good evening welcome to the space
telescope science institute in baltimore
i'm don savage public affairs officer
for nasa's office of space science this
evening we're pleased to announce the
start of a week-long campaign of
observations
of the impact of periodic comet
shoemaker levy 9 with jupiter the impact
of the first fragment occurred earlier
this afternoon at about 3 54 and
scientists around the world
participating in the nasa national
science foundation observing campaign as
well as virtually every other telescope
and observatory around the world have
been watching
that included of course the hubble space
telescope which is where we are located
here at the institute an image of the
area of jupiter which the fragment hit
will be ready by about 10 o'clock
tonight and at that time dr heidi hamill
will provide the image and we'll discuss
what you can tell from the early
analysis of the data
now i'd like to introduce our panel the
discoverers and of course the namesake
of the comet from my left
dr eugene shoemaker floral
lowell observatory
he's a research professor at north
arizona university in flagstaff and
scientist emeritus at the u.s geological
survey
to his left dr carolyn shoemaker his
wife also a staff member of lowell
observatory and research professor at
north arizona university and a volunteer
scientist at the u.s geological survey
and on the far left david levy amateur
astronomer and author and he's
discovered 21 comets and and in 1984
eight in his own backyard and 13 with
working with gene and carolyn shoemaker
and mount polymer
dr shoemaker
thanks don
well it's a
great great pleasure to be with you this
evening
we're here to
start the reporting on like on a
campaign that's been
16 months in preparation
since the discovery of the comet we were
very fortunate to be able to discover
this comet far enough ahead of time
that astronomers around the world could
actually plan carefully
an observing campaign get their
observing requests into observatories
and of course a campaign
has been carried out is being carried
out with a hubble space telescope
which is guided from here uh
as the staff the planning is done from
here
and the hubble has been very important
actually in obtaining some of our best
images of the comet over the course of
the past year actually starting july
year ago and i think we're very lucky of
course to have the new improved optics
on hubble which are going to prove their
worth tonight and through the rest of
this week
not only have been have observers been
preparing
but there have been several teams
of
theorists around the world mostly in the
u.s who worked very hard to try to
predict what the effects of the impacts
of the comet fragments would be
i and what i i want to show you very
briefly is what i regard as the
as the latest and best prediction
for the eruptive plume that will be
formed by an individual comet nucleus of
a kilometer diameter
plunging into the atmosphere of jupiter
45 degrees
the work i'm going to show you actually
has just been completed it's a team
effort primarily carried out by paul
hashig that titan research corporation
who's a close colleague of ours my
colleague david levy david roddy
i have two davids in my life
david roddy was my first graduate
student and as a colleague of mine at
the usgs
and andrew ingersoll who's a professor
at caltech
and i think that we we have probably the
best simulation
on the computer of a plume that will
erupt
from beneath the cloud tops if we can
now roll
the
the images we're starting and we're
going to go this is one and a half
minutes
if we can keep rolling
this is two minutes
and and the plume is growing this is now
three minutes
it's rising to a total height of about
700 kilometers this is at four minutes
the color it's getting cold at the top
oops
what happened there
all right
let's continue with the next one i
is that the last one
we don't know where a live signal came
in there
all right i guess that's as far as he
can take the
there we go
the plume gets very cold and then
finally falls back down you may not be
able to see the dimensions in that block
diagram but the plume spreads out
more than two thousand kilometers across
and it rises to a height of nearly a
thousand kilometers at its at its
greatest extent it reaches that greatest
height in about five minutes
now
having done those calculations
it gives me great satisfaction to be
able to tell you that
there have been two reports received at
the university of maryland
uh one from an observing team in
colorado in grenada in spain
headed by tom herbst and six other
astronomers
observing with a 3.5 meter telescope and
observing in the 2.3 micron band that's
an absorption band of methane
so that jupiter becomes very dark in
that band that's the best band to
observe at if you want to see something
bright that's rising above the cloud
tops
and they did in fact detect the plume
at 2 18 universal time
which is 18 minutes essentially after
the predicted time by paul chodos and
don yeomans at jpl for the impact now
remember it took about five minutes for
the plume to reach
its full height and at about that time
the plume actually would be rotated
fairly close to the limb
so i expect that the prediction is ac
the actual impact
probably was about 13 minutes
after the predicted impact but that's
very good because the standard deviation
prediction is eight minutes
uh and so it's about one and a half
standard deviations off the prediction
that's a very good prediction uh from
the astronomical observations
uh so it looks as though it was seen on
the limb of the planet
uh and in fact it was reported the plume
is reported to be brighter than the
satellite eo in the 2.3 micron van
now
we should all take these reports very
carefully and cautiously at this time
they need to be confirmed
by other observers
but i'm very happy to tell you the plume
is also reported to be observed in the
10 micron van by observers again with a
3.6
meter mic telescope at this
site
and and this is uh this is a 10 micron
observation which is also this deep in
the infrared and also
a spectral region in which jupiter is
not too bright to begin with so it's
easier to see the plume there so the
plume independently has been seen
in chile as well as in spain
so this is the moment of truth
we have we have all
speculated and tried to estimate the
sizes of the nuclei
and we've worried if the nuclei were at
the smaller limit which is set actually
by the dynamics the parent body could
not have been much smaller than about
two kilometers so the biggest fragments
if there are single fragments would
likely been only a few hundred meters
across
versus the other possibility the upper
limit was set by observations with the
space telescope last july and then later
this year
allowing uh the individual elijah's
fragments being about three or maybe the
largest four kilometers across
we've assumed maybe the best bet
somewhere in the middle at one kilometer
but now remember we're observing
fragment a
which is one of the small fragments
so i think there's very good news
tonight if these reports are correct
then you can expect a good show for
every telescopic telescopically observed
nucleus we're going to see things and
we're going to learn a lot that's the
good news tonight
let me now turn the podium over to my
wife carolyn we'll talk a little bit
about the discovery
the discovery of comet shoemaker levy 9
was terrifically exciting in march of
1993.
at that time to discover something like
this was completely unbelievable to any
of us
it was a dark and stormy night
to quote a famous phrase but it was a
dark and stormy night on which
this comet was discovered by us and by a
young frenchman philippe benjoya from
nice france
this was discovered in the course of our
normal work
as part of our routine survey
happily it was a field that we were able
to take
in spite of the fact that a storm was
moving in
we took the films for this two nights
before discovery
and at that time we were very grateful
that we were able to take anything we
had had a bad two months of winter
during which we took very few films
so when we were had the chance to take
any films that night and took this
particular pair we were uncommonly lucky
i searched these films two days later
in the my usual way
but maybe i should back up a little and
tell you how does this team work
first of all there's the telescope in
the 18-inch dome which is the oldest
telescope on palomar mountain it is
palomar mountain not mount palomar
this is a an 18-inch schmidt it's a
camera
and we take pairs of films
of one
field by taking pairs of films
of one field i can look at them under a
stereo microscope
and
detect images that appear to float in
three in a 3d effect
the stars lie down nice and flat the
galaxies
lie down nice and flat
asteroids and comets appear to float
it's a wonderful technique
during our night of observing
david
and gene
are usually up on the observing floor
one of them is guiding this telescope
which is open to the sky it's a very
old-fashioned technique that isn't used
much anymore
we actually do see the sky as we observe
one of them is on the telescope
guiding the other one is busy putting
the person on the telescope on the right
field
changing the film going up and down
stairs and then setting up
helping set up the telescope for the
next observation
every four fields they
take
their own turn in
one changes and gets on the telescope
and the other one
does the running up and down the stairs
after about eight fields
i usually develop the films
and after i finish developing the films
i scan
any of those that are dry so that's our
general procedure
but on that dark and stormy night
we were not able to do that sort of
thing we were i was scanning fields
trying to catch up
with what we had already taken and the
others were doing their usual thing
david writes books
gene was busy with office work of some
sort and philippe was also there and
i was trying to be careful if i clear my
throat or cough a little they all snap
to attention and say what have you found
well
that that night i
had just finished my usual litany when
i'm beginning to feel desperate i was at
the at the end of the
coming close to the end of the films
that we had taken
and i turned to david and said
i used to be a person who found comets
and then
that usually helps a little bit and i
started to scan the field that had
jupiter on it
for me that's been a lucky field
i found another comet on a jupiter field
once when i was busy confirming a comet
for another observer on that same field
so i was hopeful that maybe just maybe
something would turn up
and sure enough halfway down after i'd
come across jupiter and after i had seen
jupiter's ghost image on the film
there was a strange looking object
i almost went past and then i said
whoops
i should go back to that and i i moved
the film back
and looked harder and decided that's not
an edge on galaxy because we see
galaxy's face on
turned a little cockeyed
edge on
but this was not an edge on galaxy it
had coma and tail and most importantly
to me it floated
it had to float or i wouldn't have seen
it in my in three dimensions
and so i knew that was a comet i always
have this deep inner feeling when i find
a comet if i have to wonder it isn't
in this case i knew i had a comet but it
was strange looking
it looked like a bar instead of the
usual round halo with an atmosphere or
coma
and a tail
it was a bar with coma
and tail
and i thought that that's not natural
i turned to the others because i always
bring them in
on any discovery as soon as i can
it takes all of us working very hard all
of the time
to make these discoveries and it's their
discovery as much as mine i'm just lucky
enough to have seen it first
but i wanted them to see it right away
and furthermore i wanted them to tell me
why it looked like a bar
i turned and said
i don't know what i've got but it looks
like a squashed comet and they really
snapped too that time
and gene rushed over and looked at it
and looked very puzzled and then david
took his turn and was equally confused
and philippe took his turn he was
interested in part because he had been
studying for his phd in france the break
the not so much the breakup but families
of asteroids which would be caused by
breka
and we were very very
bemused by all this we couldn't imagine
what it was
as as david often says our brains sort
of turn off for a minute we get a rush
of adrenaline and and we were excited
and we thought we found something
unusual
so that was the beginning of this
wonderful event that has led to a
culmination tonight
during this
time that has ensued
we had
a vast amount of surprise and excitement
when we first of all discovered that the
comet
was in orbit about jupiter that was the
first ever
and then a couple of months later when
we discovered that this was a comet that
was going to actually impact jupiter
a first ever a comet scene impacting a
planet that was really exciting
i was a little dismayed i'll have to
admit
i thought
i would never lose a comet in such a
fashion
i was actually going to lose one of my
problems
and that that was
a momentary bit of sadness and then i
thought oh but how exciting
everyone will get to see a comet hit
jupiter
but at that time i had no conception
of all that was going to ensue i had no
conception of how much
all of us stood to learn
about comets about a planet in our solar
system
just from the discovery of this
particular comet
and that to me has been one of the more
exciting things to see people from many
different areas and disciplines of
planetary science and astronomy
bring together come together with their
knowledge work together to get the most
out of this
so that that has been a wonderful thing
and then this afternoon about the time
that i knew that comet was going to
hit jupiter
fragment a i suddenly discovered i had a
real emotional attachment to this comet
during all this time it's been a thing
of great beauty to me out there
the first images i saw after jim scotty
showed us his and after i saw
dave jewett and jane lose images from
hawaii
just
captured my imagination and and that
image has been there ever since and yet
here it was fragment a was going to hit
jupiter
and i'll have to admit i i had a
momentary tear at the
very prospect when i knew that moment
had happened well that's gone
but
just a few hours later than the sudden
news of actually seeing something from
spain and from chile
that's that's terrifically exciting all
i could say was right and
and so
that is one of the
phases
of this whole commentary experience i
think that has been wonderful for all of
us
now i'd like to turn the making over
to david levy who is a
well-known writer
particularly about astronomical things a
lecture
and a very close colleague
thanks carolyn that is a tough act to
follow you just said congratulations
i think the exciting thing about tonight
is that
once in a generation
we get one of those if we're lucky if
we're lucky we get one of those rare
moments
when science
stops for a moment
turns on its ear and gives us something
really really special
in the early 1950s the discovery of dna
did so much to
it was a discovery
and we learned an awful lot but the real
thing that that discovery did was that
everyone who was young at that time
looked at all the news about the
discovery
studied it and they said science is
fabulous you can you can uncover the
mysteries of life
when you get discoveries like this
in 1969 there was the apollo 11 moon
landing almost exactly 25 years ago
that another generation paused for a
moment i remember at a summer camp in
lake placid we had about 160 people
watching a television set about this big
watching the
watching that first small step take
place
and the youngest people in that audience
were
couldn't have been
seven years old
and the entire camp was there
for
four hours and nobody said anything
everybody was
absolutely quiet because
this was we knew that this this was one
of those moments
there have been other moments as well
but i'm really beginning to think that
the impact of a comet on jupiter
can be one such moment a moment with the
power
to
to have science say to the world it's
fun
to study science
nature every now and then throws us a
real
ball that we can shoot out of the park
and i think this is what's happening
here cometary impacts have had enormous
influence on our past
uh it is very likely that they provided
commentary impacts provided the water
that is on the earth right now it is
likely that they provided the building
blocks of life the simple alphabet of
life c-h-o-n carbon hydrogen oxygen and
nitrogen
a comet hitting the earth may be an
asteroid hitting the earth 65 million
years ago
probably led to the demise of more than
70 percent of the species of life on
earth including the dinosaurs
we have seen the results of comet
impacts
i think we being here is one of those
results
we have seen if you go outside and look
at the moon on any clear night with a
pair of binoculars you'll see enough
craters impact craters that gene has
studied in his life
that you will
be able to see that the earth and the
moon have been hit by craters throughout
their history
we've seen all this we understand a
little bit about it what we haven't seen
is an actual impact take place i'll
never forget
may 22nd it was my birthday we were all
at palomar mountain
carolyn is
is
scanning for comments it is actually a
scam that would have proved successful
in the next few hours when she found our
next comment
jean was in the dark room getting ready
for our observing that night and i was
checking the mail to see if there were
any interesting objects that we would
have to observe that night to follow up
new discoveries some things like that
and i logged into the email there were
two circulars from the central bureau
for astronomical telegrams
and
i read the first one and my jaw fell on
the floor
it announced that there was a good
possibility that comet shoemaker levy 9
would be hitting jupiter in july of
1994.
and
i said that i i said
our comet's going to hit jupiter
jean has spent his entire life studying
impacts from his phd thesis to prove
that media crater was the result of an
impact
from the work he did on the apollo
program from the work he's done for the
last 25 the last 15 years
studying not the craters so much as the
objects that sometimes make the craters
the comets and the asteroids
and here he is in the dark room and i
just told him that we're going to see an
impact on jupiter and i heard this
slamming of doors and closing of lids as
he's trying to save the film before he
throws the dark room door open pushes me
out of my computer chair and sits down
looks at my screen and says
i don't believe it we are going to see
an
impact and
since may 22nd of last year it has been
just one excitement after another
this is not a comet just for the
professional scientists this is
everybody's comment
we've heard a lot that you're not going
to see anything with the small telescope
that you buy at a store or that you
build yourself
that's true
you're not going to see jupiter
show major changes from this impact but
you don't have to
that's why we have a fabulous hubble
space telescope that's why we have the
large telescopes on the ground and
that's why we have television to
transmit those pictures to everybody
what we do have to do
is to go outside with small telescopes
binoculars and just look up at jupiter
with a pair of binoculars you can mount
it well against the wall of a building
you're going to see the moons of jupiter
revolve around that planet
not in one night but if you look every
night you'll see them in different
positions just like galileo did in 1610.
with a small telescope you're going to
see the bands of cloud around jupiter
that that are part of jupiter's
atmosphere the bigger the telescope is
the more of those details you'll get
the important thing is if you make those
simple observations
even if you have no pair of binoculars
just go out and look at jupiter each
night you'll see it move slightly
relative to the stars
these are observations anybody can make
without any telescope anything
to just look at jupiter it's high in the
southwestern sky these evenings
very bright the brightest star in that
area star the brightest planet
in that area the brightest object in the
sky in that part of the sky
and
this way everybody can be a part of this
event you'll be able to look up a
jupiter and say i saw jupiter the week
the comet hit and then you come inside
see the results on hubble space
telescope later on
the galileo spacecraft
we are so extremely lucky
that the impact which might take place
once a century it might take place once
in a thousand years
it's rare
but with something taking place that
infrequently it could have happened last
year it could have happened 15 months
ago if it had happened last year galileo
was far too was not in the right
position to observe it we would have
seen nothing
if it had happened
two years ago if it had happened just
maybe
last november we wouldn't have seen as
much as we're getting now
it's happening tonight
we have a fully repaired and healthy
hubble space telescope
which has been performing like a jewel
in the last few months the galileo
spacecraft despite the antenna is
producing fabulous discoveries the moon
on the asteroid ida the moon circling
ida is one of them
this is a time
when
we can really look back and say
the 25th anniversary of the moon landing
is a real time to celebrate because we
have such good instruments
to observe the most fantastic event that
we've had in a long time
this is an event i think that has the
power to generate a whole lot of
interest in science among people
especially young people
people have asked me more than any other
question
what will this event do to us on earth
and i start by saying absolutely no
effect on earth jupiter is 500 million
miles from here don't worry about it and
then i think about it for a minute i
hope this event has a powerful effect on
earth
i hope this event will make people think
that the sky
is a wonderful user-friendly place to to
watch
and that science is not just done by
professional scientists science is fun
it is alive
it is telling us things that are
important in the here and now
if
sl9s crash into jupiter does that i
think it would really have made the best
contribution of all
and now dawn
thank you i'd like to open up now to
question an audience questions and
answers from the audience here and then
we'll take a q a from the nasa centers
uh i would like for reporters to please
wait for the microphone to get to you
and then state your name and affiliation
take one in the front row
i think it is a little bit too early to
ask you about this but how deep was the
collision and the what was the uh how
the energy energy looked like and
from
this
uh to result uh what's this
comet look like it's look like asteroid
oh it's look like a snowball or
something can i ask your estimate i
guess you asked me several questions
the first question was how deep did the
comet penetrate into the atmosphere of
jupiter well of course we don't know
that yet for nucleus a
for the simulation that i showed you
this was for a one kilometer diameter
uh body with the density of ice
and it was
essentially uh decided
using what knowledge we have of the
fragility
of of the comet when it broke up
that
you know we would have it come apart
at 31 kilometers below the cloud tops
that's a somewhat arbitrary decision but
we think it's fairly representative
but we did let the comet go right
through and stay intact
punching a tunnel into the atmosphere on
the computer of course
and then it and then it comes apart and
dumps its energy and creates a very hot
fireball that expands and then rises
buoyantly if you were to watch the
evolution of the plume part of it does
shoot back out along the tunnel but most
of it just rises buoyantly and just
bursts right out above the cloud tops
so i think that's the answer to the
first question now the second question
was
is this more like an asteroid or
a listener
or maybe you're asking is it a single
solid object or is it an accumulation of
many smaller pieces is that is that your
question
that's still the 64 dollar question
uh there are two very important reports
one has just been published in nature
and the second one has been submitted
by an author who's here in this room i
think
i don't see him just this moment
both showing that you can explain
the number of objects that we see in the
string of pearls
if the original parent body was simply a
loose agglomeration of many many smaller
bodies
and it and theoretically it turns out
you should get just about 20 pieces
when it breaks up and then and then
20 individual clumps but each clump
itself is made of many smaller pieces
uh this is this looks like a very
reasonable proposition
and
in fact
is redick here
i don't see him at the moment he's here
at the space shuttle science institute
and the other and the other authors are
by ashfog and bentz who published in
nature
i think it's a very
very persuading argument
in fact i would venture to say that a
general view of comets is in in the
process of shift i think we're going to
see a paradigm shift
from the point of view where people have
been thinking of comets as sort of one
big dirty snowball
to really just a collection of finer
debris just loosely held by gravity
uh i think a lot of people are now
starting to think very much in that
direction and the evidence is coming of
course from the breakup of periodic
comments shoemaker leaving
for reuters
have any of you seen any images of the
impact site
if you have what were you looking for
and what did you see have you seen
anything from hubble yet if you haven't
when are you going to see it
well let me answer for the for the team
uh stick around till 10.
we've not seen the images yet
they're coming down and heidi hamill
will report on that
uh in about two hours
one one quick follow-up what will you be
looking for when you see these images i
know you have that model that you showed
us
but
what what are you going to be looking
most assiduously for when you see those
images from hubble
a new spot
on on jupiter and in fact i don't know
if i mentioned it
the the intensity of the brightness of
the spot as reported
from color alto and granada
was greater than the brightness of eu
in the 2.3 micron van
uh where i hope very much that the
hubble images that are going to be seen
later tonight will actually define the
dimensions and the brightness of that
spot in various wavelengths very well so
this is very exciting stay tuned none of
us up here have seen those images yet
see could you uh put your mic down just
a little bit
okay question romero from sky and
telescope
uh brian marsden recently mentioned that
he thought that such impacts probably
happened the order of decades
given the uh this recent observation of
this small fragment
do you think that that's possible that
such a feature would go unnoticed
do you want to answer david
it's hard to say i haven't i haven't
seen
based on a previous question i i i
haven't seen the pictures yet based on
the descriptions
uh that we've read
it's looking really
like fragment a fragment a is one of the
smaller fragments one of the smallest
ones
and its importance is only in that it's
the first one and
if it has really produced so far based
on ground-based images what what it what
it seems to have produced it's looking
like these the original comet would have
been closer to the larger
size the larger end closer to that
10 kilometer diameter for the original
body it's still too early to say that
for sure but if that's the case then i
would suggest
that this would be a much rarer event
than that maybe once every several
hundred maybe a thousand years what do
you think my best guess is if the
precursor were 10 kilometers across and
the fact that we're seeing such a bright
spot if these reports are correct i have
to be a caveat there we have to get
that's a big yes
these reports are correct and i think
the 10 kilometer size as david says
looks reasonable and my guess is that
you don't get a hit by a 10 kilometer
object more frequently than about once a
thousand years i think we may be
privileged to witness one of those very
rare events in australia and there's
there's something else though um this is
the second act of the two-act play well
it's the second activist play that is at
least 2x so far
this is the number this is the frequency
for just an impact
what is the frequency for the comet to
do this weird celestial dance around
jupiter breaking up two years before
impact brightening up so that it could
be discovered and we could plan for this
thing
would how do we factor that into the
equation that makes it still more rare
i i think there's one other factor and
that is that you could have an event
like that on jupiter but if no one is
looking
you're not going to see it
jupiter is not always the center of
attention
and
and on what last one looks
at the right time
you might you might you saw the
simulation
that dies down fairly quickly you might
not notice another white spot very soon
but this is prim this is a little
premature we haven't we haven't seen the
data from hubble space telescope
we're basing this on two initial reports
and they're reliable reports
but it's it's there's that big caveat we
want to see more we all want to see more
uh but it's looking pretty good right
now that we're seeing a rare rare event
i just make one other comment steve and
that is that you know i think martin was
arguing simply from a probabilistic
standpoint you know what are the odds
that we would be lucky enough like tycho
to see
the once per millennium uh supernova uh
the odds uh priori odds are this that
we're if we're going to see something at
all it's much more frequent
and
and that would be consistent with the
impact of say something
like a one or two kilometer body
or a parent body rather than a 10
kilometer
size
since jupiter
name and affiliation oh sorry uh linda
howe uh chancellor communications
philadelphia since jupiter is a planet
that is largely made of hydrogen gas
what prevents the large plume explosions
from spreading planet wide
well i can try that
hydrogen as as we know is very flammable
but you need oxygen
to uh to keep the combustion going and
jupiter the hydrogen is just there all
by itself just sitting there very cold
and it says inert as
stale bread
as
so i don't think
i
as far as another question related to
yours
because so many people watch 2010 these
days
these comets are far too small
by many orders of magnitude
to start any nuclear fusion from taking
place inside jupiter that's not what
this is about at all
um jupiter is not going to catch on fire
there's no oxygen to support that did i
do okay
i'm not was that the sense of your
question
well
any kind of explo it could be either way
i wasn't thinking necessarily of a
nuclear explosion like a sun but just
what would keep the hydrogen from
continuing to explode and explode if
they are
going to be massive as you've
demonstrated here why wouldn't it just
keep
exploding with more and more hydrogen
bear in mind what's happening it's not
that the hydrogen is burning or
that sort of thing it's just that a
tremendous amount of energy
is dumped into the atmosphere of jupiter
by a very strong shock wave
which heats the atmosphere up to several
tens of
thousands of degrees kelvin
so it's exceedingly hot in
in a very small region that's simply
because you have a body coming in at 60
kilometers per second in a very short
distance releases all of its kinetic
energy
uh so all you're really doing is just
you're point heating almost the
atmosphere
and what causes the eruption the plume
is that that just expands
and and becomes a buoyant bubble that
blows out the top
second option
shoemaker glenda chu from the san jose
mercury news i wonder if you could
repeat the bit of news that you had this
evening about the two observatories that
actually think they have spotted plumes
where are those and what are the names
of them and if you could spell them it'd
be all for the better
and and the names of the scientists were
in charge there i could give those to
you yes
the first report that was received was
from calar alto which is in granada
spain c-a-l-a-r
second word a-l-t-o
the observers were tom herbst
h-e-r-b-s-t
doug hamilton
jose ortiz
hermann
buhart
i have it down as b o e h h a b o yes b
o e h h a r d t i hope i transcribed it
correctly
uh carl heinz mandel
c-i-r-l-h-e-i-n-z
mandel m-a-n-d-e-l
and alex fiedler
and that's for they are observing at
calar alto spain
the second report this is from a 3.5
meter telescope it's a big telescope
the second report is from the nordic
optical telescope at la cia
chile
the report was relayed on by richard
west
of the european southern observatory but
i do not have information on who the
actual observers were
i'm sure that that will become public
very soon
two words l-a-n-s-i-l-l-a
pardon me
the time reported from calar alto the
plume was observed at
20 hours 18 minutes universal time
versus a predicted impact time
of 20 hours even
by
the
jpl team of paul chodes and don yumans
that means that the uh the predictions
from chodes and yeomans were really very
they're very good extremely uh take one
more question from here go to one of the
centers and then come back
it's an uh nhk
um at ten o'clock we're expecting images
in the visible light range from hubble
and uh we're curious about some of the
other uh areas that have been explored
in terms of the spectrum
have you heard of reports from uh
in the infrared range ultraviolet
uh even perhaps
in the radio telescope areas as well
there has been a report that's come over
the news wires from japan
uh
let's see miles here
don't see it
this is a report uh by the japanese
observer not familiar to me in the radio
region
reporting and and it's not specified as
to the wavelength region
that the radio emission from jupiter
this is already before the impact of
fragment a it's about a day ago
it increased by a factor between 10 and
100. but we i've not seen any details on
that so that's the only thing i know of
in the radio region
i expect we're going to see a lot of
reports coming in in the next 24 hours
from radio observers i'll be very
surprised if we don't see discrete
pulses from these impact events that's
all i know of at the present time so
actually we only knew of these things a
couple of hours ago so
it's all very fresh
i'd like to go to uh
me please we're going to have to take a
question from the johnson space center
now and we will come back to four more
questions here in a moment
johnson are you online
name an affiliation please this is
this is dan feldstein from the houston
post
and i was wondering uh you've heard the
two
reports that they have seen a plume
i was wondering have you heard from
people who were looking and did not see
anything
and have you gotten many of those or
could you characterize how many folks
called in and said i didn't see anything
i've only heard about fourth hand that
people have tried to observe in the
visible region of spectrum without
success but i have no re no real reason
to believe that that's strongly
uh
based i just don't know yeah we we just
checked the email just before coming
here and there didn't seem the only two
reports we got were those two positive
ones we did not get any negative
any negative ones i know that some of
the sites did report that they were
cloudy
but we i haven't received any other
reports
we'll uh take one question from jet
propulsion laboratory in california go
ahead please name an affiliation
uh this is robert lee host of the los
angeles times i wonder if you could tell
us based on the sketchy preliminary
observations that you've had reports on
whether the plumes that were observed
bear any resemblance to
that interesting simulation you just ran
for us
well my interpretation and this is
really you have to be very careful now
because we're working with very little
information
uh but in order for the plume to be seen
at all
it has to be in fact at the time given
it would be very near the limb
and
i think it would
he would be very consistent with the
simulation that i showed
to have a plume rising
up to about a thousand kilometers above
the limb
to be visible and to be as bright as it
was reported but we've got to see lots
more
you know follow up at jpl then we'll
come back here to this telescope
institute
am i up
go ahead yep this is alan mayerson from
national geographic magazine dr
schumacher you mentioned that article by
willie benz in nature
and the article said that um you know
that the comment wasn't supposed to be
one
um solid body but many fragments and i
just wonder whether or not the fact that
there have been two
two confirmations of the of the plume is
consistent with that theory that is to
say that
i thought the fact that if the comet
were made up of many smaller parts that
it would have just uh dissipated in the
atmosphere and not created a plume like
that
well that was a conclusion
drawn by paul weissman in a commentary
on the article by askfog and benz
predicting the great fizzle
uh and if the reports that we've
received from spain and chile are
correct
it's not a great fizzle
so
you have to remember that
this the
work by asphalt and benz does not say
whether
the p the small pieces are successfully
all re-aggregated into sort of
essentially one clump for each nucleus
or whether they're spread out
but i would i think that
the plume is reported as certainly
consistent with these smaller pieces
re-aggregating in into one clump that's
what effectively hits the top of the
atmosphere
one thing i would say is that
we if we should see these things at all
that it probably indicates we're dealing
with larger objects than was re then was
concluded by us fog and benz and i think
we may have some up-to-date information
i'd like to introduce dr heidi hamill
eugene schumacher said he would be
personally astonished if we saw nothing
well
or if we didn't see something
well he's not going to be astonished
we actually saw some amazing things
we
we just downloaded the first two orbits
in the first orbit
we were able to see a plume on the edge
of the planet
in the second orbit which i have a raw
laser printer output this is as raw as
it gets
we can actually see the impact site
itself and i'll remind you this is for a
the first one not the brightest one
so we're going to have a really exciting
week
so more details to come we just got this
data down we haven't had a chance to do
anything with it and i'll be talking
with you at 10 o'clock about what we
have actually seen in the larger data
set
what's the wavelength heidi this is a
methane filter at 8.89 do you want a
pencil or pen or something yes
i don't even have a piece of cardboard
to have this mounted on
okay we just blew up a section of the
planet this is the southern pole here
you see there's a little there's a
bright streak
see that bright streak and around the
edge of the street there's some other
stuff
tell you more about the stuff tonight
i think we may have some more questions
here
wow
like a comment
well i think you can all lay your
worries to rest those reports from spain
and chile are right
and i think i think that we
i'll personally bet another case of
champagne with brian marsden that we've
got big objects those are not puny not
not to show that
to see the effects that we're seeing you
have to put a lot of energy into the
atmosphere so i i think we're very very
privileged tonight
to see an event that's that's not once
in a lifetime
it's it's once in a millennium i think
though that brian's
de bruyne marsden's efforts to
to come out on the smaller size
were great because we have had
experiences where there's been a lot of
hype for something and then it turns out
to be not what we're expecting
we've never seen this before this is
totally new ground this is a totally new
kind of thing in science that we're
witnessing tonight
and
brian
brian's argument made a lot of sense it
certainly made a lot of sense to me we
didn't buy it but it it made a lot of
sense
and um
i would imagine right now that brian's
as excited as the rest of us
at what is happening
this is this is a wonderful time for
everybody i think i i'd like to second
that david i think brian wanted to be on
the air on the cautious side
not to build up expectations too high
uh and i think that that was a wise
course of action on his part in his role
as the director of the cbat the central
bureau for astronomical telegrams that
was the right course of action for him
uh and of course he was betting on
statistics and we beat the statistics
yeah we beat the odds
estimate of the minimum diameter
guesstimate of the minimum diameter of
fragment a yet
could you
of the single object or of the whole
original object fragment a the one that
that uh
hubble just took that uh impact image i
would guess just from the relative
brightness
and the limits that were placed earlier
by the very careful work of hal weaver
uh that we're looking at an object that
is of the order of a kilometer in
diameter that's its real diameter
and the bigger objects are really bigger
and the original object was really about
10 kilometers
by the way 10 kilometer object is um not
quite as large as about maybe what about
two-thirds the size of halvey's comet so
no that is the size of halley's the mean
diameter halley's comet is ten
kilometers all right so we're talking
about an object about the size of
howie's comet if uh this object were
near the earth it would be big and not
anymore but it would be big and bright
with a with a tail and everything um
this is a
big looks like this is a big object
you just explain a bit why the uh why
the radio wave uh
would have increased as a report from
japan yesterday why why would that
happen with this
frankly i don't think anyone made that
prediction
we don't have a model
i i maybe some people are inventing them
right now i'll bet alex destler is
working on three or four models
but
you know
what we were going to see in the radio
wave region was a grab bag people are
going to be looking but really not
knowing how to predict it theoretically
time for just one or two more questions
down here
glenda chu from the san jose mercury
news i wonder if the fact that these
impacts seem to be occurring maybe 13
minutes later than predicted is also
good news in the sense that they they
must be occurring closer to where you
all can see them
and uh did you know how if they are 13
minutes
um later than than thought how far away
from
rotating into our view are they then it
doesn't change the actual impact point
relative to our line of sight by very
much
uh it just it just means the comet's
coming a little bit later on its
trajectory but it won't shift it by very
much
yeah another thing about the sizes if
this um if it turns out that we're that
everyone's right and that this is close
to a 10 kilometer object i really want
to mention dennick sekinina paul chodas
and don yeomans at jpl
that have been saying all along that
their
models show a large a large
um a large comet before breakup not two
years ago so if this turns out to be
true this is a real mathematical victory
for them
question on the back miles o'brien with
cnn i know from over here i know from
speaking to you all this past week uh
that you had uh a fair amount of anxiety
about what might happen tonight give us
a sense of how much relief
uh this just recent announcement gives
you miles would you like to have some
fun campaign here with us
you probably can't tell that we're very
happy
it's a champagne
experience
we uh i i'm absolutely thrilled to
pieces
it's a it's it's it's such a rare night
when
nature calls you on the phone and says
i'm going to drop 20 comets into jupiter
at 138 miles an hour all i want you to
do is watch and i'm not going to tell
you what's going to happen in advance
just watch we are watching with
everything we've got tonight and nature
winked at us it's exciting
you can imagine that we've all worried
about the kahutek effect
and wondering whether we would all
whether we'd have to slink off and hide
under a flat rock somewhere
i think the answer is we're not going to
have to hide under a flat rock
see your your wildest expectations
yes but not our wildest hopes
we have uh
two more minutes to go we take a
question up here in front uh here we go
right
name affiliation please yeah paul reese
with ap uh if this is one of the
smallest what is the largest and when
you expect it to hit
good question
some of the largest fragments are g
h and k
and i think you have a press kit don
don't you that it has all of the times i
hate to give you i don't have a table in
front of me available they are available
uh
in the press case and the g h will be
coming down a couple of days
and kay
thank you thanks there's hal weaver the
one i'm personally excited about is q uh
that's the the uh president of the gang
of four the former gang of four one of
them kind of faded out
um
and another one split so we still have a
gang of four that happens on july 20th
which is the 25th anniversary of the
moon landing it's a very complex group
of fragments and they're all going to be
hitting within a very short time
i think we ought to recognize hal weaver
who's standing right back there and
spoke up hal is the one that made the
estimates
are from the hubble images a year ago in
july and came out with these estimates
of of the the largest nine being about
three kilometers maybe the very biggest
four and i think he ought to be feeling
pretty high tonight i hope he's got a
whole bottle of champagne with himself
i'm free we've run out of time uh right
now for question and answer and the
shoemakers have another engagement they
have to we're going to run down and
watch the impact of fragment b at the
naval observatory right now
we will have
our panel again tomorrow morning at 10
o'clock at the goddard space center and
also we'll have some updates later this
evening at 10 pm with heidi hamill and
the other science team members if you
would care to join us for that 10
o'clock tonight eastern thank you very
much
you