q1 is the bottom
good afternoon i'm don savage public
affairs officer for the office of space
science
and uh welcome today to the goddard
space flight center and the latest of
our comment update briefings here at
goddard
today we have a major announcement to
make a major discovery by the hubble
and uh our top news this morning we will
also have
dr renee pronjay who will tell us about
how cometary debris is making the jovian
aurora light up and uh dr lucy mcfadden
will give us a worldwide wrap up and
dave levy will be here for discussions
on the observing
i'd like to go ahead and introduce our
panel right now
to my left dr roger yell with the
university of arizona he's a scientist
from the university of arizona and a
member of the hubble space telescope
spectroscopy team
to his left dr renee pronje from the
institute astrophysics facial and orsay
france she's a scientist from the french
institute at orsay and a member of the
hst upper atmosphere imaging team
and the center to her left dr steve
maron our moderator for today he's a
senior staff scientist at the goddard
space flight center to his left dr lucy
mcfadden university of maryland and
university of california a visiting
professor at the university of maryland
and coordinator of the worldwide comet
observing campaign
and to her left david levy co-discoverer
of the comet and long-time common
observer welcome panelist
like to uh turn it over to you steve
thank you don
uh good morning ladies and gentlemen for
those of you who had the advanced
schedule i'm not eugene shoemaker and i
won't have any uh
explosive results for you it is a
pleasure
uh to be here again uh i've lost count
of all these fragments but uh fragment
p2 should have struck within the past
hour and as i think you all know many of
you led with it uh yesterday or or this
morning the first of the three uh
uh three other big fragments the qr and
s
that will be hitting jupiter at
intervals of approximately equal to its
10-hour rotation period so they'll hit
it nearly the same spot at 10-hour
intervals that will uh start at about 3
32 eastern daylight
uh this afternoon we'll hear a little
bit more about that later now for this
what i personally as an astronomer think
is a
very exciting scientific result
to uh emerge from shoemaker levy there's
more to it than just the big show we're
fortunate to have roger yell at the
university of arizona
tell us about this hubble spectroscopy
result well good morning and as you all
know there's there's two ways two sorts
of information that the hubble space
telescope has been gathering
what you've seen mostly is images where
you see the entire planet and the impact
site at a very specific color a specific
wavelength but also with the
spectrographs we look at one spot on the
planet but look at all the colors all
the wavelengths simultaneously and
that's what we call spectroscopy so i'm
going to report on some spectroscopy
results
you can see on the monitor i believe an
image of the g impact site and it's the
spectroscopy from the g impact site we
knew that was going to be a big one so
we pointed the spectrograph there
several hours after the impact
and um in the next uh could we have the
next graphic please
the arrow is pointing to the location of
where our spectra were obtained
spectrograph was a faint spain object
spectrograph
that's right
um
i don't know how to get that on next
graphic please
they'll have it up in a moment
okay and what we're going to see in this
graphic is the distribution of
brightness from this spot as a function
of wavelength or color
um
now
different molecules
okay there there it is and i'm going to
be talking about
that's ultraviolet light this is
ultraviolet light the uh the wavelength
is probably hard to read off that scale
off the image there but it goes from
about 150 nanometers to 3000 nanometers
so this is light that doesn't get
transmitted through the earth's
atmosphere you need to be above the
earth's atmosphere to observe it and
that's why we use the uh
the the hubble thin object spectrograph
to make to make these measurements
so what we see there is the ratio of the
light from jupiter
after the impact to the light from
jupiter before the impact
and
uh you can see that the ratio is not one
which tells us right away that
something's changed it's less than if it
were one it would be a straight line
right if it were one it would be a
straight line across the top of that
image it's somewhere varies from about
0.2 to i guess 0.7
so what that tells us is that these
spots are darker in the uv
after the impact than they were before
and we knew that already from the
images it's no surprise but if you look
very carefully distribution with light
with wavelength you can look for
molecules molecules absorb at specific
specific wavelengths specific colors
that are their own signatures so one
molecule will absorb at one wavelength
another molecule will absorb at another
wavelength and by analyzing this you can
identify some molecules yesterday keith
knowl told you about ammonia
which happens to absorb light
right around 2000 angstroms where which
is the minimum in that spectrum there
and there's there's ripples there if you
look here carefully you can see ripples
in the spectrum which are characteristic
of the ammonia what he didn't show you
yesterday were the larger ripples to the
right
at about 27 270 nanometers
um
they're about well i think they're
fairly obvious there it looks sort of
like fish bones or something
um
and that was very exciting when we saw
that yesterday but we had no idea what
it was and so we spent the last 48 hours
or so trying to figure out what this
molecule was
and it was some something of a mystery
there are a few clues that you can that
we went by in the spectrum first of all
it's very regular spacing of ripples in
that and that tells you that it's a
simple molecule secondly the ripples are
close together and that tells you that
it's a heavy molecule
so
armed with that that eliminates
some number of molecules in the universe
but um
i should have said first of all that we
had expectations about what we were
going to see um we knew what molecules
to look for and where to look for them
and we didn't see those we saw ammonia
which was expected but this is something
that was totally unexpected so we didn't
we didn't recognize it right away we had
to go off and search
spectra of all the molecules that we
could think of to find out what this was
and none of the simple ones matched up
so we got more and more complex uh
perplexed and kept looking
but as i said we had these clues it's
heavy uh and it's simple and finally um
about three o'clock in the morning we
started zeroing in on sulfur and in fact
it's a very those uh features are very
good match to the spectrum of sulfur
sulfur gas s2 the s2 molecule
sometimes called the dimer the two
similar molecules so similar atoms in
the same molecule um
no it's not
um
can't get them all it's a diatomic
molecule
it's um
anyway so so that's a definite detection
of s2 molecule in in the atmosphere of
jupiter
now
also there's there's some more structure
around
in addition to ammonia at the shorter
wavelengths where that big minimum is
and by looking carefully at that we
think that there's probably some
hydrogen sulfide h2s in the spectrum at
that location that's not as clear-cut as
the s2
but um
but nevertheless it it may be there the
spectrum is consistent with the presence
of hydrogen sulfide we haven't it might
be possible to explain it with something
else also and we're not sure of that yet
but but it seems to be consistent with
hydrogen sulfide
hey thank you
roger s2 was found in comet irs iraqi
alcock yes that's that's true it uh has
been seen in one comet before
sulfur is
is um
seen in all most comets i believe in uh
although not in the s2 molecule and
we're going to have to do some work to
try to determine whether this sulfur
there's of course sulfur also in the
atmosphere of jupiter and it's not
obvious just from this result at this
point whether the sulfur is from the
comet or from the atmosphere
okay and of course
as everyone knows hubble doesn't just
take spectra it also takes images
and one of the areas of the study the
comet i think we have not heard about in
these briefings thus far because we
haven't had a lot of news in that area
has to do with the effects involving the
magnetic field of jupiter and the
interaction with the comet and dr renee
pranget from the onset of destro
physique spatial and or say who can
pronounce all those words much better
than i
is involved in the hubble imaging team
working on these problems and tell us
what you've been learning
okay
it's right but our one of our major
interests in the in the observation
on top of uh
studying the up atmosphere of jupiter
was to understand the physics at work in
the meritosphere and since the
magnetosphere is not a trivial
object i will just briefly put it into
context before i discuss the
observations jupiter like the earth is a
very strong magnet and the magnetic
field lines delineate cars cavity in the
surface
where a lot of plasma which plasma
dragon is a
tenuous ionized gas of electrons and
ions are confined
this cavity is very extended it's
millions of kilometers in diameter it's
five times the sun
and the tails extends
still farther at times it goes up
up or down as you would like to saturn
which is five astronomical units
so the magnetosphere of any magnus
planet is a huge natural laboratory from
plasma physics and that's why we're
interested in that
unlike the atmosphere that you have seen
a lot in the last few days the minor
sphere of jupiter is not visible
practically invisible at all wavelengths
except in the dissymmetric radio
wavelength which is which has been used
to discover the magnetic field jupiter
so we can only study the magnetosphere
by deep space mission in situ
measurements or
by
monitoring remotely the oral emissions
and that's why we are interested in that
the arrays
that you again are like the orion earth
or which are also because polar lights
they are at the end of the chain of
processes in magnetosphere
it's at the at the place where
energetic chart particles
so electron and ions finally fall and we
say
precipitate
on the top of the upper atmosphere and
the energy of the collision of these
particles and the constituents the
species of the atmosphere
makes the atmosphere shine
either in the uv or indian fried not in
the visible spectrum
and
you can see on this
picture which is on top which is an
image of the with peak 2 camera
about around
below 2000 angstrom in the far ultra
violet
so it's not visible
just by naked eyes
on both sides and polar the polar
region north and south you can see this
light kinds of ovals with spots which
are the footprint of magnetic field
lines will go far away in the
magnetosphere jupiter and where the
particles
which are along these magnetic field
lines they fall down and they impact the
atmosphere they make it shine
for us it's a signature what happens in
the magnetosphere
we have been using two cameras we have
been using the with pic 2 which is the
american
camera we have been also using the faint
of the camera which is the european
camera on board
hst
this is an image which has been taken
on july 13
before the impact two days before the
first impact
and
already one week after the first uh
dust been
consistent
sufficient dust was inside the
magnetosphere that you could expect some
effect from the dust with the plasma in
the magnetosphere there had been a lot
of prediction of what could happen in
the magnetosphere some effects could
come from the dust in the living leading
edge some could come from the comet of
the matrix
the comet itself
interfering with the plasma in the
magnetosphere
and we could expect to see some effect
even before like precursors of the
impacts
in this image you can see also the north
pole the south pole we cannot see the
can we have that graphic back please
so we can we cannot have the whole
planet because the field of view of the
faint object camera is much smaller than
the field of view of the weave peak too
but
the interest of the internet camera is
that you can get we have a very very
good spatial resolution you can get very
faint details so they're very
complementary
and on this graphic you can see what we
are somewhat too frustrated because we
didn't see anything spectacular before
before the impacts
we already had
images of the of the aurora they looked
like that except that the north aurora
consistently look somewhat fainter maybe
at times much fainter than usual
and it looks fainter than south aurora
which is a
nice necklace
on the
on the lower panel
we got the same kind of result with our
ue we have been monitoring the aurora
with by ue4 several weeks already and we
found that the north aurora was weaker
we cannot tell why we cannot understand
that we expect that if any fainting we
expected it in the south because the
dust could be inhibiting the
process that would give rise to zero
we get it right in the north maybe it's
just coincidence but we have to but
maybe it's brighter couldn't it be
brighter in the south and it's being
enhanced by the dust from the comet
fragments oh it's clearly fainter i
don't know we have a lot of trouble
getting the nose okay normally this you
can see a novel which is around you have
a spot in the middle this is very very
obvious in all the data and you find
this both with the hubble telescope and
with the international ultraviolet
explorer with both
so we can tell for sure it's an effect
of the combat but it may be an effect a
general global effect of of the deaths
in the magnetosphere
then we got this nice image on july two
days ago with july 18
yes with the we've picked two that i
hope we'll get here
on the screen
next graphic please
and you can compare this image to the
the one we got before
you can see the aurora on top the north
it's still fainter you can see the the
left edge you can see the aurora and the
south and below
the the north oral valley you have two
bright spots which are very low for us
it's very low latitude it's totally
unusual it was not unexpected i can't
tell there have been predictions
that maybe the the comet
plasma could be ionized
they could this could drive current and
it and it could enhance the
create okay so the two bright spots
you're talking about are the upper left
and the upper left on the
just at the footprints of this new
magnetic field lines which have been
drawn now
and this is quite new we never saw that
we never saw any aura below what is the
one you have seen on the
previous two graphics so that's to make
sure i understand what you're proposing
you think that material from the from
the south pole where the fragments are
impacting might be drawn through the
magnetic field lines up to the north
pole right that's what i think
there have been well if you
if you look back to the the prediction
has been made
it's one it's clear that we expected
some effect of the of the ionized plasma
in the
material in the comet to interact with
the plasma in the microsphere
but we didn't know what we could do and
in any case we expected to get something
in the south not in the north
and we
we worked out a lot to get the
possibility to have close field lines
because the magnetosphere at times the
field lines that are open to the to the
solar wind so in that case something
which happened in the south do not have
any counterpart in the part in the other
hemisphere so we worked the geometry so
that we can get
a close field line with a footprint
print in the north visible also from her
so the north and south are connected by
the magnetic field okay they're
connected they're connected and on top
of that the footprint of the north is in
front because the field line is
distorted in the meridian plane so we
can you can see the footprint in the
south it's just right at the limb but
you can see it's already 30 or 40
degrees on the on the limb on the do you
think the
north if you imagine it's kind of a bar
magnet inside jupiter that
is responsible for magnetic field
the uh in that model then the bar is off
center and tilting off the center tilted
and that's why it can be in
these lines can be in back on the south
and in front uh on the north so we are
lucky we're not only working we work it
out
and we get this bright spot in the north
but we have nothing in the star in the
and we didn't get anything except you
maybe you can
see something very very faint and
diffuse at the footprint of the
larger in the south of the larger field
line we cannot tell well that that's
probably not precipitation of particles
we do not know what it is it may be
related
but this on the on the north pole it's
it's necessarily energetic particles so
something happened some material from
the coma from the comet itself
was liberated in the south pole
accelerated
by somewhere along these magnetic field
lines and fell into the northern
hemisphere like like an iron gun in fact
now renee would these be visible in
visible light where our eyes are
sensitive
ultraviolet the oral emission i mean the
emission
exact collisionally excited and the
atmosphere jupiter they cannot be seen
in the visible only in the ultraviolet
from the it depends on the composition
of the atmosphere on earth it's visible
on jupiter it's mainly from hydrogen or
for hydrocarbons and it's either
ultraviolet or infrared unfortunately
you can see them in the visible
so that's a major i think it's a major
discovery we have to understand what
happens we have two options so far maybe
there are other options open but we
thought of two
either the the
material was liberated after impact
and we got it along the field lines and
we we seen the north and that's why we
do not see anything in the south or
another possibility which has was
predicted in fact and i i think i should
send an email to dr wing ip we have said
the published a paper
very uh short ago telling that within
one jovian radius we have the conditions
so that the coma entering before impact
could uh create a current along the
field lines which would be the condition
for such an effect to appear so you have
to do more
than just
throw stuff up from the impact you have
to have an elec electrical or magnetic
process that accelerates these uh
electrified particles and drives them up
the magnetic field
you have to get like an electric circuit
and then you have to have like
kilo volts of potential drops to
accelerate the particle to high enough
thousands of volts to accelerate the
particles so it's it's not not an easy
process and we have to to work on that
and it's a lot of modelling probably and
we learned a lot about the plasma
physics in general and jupiter in
particular great thank you dr pranje i
think these are two uh
really fascinating findings from the
hubble telescope
and we had an assist from the iue and
i'm sure we'll be hearing more about iue
as the week goes on now i have to tear
myself away from this orbiting
observatory there are
we used to say there were hundreds of
telescopes looking at jupiter this week
now from the reports coming in that
amateur astronomers and the public are
streaming into uh observatory science
museums i think lucy mcfadden
told me this morning hundreds of people
are coming to the university of maryland
observatory uh over here near uh adelphi
uh the uh there probably are thousands
of telescopes looking they won't all see
an aurora that you have to look in
ultraviolet light but what are the
telescopes on the ground finding lucy
mcfadden well actually steve with that
with that introduction i think i'm going
to let david levy talk about the
hundreds of of telescopes that that uh
are being pointed toward jupiter and let
him talk about what the amateurs are
seeing and the role they can play in the
science and then i'll come back and okay
we'll go fill in on ground based okay
this is almost a contest as to uh which
is which is the best surprise which is
the biggest surprise of this whole
magnificent week
and i i can't say that the fact that
these dark spots are visible for
virtually everybody to see is the
biggest surprise but it sure is one of
the biggest
nobody expected this uh we have some
very large spots on jupiter they seem to
be uh the the the brightest ones at the
latest that i heard still is the one
from the impact of fragment g
and it seems to me
that
no matter what part of the world you're
on and no matter what area you're
watching that's by now there are enough
of these spots that no matter where you
are when jupiter gets to be
when jupiter is in the sky after dark
you will probably be seeing some spots
you didn't mean right it's most
prominent it's actually dark for i meant
darkest yes when i say brightest i mean
darkness thank you
his comedy can put it anyway
no these these uh the one report that i
got from a professional astronomer who
actually began as an amateur and still
has his original telescope is from clark
chapman of the planetary science
institute
he said that the the spot from fragment
g
in his years of observing jupiter is the
most obvious feature ever to appear on
this planet
and he is uh challenged over the um over
the internet anyone to argue that and so
far nobody has he sent me to the
telescope last night and it was pretty
spectacular so i looked directly through
the eyepiece and there it was so yes i
encourage everybody including all the
crew and everyone doing the support work
for all this event lucy i forgot to say
that but
uh we have and you're going to tell us
about this we have more than just
telescopes on the ground and telescopes
in space we have something
kind of part way up isn't that right
yeah but let's let's let gene uh david
finish
with his points yeah i think i think the
them it's hard to tell at the moment
just why these spots are so prominent
one of the uh theories that to explain
them has to do with these are
comet dust or a form of soot that is
from the comet there are other theories
but this is one of them
um
it's it's very important to emphasize
that if if you are an amateur astronomer
if you have any experience at all
looking at jupiter any experience these
spots should be extremely easy for you
to see
if however you have never looked at
jupiter before my recommendation is that
you go to one of the many star parties
that are being organized by planetariums
and amateur astronomy clubs all over all
over the world right now and get someone
to point it out point the spots out to
you they're very easy to see
but if you haven't had if you've never
looked at jupiter before it helps if you
get someone to point them out this is an
extraordinary thing these these spots
are major major
um
effects from the collision they're
visible to anybody the philosophical
question is that if the comet had never
been found
right now
people would be seeing one spot after
another appearing on jupiter they'd be
wiping off their lenses
what's going on that's right they'd
wonder what's going on
probably the visual observers would have
been spotting them first
if there had just been one spot if the g
impact cited in the only one someone
might have said maybe there was an
impact but these spots are now forming
all over that area of jupiter and they
would say maybe it was an impact and
they'd say no how could you possibly get
so many impacts in the course of a week
and nobody would have i guess it's
entirely possible that a comet
we hadn't discovered yet could have
jupiter make a spot that large yes
i think we're lucky that these guys were
watching and found it
so this is the time to get out and and
if there's any been ever been a time
to get out with a small telescope and
look at jupiter ever since galileo first
observed jupiter through a telescope in
1610 this is the time to do it
this is this is just a marvelous time to
be looking at jupiter thank you
can i just mention that there are
interesting you probably talked about
this earlier in the week but there's
interesting strings of craters on some
of the satellites of jupiter which are
probably
which have been theorized to be due to a
similar process to break up of a comet
falling upon a
one of the satellites yes and it may
have occurred to someone that that was
similar to so that the multiply split
comet may not be such a rare that's
right yeah phenomenon it might have
occurred and that's that's a good point
that could have happened any time in the
past four and a half billion years
there's even there is even one of these
crater chains on the moon and on top of
the crater davey there's a series of uh
of these craters and that's getting
pretty close yeah but yes but to to
these did not hit jupiter all at
those crater chains hit hit callisto or
the moon all at once all within a few
seconds of each other
these are things hitting over the period
of a week and to make that intuitive
leap to get the only way this could have
done happened is that a comet passed
near jupiter earlier at some earlier
time broke apart completed another orbit
and then hit and if someone had come up
with a theory like that he he or she
would have been laughed off the stage
yes all of which however we're seeing
occur now yes that's that's
i think we need to get on to uh lucy's
report leave room for questions while we
have the satellite okay um we have some
some some more images from ground-based
observatories around the world um the
first one coming up is from lick
observatory from the 120 inch
uh telescope there it is an image taken
with speckle interferometry i'm sorry
speckle imaging
which is a process that astronomers and
and members of the department of defense
have both been developing over the years
and with speckle imaging they have the
uh they use computer
uh uh let's see they use
complex computer algorithms to clean up
the noise and improve the uh spatial
resolution of of the image and as you
can see from looking at this the um
the parallel cloud structure um is
is quite prominent and it's very higher
yes better defined than in most uh of
the ground-based images not quite as as
clear as as the hubble so it's not as
good as getting above the earth that's
the adoptive adaptive optics project led
by dr claire max lawrence livermore
national laboratory thank you steve um
then next we have some more observations
from the keck observatory where nasa and
the nsf have been have contributed to
building the instruments that from which
we're taking these uh measurements and
we have a mosaic now these are seven
images not
ignore the time difference each image is
a different wavelength and in the upper
left corner we start at a wavelength of
1.2 microns and we go across the dark
one the third one on the right
is at 2.3 microns and we continue to go
to longer wavelengths and the final one
on the bottom that where jupiter is the
darkest
is at 4.2 microns i believe now the
importance of this um
all the features appear as bright spots
so they're still radiating thermal
heat heat they're just radiating the
heat from the impact sites
the
the advantage of using different
wavelengths
is as the wavelengths get longer the
wavelengths penetrate deeper into the
atmosphere so this is like a
a stratigram we're looking at the
layers
through jupiter's atmosphere so i guess
besides the fireball that came up that
gene shoemaker's been talking about from
the simulations you still have some hot
material down under yeah that's glowing
after days and after the event right and
and this is important once we can
interpret these and coordinate correlate
the information from the different
wavelengths we hope to be able to
determine how deep the
projectile went into the atmosphere i
don't have any numbers and we haven't
really understood that yet so i can only
present it in a generic case
we have a report from the kuiper
airborne observatory which is a
it's a c141 cargo aircraft it's a really
spectacular aircraft there's it's been
compartmentalized they blocked off one
part of it where they place the
telescope there's a 36 inch telescope in
this compartment which is pressurized
and they cut a hole in the side of the
cargo plane
and they point the telescope out the
hole in the plane now this plane
flies at 41 000 feet
and there are astronomers on board and
everyone who's flown on it uh reports an
exciting adventure at 41 000 feet they
are uh they have oxygen within reach um
in case the um the interlock between the
telescope and the observer's brakes
they'll they have 15 seconds to get
their oxygen masks on
the advantage of this telescope is that
they can fly anywhere around the world
and
they can fly anywhere around the world
they get up above the atmosphere and we
will have a report um from gordon
boyaker from goddard space flight center
who's reporting some of his results
we have two two channels one is a
temperature channel and one is a search
for water the temperature channel was
truly dramatic and we have very good
coverage of both the g and the k
fragments
after having looked at the g fragment
then we decided to
to set up the investigation a little
differently
for the k fragment we concentrated
almost exclusively on the temperature we
wanted to make sure that we pinned that
down very precisely and we have
even even better data for the k fragment
the
going from the pre-crash signal level to
the peak of the fireball it went up by a
factor 25 so it was absolutely stunning
and you know since we have some spatial
resolution
um you can see all of all of jupiter
jupiter at once and then in the the limb
of jupiter where the fireball was it's
like seeing a supernova go off or a star
go off the main reason for using the
kuiper airborne observatory is that um
you're flying above
99.9 percent of the water vapor in the
earth's atmosphere and you're above just
80 percent of the total atmosphere
our key thermometer is the methane
molecule which is present in the earth's
atmosphere
by flying at 41 000 feet
this opens up a window where we can
measure very strong methane features on
jupiter that are not measurable from
ground-based telescopes
now what's important here is that they
have they're penetrating deeper into the
atmosphere at 10 microns and they are
measuring emission lines from methane so
they're getting they're getting heated
methane uh they're heating there's
evidence of heating of the methane
clouds in
jupiter um
that's the methane gas in the
stratosphere they're observing
okay it's not below okay so it's the
high the stratosphere the high levels
higher levels of the atmosphere okay and
they're they're floating in our
stratosphere as they do it that's right
stratosphere stratosphere okay um now i
think out of time let's see well the
next images are from the i from the irtf
at
mauna kea
um
and those show
these are at four different wavelengths
we have
in the
four different wavelengths
at the upper left is the temperature in
the upper atmosphere the one on the
right is ammonia in the region of
ammonia band the one on the lower left
is the region of methane and
the lower right is another ammonia
region
let's go on to the next one we can take
questions about that later we've
reported have a report from galileo that
the
the photo photopolarimeter radiometer
has uh
has detected
uh the impact of fragment
fragment g i believe um and they radioed
they sent back some
preliminary observations these are not
images so i do not have a visual for
that but
galileo we have data back from galileo
and remember galileo is getting the
direct
eye
straight eye straight line shot of these
collisions and the
profile uh the change in time of the
intensity measured by the
photopolarimeter
will show us how the flash intensifies
in the rate at which the flash decays
um then our last images are h actually
okay thank you and our last images are
from a mcdonald observatory um and we
have a report from anita cochran there
we were able to get on in with both of
the telescopes and start imaging
uh so we didn't actually catch the flash
of l but we were able to start looking
at the morphology of the l-site very
very quickly
the
conditions turned spectacular very soon
on we had excellent excellent
transparency
almost all the night
and extremely stable atmospheric
conditions so we have some really really
pretty images that we've gotten out with
both an ir camera on the 2.7 meter
telescope and
a
ccd camera on the 0.8 meter telescope
we've mostly been running around like
giddy little kids because it's very
exciting to watch this we've we've all
had to take our turns looking through
the eyepiece because you can see the
structure of the spots in the eyepiece
in good conditions and
things are just changing and it's so
much fun to watch
jupiter change below our
eyes
image number two
is
a methane image taking the ccd camera
and in this image we see a number of the
spots but
one of the striking features of this
image is that the h spot is just
rotating into onto the limb and we've
caught it in this image at a point where
we see it detached from the planet
a hydrogen molecular band
uh that is again observed with the ir
camera on the 2.7 meter in this we have
four spots and the great red spot in the
middle of the planet
uh we sent this in the conventional
orientation we find amusing to turn this
and some of the other images upside down
and look at it you'll see why when you
see the image
okay that sums it up thank you very much
lucy and if i can just sum up all the
news we've heard today or not all but
the high spots uh we have the detection
of the diatomic sulfur molecule s sub 2
s2 from the hubble space telescope with
the
faint object spectrograph roger yell
told us about that we have the
these wonderful auroral glows at the
foot points of magnetic field lines in
the north polar cap of jupiter at a
lower or more southern
more southerly northern latitude than
aurora has been observed before that was
done in ultraviolet light as explained
to us by renee prange
with the wide field and planetary camera
too and they know it wasn't there before
because a few days prior they looked
with the faint object camera also in the
ultraviolet david levy told us the g
impact site is so extraordinarily
prominent wonders if maybe that's
comet dust that's making it dark in
visible light the keck telescope
we saw the
hot impact spots still glowing in the
infrared
there's still some heat there after some
days after the first impacts the first
report back from the galileo space probe
you're wondering why we told you you
won't see anything for weeks from
galileo that's images these
photopolarimeter measurements the much
lower data rate you get it back pretty
rapidly galileo at a distance of about
150 million miles looking in the 90 450
nanometer 450 angstrom or 945 nanometers
sees
the h-spot
the
the kuiper airborne observatory the
audio report from gordon yoracker
told us about the heating of the methane
gas in the stratosphere and then anita
neil cochran at the mcdonald observatory
fort davis texas looking in the
molecular hydrogen or h2 band you see
some glowing features and spots you turn
it upside down and you have jupiter
doesn't seem so unhappy
after all don
thank you steve we're going to turn to
question and answers here at goddard and
i understand we have a lot of questions
from our center so i hope we have enough
time on the satellite we'll start here
front row with
bill
please state your name and affiliation
bill harwood cbs and i'm maybe asking
you if you'd maybe be more elementary in
terms of the significance of the sulfur
observation if you knew that sulfur is
in the atmosphere anyway and you don't
know where this sulfur comes from i'm
confused as to the significance of that
and also i was reading a message on the
internet yesterday from some other
university of arizona researchers who
were claiming that they had done some
studies or observations that indicated
they were actually seeing commentary
material and i'm wondering if these two
things are linking up somehow or there's
totally separate issues
um
okay first of all we we believe that
there's sulfur in the atmosphere of
jupiter
although we hadn't detected it yet just
because the solar system has sulfur in
it and jupiter should not be an
exception however that sulfur is deep in
the atmosphere
it's in the form of hydrogen sulfide we
believe h2s and as you go higher in
jupiter's atmosphere it gets colder just
like it does in the earth's atmosphere
you form clouds
and the
hydrogen sulfide should disappear into
clouds at a fairly deep level in
jupiter's atmosphere so
just as an example potentially we could
convince ourselves that this material
was coming
from jupiter not from the comet that
would tell us something about the depth
to which the cometary fragments
penetrated
i think maybe you're referring to the
second part of your question i think
perhaps you're referring to an article
that was in the new york times this
morning i understood on the internet
no
that the material was commentary
well i i didn't see it but what what's
what jumps out at us from looking at
this at least from the hst data is that
the molecules we've seen so far ammonia
and sulfur molecules are things that are
in the clouds of jupiter
um there's also an ammonia cloud in
jupiter the visible clouds on jupiter
that we
see those are ammonia that's right and
the there's an ammonia hydrosulfide
cloud which is at a deeper level below
one bar
there are other molecules associated
with comets oxygen
you might expect to see oxygen molecules
for example we don't see any of those
what we see so far is things from
jupiter and
well you know this is going to be a long
story but
i don't understand that that internet
message
i'm still awfully um ignorant of
chemistry what is exciting what bob cook
at newsday what is so exciting about
finding this sulfur is why would the man
in the street want to jump up and down
about this
um well as i just said i might tell you
something about the impact itself
uh the particular molecule
to be perfectly honest i don't know a
lot about it because i didn't expect to
see it
so it's a surprise
it'll be interesting to watch how this
develops in time one of the
one of the reasons this is interesting i
study atmospheres rather than comets
although i think comments are
interesting too but the best way to
learn about something not just an
atmosphere is to poke it and see what
happens so we just gave jupiter's
atmosphere a giant poke and we're going
to see how it develops in time and
that's going to tell us something about
how atmospheres behave it's going to add
to our knowledge base of atmospheres and
that's going to be useful for uh for our
society it'll help us understand the
earth's atmosphere ultimately
uh shin yoshi
i have a question a question to dr
branje
you told us about the change of aura of
jupiter and we have some example that
the same thing happened
to earth in the past and the what is the
meaning of your discovery from jupiter
to us like
knowing about the aura of earth and
knowing about the
meaning of the weather of earth and what
if something happened
like jupiter to earth
what is the meaning for our life i mean
like a short wave transmission or
something
well i think what we see
is the effect of the comet the
gas or the or both maybe the the dust in
the in the comma of the comet which has
been ionized or the other option the gas
which has been ejected in after the the
fireball and it was very very hot hot
enough to be ionized so these are the
two options
in the case we get
uh some ions and electrons which are
free in free space and we we know from
the fact that they have been
they have been able to go
along the field lines and to to excite
to glow they are on the other side we
know that they have been put at very
high energy
the kind of thing we can learn from that
is the processes in the in the
process in the command which how they
can
ionize how they can be accelerated and
then how how these particles are
accelerated in the microsphere itself
this this is a problem which is of high
interest for physics and on earth there
are numbers of satellites which have
electron guns ion guns which
artificially accelerate ions and
electrons to
thousands of volts and see what happens
at the footprint on earth of course
there were one or more experiments i i
don't remember when but the first one
was authorized by president kennedy the
uh to explode a nuclear weapon up in the
magnetosphere and see the effect of the
precipitating
particles of the famous was debated
whether it would be safe or not and
finally kennedy called van allen he said
it's his belts and
he's all right
i think the other part of your question
was what would be the effect on the
earth well of course there might be
geomagnetic storm or something like that
but comet hits the earth then the
the uh effects and magnetosphere will be
of secondary interest to many of us
well i guess it wouldn't be a terrible
effect because storms it would affect
communication ionosphere but magnet even
great uh very strong magnetic stops from
the effect of the solar wind they do not
affect life
just communications and broadcasting
uh paul hoverstein usa today back on the
sulfur question for a moment
uh dr yell if it turns out that the
sulfur
is from the comet
and not the atmosphere what would be the
significance of that
well it would tell you that there was
sulfur in this comet and
eventually you might be able to figure
out something about the abundance of
sulfur in the comet and the reason we
study the abundances of comets is is so
we can understand comet's one of the
building blocks of the solar system are
remnant of the building block of the
solar system so you might be able to say
eventually something about the
composition of the early solar system
i should also point out that when you do
observe comets
sulfur other molecules and comets you're
seeing gas around the
around the main body and most of the
masses in the main body and it's always
difficult to try to infer something
about the bulk composition from what you
see in the
in the coma because there's chemistry
that goes on and alters things and stuff
like that so what we just did is we just
pulverized the comet to find out what
was inside it perhaps
and um it's a different way to look at
things
miles all right miles o'brien with cnn
i'd appreciate from anybody here sort of
a little more of a layman's term
explanation of what's going on in the
magnetosphere of jupiter here uh i'm not
sure that i'm real clear on what's going
on
i think what we were what dr pranje was
talking about was that
these of course
observations we've only just seen the
last day or two but uh the uh
preliminary impression is that we have
this
big impact the big splash and the
fireball on the southern part of
uh jupiter and that to send up some
plasma like the fireball you saw some of
this material gets electrified loses the
atoms or molecules lose electrons and
then these uh they become charged right
you have charged particles now and i
think the electrons in particular
probably you're talking about they get
accelerated by some forces that have to
be worked out that uh but we know things
like this happen on the earth in other
situations
they get accelerated they travel
uh to the other side of the globe of
jupiter and cause an aurora there in a
place we've never seen before because
it's further south whatever makes the
aurora and jupiter ordinarily
doesn't bring it down that far uh south
it's like uh normally we see nice aurora
in canada and new england and so on and
it's a rare time when you see a mexico
city that does does happen after a big
flare
the
the charged particles are constrained to
move along these field lines magnetic
lines of magnetic field that you can see
in the image so they want to escape the
atmosphere but they they can't they have
to move along these field lines and end
up getting turned around and you know
come back on the other side of the
planet
so if you were on jupiter right now
you'd see northern lights like you've
never seen them before you'd be glad you
were seeing northern lights you weren't
down south
actually one of the things is there any
evidence that you've seen over the last
24 hours which has is settling one way
or another whether this is a comet or an
asteroid once
oh no that that's a very important
question
um but it's going to be very difficult
to get an answer to that um so
i'm i'm afraid i just have to say flat
out there's no evidence that will help
us determine whether it's a comet or an
asteroid well there may be evidence we
just haven't had enough time to think
about it exactly
i would like to go to some of the
centers for questions now as we're going
to run out of time on the satellite
which first one up please
okay well we're holding on that is there
one more here first
right here in front
matt crenson the dallas morning news for
dr yale uh i don't want all the gory
details but
in general
how can you tell whether the sulfur came
from jupiter or from the comet uh and
what are the chances that you'll be able
to do that
i don't know how the how good the
chances are but to finally get the
answer we're going to have to correlate
lots of different pieces of information
left
you know what we've seen so far as far
as chemistry goes through the molecules
that are easiest to detect with more
work and with all the other observations
being made we'll undoubtedly hear about
a lot more molecules you look at the
whole suite of molecules that will help
you try to infer something about the
temperatures in the fireball and that
will tell you about the chemistry in the
atmosphere that'll help you understand
what's going on by trying to correlate
all this i have hopes that we'll be able
to say something about how much of the
what we see is due to the comet and how
much of what we see is from jupiter
itself
so i'm optimistic but it's hard to put a
number on the chances we'll be coming
back to questions here
pardon excuse me we'll be coming back to
questions here in a moment but let's
have one from jpl uh please state your
name and affiliation
this is robert lee house from the los
angeles times two related questions one
i guess i'm surprised to be hearing at
this stage of the game that we're not
sure this is a comment uh can you tell
us why there's a
any
question at this stage why this might be
a comment or an asteroid and then
secondly is it uh disconcerting to you
folks that you're not seeing uh evidence
of water yet
okay i'll i'll field that one if if gene
where gene shoemaker were here he would
say oh it's definitely a comet and the
probability of it being a comet and gene
can argue persuasively that it's
probably a comet
dynamically it is possible um to to
give a gravitational push to an object
anywhere in the solar system and so
dynamically it's also possible to to
exert a gravitational force on an object
in the outer region of the asteroid belt
and perturb it so that it goes into
orbit around jupiter as this co as this
object did and we call it a comment
because it was discovered as a diffuse
object um which is the the
uh discriminating characteristic of a
comet observationally now it's a very
important question to determine whether
this was a comet or an asteroid because
the comets are
remnants of the
original solar system they've been kept
in cold storage for four and a half
billion years and we can get a better
handle on the starting material of the
solar system if we're studying a comet
if we're studying an asteroid the
asteroids have been in the inner solar
system they've been subjected to higher
temperatures they've been subjected to
greater uh frequency of collisions and
so the material is altered and we just
need to know what we're looking at and
presumably
the reason you might even though it's
diffuse you might think it could be an
asteroid is we know it's something that
was fragmented by the title
it could be dust
from this fragmentation and not an
atmosphere like a comet has of
evaporator or sublime gases and the
other question was about water are we
surprised that we haven't seen water
well yes or no yes and no um
uh i appreciate the difficulty in
analyzing the data from the kuiper
airborne observatory um
and and i continue to think of scenarios
which would exist where water is there
but we don't see it and it may not be
stable in jupiter's atmosphere for long
enough to get a
detectable signal with the
instrumentation or it could be some
chemical thing
so
we have a lot to think about and we also
have to wait patiently and get some
results back let the the scientists
analyze their data instead of showing us
their raw images that have spectacular
uh signatures on them
just a quick follow can you tell us what
fragment we were looking at in the irtf
images
um
maybe
you always catch me on these questions
on which what image was it um oh
actually that was the a site
remember a long time ago so this is um
they were observing a to watch for its
evolution it's it's very
we're going to become interested in how
these things evolve with time so that
was the site of the first impact there
are so many of these sites now that
we've already seen reports where
as swiftly pointed out by their
colleagues astronomers are saying this
site
looked like thus and so and someone else
says no at that time you look you were
seeing a different side there's so many
of them now you
you need a program when you go to the
telescope to
tell the spots on jupiter
okay we have some questions now from the
kennedy space center in florida please
state your name and affiliation
hi jim banke of florida today a question
maybe for uh dave levy or lucy
you said earlier in the week that you
thought these spots would last for weeks
if not months is there any evidence from
the ground-based observatories the
telescopes that any of the earlier spots
are fading away we can ask lucy mcfadden
to answer that because dave levy was
called away he is in great demand
um
there is evidence of fading of some of
the spots changes in the brightness of
some of the spots um none of them have
disappeared remember some of the impacts
didn't leave a
scar
fragment b did not make a significant uh
feature
um
there's some change galileo people told
us that besides spotting h they looked
for
an impact site from b and did not see it
with that photopolarimeter
and the second question uh maybe a
little trivial for you folks but in the
forest of jupiter did the comet make a
sound when it uh when it hits
in i know there's no one there to hear
it but uh did it make a sound what would
be the sound of a comet hitting jupiter
very loud
made a very big sound
um one of the things we'll be looking at
for seismic waves which are a wave that
sounds through a wave i don't think
there's any
conclusions on that yet but it certainly
did make a big noise not just a sound
but it's a sonic boom that going on
there oh
undoubtedly
yes this is phil chan earth news for
roger and how certain are you that this
is sulfur have you eliminated all the
other possible molecules um is there any
possibility that this might be from the
iotaurus or from the magnetosphere some
kind of ionized sulfur
uh
we're absolutely sure it's sulfur we um
you saw that it had this this very
interesting structure where the there
were wiggles up and down and there's
about 30 of those wiggles and they all
line up with 30 lines expected from
sulfur and then the distribution of
intensities is also understandable in
terms of sulfur so i think there's no
doubt now i also reported a more
tentative
detection of h2s and i want to be
careful with that
the
the spectrum is consistent with with
hydrogen sulfide but it might be
possible to explain that feature with
some combination of other molecules
we'll have to be more careful and wait
and see on that but for the for the s2
there's just no doubt couldn't be
anything else the other part of phil
chan's question was could this sulphur
be in the volcanoes on eo that's very
hard for me to imagine i think i'd have
to say no
okay and will you be making this data
available on the internet and using
heidi hamill's
analogy how bad is the traffic jam on
information superhighway
um traffic's very heavy on the
information super highway
i've have reports that the
computer up at space science telescope
institute is uh
jammed standstill just like los angeles
our computer at university of maryland
which is available for professional
astronomers and the observers
has been running at 50 to 70 percent
capacity
and we have anywhere from one to two
dozen people on at any one time
and we cannot compute
we can't keep track of how many people
log on and the same at hubble space
telescope they had to move their program
that counts how many people are logging
on to another machine because the
machine couldn't handle the incoming
traffic so
uh it's
it's busy
it's the way it's supposed to be i guess
we'll go to headquarters now for some
questions please state your name and
affiliation
i'm not sure if we're having a technical
difficulty
headquarters are you there
okay we're going to have time for one
more question here and i've been
assured the panels will stay around for
questions later on
this is mark carrara the houston
chronicle could you talk a little bit
about
qr and s and even the
the last fragments and how they're going
to how they compare in size brightness
or whatever with those that have hit
before
the qr and s impacts will occur within
about 10 hours of each other which means
they will land on jupiter at the same
location
let's see dave jewett at university of
hawaii has done some recent astrometry
he had a
an instrument which allowed which
blocked out the light from jupiter and
allowed him to look at the fragments as
they were approaching jupiter very close
and
with his measurements of the positions
of the fragments he enabled paul chotis
and don yeomans at jet propulsion lab to
update the impact times and those impact
times have moved forward about 15
minutes
so they but the spacing between them i
believe is still the same so we're we're
interested in watching what's going to
happen when these sites land on top of
each other and and
it's going to make it harder for us to
disentangle the information but we may
learn something from it as well q should
be big right i think that's part of the
question yeah q should be big p's p
should be big too they're they are
they're all big
let's try headquarters again uh go ahead
please
uh yeah this is ron kellen from science
news for dr pronjay can you tell me how
many kilometers
uh this this new footprint is below the
the existing one is there a way to
understand why
this commentary debris just getting onto
the north pole why it wouldn't just
brighten the existing footprint why
would indeed create a new one and again
how many kilometers beneath is it
well the size in terms of kilometers
it's rather
narrow in terms of latitude it may be
like it's less than a thousand
kilometers in latitude
in longitude it's elongated and
i would say
probably like
a few thousand kilometers maybe 10 000
kilometers but out of that we cannot
tell whether i should spot which has
been moving on on top of the planet
because
the the exposures have been four
five six seconds six minutes long during
that time a fixed spot in the
magnetosphere rotates in the in front of
the of the telescope by about four
degrees i guess i'm not sure but that's
the order the spot itself we have
measured the trace which is about 15
degrees so in fact it's longer than that
either this is a remaining light and it
has been created locally by the by the
comet but the comet
in the last two hours the comet is going
from the dusk side to the node at noon
and then to the morning site very very
fast so in if you have emission
which is blowing growing from for say 10
minutes you will see it like a track on
the on the observations so we cannot
tell so far how how large is the spot if
it's a temporal effect of if it is a
special effect
and the other answer the other part of
ron cowan's question why doesn't it just
shine in the
normal a rural place is that it's not
like all the bees go to the same nest to
get honey but the the the magnetic line
from the normal northern or rural zone
doesn't come to the place where the
comet hit the normal the normal aura
comes from
apparently the last observation we got
with the with the hubble last year
suggests very very strongly in the
comparison with ulysses we did
comparison with herbal and ulysses this
year
and it's very strongly suggest that the
normal or
observed glow we see it's related to
currents which flow right at the limit
between what we call the polar cap and
the closed fill line inside the
magnetosphere the close field line they
rotate to the planet in 10 hours the
open field lines as we say in our jargon
the one which are pushed away in the
tail by the
solar pressure solar in pressure and
which are open to the solar wind
normally they do not rotate with the
with the
the planet itself this creates a
condition for strong currents and there
we see a sheet of precipitation this is
very very high latitude it is connected
at something like
60
60 uh planetary radius the the opposite
the the glow we have seen this transient
glow is on field lines which go like two
or three rg at maximum at the equator
from the from the center of the planet
very very closely line in what we call
the inner magnetosphere in the inner
magnesium sphere normally we do not have
plasma to get this uh this effect
and it it was also connected to the path
of the comment itself
i think we have one more from
headquarters
uh yes this is tracy
report i guess for uh
i wonder if you've seen any uh white at
the thin dark ring from
can you hear me no please repeat um i'm
wanting to see any whitening yet of the
thin dark ring from
from fragment g the one surrounding the
dark swatch
that's that's for me
sure it's a hubble question oh i don't
think we're
we have any more results on that at this
time
okay that's all the questions we have
time for today we'll rerun the video and
uh feed that on the satellite and uh
that's in the press conference thank you
and start imaging
so we didn't actually catch the flash of
l but we were able to start looking at
the morphology of the l site very very
quickly
the conditions turned spectacular very
soon on we had excellent excellent
transparency
almost all the night
and extremely stable atmospheric
conditions so we have some really really
pretty images that we've gotten out with
both an ir camera on the 2.7 meter
telescope and
a
ccd camera on the 0.8 meter telescope
we've mostly been running around like
giddy little kids because it's very
exciting to watch this we've we've all
had to take our turns looking through
the eyepiece because you can see the
structure of the spots in the eyepiece
in good conditions and
things are just changing and it's so
much fun to watch
jupiter change below our eyes
image number two
is
a methane image taking the ccd camera
and in this image we see a number of the
spots but
one of the striking features of this
image is that the h-spot is just
rotating into onto the limb and we've
caught it in this image at a point where
we see it detached from the planet
a hydrogen molecular band
uh that is again observed with the ir
camera on the 2.7 meter in this we have
four spots and the great red spot in the
middle of the planet
uh we sent this in the conventional
orientation
we find amusing to turn this and some of
the other images upside down and look at
it you'll see why when you see the image
we have two two channels one is a
temperature channel and one is a search
for water the temperature channel was
truly dramatic and we have very good
coverage of both the g and the k
fragments
after having looked at the g fragment
then we decided to
to set up the investigation a little
differently uh
for the k fragment we concentrated
almost exclusively on the temperature we
wanted to make sure that we pinned that
down very precisely and we have
even even better data for the k fragment
the
going from the pre-crash signal level to
the peak of the fireball it went up by a
factor 25 so it was absolutely stunning
and you know since we have some spatial
resolution
you can see all of all of jupiter
jupiter at once and then in the the limb
of jupiter where the fireball was it's
like seeing a supernova go off or a star
go off the main reason for using the
kuiper airborne observatory is that um
you're flying above
99.9 percent of the water vapor in the
earth's atmosphere and you're above just
80 percent of the total atmosphere
our key thermometer is the methane
molecule which is present in the earth's
atmosphere
by flying at 41 000 feet
this opens up a window where we can
measure very strong methane features on
jupiter that
are not measurable from ground-based
telescopes
for more information about the nasa sti
program please write to the nasa center
for aerospace information or call us at
301 621-0390
you