I think it should have started 10 minutes ago.

Started......


Hubble images: http://hubblesite.org/newscenter/newsdesk/...leases/2005/17/

It should start at any time now. They're having some technical problems (!).

Arggghhhhh!! Maybe not.

WOOOHOOO!!!

Wow, more hits than Cassini and MER combined!

That's huge....

Here's a blog from Planetary Society for those who can't watch the conference.

Someone did a nice animation on web:

http://planetary.org/deepimpact/images/enc...ation-small.gif

Still image from impactor. Impact point is in center of photo

Did anyone get the reaction of the Deep Impact Team on file?

I missed it. I work nights.



I really would love to see this.

Before and after by Hubble

http://deepimpact.jpl.nasa.gov/gallery/jpg...esses_Crash.jpg

I heard the rep from ESA say that Rosetta was also watching the impact so they could fine-tune their comet encounter 10 years from now.

The untold story: Rosetta actually impacted Tempel 1 last night, too...but it is going to take ESA 10 years to release the images!

There is an QT movie that shows most approach so far: http://www.nasa.gov/mission_pages/deepimpa...a/pia02125.html

But it's diificult to compare the surface of comet when final approach comes close. I treid to make a frame set that shows marks from frame to frame. In fact there are two main sequences that fit and two frames which do not. The order is the same as in the movie.

http://www.greuti.ch/deepimpact/Tempel1_ap...ch_impactor.jpg

It may be that it started to tumble / wobble with impacting in the last few seconsd perhaps?

Doug

The hubble image posted earlier has been updated with an image taken in 7:20 UT, where the debris cloud has expanded much larger:

http://hubblesite.org/newscenter/newsdesk/...leases/2005/17/

It may be possible. I got the impression that it was bombarded pretty heavily before the impact.

WOW, thanks for that sheet correlating features. I'm still trying to rap my head around this topography. They are definitely not craters. Given the scarps nature (with circular extentions), the seem most consistent with sapping, which makes perfect sense for a comet if these are the sites were jets form.

http://pirlwww.lpl.arizona.edu/~perry/images/impact_site.jpg

I want to thank tman for his work on trying to track the motion of the impactor. I have taken two of his frames, one from early on and the second to last frame, to show the motion. I have identified the location of the second to last frame in the fourth from the beginning. This shows that the nucleus rotated under the impactor so that the sub-spacecraft point moved from lower right to upper left, from those two bright deposits to the low scarp at upper left. Some of the motion I see is definitely from lower right to upper left, on average, but there are a few deviations. Still, very odd frost deposits, definitely suggesting that we will find fresher ice beneath this dark surface layer (a la Phoebe).

wow, you found likely the right impact spot! I agree with it! Never thought that it's so far on the left.

Additionally we have to consider the shape of the comet that was "hanging over" for the impactor.

Click to view attachment
Looks Like your spot on.
I overlayed the closeup with the image taken further up.
They line up exactly.

In fact the last one seems to fit in too here.
This is very rough. But you get the idea.

Any takers....?

Edit: Although looking again....not too sure

Cool animations!


This is a great press conference!

1600GMT Press Conf Highlights

Web Hits : Last 24 hrs 1 billion hits. 2.5X that of busiest day for MER

Flyby Spacecraft in Great Shape - amazing picture post-shield mode, plume looks as large as the whole comet

Pre-Release targetting was a few km off to the left. Post ITM1 was way below the comet, Post ITM2 was just left of centre, and ITM3 just below and to the right of it.

New result : Map of temp of the Neuc pre-impact. Sub-solar part is warmest (obviously)

Ejecta/Outgassing coming out for several hours after impact.

Lots of topographic relief - things that really do look like impact craters.

Bright spots, mostly just steep sun-facing slopes - a couple are not. Almost certainly there is layering, jets coming from somewhere they hope to trace

Two circular features were refered to as craters

Sequence of videos - shadow caused by ejecta

Processed HRI imagery movie of impact - not THAT much better than the MRI movie

Height of ejecta on lookback image (at about 27,000km) 1000's of Km's height to ejecta. Mainly dust

Not 100% sure if they can actually see the crater - they have a 'feature' that may be the crater.

Approx 160kg useable fuel onboard flyby. Do not have specific extended mission plan currently, will probably mothball the spacecraft in a few weeks. (I assume to pick it up again in the future)

Further simualted impacts at the ames canon.

'Dual-ish' plume, i.e. one narrow straight-out plume, then a wider plume to follow. Happens when the impactor goes into the surface ( a soft layer ) then goes kerpow.



Doug

Are raw images available yet?

Found a couple more matches in Tman's image

Looks like you found a much better match alan.

It doesn't look like there are any plans for an extended mission.

........also I wonder if the focus problem with the HI camera has had a more serious efect on the science than anticipated.

I loved the animated sequence showing the crater formation and the 'jet' it caused. I can't wait to see some of the other processing in the next few days.

I wonder if the new jet has changed the trajectory at all (you would think it would have to have). I've seen several places where people have expressed concern that they will have knocked the comet into an Earth collision course. I find it interesting that people think Nasa would even consider attempting doing something like that. I mean, the first thing they probably looked at was "will this endanger the Earth in any way?" There will always be the Chicken Littles I guess.

Well, the 'electrical comet' people will have reassess their theories, I didn't see any lightening bolts leaping off the surface toward the copper impactor.

I'm sure there will be some adjustments necessary to mainstream comet structure ideas too though...don't think they expected the craters.

Eric P / MizarKey

I'm still finding it hard to believe think of those circular features as craters, the shadows are all wrong, but I'll reserve judgement. The circular feature at left in this image:

http://pirlwww.lpl.arizona.edu/~perry/images/impact48.jpg

maybe a crater though

Here I've tinkered with the brightness to see the terminator area better.

Click to view attachment

A lovely new world! Despite what A'Hearn said I think this is quite a lot like Borrelly in many respects - but we see it a lot better. It's VERY different from the weird Comet Wild-2, with its amazing spiky hills and scarps. The top is rotating towards us, meaning cometary north is to the right (the new IAU definition of north on objects like these).

Note how the two smooth patches give the appearance of lying in the the central portions of broad shallow depressions. A proper shape model will be made later, so I hope it confirms this. Despite VP's comments, I don't have a problem interpreting the circular features as impact craters, though presumably if the artificial impact tells us anything it should be that natural impacts will trigger venting and the crater will evolve rapidly. But the dark shading VP mentions looks to me like the outer part of the rim on one side, and the inner part of the rim on the opposite side... it looks OK as a crater to me. Well, we'll see... I have my opinions, but I've been wrong before. (just ask my kids!)

Phil

Let me get this straight: they're not sure if they see the crater? The whole point of the mission was to look inside the crater to see the interior of the nucleus! Don't get me wrong, the nucleus photos are great and the impact photos are absolutely spectacular, but what about the science?

I don't think it's that bad- the main way they planned to see what was in the crater was to watch that stuff being blasted out into space, rather than look at what was left behind in the hole- they will have lots of data on what's inside the comet. But seeing the crater would tell a great deal about the strength of the nucleus and about impacts in general. If they can't see the crater through the the plume, it will be a disappointment, but not a disaster.

I see. I thought they wanted to see the layers of the interior of the comet in cross-section. Although it seems like the majority of the imaged are still being downlinked.

Trying to make sure I understand the geometry of the image: in the lookback image, the really bright spot is the sun, right? (As opposed to the plume from the impact)

I though we would get better lookback images for mapping.

MiniTES, the brightest spot in the lookback image is the plume. The illuminated part of the nucleus shows the general direction to the sun, but it's far off to the side. The plume looks extra-bright in forward-scattered light.

Phil

Actually, the scientific seriousness of the HRI focusing problem has been greatly diminished by the other problem: the fact that the ejecta cloud utterly hid the impactor crater. When you read A'Hearn's and Belton's original article setting forth the science rationale for this mission ( http://deepimpact.jpl.nasa.gov/science/cospar-ms.pdf ) , they DO emphasize looking for layering in the crater walls as one of its most important justifications -- and it's precisely for that reason that they wanted such a very high-powered HRI with a top resolution of "1 meter/pixel", since the layering structure may well be that fine.

Well, of course, the obscuring ejecta cloud has totally ruined that scientific goal for the mission, and would have in any case. And since the Impactor Camera imaged the approach side of Tempel every bit as well as a perfectly focused HRI would have (its resolution and viewfield at 140 km distance was the same as the HRI's at its own minimum distance of 700 km, and at that point the Impactor Camera was still totally non-sandblasted), virtually the only thing we ended up actually losing from the HRI problem was somewhat sharper photos of the OTHER side of the nucleus. Moreover, when you compare the deconvoluted HRI photos of the impact itself with those from the MRI ( http://www.nasa.gov/mission_pages/deepimpa...a/pia02123.html and http://www.nasa.gov/mission_pages/deepimpa...a/PIA02131.html ), it's clear that deconvolution -- even if it didn't completely solve the HRI problem -- has still allowed the creation of photos maybe 3 times sharper than those from the MRI (as opposed to the originally hoped-for 5 times).

But that ejecta cloud -- whose power to blot out the impact crater was always a very strong possibility, even if it hadn't been remotely as big as it actually turned out to be -- raises the question: just how good, really, was the science rationale for this mission? (Hawaii's Jeffrey Bell, playing his usual role as the Skeleton at the Feast, has been raising this point in E-mails to me for years.) It's now clear that, if we really wanted to study the comet's surface layering, it might have been a far more dependable technique to simply put a radar sounder on the craft -- which would also have covered a vastly wider area on the surface, perhaps incuding sites of activity, and could have been used on more than one comet. (The sounder's antenna could have been put in the "shadow zone" protected by the craft's forward dust shield.) Moreover, by eliminating the great mass and cost of the Impactor, we could also easily have added gas and dust-impact mass spectrometers a la CONTOUR and Stardust. In short, this mission -- for less cost -- could have instead been a vastly improved version of the multi-comet CONTOUR mission. Just about the only thing we actually got out of Deep Impact that such an alternative mission couldn't have provided was the data the impact may have provided on the chemical composition of really deeply buried subsurface ices -- and was this enough to compensate for the other stuff we passed up?

This returns me to something I've wondered about for years: just how did Deep Impact actually get selected? Its selection was a total surprise to me; it muscled ahead of other Discovery finalists -- Aladdin, and a VESAT or VESPER Venus orbiter -- which were not only finalists this time but had been during the previous selection, too (which D.I. never had been). Is it possible that Dan Goldin intervened and ordered the selection of Deep Impact as yet another of his harebrained NASA PR stunts with questionable science return (Mars Pathfinder, with its cute but scientifically mediocre rover and not-very-efficient airbag system; the cancelled 2003 miniature Mars Airplane; the proposed all-girl Shuttle flight; the cancellation of a sensible 2003 Pluto probe in favor of a far more difficult and technically sophisticated early Europa Orbiter, with the highly predictable result thaat we got neither)? I already know that NASA HQ virtually ordered the selection of Phoenix in the supposedly "independent" 2007 Mars Scout selection; we were explicitly told so at the first Mars Roadmap meeting.

Were the images taken after impact monochrome or multispectral? If multispectral, there a chance that anything "behind" the cloud might be pulled out. Actually, depending on opacity, this might happen with monochrome images too.

Bruce: You bring up some interesting points. However, one thing to note about Deep Impact is that the media coverage of it, at least in online sources, is about as good as anything I've seen on an unmanned mission, and probably better, and I fully expect to see photos of impact on the front page of every major newspaper tomorrow morning. The explosion and the July 4th impact seems to really provide instant gratification for those who don't like waiting for all that boring science to come out of these missions. After all, why wait a week or two to wait for the data to be downlinked and some extremely basic conclusions made about the comet when you can ask questions about tunnels on the nucleus today?

That said, I think there is some valuable science here. We will have some good information on the interior makeup of the comet if the spectroscopy goes well, and we already have some good images. And you must admit that whatever their scientific value may be, those impact images are jaw-dropping. Usually you only see stuff like that in artists' conceptions! Bruce, do you know if the July 4th date was chosen intentionally or "ordered" by our good friend Mr. Goldin?

To Ted: both the HRI and MRI images were multispectral -- but as yet, I don't have the wavelengths or even the number of filters. I'll continue digging. (There is a good simulation of what they were hoping for from the HRI, when it came to observing layers in the imact crater walls, at http://deepimpact.jpl.nasa.gov/tech/hri.html .)

I think there are six colors in the MRI filter wheel, if I recollect an article in the Planetary Report correctly.

Edit: This source gives nine colors for MRI: http://www.deepimpact.umd.edu/collaborativ...IntervSheet.pdf

Edit 2: This source gives nine for both. Nothing on the wavelenghts they let in, though. http://www.beltonspace.com/bsei_web_page_g000000.pdf

I also think NASA could have milked the publicity far more effectively than they actually did with just the one press conference. Although kudos must go out to the Deep Impact team for providing us space aficionados with images and animations within just minutes of impact.

To "Mini-TES": actually, your second source -- an EXTREMELY useful-looking paper I'd never seen before (thanks) -- DOES list the colors of the two cameras' filters. It describes both cameras as having 9 filters, but only 7 color filters: the others probably include one clear filter, and one specialized one (such as polarized).

"Filters for the MRI (Hampton et al., this issue) are chosen to detect coma
components; five of the seven filters in the MRI camera set are narrow bands optimized for coma observations, leaving two wider bands centered at 750 and 850 nm matching those on the HRI. The HRI filters are set at 100 nm intervals between 350 and 950 nm, to determine visible color characteristics without detailed spectroscopy, which investigation is done by the infrared instrument. At visible (.4 to 1 µm) wavelengths, cometary nuclei exhibit a wide range of linear slopes (Jewitt 2002). Reasons for this diversity remain unclear."

As for an extended mission to a second comet; I carefully examined that statement at the press onference, and it definitely isn't a disavowal of it -- it's just a statement that whether or not they do it depends on whether they can scrounge the money from NASA. (I think they'd be fools not to, especially given the failure of CONTOUR and the fact that the DI spacecraft can spend most of its cruise time to the second comet in hibernation mode to save money.)

And as for the impact being precisely on July 4 (well, actually, July 3 U.S. time): A'Hearn once dropped the comment that this was "not accidental". Beyond that, I know nothing.

And here, finally, is the only additional data I was able to scrounge on Google about the cameras' filter wheels -- A'Hearn's brief descriptions of them:
pds-smallbodies.astro.umd.edu/review/ comets200410/di/ditv_0004/catalog/inst_hrivis.cat

pds-smallbodies.astro.umd.edu/review/ comets200410/di/ditv_0004/catalog/inst_mrivis.cat

Both are described as having "two clear apertures" in addition to their color filters -- but the MRI is descri bed as having 8 color filters instead of 7. Since the description of the mission in Mini-TES' paper is more recent, it's probably correct in saying that the MRI was reduced to 7 filters. (There is a little more data on the exact nature of the filters in A'Hearn's descriptions, though.)

"Mini-TES'" paper is from the June issue of "Space Science Reviews", devoted entirely to this mission. Unfortunately, Hampton's article in that issue describing the MRI filters is not yet on the Web -- but another paper from that issue, on the nature of Tempel 1 itself, is also available already:
http://www.beltonspace.com/bsei_web_page_g000007.pdf

And here's a third one, which is useful in being the most detailed description yet of exactly what the hell they hoped to get out of this mission scientifically. I'll take a careful look at this before criticizing this mission again.

http://www.beltonspace.com/bsei_web_page_g000002.pdf

Bruce:
The pds site with the calibration data has a file describing the filters with a bit more detail :
http://pdssbn.astro.umd.edu/review/comets2...index/index.lbl
DESCRIPTION = "Provides the number of the commanded filter;
For HRIVIS:
Fil Filter Center
# Name (nm)
--- ------- ------
-9 N/A N/A; used for HRIIR
0,1 CLEAR1 650
2 BLUE 450
3 GREEN 550
4 VIOLET 350
5 IR 950
6 CLEAR6 650
7 RED 750
8 NIR 850
9 ORANGE 650

For MRIVIS:
Fil Filter Center
# Name (nm)
--- ------- ------
-9 N/A N/A; used for HRIIR
0,1 CLEAR1 650
2 C2 514
3 GREEN_CONT 526
4 RED 750
5 IR 950
6 CLEAR6 650
7 CN 387
8 VIOLET_CONT 345
9 OH 309

Splendid! Thanks.

Maybe you want to get a deeper look at the impact area

http://www.greuti.ch/deepimpact/Tempel1_final_approach2.jpg

I'm not really sure about the location of the last picture. The small mound beside the dark "cave" don't fit exactly enough (to me).

What small mound?