here go ahead
Kennedy still along the Miami Herald to
questions but a non-technical and they
sort of come from what Heidi said about
the possibility or the good thing that
it's going to Jupiter a lot of people
are wondering today kind of a what if
question so what effect would it have
had if this would command anywhere
around North America and the second
question is a lot of people don't
understand an object of this relatively
small size how does such massive damage
well if a had hit North America it's
likely first of all it would have made a
crater about 20 kilometers in diameter
of course if that happened over the
baltimore-washington area it would have
taken us all out we wouldn't be here so
the local damage would have been just
enormous you not only take out what's in
the crater but you take out everything
that's in the ejecta blanket of the
crater and you knocked down things for
hundreds of kilometres a hundreds of
miles beyond that but also then you a
tremendous amount of polarized material
would have been carried up into the high
atmosphere and ultimately would spread
over all of the northern hemisphere
you'd probably get a very significant
global climatic effect from that single
fragment so it would
be a major disaster be probably the
worst natural disaster ever witnessed by
man and that's just for a single for a
single one i nee first fragment that we
didn't expect anything from and the
second part of the question how does a
such a relatively small object cause
that much disturbance okay the thing to
remember is that any mass of material
doesn't matter it matter whether it's
lead or custard pie if you take one gram
of that material and move it at the
speed of three kilometers per second
that's getting pretty fast that's faster
than a very high-powered rifle bullet
its kinetic energy is equivalent to the
same man to the combustion of the same
mass of high explosive like TNT now the
energy goes up as the square of the
velocity so for each gram of that comet
coming in will have not just the
equivalent mass of combustion of a gram
of TNT it will have 20 squared times as
much in other words four hundred times
as much energy packed into each gram as
the energy of combustion of TNT that's
why it's so damaging now this is taha
personal 40 today we've heard y'all
talking about fragment a I'm wondering
whether or not at this time you can
describe what was seen with fragments B
and C and I realized II was just
happening Vegas right before he came on
the air here C was observed as strongly
as a was and more recently we don't have
as much analysis from see as we did from
from a B was seemed to be a lot weaker
and so far we're interpreting that as
being the B is probably composed of more
of a rubble pile by the rubble pile it
was just a loosely congealed group of
very tiny fragments and as it got closer
to Jupiter just before impact they just
kind of fell apart
and what probably happened is it most of
be exploded much higher up in Jupiter's
stratosphere probably little of it or
not as much as we thought got down into
the atmosphere however the Keck
telescope which is now the world's
largest ground-based telescope did
observe an explosive plume from B this
is something that we thought would be
lucky to get on any you know remember
when we were upset earlier that these
fries impacts are going to be on the
night side we're not going to see
anything from Earth even with weekly put
together fragment be we're still free
seeing the explosive plume from Earth
with ground-based telescopes see on the
other hand appears to have been more of
a solid fragment came right down like a
did and made a much larger explosion
this is just our tentative idea but most
of us seem to agree with that at this
time just quick power at this time can
you give us an idea of how high above
the limb the DMC plumes traveled we can
only speculate that for a at this point
because that's the one we have the
highest resolution imaging and we seem
to believe that that the bright detached
portion of that plume was about a
thousand kilometers above the limb of
Jupiter and I'm wondering if you could
just review quickly for me the impacts
that you anticipate the rest of today
and tomorrow okay can give you a rundown
on that in eastern daylight time
fragment II is is coming down at 11 05
so not very far away fragment F will be
at 20-27 Zulu time of course that's 827
this evening and then fragment G will
come down tomorrow morning
329 okay so a 27 this evening Eastern
that June day like that I miss turned a
lifetime so observers with small
telescopes should be trying to watch at
the right spot on the limb for brief
flashes be really careful though I'm not
saying the Jupiter is going to get
millions of times brighter this is this
is going to be something that if you
really know what you're looking for you
there is a chance that you might detect
the flash I want to add I want to
qualify that to say that there have been
no reports from any professional
observatories detecting those flashes
and they've been looking so I would add
to that that we went to the US Naval
Observatory last night to put our eye to
the telescope in hopes of seeing a flash
and when you really want to see a flash
you can almost imagine that you do so we
all have to be careful that we aren't
imagining something that isn't quite out
there yeah very true we've always tried
to explain those those too tentative
reports they have to be mentioned
because they were reported by more than
one observer but it is something that
has not I don't consider that it's been
confirmed the only way to confirm
something like that is to increase the
number of people trying to observe them
timing would be all important the one
thing to remember however is a visual
Observer has the advantage of being
there watching all the time and you may
not capture that very brief event which
will last only two or most at the most
three seconds if you're not taking the
image at the right time so so there are
some advantages the visual Observer has
the disadvantage is it's hard to prove
that you saw more questions from Kennedy
yeah what another quick power for me
there are other anticipated impacts
tomorrow besides G earn addition to G oh
sure let me let me say that what we have
that information available and that
should be at the newsroom at Kennedy and
if it's not there we will fax a full
list of all the
times and locations where those can be
viewed from and the observatories that
are likely to have an opportunity to
observe those as well as a Hubble
observing schedule so that should be in
the newsroom at the end of this briefing
if it's not already there any more
questions from Kennedy yes two more
reporters this sojourn earth news to
Heidi I'll make it easy on your video
person to tell them that I need you to
display the graphic showing your little
movie in the travel coming in disgusting
vertical skills one of time and one of
the wavelength what happens when you
stay at one wavelength says do you still
see the same expanding or ultimately
what happens did you say at one time how
different does it look in the different
wavelengths well the data you saw are
the data we have we only took that data
because we were sampling various
wavelengths so I can't answer that
question not yet I think that if these
things are visible at this level and
particularly for the brighter fragments
that some of the other ground-based
observatories will be able to do that
experiment we're not really particularly
designed to do this kind of an
experiment with experiment with the
Hubble Space Telescope but I buy this
kind of experiment I mean something that
has very rapid time sequence that really
wasn't the point of this this was purely
certain diffidence that we did see it in
a time sequence like that so I think
you'll have to wait and hear from the
ground-based telescopes that are
designed to do that kind of an
experiment another side of the spectrum
and infrared have you heard any reports
McDonald Observatory or from the kuiper
airborne observatory which i believe is
flying out of Australia we haven't
gotten a report yet from the kuiper
airborne observatory observations were
scheduled so I hope maybe we'll be able
to report on that tomorrow we're
attempting to contact them throughout
the morning to get what we can and post
that as soon as we could okay Angie and
a really big picture question couple of
the year and on a panel were in
elementary school at the time but would
you where you bought started 20
years ago Praetorians Apollo 11 then you
were now for this or more started now
that's kind of hard to compare their
different events I think that we all had
a lot of confidence in Apollo 11 that it
was going to be a successful landing so
when it happened we said all right that
happened and we were all delighted and
grateful for that achievement what's
different with this situation is we
didn't know how nature was going to
perform and we're just elated that
nature has outdone herself has to give
us this spectacular experiment that
we're looking now at now still long
Miami Herald again just one more quick
question about the spots themselves to
the layperson there might be some
confusion it's described as a dark spot
or a light spot that maybe just simply
the technology that observes it but to
someone who is going say to the local
community college observatory what
should they look for what could they
expect to see and could you explain a
little bit ly one it appears light 21
and dark to the other yeah I still doubt
that people with small telescopes are
going to be able to detect these
features at all I debt very very much
they looking awfully nice that remember
these pictures are with our with very
large ground-based telescopes or with
the Hubble Space Telescope I strongly
suggest that people go to their local
observatories planet area and look at
you bitter and I still think that you
will probably see no changes on Jupiter
I will be thrilled and delighted if I'm
wrong on that but go to go out with your
telescope look at you bitter don't
expect to see more than the beautiful
Jupiter it always is and then keep our
keep posted to HST and the other
ground-based telescopes to see the real
changes that we are seeing and if I'm
wrong on that then I'll be just as
thrilled as anybody else to answer the
question more directly at visible
wavelengths if you were looking
your eyes if you were out at Jupiter you
would see dark spots invisible these
features right now are dark when they're
fresh they're dark the only time that
they're bright is when we're looking in
the infrared and that's because these
features are hot when they're hot
they're bright in the infrared so we
have something that's visually dark and
hot so it's dark in the visible and
bright in the infrared and the methane
band is bright because the methane
molecule is absorbing all the other
photons except the ones that are getting
reflected off of these particles does
that help clarify alright we'll go to
JPL now for a question and we'll be back
here for follow-ups go ahead JPL this is
robert lee host with the los angeles
times just a simple fact question if
fragment a you best guess is that it's
about a half-mile wide then what's your
best guess on the literal size of b c
and d i'd say a fragment c is very
comparable to fragment a they're very
very close so we're talking about
something of order of a kilometer six
tenths of a mile something like that
these are rough numbers please remember
as far as be it's much harder to say it
clearly produced much less effect so the
total mass is less and it may have been
a loose swarm by the time it hit the
atmosphere not a single object so it's a
little bit hard to put size on that if
you wanted it all up together perhaps it
was something that was of the order of a
few hundred meters across I guess we
want to want to take a shot at that
Heidi do you have it no I think we did a
great job okay we got the letters on
this fragments now oh good now we got
wonderful okay well come back here to
Goddard and take some questions have one
up in front here
with gallant Galileo on the way out
there carrying a probe to drop into this
very same atmosphere how do you think
these results are going to inform what
people are looking for when that happens
you won't try it I can try we're going
to be thinking very very carefully about
what we see and Galileo is actually
taking pictures of these events so that
will be fascinating to see what the
Galileo spacecraft sends back because
they had direct views of these impact
sites certainly the changes in the
Jovian atmosphere are going to be very
interesting and I think it's great
timing that we the NASA has a spacecraft
on its way to Jupiter right now and
we'll get there and see these things up
close the other thing is that the
Galileo probe the the probe part of it
was very carefully designed to go down
into a certain depth below Jupiter's
cloud tops one probe an active probe
with instruments we now have 21 small
positive probes going down all the
different layers of Cuba ters atmosphere
and revealing whatever they can reveal
each one of these comet impacts is a
little bit like a probe going down very
much like a pro going down and below the
cloud tops siming up stuff from the
interior telling us an enormous amount
of what to piter's made of and what it's
like we need to look at these things as
being almost like probes next question
Mike Nickerson NHK on yesterday we
learned that there was a 13-minute
deviation from the predictive time of
the impact of a and do we have specific
impact times and same sort of the
deviations regarding b c and i guess d
now Heidi you've got the the first
timing that shows the plume coming up
and it was a 20-18 which was exactly the
time given by the people at Keller Alto
and Spain so the impact probably
there's a little bit before that by as
much as perhaps three to five minutes I
would just that that's the offset no i
don't i haven't heard any reports of
accurate timing of the other ones yet so
i don't think we know the answer to that
question as to whether the whole chain
is offset by that amount will be working
on that throughout the day today to find
out information out if we can get
reports of the direct radio signals for
example from ulysses that would probably
give us that might give us the most
precise timing because that Ulysses can
look directly at the impact site at
Short radio radio wavelengths and we
might see that that plume should produce
a or even the meteor may produce a radio
signal that would give us the exact
impact Hank I also want to ask you about
some the other phenomena stat had been
predicted such as a Nora effect and or
reflections off of this some of the
Jovian satellites have any of those been
served no observations are that we've
gotten yet of reflections off the
satellites that's that's interesting
that we haven't gotten that and yet
we've gotten so many positive things in
other ever those are hard to get hard to
observe when the satellites are in
sunlight wait for fragment k the
fragment k is going pregnant k is going
to impact europa will be in the shadow
of jupiter and that will be a very
sensitive test then and and the initial
we should see the flash of the initial
entry meteor there we may be able to get
that directly from observations of
europa at that time and i believe we're
getting some ultraviolet images with the
Hubble today and those will be very
interesting for studying the Aurora
hopefully John Clark will be able to
talk about that tomorrow or perhaps the
next day is it that the comet fragment
encounters from the time it enters the
atmosphere down to the
point where it explodes and what is it
that causes it to explode okay the comet
is entering a very tenuous uppermost
part of the Jovian atmosphere initially
and it simply increases a denser and
debts or atmosphere as it goes down by
the time it hits the ammonia cloud tops
it's reached the half bar level another
is a pressure about equal to half the
pressure in this room but it continues
for these larger fragments theory
predicted if there are single fragments
it will punch right on down and go to
the depths of order about ten or several
tens of kilometers below the ammonia
cloud tops at some point for a given
size fragment what will happen is the
comet is being decelerated by the
intense shock the bow shock ahead of it
and it simply becomes crushed by its own
inertia but it's because of that
deceleration in by the shockwave and
when they because when it crushes it
just falls apart it just spreads out and
falls apart and that then presents a
very broad area which which again now is
going to stop it very quickly in other
words it meets much more atmospheric
resistance and a stop very suddenly so
that essentially all of the kinetic
energy that was in the comet fragment to
begin with is delivered to that
shockwave and a little bit of a course
remains in the comet which itself gets
heated to tens of thousands of degrees
Kelvin as well so it's but it's
basically just transferring that initial
kinetic energy into a shockwave and most
of it but not all ends up at the lower
part where the comet sensually just
comes apart rather suddenly it's below
them hope we think it's below them well
remember it's still mostly hydrogen
ammonia clouds are just a portion of the
atmosphere but the atmosphere is mainly
hydrogen all the way down
howdy are we are we have to see HST
images of the impact of E today I know
there's nothing officially scheduled but
yesterday there was sort of an early
release and I'm wondering if there's
some excitement about what you see they
might be released sooner than expected I
don't really know the answer to that I
think we're not getting our images
downloaded until later in the afternoon
they're not coming down from the
spacecraft and so we may just have to
wait till tomorrow tomorrow morning mark
this marker of the Houston Chronicle
could you I know the questions other
basic but I'm still not sure I
understand what you've learned about
what the fragments are made of and in a
general sense kind of how they're if
there if there are multiple pieces how
they're grouped together and interacting
with each other has anything that you've
seen from the impacts help clarify that
well only the one thing is that when you
have pieces that appear to be the same
size in our Hubble Space Telescope
January photograph photograph and a and
C come down really really strong and
then B is really weak the implication is
that B is really loosely held together
what is it that the comet fragment
encounters from the time it enters the
atmosphere down to the point where it
explodes and what is it that causes it
to explode okay the comet is entering
the very tenuous uppermost part of the
Jovian atmosphere initially and it
simply increases a denser and debts
their atmosphere as it goes down by the
time it hits the ammonia cloud tops it's
reached the half bar level and oh
there's a pressure about equal to half
the pressure in this room I but it
continues for these larger fragments
theory predicted if there are single
fragments it will punch right on down
and go to the depths of order about ten
or several tens of kilometers below the
ammonia cloud tops at some point
for a given size fragment what will
happen is the comet is being decelerated
by the intense shock the bow shock ahead
of it and it simply becomes crushed by
its own inertia but it's because of that
deceleration in by the shockwave and
when it because when it crushes it just
falls apart it just spreads out and
falls apart and that then presents a
very broad area which which again now is
going to stop it very quickly in other
words it meets much more atmospheric
resistance and to stop very suddenly so
that essentially all of the kinetic
energy that was in the comet fragment to
begin with is delivered to that
shockwave and a little bit of a course
remains in the comet which itself gets
heated to tens of thousands of degrees
Kelvin as well so it's but it's
basically just transferring that initial
kinetic energy into a shockwave and most
of it but not all ends up at the lower
part where the comet centrally just
comes apart rather suddenly it's below
them hope we think it's below them well
well remember it's it's still mostly
hydrogen ammonia clouds are just a
portion of the atmosphere but the
atmosphere is mainly hydrogen all the
way down
howdy are we are we have to see HST
images of the impact of E today I know
there's nothing officially scheduled but
yesterday there was sort of an early
release and I'm wondering if there's
some excitement about what you see they
might be released sooner than expected I
don't really know the answer to that I
think we're not getting our images
downloaded until later in the afternoon
they're not coming down from the
spacecraft and so we may just have to
wait till tomorrow tomorrow morning this
marker of Houston Chronicle could you I
know the questions other basic but I'm
still not sure I understand what you've
learned about what the fragments are
made of and in a general sense kind of
how they're if there if there are
multiple pieces how they're grouped
together and interacting with each other
has anything that you've seen from the
impacts help clarify that well only one
thing is that when you have pieces that
appear to be the same size in our Hubble
Space Telescope January photo photograph
and a and C come down really really
strong and then B is really weak the
implication is that B is really loosely
held together and wants to just come
apart as soon as it starts getting and
interacting with Jupiter's atmosphere
other than that spectroscopy
spectroscopy does it oh wait until we
get some spectroscopic results from some
of the ground-based telescopes and the
Hubble Space Telescope and that will
give us information about composition of
the material that we're seeing and
whether it's Jovian dredged up from
below whether it's commentary spilled in
or whether it's some incredible mixture
of the two is going to take a while to
sort out but that's one place where we
will get some interesting information
about the comet the Comets composition
so you'll be doing a chemical analysis I
gather but is is this dust ice rocks is
that still what you think's
there I mean that's what I'm not clear
on yeah prevailing party line on comets
is it's a mixture of ice and and
silicate rocky particles and now we know
from the observations of halley's comet
that there's a fair amount a very
complex organic material that are called
Sean grains they're composed of carbon
hydrogen oxygen and nitrogen to some
kind of it's kind of a tari gunk if you
want to think of it that way that was a
substantial fraction of the dust that
was coming off of halle all of thats
mixed together in some kind of a mud
ball if you want to think of it that way
an icy mud ball whether it's solid or
whether it's porous and fluffy those are
all $64 questions there's a wide variety
of opinion about that and I don't think
that we can really say yet from what
we're seeing with these impacts we can't
shed much light on it I have my I have a
personal prejudice that these things are
not all that porous that is to say the
pore space might be a few tens of
percent but the density of the object is
more or less like the density of a ball
of ice we have time for just a couple of
more questions before will lose the
satellite today and we would like to
replay all the images stills video and
animation that we had available today
while we still have the satellite so we
will go a couple more questions of
course the people here in the room will
still have an opportunity to ask a few
more following that but we'll take
another second row Matt grunts and the
Dallas Morning News g is 25 times more
massive than a and C do you expect that
that extra energy will bump you up into
a different kind of scenario from the
fireball one that you've been describing
or is it just going to be a bigger boom
I think we're getting it basically the
same phenomenon but a much bigger boom
now there is the possibility that some
of these much larger objects if they
remain intact can go very much deeper
into the Jovian atmosphere and so there
is a possibility that boom may be
muffled that not as good an eruptive
plume will come back out so well that
will be very interesting to watch and
see but we're certainly delivering that
much more energy to the planet a better
chance for some of these wave phenomena
whether it's an atmospheric waves of the
seismic waves that gene is sure he sees
already much more likely that for a
large body that those effects will be
visible question in the third row
Michael to take TV asahi this is a
question for Carolyn shoemaker and
rotated lady this shoemaker levy 9 was
discovering what is essentially very old
technology and now it's being observed
with the latest and most expensive of
technology if you I'd like to get your
comments about the way Sciences can be
done in the way it has been done here ok
I think that scientists tend to use
whatever is available for the funds that
they have I think very good technology
can come out of older methods the
telescope that we use at palomar
observatory's ideal for that purpose for
the search of small bodies in the solar
system because we can cover such a wide
area of the sky you could not use a one
of the beautiful big new telescopes that
can look very deep and cover a lot of
sky but I think that we're very
fortunate today to have the advantage of
all the new technology because once you
find something then you want to look a
lot deeper if we didn't have the
wonderful telescopes that exist today
and and the new technology we wouldn't
begin to know
but this comet is really like and what
it's doing it's it's it's really
important and valuable to be continually
developing new technology one of the
things that we always love when we're in
palomar is to watch ourselves observing
with Paula Mars first telescope built in
1936 designed designed essentially by
amateur astronomer Russell Porter and
still in use a telescope that has made
more common and supernova discoveries
than any other telescope in the world
and it's important to have the new
technology that is necessary now without
all the new technology we wouldn't be
nearly as excited today we wouldn't be
excited all the days as we are but I
think it's also important not to toss
out the old technology too fast we're
seeing how valuable that was and at
least bringing this comet to everybody's
attention we have time for about one
more question before we lose to
satellite anyone glendon David you said
you're a little bit surprised by by the
idea that people would be able to see
some flashes especially from a big
object that these usually flashes would
come from smaller meteors but I wonder
if it's possible artista aren't these
comet fragments traveling along with a
lot of other little bitty things that we
can't really see and I wonder if it's
possible what if these people saw
something that they were actually much
smaller little bits traveling along with
the main fragments that might have
produced flashes that's a good treating
question i don't i don't think so i
think a small fragment the only the only
way that a small fragment could give a
brighter flash is if it exploded so much
higher in Jupiter stratosphere that it
was simply visible from the earth
because it was simply so much higher the
smaller the fragment is the higher up in
Jupiter's atmosphere is likely to
explode my guess is if these visual
observations are correct and that is a
huge if
if they're confirmed then my guess is
that they were the main impacting
fragment of a but can't be sure based on
that limited data set we're going to
hold other questions for now what we
would like to do is give the cameramen
and TV crews an opportunity to reset up
for a replay of the images and video
animation coming across and in just a
couple of minutes if you need that kind
of time to set up if you're ready to go
which is give a sign and we'll roll the
tape whenever you're ready and while
you're setting up on that just want to
make an announcement about our briefing
tomorrow to remind everyone the comet
update tomorrow well we hope have
information on e f and we may
conceivably have some sort of
information on G but I understand that's
that's pushing it for Hubble information
that's very close to the time that the
impact will have occurred so we may only
just know that it happened but whatever
we have at that time of course we will
make available as soon as we can other
observations from I RTF and from Kuiper
and other observatories of course we
will try to get that information and put
it out as soon as we can and have a
briefing on that tomorrow morning here
at Goddard at eight a.m. eastern time
and please stay tuned also to us for any
possible time changes or briefing
changes throughout the week if we have
an opportunity to include a report
that's more inclusive or has some better
images we may in fact go to a later time
in the day if that's necessary we'll put
out the word and please check with us
and we will let everyone know and I
think we're ready to roll the video and
at that point i think would like to
thank everyone for coming today and we
will see you tomorrow morning and Thank
You panelists
you
when the second impact was due and we
thought a distinct signature of the
plume of one of the other one the
impacts and then subsequent images show
very bright features on the surface of
Jupiter at the impact sites incredibly
bright very clear the very spectacular
event one of the things that that
surprises is just how bright these
events are and so the thing that the
cake the advantage of the check has is
that can see much fainter things going
on and particular one of the experiments
that we did this evening that will take
some more time to analyze was looking at
jupiters ring and that has the advantage
is that by looking at reflected light
off the ring we can in a sense view the
impacts ice directly so hopefully when
we look at that data carefully we will
see the initial flash when the comet
fragment head jupiter
the image that you're looking at is a
picture from the Keck telescope it's an
infrared picture at the wavelength of
3.3 microns which is about six times the
wavelength of visible light the features
that you see are the bright polar caps
which are always present and just as the
equator is the storm system in the red
spot but five thousand forty degrees is
our most prominent features which are
the aftermath of the comet impacts that
occur in early this evening the
brightest spot is the very first impact
the one at the end on the left-hand edge
is the impacted impact number see
how it very clearly had produced the new
cloud which was quite long when we
observed the plume from C was clearly at
the same latitude but at first very
difficult to distinguish from the the
cloud of a and as the planet rotated and
time passed the plume from sea became
very much brighter several times
brighter than that cloud the cloud from
the a fragment turned out to be about
the same brightness as the north and
south polar caps I'm very ecstatic about
any of this witnessing this is kind of
amazing and what what's amazing about
both of these is the fact that B and C
are both brothers faint objects
certainly in the turbulent drops in the
near infrared so f and g are known to be
much bigger much brighter and therefore
expect the mirror as they're both much
betta spriters biggest objects than a
and so this is going to be a real show
so it's movie night we're looking for
something much i'm going to do that yeah
this is the latitude that we're looking
for something right there
you