Looks like the Deep Impact list has been revived. Posting here for others to get back on board:
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EPOXI E-News #1 May 2008
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WELCOME BACK!
Did you know that the Deep Impact Flyby Spacecraft has a new assignment? The
EPOXI mission combines two exciting science investigations in an entirely
new mission that re-uses the Deep Impact spacecraft. The Extrasolar Planet
Observation and Characterization (EPOCh) investigation will observe stars
that have known transiting giant planets. The Deep Impact Extended
Investigation (DIXI) of comets observes comet 103P/Hartley 2 during a close
flyby in October 2010.
The education and public outreach team decided to get back in touch with our
Deep Impact friends and begin sending out newsletters again to keep you
informed of these two exciting investigations! During the two years since
our last newsletter for Deep Impact, the science team has stayed busy
continuing to do more analysis on the data collected in July 2005. The
science team also proposed and was awarded an extended mission teaming up
with a group from Goddard Space Flight Center.
EPOXI website: http://epoxi.umd.edu/
Mission Overview: http://epoxi.umd.edu/1mission/index.shtml
Press Releases: http://epoxi.umd.edu/7press/index.shtml
DI Results: http://deepimpact.umd.edu/results/
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MISSION STATUS
Dr. Deming, Principal Investigator (PI) for the EPOCh portion of the
mission, sends us the latest mission status report in which he tells us
about the current observing target GJ436. “This is an exciting time for
EPOCh, as we search for an exo-Earth orbiting a stellar neighbor of our
Sun!” reports Dr Deming. He also talks about the plans to observe a very
special planet in late May and early June.
Read his status report as well as past reports from other team members at
http://epoxi.umd.edu/1mission/status.shtml
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EPOCh TARGETS
The EPOCh component of the EPOXI mission will carefully study a small number
of stars in order to learn more about planets that we know are orbiting
those stars by watching the planets as they transit (cross in front of) the
star. EPOCh will also search for clues to other planets that might be
orbiting the same stars.
Read more about the EPOCh science targets to find out which stars are being
observed.
http://epoxi.umd.edu/2science/targets.shtml
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PLANET QUEST
Are we alone?
For centuries, human beings have pondered this question. Medieval scholars
speculated that other worlds must exist and that some would harbor other
forms of life. In our time, advances in science and technology have brought
us to the threshold of finding an answer to this timeless question.
The recent discovery of numerous planets around stars other than the sun
confirms that our solar system is not unique. Indeed, these "exoplanets"
appear to be common in our galactic neighborhood.
The EPOCh investigation is part of a larger family of missions studying
extrasolar planets. Learn more at the Jet Propulsion Lab Planet Quest Web site.
http://planetquest.jpl.nasa.gov/index.cfm
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OBSERVING CHALLENGE
The transits that will be studied for EPOCh are extremely difficult to
observe because the change in brightness is very small and requires high
precision photometry that can be accomplished with instruments on the Deep
Impact spacecraft. Observers on Earth can still take a look at the stars in
the night time sky. The selected stars are also pretty dim because we don’t
want them to saturate or over expose the spacecraft instruments but they are
bright enough to be visible in amateur telescopes if the sky conditions are
good and the skies are dark.
Like people, stars have multiple identifiers. EPOCh’s first target was a
star labeled as HAT-P-4 by the scientists observing it. They made their own
list of target stars so that was their shorthand name. But HAT-P-4 has
numerous other names which are more useful in identifying it in other databases.
HAT-P-4 = SAO 64638 = TYC 2569-1599-1 is a magnitude 11, G-class star
located in the constellation Boötes.
Chart: http://epoxi.umd.edu/2science/challenge.shtml
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SUBSCRIPTION INFORMATION
Please forward this e-mail to others interested in NASA missions. New
subscribers may join the EPOXI Mission e-news mailing list on our website
at: http://epoxi.umd.edu/6outreach/newsletter.shtml
http://epoxi.umd.edu/4gallery/Earth-Moon.shtml
Wow, it got a beautiful shot. I can't wait for the raw data release.
Here's a simulated view:
I still can't wait for the raw data. There really is a lot of data in the images. For example, here is a cleanup of a view of the moon from shortly after launch.
Here is the earth moon shot using the same technique I used on the lunar shot.
Two papers about EPOXI published yesterday by arxiv:
http://arxiv.org/abs/0807.2852
http://arxiv.org/abs/0807.2803
As a member of the EPOXI flight team, I am astonished that this data has been made public yet. The EPOCh portion of EPOXI finished 8/31/08 (photometry of transiting hot-jupiters and observing Earth as an exo-planet analog). The science team has had over 7 months to analyze the data and the only thing made public is the lunar transit animation. Granted, that's pretty sweet, but you'd think they would release some more data.
I met Doug (UMSF founder) on Tuesday (3/17) when he was here at JPL. I'm impressed with what you all are doing on the site with MER data, among the other missions. I'd love to see UMSF participate real-time with the Hartley-2 flyby similar to the DI prime mission flyby of Tempel-1.
Let me talk with our Public Outreach people and our science team and I'll see if I can get any data released to the "world". What exactly would you guys want? .jpgs? raw binary images? Please let me know and I'll see if I can get any data released.
Many thanks and keep up the great work! I always like to see people excited about EPOXI when most people at JPL don't even know we exist!
~Rich
p.s. we just published a paper on how we did the EPOCh observations at the 2009 IEEE Aerospace Conference. I'm not sure if the paper is available to the public free-of-charge, but I'll see if I can get a copy of the paper and presentation out...
Welcome aboard Rich, good to have you here! Anything you can drop into our eager little hands will be greatly appreciated!
Daniel, the SPICE kernel you have is slightly out of date. Your version was generated before TCM-14 without the TCM-14 burn. You want to be using spk_drm224_Burn-full.bin That's the latest and greatest o.d. solution. Where are you getting these by the way? Are they public?
I sent an e-mail to the webmaster for space.jpl.nasa.gov and asked him to add EPOXI. He hasn't gotten back to me, but I hope we'll get EPOXI in there.
I talked to the P.I. about getting EPOCh images released to the public. They're thought is, "why should we release them is no one will want to look at them because they're ugly, fuzzy images, especially in .jpg format." The data should be published to the PDS next month and made public about a month after. So, images around May perhaps... don't hold your breath.
Oh, and we're going to do another Earth observation of the North pole on Friday 3/27/09. It should give us some more pretty pictures
~Rich
So I just got a blessing from the Ethics office. Attached is the presentation on EPOCh observations I gave at the IEEE conference in Big Sky. Feel free to bug me with questions. I'm continuing to research the legal aspects of posting the paper here too. Stay tuned!
EPOCh_IEEE_Presentation_umsf.pdf ( 963.67K )
: 928
~Rich
Dear Rich,
Mission update:
FYI, we will be taking more pictures of the Earth tomorrow in a similar fashion to how the previous Earth observations were performed (in fact, we're using the exact same sequences, fancy that). However, we will be significantly closer than the Earth Observation that took the lunar transit movie (17 Gm compared to 50 Gm (that's giga-meters, or Mkm (that's Mega-kilometers) (and yes, that's a subnested parenthetic remark)). Since the spacecraft is now north of the ecliptic plane, we will be looking down on the Earth's north pole. A simulated image of what we might see has been floating around JPL. I'll ask around to see if I can post it.
Images will be coming down Saturday.
~Rich
Sweet. Can't wait to see the pics. --Emily
Hi all,
I just noticed a new article on the EPOXI website by the EPOCh P.I. Drake Deming:
http://epoxi.umd.edu/2science/alienmaps.shtml
Enjoy!
~Rich
FYI, Hubble is presently studying Hartley-2 to try to pin down the basic properties of the nucleus, especially the rotation period, so that the information can be incorporated into mission planning.
http://www.stsci.edu/cgi-bin/get-visit-status?id=11990&markupFormat=html
http://archive.stsci.edu/proposal_search.php?mission=hst&id=11990
A nice presentation http://www.stsci.edu/institute/itsd/information/streaming/archive/SpringSymposium2009/DrakeDaming050409Hi_supporting/Deming
There is a mission update on the EPOXI site: http://epoxi.umd.edu/1mission/status.shtml
Characterizing Comet Hartley 2
Although the EPOXI mission's spacecraft is in a period of relative inactivity, the team is still actively working on a variety of questions. One of the key areas of investigation is the characterization of the next target, comet Hartley 2. Several investigations have been carried out to characterize the nuclear size and albedo, the large dust, and the rotation of the nucleus. These investigations have been aimed for the period before the nucleus begins outgassing significantly as it approaches the sun.
Observation were taken with the Spitzer Space Telescope in August 2008. The analysis of those data yields a nuclear effective radius of 0.6 km, slightly smaller than, but still comparable to, the size deduced using the European Infrared Space Observatory at the previous apparition. These observations also show that there is a trail of large dust particles released much earlier and still orbiting the sun close to the nucleus. This is a common phenomenon among comets.
The next step was an effort to determine the rotational period in order to design the observing sequence for the approach to the comet. A series of observations with the Hubble Space Telescope in late April were somewhat puzzling. Subsequent observations with a variety of ground-based telescopes, particularly with Gemini-South and Gemini-North on the same night, have suggested a rotational period near 2/3 day, but with narrow minima that were not caught in the HST observations.
From the latest Discovery and New Frontiers http://discoverynewfrontiers.nasa.gov/news/newsletters/newsletter_archive/2009/June2009.pdf
Although the EPOXI mission's spacecraft is in a period of relative inactivity, the team is actively working on a number of areas of interest, including characterizing the next target, comet Hartley 2.
Several investigations have been carried out to characterize the nuclear size and albedo, the large dust, and the rotation of the nucleus. These studies are timed for the period before the nucleus begins outgassing significantly as it approaches the sun. Another effort is to determine the Hartley 2’s rotational period to design the observing sequence for the approach to the comet. A series of observations with the Hubble Space Telescope in late April were somewhat puzzling. Subsequent observations with a variety of groundbased telescopes, particularly with Hawaii’s GeminiSouth and GeminiNorth on the same night, suggest a rotational period near 2/3 day, but with narrow minima that were not caught in the HST observations.
The team is preparing to continue its role in testing software that could lead to improved interplanetary network communications. Last fall, a NASAwide team used DisruptionTolerant Networking, or DTN, software to transmit dozens of space images to and from the Deep Impact spacecraft which was more than 20 million miles from Earth. The test was called DINET (Deep Impact DTN experiment). Computers on the ground at JPL were used to simulate stations on Earth, Mars, and the Martian moon Phobos. The experiment was successful, with all the data transmitted without corruption even as various faults and breakdowns in the system were simulated.
The team was pleased to support this activity that will ultimately lead to much better communications across the solar system. The Preliminary Design Review for DINET2 was conducted on May 13. The current timeline is being reviewed to determine when to begin DINET2 activities on the spacecraft. It may begin following the infrared imaging of Earth at high southern latitudes scheduled for August 17.
Published at last http://arxiv.org/abs/0906.4733
There was a somewhat distant Earth flyby of Epoxi on 29 June at some 1.3 million km ... distant yet Epoxi is still closer to Earth than Planck is at the moment. Next close-ish approach at the end of the year
http://epoxi.umd.edu/1mission/status.shtml#31Jul2009
Browsing the DSN schedule (http://rapweb.jpl.nasa.gov/Planning/TMODMISS.pdf) I noticed that EPOXI is to conclude in November 2010 after the Hartley flyby, but the document gives a "probable end" date for the mission of 31 October 2011. Any idea what they plan to use the spacecraft for during the intervening year?
I wrote to EPOXI PI to ask for some clarifications and he tells me that
On ArXiv today http://arxiv.org/abs/0909.2875
I'm pretty sure the answer is "no" but I thought I'd check here...has there been a PDS release of any of the Deep Impact / EPOXI data from after the Tempel 1 encounter? Specifically, have any of the MRI or HRI images of Earth and/or Moon hit the PDS?
--Emily
http://pdssbn.astro.umd.edu/missions/epoxi/index.html
Nothing.
Hi all:
Just a quick update. EPOXI scientists have discovered water absorption features on the moon. The data was obtained from the IR spectrometer calibrations taken in December and twice in June. Chandryaan's M3 instrument also observed similar absorption features. This was published in Science yesterday. Read more here:
http://epoxi.umd.edu/2science/hydratedmoon.shtml
~Rich
Yet another EPOXI-related paper on arXiv:
http://arxiv.org/abs/0912.2132
Egads. Merry Christmas from EPOCh! Thanks for the heads up, Gordan. I think I'll sit this one out and watch you wizards try to make something better of these data
Now if I could only remember why I was asking that question in the first place...
--Emily
23 frames from March 18, 2008, covering over 5.5 hours, again motion-interpolated in an http://www.fileden.com/files/2007/9/14/1431389/78.avi (1 meg). I believe there's material for a complete rotation as it goes on to March 19 so this is still a work in progress.
No one seems to have noticed this release yet
http://epoxi.umd.edu/7press/news/20100105.shtml
Ooh, neat! More, higher resolution movies of Earth! Can't wait for it to hit PDS in about a couple of years from now!
PDS RELEASES EPOXI (EPOCh) MISSION DATA
The NASA Planetary Data System is pleased to announce release of the data from EPOXI, Extrasolar Planet Observation and Characterization (EPOCh) stage of the mission. The delivery includes raw and calibrated images (exoplanet transits and Earth) and infrared spectra (Earth) acquired during 2008.
The data are available through the PDS Small Bodies Node. To see and download the data as well as mission and instruments information, go to:
http://pdssbn.astro.umd.edu/missions/epoxi/
After more than six months, the EPOXI mission site has some http://epoxi.umd.edu/1mission/status.shtml. Nothing particularly interesting anyway
According to the two Facebook profiles related to the mission (EPOXI Mission and Deep Impact Flyby), AutoNav on the flyby probe, unused for years, is being checked next Tuesday.
today on arXiv: http://arxiv.org/abs/1005.1505
EPOXI is now 3.5 days from its final(?) Earth flyby. It's already closer to Earth than Herschel and Planck!
Update on the Earth flyby with a few notes about the November encounter with Hartley 2 posted on the Deep Impact website:
http://epoxi.umd.edu/1mission/status.shtml
There was http://arxiv.org/abs/1008.4556 on Hartley 2 this week on ArXiv.
In particular, it is predicted that H2's surface will not be too different from comets already visited by spacecraft. It seems to be loosing a significant percentage of its radius at each perihelion, and could be extinct in just a century.
The author also calls for a mission to a really old comet like Wilson-Harrington or a relatively old one like Encke. He predicts that they "will have a more extreme surface morphology, than the cometary surfaces that have been imaged up to now"
Salutations UMSF members,
We just completed a point-spread function calibration of the HRI this morning in preparation for Encounter. We also uplinked and activated the sequences to take the first 20-days of approach images from E-60days to E-40days. The first images should clock out around 13:30 UTC Sunday 9/5 with the images hitting the ground at 14:23 UTC. There's talk of putting a few of these on the website, but 60-days out, it should be just a fuzzy blob a few pixels across.
Keep refreshing epoxi.umd.edu or the EPOXI facebook page for updates!
~Rich
Thanks for the update, Rich, really looking forward to this encounter.
first Hartley 2 pictures from Deep Impact
http://epoxi.umd.edu/3gallery/Hartley2_first_light.shtml
Any Epoxians here? Would love to know which current SPICE kernel to use in my realtime simulation (http://www.dmuller.net/epoxi ... version 3 rolling out in due course):
spk_drm230_WithBurn-full.bsp
or
spk_od230_NoBurn-full.bsp
Thanks in advance!
I've attempted to create an RSS feed for the "Daily Comet" at http://epoxi.umd.edu/6outreach/daily.shtml here:
http://feedity.com/rss.aspx/umd-edu/UVdbWlZV
(I'm sure someone is about to post an official one, but I couldn't find it, so I got to try out feedity.com's advanced features.)
Also, I'd suggest the moderators split this thread into a Comet Hartley Encounter thread beginning with the Sept. 3rd post.
after Deep Impact, after EPOXI, an encore...
I'd been wondering if they would try an XXM with it
Of course with the 4.15 kg of fuel remaining I doubt that they will manage to do anything more significant than EPOCh-like observations.
I tried to play a little bit with the orbital elements given in the RFI document, but it seems like the probe will not come back to the vicinity of Earth before 2018, so no gravity assist possible
I get the loading screen, then it crashes out
Yup - it works now
Managed to get a shot of Hartley 2 the other night:
http://i187.photobucket.com/albums/x269/jmknapp/103p_garden_det.jpg
Here's a little wider context:
http://i187.photobucket.com/albums/x269/jmknapp/103p_garden.jpg
That's a 60-second exposure with an Olympus E-510 DSLR, 1000mm refracting telescope as a telephoto lens.
Stellarium had this configuration:
http://i187.photobucket.com/albums/x269/jmknapp/103P_stellarium-1.png
By the time of the Deep Impact flyby on Nov. 4th around 10:02 a.m. ET, Hartley 2 will be a little further away (0.156 AU vs. 0.122 AU). It should be possible to photograph the comet that morning. From my location in Ohio Hartley 2 will rise around midnight on Nov. 4 and will be at about 60 degree elevation in the south around daybreak, and it will be a new moon. Ah, to be in Hawaii to photograph it at the actual time of the flyby--among other advantages.
ADMIN : Embedded images changed to links. Don't put huge images in-line in posts.
At what point will Deep Impact's pictures be higher resolution than Earthbound observatories'? I thought I'd seen that information on Emily's blog, but I can't find it now...
Well, neither can really resolve the nucleus. DI will likely be able to do so just several hours before C/A. Calculating when the pixel scale on the coma will exceed earthbound observations is probably not a very useful number.
About the flyby, here is an excerpt from the official encounter schedule (http://epoxi.umd.edu/7press/schedule.shtml):
"The cometary nucleus will be resolved ~1 hour out with the spacecraft 45,000 km away from its target. **Closest approach of comet Hartley 2 is expected to occur at ~6:50 am PDT at a distance of 700 km.** [...] The MRI pixel scale at closest approach will be 7 m/pixel, giving a nuclear diameter of ~170 pixels in the highest resolution images."
Nature published today a nice summary of the flyby http://www.nature.com/news/2010/101026/full/4671013a.html
Am I the only one intrigued by this story of cyanogen?
First look at the shape of a comet Hartley 2 !!! For now from Earth.
Link to Emily's post:
http://www.planetary.org/blog/article/00002742/
NASA's link:
http://www.nasa.gov/mission_pages/epoxi/epoxi20101028.html
Additional observations of comet Hartley 2 from 29 October (fourth row).
http://www.naic.edu/~pradar/103P
Emily's post on the elongated shape of this and other comets http://www.planetary.org/blog/article/00002742/ started me off wondering if elongated shapes are a particular feature of comet nuclei and why that might be so. Here's what I came up with.
Think of a framed picture with an even width of mount all round. The frame is, proportionately, less elongated than the picture. Reverse the process and it's easy to see that removing uniform layers of material from any slightly irregular object will leave a progressively more flattened and elongated residue. Individual cases can have individual explanations of course but I wonder if, statistically, the shapes of comet nuclei could provide a measure of the amount of material lost and therefore the likely original size of these bodies before they were perturbed into low perihelion orbits?
Yeah, I was just thinking about that too, coincidentally. Haven't had time to really muse on it, but my first thought was whether comet nuclei like Borrelly & now Hartley-2 are products of mergers of binary objects. Are the rotation axes on both such that they 'tumble end-over-end'? That might be an interesting correlation, if it exists.
What is the most likely origin of a contact binary? It could be erosion of an elongated object until the neck breaks.
Are most comets we've visited primordial, or shattered debris from objects deeper in the Kuiper Belt? I think the comets we usually see are broken off chunks of KBO's, with only the very occasional "raw" object. My thought is that debris from a collision is much more likely to be elongated than round due to the types of forces ejecting material away from an object; ie circular and radial forces from the point of impact.
Time lapse observations of Hartley 2 from EPOXI showing rotation of the comet as seen in the drection of plume(s).
http://www.youtube.com/watch?v=wMRMHnxBQ8A
NASA TV Coverage of the EPOXI Encounter
The shuttle has it's own TV schedule, but these are also listed on THAT TV schedule! However,
if something changes with the shuttle anything might happen.
REMEMBER the Encounter is on the (Media Channel) & the Post Encounter is on the (Public Channel)
http://www.nasa.gov/multimedia/nasatv/MM_NTV_Breaking.html
November 4, Thursday
9:30 - 11:30 a.m EST (13:30 GMT) - Live Commentary and Coverage of the EPOXI Spacecraft Close-Up Encounter of Comet Hartley 2 – JPL(Media Channel)
4 p.m. EST (20:00 GMT) - EPOXI Encounter of Comet Hartley 2 Post Encounter News Briefing – JPL (Public Channel)
Jack
Watch the EPOXI encounter from the spacecraft's perspective through this fantastic, brilliant, wonderful and downright best program EVER - http://solarsystem.nasa.gov/eyes/.
Well somebody had to tell you all it was there
Be kind, it's still in Beta
But go find the NEAR mission and watch it's orbital phase with Eros.... see the Pioneer 11 flyby of Jupiter, and go 'OMFG' at the Ulysses trajectory
There's a million things we're still trying to put into it - chances are any suggestions someone might have, we've already got it on a very very unfunded list of 'love to put in...' - but make suggestions
djellison said: Be kind, it's still in Beta
That it may be, but it's still light years ahead of anything else!
Good idea about suggestions, but maybe just not here....maybe http://www.unmannedspaceflight.com/index.php?showtopic=6793 instead.
Does anybody know of any webpage showing live minute-by-minute mission status, as sometimes happens for NASA missions?
The closest thing I know of is either the http://www.unmannedspaceflight.com/index.php?s=&showtopic=6793&view=findpost&p=166128 or the http://www.dmuller.net/spaceflight/realtime.php?mission=epoxi&mode=scet provided by dmuller.
damn, twitter does not work at office!
I'd like to see a real-time mission status update like this old one:
http://spaceflightnow.com/cassini/status.html
I installed the Eyes on the Solar System s/w at work .
Watches over shoulder for bosses........
NASA TV should be covering it live.
9:30 (13:30 GMT) - 11:30 a.m. - Live Commentary and Coverage of the EPOXI Spacecraft Close-Up Encounter of Comet Hartley 2 – JPL (Public and Media Channels)
4 p.m. - EPOXI Encounter of Comet Hartley 2 Post Encounter News Briefing - JPL (Public Channel)
http://www.nasa.gov/multimedia/nasatv/index.html
http://www.neil-online.com/nasa/
Jack
10 minutes to closest approach.
When will the pictures be sent back ?
They'll begin coming back 30 min after C/A, but high-res ones will not hit Earth until at least an hour after C/A.
Kevin Hussey is demoing EOTSS on NASA TV!
Meanwhile, I'm getting Fail Whale on Twitter. Argh.
HGA is not steerable. They're still doing observations as they depart. Data rate is low.
Damn twitter.... never seen that stuipd whale so much
NASA TV First images are down. Low res or distant. 18 hours old.
Sounds like I woke up just in time
Did they just say hi-res images won't be available till 8:00 PST?!? (rather than 7:00)
first hires images arrived!
It looks like a jelly baby.
Is that a moon?
Reminds me of Borelly quite a bit!
Is that the discoverer in the room itself?
EDIT: Never-mind, found confirmation, it's him! What a great day for him!
I count no less than 8 sources. No idea how many sources comprise the obvious group of sources at the right, bright side.
Weird, the comet's "waist band" looks completely smooth
Looks nearly identical to Itokawa...
Love the smooth band in the middle. It's like it's wearing a cropped T-shirt.
Animation from the 5 frames:
Yeah, I was just thinking how it looks like Itokawa with gas...
Wow! that's just phenomenal!
Easy to see how comets like this would be torn apart during a close encounter with Jupiter and end up like schumacher-levy 9.
Breathtaking!
I'll bet that large boulder on the bridge between the two rolls around the body, gnawing it down, smoothing it out
Congratulations to the team for yielding these magnificent images.
Looks like the bone from 2001:A Space Odyssey, interestingly enough
...of the small sample of rocks and comets we have visited , most (alot?) tend to exhibit this shape architecture -- is there a clue here?
Attempt to make two stereo pairs from images #495378/385/389 (caution: very large baselines!)
Phenomenal!!! Late to the party as usual because of pain meds, but remarkable work as always, guys!
There's a directory full of images here:
http://epoxi.umd.edu/3gallery/ENCOUNTER/
It includes the five close-approach pics, plus some more distant views from the 24 hours before close approach. The pictures are all posted with fairly detailed metadata embedded within the pixels of the images themselves, including information on the stretch that was applied to them (the min and max original DN in the 16 bit image) as well as filter and exposure information. Most images were taken through a clear filter but some were taken through narrowband filters in emission lines of OH, CN, and C2, which are in ultraviolet and green wavelengths. Anybody out there planning to take a crack at some color combos? I may not be able to try until I get home after the afternoon briefing...
Where are images taken by the High Resolution Instrument (HRI) ? I know that the instrument is out of focus, but it always HRI.
Damn; where's the "like" button?
Good one, Stu!
been watching the press event on NASA TV. two good questions by Emily!
I have lost the part about the engineering aspects of the flyby. what was the final distance? and does anybody know whether a transcript or podcast or recorded video of the event is available?
Enhanced version of opposite end of comet with tons of jets silhouetting night side
I found more radar data (October 24-27,29-31) and Hartley 2 model.
http://www.naic.edu/science/ao_hartley.html
We can compare the model with reality, a perfect fit.
Little animation experiment.
Timewarp 5× (1s ~ 5s real).
Machi, that is brilliant!!
Golly - blurry instruments or not, this is just spectacular - and dynamic on a timescale that is very human.
With that 'waistband' that thing has got to be a contact binary. But hang on, how long is its rotation period again? There must be some internal strength there or this thing would fly apart!
P
Incredible, machi.
That's stunning, Machi... just stunning...
Wow, Machi, my jaw just hit the floor!
Clearly that's witchcraft.
But the cool thing is, they took SO many images during CA that we'll have something not too far off that, for real, eventually
Thanks!
It's beautiful! Do you mind if I tweet a link to it from @NASAJPL?
Of course you can tweet a link!
After all, it's your (NASA's) spacecraft .
I was most intrigued by an answer to Emily's last question near the end of the briefing about the "bouldery" appearance of the comet. Although they look like the boulders of Itokawa, they are apparently a totally different beast. They are being called "clumps". But they are REALLY BIG clumps! Here's a rough size comparison of Hartley and Itokawa (the small one). The "clumps" of Hartley dwarf the boulders of Itokawa.
They could be locations of reduced sublimation, kind of like these on Callisto:
http://photojournal.jpl.nasa.gov/catalog/PIA03455
Hard to tell at this resolution what the warts are. But just maybe they're white spots casting shadows. There are some white spots that aren't.
The ridges where the two main lobes and smoothe section meet, I'm guessing that has something to do with a contact binary scenario?
Could someone explain how these form?
Edit: The comet's shadow in the coma?
It looks like NASA found the giant space bowling pin.
So far we have seen:
a boomerang shaped Eros
Another asteroid, Itokawa shaped like an eggplant
a diamond shaped Steins
and now a comet Hartley 2 shaped like a bowling pin
Don't forget Comet "Bowling Pin" Borrely!
This odd morphology seems as if it may be common for smaller comet nuclei. We need a LOT more samples, of course, but I'll be very interested to hear what the pros have to say when they chime in.
Machi, that animation is so graceful -- thanks for showing us the magic!
Machi, I don't know how you obtained that amazing animation.... but I know it allows creating anaglyphs! Animated anaglyphs!
I made the 3d-anaglyph movie.... but I can't upload it anywhere from office! You'll have to wait...
Machi, it would be great if you could make the complete movie statring from comet being large just like a bean on the screen...
Maybe I successfully uploaded it...
Put on your red/blue glasses and have a good space travel! ;-)
Cassioli:
WOW, it looks fantastic even with red/green glasses .
So Borrelly, Itokawa, Hartley, I believe some TNOs, and a number of NEOs all have the appearance of being contact binaries.
I guess the surprise to me is the really low relative velocities at impact. When I thought of accretion events, I always imagined them as being not very efficient, where two things would go splat and a significant portion of the mass would be lost at greater than escape velocity. This could be telling us something important about the timescales for planetesimal growth in the early solar system. If accretion events at low relative velocities were very common, then growth timescales would be comparatively short.
(Alternatively, the contact binaries might be a large portion of the *surviving* planetesimal remnants, the rest having been smashed to bits.)
I've been "out of the business" for about 7 years now, so haven't kept up with any of the dynamics work. Anybody out there have a sense of what's being bandied about these days?
Jeff
(and Machi: We-Are-Not-Worthy!)
Re: the discussion about boulders vs clumps etc.
Generally speaking, words like boulder - and sand for that matter - are referring to the size of the particles, not what they are made of. No problem calling these lumps boulders even if they are rather low density.
These pics are fabulous - I hope the approach and departure images will also show the dark limb silhouetted against the coma and jets.
Phil (foiled by the last gas leak, coming home without seeing Discovery launch)
^ sublimation is possible - as is, I suppose, fracturing due to gravitational influences, with later low-speed re-accretion. After all, these comets got into the inner system somehow.
Andy
We can add to that list of things that look like Hartley 2, the asteroid Toutatis, seen quite well by radar.
Phil
There are some problems with longer animation. Images taken longer time before flyby are overexposed (without details) and time delay between first image in animation and
nearest (in time) image is too big, when same timewarp is used (thus final animation is over 1MB limit). But I will try make another intersteps and I will see what can be done.
I read somewhere that these are just medium resolution images, and hi-res images are currently being downloaded!! :shock: More of your pathetic whining?
Careful. These are all images from the MRI ( medium resolution imager ).
There IS a 'High Resolution Imager' that has 5x the res of the MRI. However, it has a flaw - it is out of focus, and out of focus such that it's actual resolution is only about the same power as the MRI. SOME of that out of focus problems can be backed out using deconvolution - but it's not perfect, it's not great, it's not taking it back to its design resolution.
We MAY have images to come that are a LITTLE better than these, but don't expect miracles.
Is there any links to a repeat of the JPL Coverage of the flyby?
Go to the Ustream page ( www.ustream.tv/nasajpl2 ) and it's archived below.
I'm confused. The first two images below are from http://www.jpl.nasa.gov/news/news.cfm?release=2010-373&cid=release_2010-373&msource=10373&tr=y&auid=7313419#4 the third is from http://planetary.org/blog/article/00002763/
The sizes indicated for Hartley vary widely. Which is it?
I think that 1.25 miles/2 km is length of longer axis and 1.2 km is medium diameter.
Puts me in mind of a young Amanita
http://etc.usf.edu/clipart/14800/14815/yng_amanita_14815_lg.gif
Movie of the flyby imagery here, seems to show some images we haven't seen.
http://epoxi.umd.edu/3gallery/vid_20101104_approach.shtml
(requires quicktime)
Just be patient. They haven't had time yet to come to agreement on an official new diameter for Hartley 2. They have to get the final navigation solution to be sure of range to the target, figure out what angle they're seeing the long axis at, etc etc. There's no point in them issuing a number that they'll have to correct later. They're using whole- and half-kilometer estimates and then doing low-precision conversions to Imperial units. Just be patient and we'll eventually see an official diameter announced. Consider everything between now and then to be imprecise, plus or minus 50%.
Returning to the question of the Hartley 2 shape and whether sublimation can cause such a shape, I ran a simple simulation; starting from a spherical shape and solving the sublimation differential equation in time for different rotation axis angles. For alpha=0 (i.e. axis perpendicular to the orbital plane, the arrow points to sun), the object elongates and then develops a waist. For alpha=90, it morphs into a discoid shape. For alpha=30 and 60, the shape looks like a bottle and a bullet, respectively. Of course, this is a very simplified model (starting from a perfect sphere, no shadowing...), but it shows that sublimation is one of the forces shaping a comet shape.
Nice work siravan!
A couple of amazing facts about Hartley 2.
http://scienceblogs.com/startswithabang/
And btw. great, great science blog!
Boy, no kidding nice work, Siravan! Heck, I'd call it fundamental work! The bowling-pin shape seems much less mysterious now.
the only problem that I see with the model is the assumption of starting with a sphere. what would happen with other, more likely shapes?
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yeah, would any asteroid behave like a comet if "coming too close to the sun"?!?
I'm also very dubious about that statement concerning Hartley-2's effluent composition. For one thing, the nucleus is extremely active, and unless it's very, very anomalously enriched in CO2 the bulk of those jets has to consist of water vapor.
Not buying it.
I think we'll find plenty of water in the asteroids. (Looking forward to Vesta snd Ceres!) I think that the asteroid belt and the Kuiper belt are parts of a continuum, albeit one that has had a large swathe carved though it by the giant planets making intermediate objects rare.
On the subject of bowling pins (or dumbells) here's another: http://t2.gstatic.com/images?q=tbn:ANd9GcTi6mN2QD812nyQ96Re3M_om6X_Q0Ppl6nq-TTlBpEr5ON02uw&t=1&usg=__xL4KNMtb7bJAYvwBbwQkdYu8MoU=
http://www.google.co.uk/imgres?imgurl=http://www.cfht.hawaii.edu/Science/Astros/Imageofweek/ciw-image/061100.gif&imgrefurl=http://www.cfht.hawaii.edu/Science/Astros/Imageofweek/ciw061100.html&usg=__0AX1uulPYKLNXQDRZtmxgPr3NQE=&h=742&w=826&sz=92&hl=en&start=41&zoom=1&tbnid=q0Z-fBb6nsJcAM:&tbnh=154&tbnw=171&prev=/images%3Fq%3DAsteroid%2BKleopatra%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-GB:official%26biw%3D1280%26bih%3D825%26tbs%3Disch:10%2C1723&um=1&itbs=1&iact=hc&vpx=362&vpy=145&dur=10846&hovh=213&hovw=237&tx=35&ty=239&ei=rOfVTIWrHtS7jAf46LzHCQ&oei=nefVTJrFAYq1hAfP1fTJBQ&esq=3&page=3&ndsp=20&ved=1t:429,r:11,s:41&biw=1280&bih=825
I think you have here discovered the reason for the ubiquity of 'contact binaries' in the asteroid and Kuiper belts. They don't form by two objects coalescing from a very gentle mutual orbital dance. They form, they must form, by the erosion of larger bodies.
Siravan, quick write a paper. Even a small one. G
One comment on Siravan's model: It suggests that the bilobate shape would only exist for a short time late in the object's evolution - for most of the time it's a prolate spheroid. And presumably soon after the object takes that shape it disintegrates entirely. If it only has that shape for (say) 10% of its life it suggests we should only see 10% of objects looking like that. If we see a lot of these objects, another theory might be needed.
Phil
One comment on the real world situation: as a body narrows, it's likely to change its spin axis - not continue rotating along its long axis. This would suggest, over time, the trend of continued sublimation on a spherical body would be for it to stay spherical.
I think.
Andy
Wild 2 and Tempel 1 do not subscribe to this model. What does that say about them, and the model?
I checked the perihelia since that is one factor that must have a bearing on sublimation: Wild 1.592, Tempel 1.509, Borelly 1.35, Hartley 1.05, Halley 0.587.
One other point - don't think it's been raised before. The model presumably assumes globally unifiorm sublimation rather than localized active regions. An alternative hypothesis might be that many comets are eroded away at one or more points so deeply that they spontaneously break up into two or a few chunks, which reassemble into bi- or poly-lobate forms with the loose debris falling into the middle region. That could happen several times during the life of a nucleus. Same thing would apply to asteroids disrupted by collision, accounting for the similar forms we see in both populations.
Phil
meanwhile, ESA has released an infrared image of Hartley 2 taken by Herschel
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=47909
I just made one of my handy-dandy index pages to the Deep Impact Hartley 2 Encounter images:
http://www.planetary.org/data/di/
Strange I read on Space.com that thousands of images where taken.
Is that a error?
In the entire encounter - from a few months out, and the next few weeks - in total it's more than 100,000
During the close encounter phase, it's certainly hundreds of image. We put the actual imaging sequence into Eyes on the Solar System - you can see it still under the EPOXI Replay http://solarsystem.nasa.gov/eyes/ . None of the images marked AutoNav are downlinked, but all the ones marked science should be. As a point of note - the image names that include 600000something - watch out for those in the top right corner as the replay happens - you will see them appear. That's the 5 'early downlinked' images that we've had released to date.
Check the http://www.planetary.org/explore/topics/deep_impact/hartley2_timeline.html, you can answer that yourself!
Back to EPOCh mission, on arXiv yesterday there was a nice paper resuming all the exoplanets observations
http://arxiv.org/abs/1011.2229
Yes, that is a good point... but remember that the encounter is still going on and a fantastic dataset has to be looked at to get some early analysis done for upcoming scientific meetings. There's lots to do, and extended missions are always run with limited funds and staff. There's lots of time to get the full details out. It will become clear.
Phil
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Looks like it does not work on my 16:9 monitor, all controls appear garbled, can't see help button, can't understand how to use controls...
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Actually it's a 32" TV set 1360x768.
Then try a monitor. A laptop. Something else.
I don't wish to seem rude here - but it does seem like you're essentially refusing to think for yourself.
Your continued full inline quoting also shows you don't take note of UMSF admin either.
My patience is just about expired.
one fundamental detail of the Hartley 2 images that I have not been able to find: what is at best the pixel size (I dare not call it "resolution") at closest approach?
http://epoxi.umd.edu/7press/schedule.shtml
"The MRI pixel scale at closest approach will be 7 m/pixel"
NASA Announces Comet Encounter News Conference
http://www.nasa.gov/home/hqnews/2010/nov/HQ_M10-161_EPOXI_Update.html
I'm liking the reasoning, centsworth_II - but for two elliptical chunks perhaps originally separated by earlier sublimation, their speed at re-contact will have to be below the local escape velocity. That's going to be under 5m/s or so in the Hartley case.
At collision speeds as low as this, and with inelastic structures (voided rubble & ices) I could imagine these bumping together, settling and sticking any way on - not neccesarily in a minimum axis/"best gravitationally settled" condition. Later loose dust and fragments would gravitate to the waist to make the observed contact beach.
Andy
cryptic message on Twitter and Facebook about tomorrow's press briefing:
Not cryptic... they used a green plastic drinks bottle during the first press conf to show the orientation of the comet etc.
It seemed like about 75% of the AP photographer's shutter clicks during the press briefing were while Mike A'Hearn was holding up that bottle. Has anybody seen any of those pics -- did any of those photos make it onto the Internet anywhere?
http://www.csmonitor.com/var/ezflow_site/storage/images/media/images/1104-ahearn-comet-encounter.jpg/8979447-1-eng-US/1104-AHEARN-COMET-ENCOUNTER.JPG_full_600.jpg from here:
http://www.csmonitor.com/Science/2010/1104/Comet-Hartley-2-flyby-yields-stunning-photos-of-a-cosmic-oddball
Fill that bottle with some diet coke and Mentos, then poke holes to demonstrate jets!
(I was thinking for a second, what, they brought LIPOVITAN-D?)
So apparently Deep Impact imaged "snowballs"!
fantastic HRI images!
I can't help but pray that Rosetta will not have to deal with "snowballs" like these!
Is anybody else having trouble making the anaglyph they released today pop into 3D? I find the circles just refuse to overlap, they stay stubbornly non-overlapping no matter how close or far I bring my face to the screen.
Besides the halo of fluffy snowballs, a big surprise was the large amount of water vapor escaping from the waist contrasted with large amounts of CO2 from the ends. To me, this fits in with the idea of single, solid object being narrowed at the center by differential wasting. Especially if the lack of CO2 from the waist is due to its already having been removed in past passages around the sun. Of course this is a totally inexpert opinion.
I could not make the anaglyph they released on the TV today pop into 3D. Had to wait for the webpage release. NOW it pops out.
http://epoxi.umd.edu/3gallery/20101118_Schultz5.shtml
Craig
Impressive images!
But I doubt Rosetta will have trouble during their landing, these snowballs seem quite benign from what Emily wrote on the blog, plus we don't know yet how active C-G will be in 2014 either.
I'm sure they'll have an extended observing campaign once in orbit to find a perfect landing spot, as Hayabusa did.
I expressed a LOT of skepticism about the CO2 enrichment as stated in early reports...time to eat those words (nom nom nom...burp!)
And snowballs to boot.
Always the utterly unexpected...I should get used to it by now. Can't wait to see the hypotheses to come!
After seeing the snow storm surrounding Hartley 2, I was glad to see this in http://www.springerlink.com/content/yp57q2325066674v/fulltext.pdf regarding Rosetta:
"10. Front Door Mechanism
The Front Door Mechanism, FDM, is primarily designed to protect the optical components inside the NAC and theWAC by reclosable front doors.... "
Let's get Rosetta to rendezvous with some of those snowballs! (just kidding... but imagine some of these things collide, accrete and grow into a moon... )
Phil
From what I made out at the recent conference, the evaporation of these snowballs is what comprised the majority of water in the coma.
As such, I would suspect that the formation of moons via agglomeration of these would not be very stable over the long term. If the comet is close enough to liberate enough of the 'snowballs' to form metre+ sized moons, then it may be close enough for these 'snowballs' to evaporate.
Which is not to say I've done the math or run simulations.
For those wondering about Rosetta... remember, Deep Imapct flew past Hartley 2 at 12km/sec.
Rosetta will be rendezvousing with C-G, i.e. close to ZERO km/sec - it's just the speed imparted by the out gassing process that will be troublesome
Sounds like Rosetta needs a bicycle helmet to protect against low-speed impacts
I wonder what brave putative PI will someday propose a mission to catch & return snowballs from a comet...?
I don't really think that any visible lumps on the surface are fallen snowballs. If I were to guess, maybe as the comet shrinks its dessicated surface breaks up into the clumps we see on the ends. I envision the "boulders" to be composed of freeze-dried masses of dust and organics. Maybe similar in texture to "astronaut ice cream".
Earth-based radar might let us see which comets are surrounded by "snowballs" - not resolving them of course but revealing a diffuse target around the nucleus.
Phil
Interesting thought. It would have to be a very close approach to Earth by a target comet, though, and I wonder if anyone has any idea what the dielectric constant might be for a "typical" (is there such a thing?) comet nucleus, to say nothing of fluffy stuff like a snowball halo?
Definitely worth trying by Arecibo if there's ever an opportunity.
They did use Arecibo with Hartley 2. It'll be interesting to see, if with the benefit of hindsight, they can say 'Yup - we saw the golf balls'
Argh...I forgot that! Thanks, Doug.
Looks like it didn't penetrate the 'regolith' as much as I would have thought; good solid skin painting. Sure hope that they take a hard look now for any scattering around the nucleus. Could tell us something about the composition of the balls if they get any sort of returns since the radar frequency is constant.
Are there any better Hartley radar images than this? It doesn't look like the snow storm rises above the noise.
http://spacespin.org/article.php/101070-arecibo-comet-hartley-2
On the other hand, decreasing the brightness leaves a few suspicious spots. I guess it will take some statistical work to determine the chances that those spots represent something real as opposed to random noise.
The thing is, these snowballs have been described as "fluffy aggregates of very small particles of ice, like a dandelion puff" and up to basketball size - which must mean most are smaller than the wavelength of a typical radar signal.
I suspect Arecibo stood no chance spotting these.
Andy
Oh - I don't for one second think we're going to 'see' them in those visualizations of the radar return for the Nucleus. If there's anything present, it'll be in the signal in some other way.
Snowballs like this have been detected by radar before, e.g. Hyakutake, as reported in http://www.sciencemag.org/content/278/5345/1921.abstract?sid=384733ca-9f18-4747-82db-97407394d25c. A trail of these objects were also observed from Earth, including by amateurs, as an anti-sunward "spike"; larger telescopes resolved mini-comae surrounding 1-10m-sized "snowballs", as reported http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WGF-45FC19C-6W&_user=125795&_coverDate=03%2F31%2F2000&_rdoc=14&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info%28%23toc%236821%232000%23998559998%23295375%23FLP%23display%23Volume%29&_cdi=6821&_sort=d&_docanchor=&_ct=18&_acct=C000010182&_version=1&_urlVersion=0&_userid=125795&md5=910961128b028cd2cab751fa81ee221a&searchtype=a.
I was reading an article about H2 in an Italian popular astronomy magazine. it mentions as a possible origin for the nucleus' smooth surface tidal interactions with Jupiter during the April 1971 flyby at 0.09 AU.
Anyone heard of a similar theory? My impression is that the distance is too large for it to tear apart and re-aggregate even a loosely-bound "rubble pile", but maybe I am wrong.
.09 AU would put it ~7 times farther out than Callisto. I dunno nuthin' 'bout no gravity, but that seems awfully far to do any sort of resurfacing.
Agreed. The idea isn't bad but I might be looking for an earlier and much closer encounter if orbit data are good enough - might be too chaotic, though.
Phil
there is a new article on EPOXI's "Earth as an alien planet" observations on arXiv today
http://arxiv.org/abs/1102.3625
Very cool. Thanks for that link!
I noticed this paper on Astronomy & Astrophysics http://www.aanda.org/index.php?option=com_article&access=standard&Itemid=129&url=/articles/aa/abs/2011/04/aa16060-10/aa16060-10.html (in free access at this moment)
It seems comet Tuttle has yet another dumbbell-shaped nucleus:
I was expecting tomorrow's "Science" to include articles on early MESSENGER science and instead: http://www.sciencemag.org/content/332/6036/1396
A nice summary, but don't panic, folks, there's no new map of the nucleus yet! Interesting description of the rotation state though - a long axis mode like those of Halley, Toutatis and maybe Hyperion.
Phil
Looks like the Rosetta Steins data wasn't the only one to hit the Small Bodies node recently. Here's Hartley 2 in natural color, OGB filters overlaid over a slightly better quality (closer and less smeared) clear frame. A bit of gapfill was used from that low res OGB data at the right limb where deconvolution ringing was caused by proximity to the image edge. Magnified 1.5x from the original pixel scale.
Very nice! Thanks.
Phil
ugordan - Amazing work!
Comet Hartley 2 from High Resolution Imager. Color data are similar to the Ugordan's image of Hartley. Only difference is, that I used red filter and not orange one.
I was focusing more on nucleus, so I used higher resolution underlaying image and jets are somewhat suppressed (and processed with different type of deconvolution).
Image has original size with resolution 4.5 m/pix (original resolution of color images is around 15 m/pix).
Nice! I used "orange" because being centered at 650 nm it is in actuality red, whilst the "red" filter is centered around 750 nm so is in fact near-infrared.
Thanks!
So this is result, when one looks more on filter names and not on nanometers.
Even though that name is a bit clumsy, I actually quite like the way they chose HRI imager filters, a simple and straightforward approach. Pretty much each filter has a bandpass of 100 nm, sharp cutoff and neighbors nicely with the next filter and the wavelengths are easy to remember. If it wasn't for the defocus problem, it would have been one sweet instrument.
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