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Unmanned Spaceflight.com _ Telescopic Observations _ Jupiter Impact 2009

Posted by: Stu Jul 19 2009, 08:13 PM

Very interesting observation of a dark mark on Jupiter... it's starting to ripple out across Twitter...

http://www.irishastronomy.org/cms/forum?func=view&catid=2&id=79644#79647

More info: http://www.acquerra.com.au/astro/ObsReport/jupiter-impact.html

Posted by: ugordan Jul 19 2009, 08:23 PM

Precisely 15 years after Shoemaker-Levy 9 barrage. If only we had advance notice, maybe this time it was a dayside impact...

Posted by: dvandorn Jul 19 2009, 08:26 PM

I daresay it wasn't a cometary impact, as a comet of any reasonable size (i.e., big enough to leave such a visible mark) would have been spotted before now, I would imagine. As long as it had an observable coma and tail, that is (which comets usually do by the time they reach Jupiter's orbit).

-the other Doug

Posted by: SFJCody Jul 19 2009, 08:36 PM

QUOTE (ugordan @ Jul 19 2009, 09:23 PM) *
If only we had advance notice


One of many reasons why we need LSST and Pan-Starrs. They'll get pretty much everything right down to the crumbs.

QUOTE (dvandorn @ Jul 19 2009, 09:26 PM) *
I daresay it wasn't a cometary impact, as a comet of any reasonable size (i.e., big enough to leave such a visible mark) would have been spotted before now, I would imagine.


SL9 was in orbit around Jupiter from the 60s or 70s. It didn't get spotted until after it had made a particularly close approach in 1992. This seems to have been the point at which it got pulled apart.

Posted by: Floyd Jul 19 2009, 08:48 PM

Now picked up by http://cs.astronomy.com/asycs/forums/t/41364.aspx.

Posted by: tasp Jul 19 2009, 09:48 PM

Maybe we are getting another Venus ??


laugh.gif


Posted by: nprev Jul 19 2009, 09:59 PM

Interesting! It does look quite a bit like one of the big SL9 hits; seems to be a hint of dark 'fallout' to the right of the spot. Gotta wait for an authoritative call from the pros, of course.

Not too surprising, really, but so cool that we're seeing it. Jupiter probably sucks up at least a dozen or so comets every century. (oDoug, I'd guess that it probably was a previously undetected comet that came straight in unlike SL9's capture/decay.)

Posted by: volcanopele Jul 19 2009, 11:06 PM

Very cool. Given how much Jupiter eats comets and asteroids, wouldn't be all that surprising. Now if only this would happen on Saturn wink.gif

Otherwise, the monolith seems to be a year early wink.gif

Posted by: john_s Jul 20 2009, 02:42 AM

I started my own topic, but then nprev pointed out that Stu beat me to it here, so I'm reposting...

It looks pretty convincing to me. Apparently it wasn't there a couple of days ago.

The clincher will be methane-band images which will reveal whether the dark spot is at low altitude (and thus meteorological) or at high altitude (and thus probably impact-generated). The NASA Infrared Telescope on Mauna Kea is planning to check it out tonight, and I'm sure there will be lots more amateur images soon.

nprev asked how soon Hubble could be reprogrammed to look at this, if it was considered worthwhile. It's normally a couple of weeks at the shortest, but with the post-repair recommisioning still in progress, it might be harder to respond so quickly at the moment.

John.

Posted by: volcanopele Jul 20 2009, 02:50 AM

No problem. This topic belongs in the Telescope Observations sub-forum anyway, so I'm moving this there.

Posted by: nprev Jul 20 2009, 03:02 AM

QUOTE (john_s @ Jul 19 2009, 06:42 PM) *
...how soon Hubble could be reprogrammed to look at this, if it was considered worthwhile. It's normally a couple of weeks at the shortest, but with the post-repair recommisioning still in progress, it might be harder to respond so quickly at the moment.


Yeah, I was afraid of that, but had to ask. If it is an impact (scar? tear? hole? astrobleme? What do we call atmospheric impact artifacts on the gas giants, anyhow???) it probably won't persist for more than a few weeks regardless.

Guess it's up to the big Earthside observatories to carry this one. Clear skies & good luck, you guys!

Posted by: tedstryk Jul 20 2009, 04:57 AM

They have already done one science observation (a KBO mutual event with STIS that couldn't be rescheduled), so it might be doable. I took a look when Jupiter was low in the sky earlier this evening, just be fore it rotated out of view. It is definitely visible, but if it is an impact, it definitely isn't as big as the large SL-9 fragments. Incidentally, I was looking at it with exactly the same setup (scope (10 inch) and eyepiece) that I used for SL-9.

Posted by: Sunspot Jul 20 2009, 07:38 AM

QUOTE (Stu @ Jul 19 2009, 09:13 PM) *
Very interesting observation of a dark mark on Jupiter... it's starting to ripple out across Twitter...

http://www.irishastronomy.org/cms/forum?func=view&catid=2&id=79644#79647

More info: http://www.acquerra.com.au/astro/ObsReport/jupiter-impact.html


What Twitter sites would that be?? I've only looked at the Phoenix Lander on Twitter so far.

Posted by: Stu Jul 20 2009, 07:52 AM

Universe Today... Bad Astronomer... sites like that.

Posted by: djellison Jul 20 2009, 08:15 AM

I'm wondering if the fact that Hubble is still in a recomissioning phase means that maybe, quick turnaround response for an orbit or two won't be too hard. I hope Damian Peach has had a look at it smile.gif

Posted by: SFJCody Jul 20 2009, 08:19 AM

I think the forum might enjoy this, one of my favourite bits from Terry Pratchett's Discworld series:

QUOTE
People don't live on the Disc any more than, in less hand-crafted parts of the multiverse, they live on balls. Oh, planets may be the place where their body eats its tea, but they live elsewhere, in worlds of their own which orbit very handily around the center of their heads.

When gods get together they tell the story of one particular planet whose inhabitants watched, with mild interest, huge continent-wrecking slabs of ice slap into another world which was, in astronomical terms, right next door—and then did nothing about it because that sort of thing only happens in Outer Space. An intelligent species would at least have found someone to complain to. Anyway, no one seriously believes in that story, because a race quite that stupid would never even have discovered slood.

laugh.gif

Posted by: Stu Jul 20 2009, 08:32 AM

Some more pix here...

http://jupiter.samba.org/jupiter-impact.html

Posted by: volcanopele Jul 20 2009, 09:02 AM

Yeah, some of those other images have really convinced me. You can clearly see a reddish plume deposit to the west and north of the impact site (or sites), akin to what was seen at many of the SL9 impacts.

Posted by: 4th rock from the sun Jul 20 2009, 09:14 AM

Hi,

A nice place to check for updated daily planetary images is: http://alpo-j.asahikawa-med.ac.jp/Latest/Jupiter.htm
Very good images there, including methane one from earlier days.

Posted by: Stu Jul 20 2009, 10:00 AM

QUOTE (4th rock from the sun @ Jul 20 2009, 10:14 AM) *
A nice place to check for updated daily planetary images is: http://alpo-j.asahikawa-med.ac.jp/Latest/Jupiter.htm


Now that's a v useful site to keep an eye on, thanks! :-)

Posted by: Sunspot Jul 20 2009, 10:20 AM

I've often wondered why we see so few planetary images from professional ground based observatories?? The quality of images from amateurs with 10-14" scopes is breathtaking these days, I wonder what this "impact" would look like with a 8 or 10 metre class telescope.

Posted by: 4th rock from the sun Jul 20 2009, 10:23 AM

Yes, the ALPO Japan Planetary Section it's full of great stuff. For example, there are updated planetary maps rolleyes.gif and the "database" goes back some years. All amateur work but very organized and well documented.

Posted by: Stu Jul 20 2009, 11:51 AM

From Twitter: "Glenn Orton from JPL is imaging the Jupiter impact site now w/ the NASA Infrared Telescope & he's confirmed it's an impact!!"

Posted by: Sunspot Jul 20 2009, 12:40 PM

can you give me the link the the twitter sites your using?

Posted by: Hungry4info Jul 20 2009, 12:44 PM

Die! Die! Watch them die!


QUOTE ("Sunspot")
can you give me the link the the twitter sites your using?

A quick Google search of the quoted text quickly reveals that it came from this Twitter.
http://twitter.com/mikesalway

Posted by: ElkGroveDan Jul 20 2009, 07:58 PM

Too bad it wasn't Saturn.

Posted by: Decepticon Jul 20 2009, 08:08 PM

ohmy.gif

Posted by: Phil Stooke Jul 20 2009, 08:19 PM

EGD: "Too bad it wasn't Saturn. "

Very good point!

Phil

Posted by: Stu Jul 20 2009, 08:26 PM

Interesting Twitter site to follow re this story...

http://twitter.com/LeighFletcher


Posted by: ugordan Jul 20 2009, 08:40 PM

Would we be able to measure the temperatue and cross-referencing the decay with SL-9 data come up with a rough impact time? Which would then show us if it was the Earth-facing hemisphere or not - not that it would be a terribly useful piece of info.

Regarding a Saturn impact - two things:

1) It would probably be harder to spot by an amateur and thus more likely to be missed
2) I'm not sure Cassini could be retargeted so quickly anyway. It's running sequences preprogrammed weeks if not months ahead.

Posted by: tedstryk Jul 20 2009, 08:59 PM

Yes, but Cassini would undoubtedly serendipitously make some measurements sooner or later. I imagine that once they have approximated impact time as best they can, many people will be scouring webcam video as well as deep exposures in the general vicinity to try to pick up something. I would say finding imagery of the impact is unlikely - there is nearly a 50% chance that it happened out of view of earth, and even if it was in view, it would take a really good telescope and imaging system to get it, unless it was an infrared telescope, but that would require even more tremendous luck. Also, an infrared observation would have been so obvious and likely taken by professionals, so it is hard to see it being missed. Basically, a more likely scenario is that we narrow it down by finding the first time it should have transited and wasn't seen. This may improve, as many amateur observers take a while to submit their data. Then, hopefully, based on the time frame, any deep wide field frames that might show something can be searched. Still, this is a real needle in a haystack. SL-9 was much larger - based on this spot, it would seem many of its fragments were much larger - than this impactor. Plus, correct me if I'm wrong, but SL-9 wouldn't have been nearly as active had it not been ripped to pieces by Jupiter's gravity. Plus, has anyone considered the fact that this might have been an asteroid? That would likely never be found.

Posted by: ugordan Jul 20 2009, 09:08 PM

QUOTE (tedstryk @ Jul 20 2009, 10:59 PM) *
Plus, correct me if I'm wrong, but SL-9 wouldn't have been nearly as active had it not been ripped to pieces by Jupiter's gravity. Plus, has anyone considered the fact that this might have been an asteroid? That would likely never be found.

I read SL-9 was likely in orbit around Jupiter since the 1930s, but wasn't picked up until after it was torn apart as you say. A small inbound comet or an asteroid would never have been picked up, probably even if we knew where to look. The magnitude would just be below detectable.

Posted by: nprev Jul 20 2009, 09:35 PM

Re Saturn vs. Jupiter impacts: Another thing to remember is that there are a LOT more "amateurs" (these days, I almost hesitate to use that word; perhaps volunteer professionals?) watching Jupiter simply because its disc is always changing, what with the Spot, lesser Spots, the belts, eclipse shadows, etc.

Saturn's disc, unfortunately, is extremely bland due to high hazes and of course is completely overshadowed by the rings, which themselves aren't very dynamic in telescopic views. Although it's possible that a Saturn hit might be even more conspicious by contrast with its subdued surroundings, the odds of an amateur picking it up aren't as good; nobody pays much attention to the planet itself.

Posted by: Sunspot Jul 20 2009, 10:59 PM

QUOTE (Stu @ Jul 20 2009, 09:26 PM) *
Interesting Twitter site to follow re this story...

http://twitter.com/LeighFletcher


That seems the best site to follw for information....and we might get more images soon it seems.

Posted by: Floyd Jul 20 2009, 11:10 PM

http://jpl.nasa.gov/news/news.cfm?release=2009-112 In part:

Scientists have found evidence that another object has bombarded Jupiter, exactly 15 years after the first impacts by the comet Shoemaker-Levy 9.

Following up on a tip by an amateur astronomer that a new dark "scar" had suddenly appeared on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and noon EDT) scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., using NASA's Infrared Telescope Facility at the summit of Mauna Kea, Hawaii, gathered evidence indicating an impact.

New infrared images show the likely impact point was near the south polar region, with a visibly dark "scar" and bright upwelling particles in the upper atmosphere detected in near-infrared wavelengths, and a warming of the upper troposphere with possible extra emission from ammonia gas detected at mid-infrared wavelengths.

"We were extremely lucky to be seeing Jupiter at exactly the right time, the right hour, the right side of Jupiter to witness the event. We couldn't have planned it better," said Glenn Orton, a scientist at JPL.

Orton and his team of astronomers kicked into gear early in the morning and haven't stopped tracking the planet. They are downloading data now and are working to get additional observing time on this and other telescopes.

Really tacky JPL that you couldn't mention Anthony Wesley by name.

[Edit] JPL corrected their release to name Antony Wesley.

Posted by: volcanopele Jul 20 2009, 11:16 PM

http://photojournal.jpl.nasa.gov/catalog/PIA12148

Posted by: ugordan Jul 20 2009, 11:20 PM

It would have been nice if they actually mentioned Anthony Wesley's name in the release. I can already see the media picking this up as a NASA discovery.

Posted by: Sunspot Jul 20 2009, 11:24 PM

QUOTE (ugordan @ Jul 21 2009, 12:20 AM) *
It would have been nice if they actually mentioned Anthony Wesley's name in the release. I can already see the media picking this up as a NASA discovery.


Yeh that's the first thing I thought about when reading the press release, a bit naughty really.

Posted by: nprev Jul 20 2009, 11:31 PM

Agreed. mad.gif

Again, I find it hard to even describe Mr. Wesley as an "amateur", and he certainly deserves name credit as the discoverer of this event. If a comet is named after its discoverer, then a discovered (probable) cometary impact rates acknowledgement of the person who first spots it!

Posted by: Sunspot Jul 20 2009, 11:32 PM

There is contact info at the bottom of the press release.

Carolina Martinez 818-354-9382
Jet Propulsion Laboratory, Pasadena, Calif.
carolina.martinez@jpl.nasa.gov

Posted by: tedstryk Jul 20 2009, 11:32 PM

It may be that the public relations office nazis are waiting to get some privacy release consent...

Posted by: ugordan Jul 20 2009, 11:32 PM

Someone should email them about that, to be honest. Why is it a postdoc student is worthy of mentioning and even eligible for a comment and the original discoverer (whom Spaceweather.com labeled as "veteran Jupiter observer") isn't?

I understand this is JPL's own observation, but they were working off of another discovery. Isn't it customary to reference the original author/observer then? As it stands, this wouldn't be too far from a scoop, media-wise.

Posted by: Floyd Jul 20 2009, 11:34 PM

I just e-mailed her

Posted by: nprev Jul 20 2009, 11:37 PM

Thanks, Sunspot. I just left her a very polite voicemail with a callback number & everything; hopefully it'll do some good...(?)

Posted by: stevesliva Jul 20 2009, 11:38 PM

Just name the deceased impactor after him. wink.gif Heck, if they do find it in old images... would they?

Posted by: Sunspot Jul 20 2009, 11:41 PM

http://www.newscientist.com/article/dn17491-jupiter-sports-new-bruise-from-impact.html

Well, pleased to the New Scientist article gives Mr Wesley full credit

Posted by: nprev Jul 20 2009, 11:43 PM

QUOTE (stevesliva @ Jul 20 2009, 04:38 PM) *
Just name the deceased impactor after him.


That'd be an IAU call, but it's an interesting thought. The object was never spotted (and my guess is that it probably won't turn up in any old images, either), yet there is unmistakable, observable, confirmed evidence that it once existed...

Posted by: ugordan Jul 20 2009, 11:47 PM

Wow, the Keck image really shows some interesting structure in the infrared. Almost looks like two discrete impacts.

Posted by: nprev Jul 20 2009, 11:54 PM

Yes, it does indeed, Gordan!

VERY interesting, actually. For starters, it looks like the prevailing winds are coming from about 1 o'clock (with respect to the orientation of the image). What's really cool is that slightly fainter yet broader patch at 5 o'clock just next to the bright spot of the presumed main impact. I'm guessing that this might just be the main "ejecta" zone, and that the impactor hit Jupiter slightly obliquely from the 10 o'clock direction.

Posted by: Floyd Jul 21 2009, 12:03 AM

Just received the following:
Hi Floyd,

We were rushing to get this out the door today. We will add the name and issue an update.

Thanks,
Carolina



Posted by: nprev Jul 21 2009, 12:04 AM

Well done, Floyd!!!!!

Posted by: rogelio Jul 21 2009, 12:42 AM

Why not honor the discoverer by referring to this feature (and all future features of this type; that is, caused by the impact of undetected comets and asteroids) as Wesley’s Spot? As we honor the discoverers of comets, be they amateur or professional?

A more original name for this type of feature would be nice (admittedly "spot" is kind of uninspired). “Macula” is already in use for features on solid planetary and moon surfaces. This “spot” resembles and is in fact a kind of bruise or contusion – Latin for bruise is cicatrix, but Wesley’s Cicatrix doesn’t exactly roll off the tongue...


Posted by: nprev Jul 21 2009, 12:47 AM

Problem is that it's extremely transient, Rogelio. It'll probably be completely gone in a few weeks, a few months at most.

Posted by: john_s Jul 21 2009, 02:23 AM

QUOTE (ugordan @ Jul 20 2009, 11:47 PM) *
Wow, the Keck image really shows some interesting structure in the infrared. Almost looks like two discrete impacts.


I'm not sure- notice that the "cusp" of the bright south polar hood also looks doubled. I think this might be a seeing artifact or a hiccup in the AO system, if they were using AO.

John.

Posted by: nprev Jul 21 2009, 03:18 AM

Hmm. I see what you mean, John. If this is the cause, then it's logical that the secondary image would be so pronounced since the primary's so bright.

In fact, at second glance it looked oddly 3D to me as well, almost as if the faint image was a reflection underneath the bright one, and THAT ain't real!

EDIT: Well...I dunno now, maybe it is a reflection @ Jupiter (not an AO artifact), but on an upper cloud layer. Presumably the bright IR source is deeper if both features are real.

EDIT2: JPL has updated their press release by adding Mr. Wesley's name. However, SpaceflightNow is running the earlier version as its lead story without his name. There ain't no justice. sad.gif

Posted by: Pertinax Jul 21 2009, 03:58 AM

Saw a mention of this on SpaceWeather this morning:

http://www.nasa.gov/topics/solarsystem/features/jup-20090720.html


-- Pertinax

Posted by: ynyralmaen Jul 21 2009, 06:33 AM

QUOTE (ugordan @ Jul 21 2009, 12:32 AM) *
Why is it a postdoc student is worthy of mentioning and even eligible for a comment and the original discoverer (whom Spaceweather.com labeled as "veteran Jupiter observer") isn't?


I absolutely agree that Wesley's name should have been given from the outset, but note that "postdoctoral fellow" doesn't mean student. The person you're referring to definitely has a PhD and is playing a key role in the JPL observations (and it's his informative tweets that many of us are following!). smile.gif

Edit: Sorry ugordan, I've now seen the original version of the JPL release, and can see that it's the release's authors who erroneously used the term "postdoctoral student" (corrected in the newer version that I first read).

Posted by: dtolman Jul 21 2009, 03:21 PM

This has been picked up on the NY Times breaking news blog (explicitly a blog, so not held to whatever standards [insert joke here] for official/published stories). From a viewpoint of someone familiar with NASA and astronomy, the comments are an interesting window to the public at large.

http://thelede.blogs.nytimes.com/2009/07/21/amateur-astronomer-finds-new-earth-size-impact-mark-on-jupiter/

Posted by: SFJCody Jul 21 2009, 03:59 PM

QUOTE (dtolman @ Jul 21 2009, 04:21 PM) *
From a viewpoint of someone familiar with NASA and astronomy, the comments are an interesting window to the public at large.

http://thelede.blogs.nytimes.com/2009/07/21/amateur-astronomer-finds-new-earth-size-impact-mark-on-jupiter/


Yeah, there's a scattering of crazies in there, but the comments don't seem too bad, on the whole. A word of caution- never read the comments on any youtube video, astronomy related or otherwise. Your brain will leak out of your ears!

Posted by: imipak Jul 21 2009, 08:03 PM

QUOTE (dtolman @ Jul 21 2009, 04:21 PM) *
...an interesting window to the public at large.

Pass.

Posted by: volcanopele Jul 21 2009, 08:39 PM

Obviously, the quick comment that can be answered here (meaning not kooky), the impact scar is the ~ the size of Earth, NOT the impactor. Somehow there is some confusion about that among the commenters. The impactor was at best 1-2 km across, a faint object to observe from that distance. Not impossible by any means, we have observed outer moons of Jupiter that small, but we have no indication at this point that the impactor went through a period were it was temporarily captured by Jupiter, like SL9.

I think a lot of people in the general public extrapolate the fact that we have found nearly all the earth-orbit crossing asteroids of that size to mean that we have found all the objects in the Solar system of that size. That maybe another source of confusion.

Posted by: Mongo Jul 21 2009, 09:23 PM

Will it be possible to determine the bulk nature of the impactor -- icy vs. rocky vs. iron? According to my understanding, a higher strength impactor would burrow further into Jupiter's atmosphere before fully disintegrating, thereby dredging up deeper (and presumably compositionally different) layers of that atmosphere, which might be detectable on large Earth-based telescopes.

The fact that the impactor was not detected prior to impact suggests (although it does not prove) that the impactor was relatively faint, suggesting a rocky or metallic composition to me.

Bill

Posted by: SFJCody Jul 21 2009, 09:25 PM

Interestingly, there http://www.ingentaconnect.com/content/ap/is/1997/00000126/00000001/art05636 which said that the mean interval between impacts of comets >0.3km on Jupiter is on the order of 500 years. I guess the real figure might be a lot less than that.

Posted by: volcanopele Jul 21 2009, 09:38 PM

Wasn't that based on two data points, Shoemaker-Levy 9 and the observation of a possible impact scar by Cassini (the astronomer, not the spacecraft)?

Obviously, it looks like the impact rate is greater than that, but I think with further study of this impact and comparisons with the impacts by the SL9 fragments, we can obtain an estimate of the impactors size assuming a similar composition and structure to the SL9 fragments.

Posted by: tedstryk Jul 21 2009, 09:39 PM

QUOTE (SFJCody @ Jul 21 2009, 09:25 PM) *
Interestingly, there http://www.ingentaconnect.com/content/ap/is/1997/00000126/00000001/art05636 which said that the mean interval between impacts of comets >0.3km on Jupiter is on the order of 500 years. I guess the real figure might be a lot less than that.

Some put the size of she SL/9 parent body at 1-3 km. Given that many of the fragments made bigger marks than this, it is quite possible that this object is significantly smaller than .3 km.

Posted by: SFJCody Jul 21 2009, 09:51 PM

QUOTE (volcanopele @ Jul 21 2009, 10:38 PM) *
Wasn't that based on two data points, Shoemaker-Levy 9 and the observation of a possible impact scar by Cassini (the astronomer, not the spacecraft)?


Yep, I believe so, and the paper detailing the possible 1690 impact http://articles.adsabs.harvard.edu//full/1997PASJ...49L...1T/L000001.000.html.


QUOTE (tedstryk @ Jul 21 2009, 10:39 PM) *
Some put the size of she SL/9 parent body at 1-3 km. Given that many of the fragments made bigger marks than this, it is quite possible that this object is significantly smaller than .3 km.


http://www.lpi.usra.edu/meetings/lpsc97/pdf/1351.PDF has a useful comparison of impact scar class to parent body diameter for SL9. The recent impact mark looks like it is well into the class 2 category, larger than any scar formed by sub 0.3km fragments of SL9. Still, I guess the impactor could have been smaller provided it also had a higher impact velocity or higher density than the SL9 fragments.

Posted by: Juramike Jul 21 2009, 11:43 PM

Here's a paper putting the impact rate of 2 km comets at 4E-3 yr-1. (= one per 250 years average)

Zahnle et al. Icarus 163 (2003) 263-289. "Cratering rates in the outer Solar System." doi: 10.1016/S0019-1035(03)00048-4.

Full article freely available http://lasp.colorado.edu/~espoclass/homework/5830_2008_homework/Zahnle2003CrateringRates.pdf (684 kb)


Either we've been really lucky and we've observed an extraordinary exciting period, or the impact rate needs to be adjusted upwards.
(Makes you wonder how many we've missed??? A permanent "Jupiter-cam" set of observatories might be a worthwhile investment.)


Posted by: dvandorn Jul 22 2009, 01:03 AM

It occurs to me that the most massive objects in the Solar System ought to vacuum up the most pieces of debris per any given time period. And we know from the observations made for decades now by solar observatories that the Sun is probably the most frequently impacted body in the Solar System. (How many comets per year make death dives into our local star?)

It would make sense, then, that Jupiter would have the second-highest impact rate in the system. I know this is dependent on the relative abundance of potential impactors at various locations... but, on the scale of the entire system, it still makes sense to me.

-the other Doug

Posted by: djellison Jul 22 2009, 07:30 AM

Two points - one is the "Friend or Foe" nature of of Jupiter- google that exact phrase for the research, it's very interesting.

Secondly - twice I've seen people cite Comet impact rates.

Who says this is a comet? Could have been an asteroid. If it's one 2km Comet / 250yrs, then what does the statistical distribution tell us for, say, 100m sized objects? 10x more frequent? 100x?


Posted by: Sunspot Jul 22 2009, 08:25 AM

Hubble will be observing the spot in the next couple of days with it's new WFC3, along with Keck.

http://www.space.com/scienceastronomy/090721-jupiter-impact.html

It's pretty amazing to me that the image of the impact made by Anthony Wesley is as good if not better than the first image of Jupiter made by . http://hubblesite.org/newscenter/archive/releases/1991/1991/13/image/a/

I guess it shows how bad the spherical aberration was.

Posted by: djellison Jul 22 2009, 09:03 AM

Also shows how damn good the amateurs have got using the webcam techniques.

Posted by: 4th rock from the sun Jul 22 2009, 09:19 AM

QUOTE (Juramike @ Jul 22 2009, 12:43 AM) *
... A permanent "Jupiter-cam" set of observatories might be a worthwhile investment....


Amateurs already do that. You have almost 100% daily global coverage of Jupiter. Quality does vary, but on average it's very good. At least good enough to catch the present collision.
Also, please check the JUPOS project (http://jupos.privat.t-online.de/index.htm) for nice nice Jupiter feature position studies.
Of course, some funding might get more scientific results out of all that data.

Posted by: nprev Jul 22 2009, 12:29 PM

QUOTE (djellison @ Jul 22 2009, 12:30 AM) *
Who says this is a comet? Could have been an asteroid.


True. I've been assuming that it was most likely an inbound long-period comet on a "bang for the buck" premise; think that would maximize impact kinetic energy while minimizing the object's mass (and therefore chances of pre-impact detection.)

There doesn't seem to be any way to really know for sure, though. The spectral signatures are undoubtedly dominated by indigenous Jovian material, so we'll never know the impactor's gross composition. Looks like the only potential clues would come from finding it in pre-impact imagery, and then only if there were enough of them to determine its orbit (assuming that it wasn't already captured like SL9).

Posted by: Juramike Jul 22 2009, 02:21 PM

QUOTE (4th rock from the sun @ Jul 22 2009, 04:19 AM) *
Amateurs already do that. You have almost 100% daily global coverage of Jupiter. Quality does vary, but on average it's very good. At least good enough to catch the present collision.
Also, please check the JUPOS project (http://jupos.privat.t-online.de/index.htm) for nice nice Jupiter feature position studies.
Of course, some funding might get more scientific results out of all that data.


Very cool! I didn't know about that!! (And I don't know if anyone in our local astronomy club is aware of it either (yet)).

Thanks muchly!!

-Mike

Posted by: 4th rock from the sun Jul 22 2009, 03:03 PM

Regarding lesser known amateur planetary observation projects, ALPO has some long lasting programs.

I've participated with some Mercury images some years ago and at that time there were enough good images to monitor some permanent surface albedo features on the planet's unimaged side. Also, there's some work related to monitoring seasonal changes in Uranus. As for Venus, although there are frequent UV images, I'm not aware of any particular aspect being studied, just general cloud monitoring.


Posted by: tedstryk Jul 22 2009, 04:26 PM

To be fair, given the bright background and having looked at the raw data, that Hubble image looks like a bad scan of an already poorly processed version. Looking at the moons in some of these early HST images and comparing them to modern webcams, the HST images have a slight edge, but that is all.

Posted by: ugordan Jul 22 2009, 04:29 PM

QUOTE (tedstryk @ Jul 22 2009, 06:26 PM) *
To be fair, given the bright background and having looked at the raw data, that Hubble image looks like a bad scan of an already poorly processed version.

Yep, that's got "scan" written all over it, down to the print scratches on the high res version.

Posted by: PFK Jul 23 2009, 11:33 AM

QUOTE (ugordan @ Jul 20 2009, 09:40 PM) *
1) It would probably be harder to spot by an amateur and thus more likely to be missed

I'm sure that's true, but the fact that we're just two weeks from the 76th anniversary of film comedian Will Hay doing just that shouldn't go unremarked
<insert double take and grimace smiley>
http://cdsads.u-strasbg.fr//full/seri/MNRAS/0094//0000085.000.html

Posted by: tedstryk Jul 24 2009, 12:11 AM

http://archive.stsci.edu/proposal_search.php?mission=hst&id=12003

The HST observations have begun...the first set wrapped up about four hours ago.

Posted by: nprev Jul 24 2009, 12:32 AM

Is that a restricted-access page, Ted? I get nothing but the frame.

Surprisingly good news, in any case!

Posted by: tedstryk Jul 24 2009, 12:45 AM

It did that for me on the first few tries.

BTW, Gemini has also looked http://www.gemini.edu/node/11300

Posted by: Sunspot Jul 24 2009, 07:17 AM

QUOTE (tedstryk @ Jul 24 2009, 01:11 AM) *
http://archive.stsci.edu/proposal_search.php?mission=hst&id=12003

The HST observations have begun...the first set wrapped up about four hours ago.


I'm assuming that with Hubble still in it's recommissioning phase and images not supposed to be released until some time in September we are unlikely to see these observations for some time??

EDIT: OK just saw this at spaceflight now http://www.spaceflightnow.com/news/n0907/24hubble/

"Engineers programmed Hubble to spend a few hours observing Jupiter Thursday afternoon. Imagery of Jupiter could be released by late Friday, according to Ray Villard, spokesperson for the Space Telescope Science Institute."

Posted by: Hungry4info Jul 24 2009, 11:26 AM

Definitely looking forward to this first example of the improved capabilities with WFP3.

Posted by: Sunspot Jul 24 2009, 12:12 PM

QUOTE (Hungry4info @ Jul 24 2009, 12:26 PM) *
Definitely looking forward to this first example of the improved capabilities with WFP3.


Yes, and it's a shame they couldn't get the High Resolution Camera on ACS working again.

Posted by: tedstryk Jul 24 2009, 01:45 PM

They repaired the ACS HRC, but it is much more complex to operate and would take much more time. At any rate, the WFC3, while having a much larger field of view than WFPC2, has significantly higher resolution than the PC chip in WFPC2, so this should be good.

Posted by: Hungry4info Jul 24 2009, 02:11 PM

QUOTE (tedstryk @ Jul 24 2009, 07:45 AM) *
They repaired the ACS HRC, but it is much more complex to operate and would take much more time. At any rate, the WFC3, while having a much larger field of view than WFPC2, has significantly higher resolution than the PC chip in WFPC2, so this should be good.


They repaired ACS HRC? When? Last I heard the last servicing mission wasn't able to do that. Were they able to do it from the ground via some software method?

Posted by: tedstryk Jul 24 2009, 02:42 PM

OK, I see that now, I didn't realize the HRC had further problems (although they are still trying to find a work-around).

Posted by: nprev Jul 24 2009, 05:07 PM

Good http://www.spaceflightnow.com/news/n0907/24hubble/ re yesterday's Hubble obs; images may be released later today!

Posted by: stevesliva Jul 24 2009, 07:10 PM

Yup! http://hubblesite.org/newscenter/archive/releases/2009/23/

Posted by: nprev Jul 24 2009, 07:22 PM

YESSSSS!!! smile.gif

Wow. Obviously these are rush images that haven't been calibrated, but at first blush that hit looks a lot more pronounced than I remember for even the largest SL9 fragments. In fact, it almost looks like more dark material may have been boiling out from the deeper levels of the atmosphere since the impact occurred, and the 'ejecta field' to the left of center's still there.

Wow. Just wow. WFC3's performance is looking pretty good at this early stage as well!

Posted by: PDP8E Jul 24 2009, 07:34 PM

Man, I love the Hubble! That picture is incredible

Posted by: lyford Jul 24 2009, 07:40 PM

Sweet Fancy Moses!!!!! biggrin.gif

Posted by: ugordan Jul 24 2009, 09:05 PM

Also, http://www.gemini.edu/node/11300

Posted by: ElkGroveDan Jul 24 2009, 10:26 PM

That downrange disturbance almost looks like the measurable effects of a shock-wave which in turn probably says something about the atmospheric density and structure in that region. Clearly there's a whole lot of derived science that likely will be gleaned from these images.

Posted by: nprev Jul 24 2009, 10:33 PM

You know, if we keep seeing these things happen on Jupiter & (hopefully!) the other gas giants, we're going to have to come up with some sort of workable nomenclature for all these features.

Virtually every bit of impact terminology relates to solid matter (craters, ejecta, etc.). What do you call a persistent hole in a cloud deck that apparently spews stuff out & has other stuff laying around on surrounding clouds?

Posted by: Sunspot Jul 24 2009, 10:52 PM

I sharpened the BW image slightly... this new camera is going to be amazing.



 

Posted by: Stu Jul 24 2009, 11:30 PM

QUOTE (nprev @ Jul 24 2009, 11:33 PM) *
we're going to have to come up with some sort of workable nomenclature for all these features.


"Impact"... "dwarf impact"... "brush with"..."jeez, that was close!"...

rolleyes.gif



Posted by: nprev Jul 24 2009, 11:57 PM

Just don't put ME in charge of that...doubt that many (if any) of my terms would be printable! tongue.gif

Ordinary adjectives just aren't sufficient to describe these titanic events.

Posted by: dvandorn Jul 25 2009, 12:27 AM

I think in the case of impacts onto gas giants, the old term for a meteor crater, "astrobleme," works well. It really is more of a blemish than a crater -- and like a blemish, it will fade over time.

Almost looks like there was the familiar-from-SL9 "black-eye" effect of downstream ejecta to the left, plus a very long, very dark ejected plume that pushed back out from left to right in these images. I get the feel of an impactor on a shallow, fast trajectory moving from right to left (in the Hubble images; all this would be reversed in the original discovery photos and the Gemini images), the "black-eye" ejecta pushing ahead of the impact site (perhaps defined by shock waves from the impact), and a plume of very dark material (mostly gas, I imagine) being fountained out of the impact site back along the impactor's track, from left to right, making up the very dark, now-deforming oval marking the astrobleme.

Just my gut-level feel from looking at these new, sharp images...

-the other Doug

Posted by: nprev Jul 25 2009, 12:44 AM

Yeah, I was thinking about "astrobleme" myself, oDoug; it really is apropos for these things, as you pointed out.

I'm sure that there are hordes of scientists that would gladly give one or more internal organs to know exactly what that dark material is composed of. I suspect that it's some sort of precipitate: hot, formerly highly pressurized gas from down below that's abruptly been exposed to cold & low pressure in the cloudtops.

Wonder if astroblemes might be a productive molecular synthesis mechanism over time.

Posted by: john_s Jul 25 2009, 02:18 AM

I think it's most likely that the dark stuff is hydrocarbon gunk cooked up from the ambient methane by the high temperatures of the impact. The dark stuff in the diffuse halo may even form in place, from the high temperatures generated when the ejecta slams back into the upper atmosphere- heat from that mechanism was what produced the bright near-IR flashes seen in the SL9 impacts.

John

Posted by: tty Jul 25 2009, 08:51 PM

Since these impacts are apparently fairly frequent (since we have observed two in a short time) and the "gunk" produced should be fairly stable in the low temperatures prevailing in the upper atmosphere one wonders how much "gunk" accumulates and to what extent it contributes to Jupiter's colourful atmosphere.
I would expect that the molecules will ultimately sink deep enough into the atmosphere for the heat to break them up into simple molecules again, but that should be a slow process.

Posted by: ups Jul 25 2009, 09:24 PM

The new images from Hubble are going to be incredible -- does anyone have an idea of how frequently they will be updating?

Posted by: 4th rock from the sun Jul 25 2009, 11:24 PM

The impact feature is easily visible on small telescopes.
Here's an image I got last night:



I didn't expect it to be that detailed, so it's really worth to observe if you can, even if just visually.

Posted by: antipode Jul 26 2009, 02:25 AM

Given that the frequency of large impacts may be higher than we have thought, Junocam might end up being a very useful asset indeed!
P

Posted by: NGC3314 Jul 26 2009, 05:55 PM

QUOTE (ups @ Jul 25 2009, 04:24 PM) *
The new images from Hubble are going to be incredible -- does anyone have an idea of how frequently they will be updating?



The status of the HST program (number 12003, PI Heidi Hammel) may be found http://www.stsci.edu/cgi-bin/get-proposal-info?12003. It shows an initial 2-orbit allocation later increased to 5. Two orbits were used for a series of 18 exposures on 23 July, 1812-2027 UT. The others do not show schedule dates yet; it looks as if two more visits are in the proposal.


That link is already in the thread. - Moderator

Posted by: Mongo Jul 26 2009, 07:56 PM

From the above:

We request 7 orbits of HST time to characterize this rare event. We hope that two orbits can be as soon as is feasible (Wednesday or Thursday, 22 or 23 July). We would like a second pair several days later, perhaps Saturday. We request another 2 orbits the following week. The last, seventh, orbit can be several weeks or a month later.

Posted by: remcook Jul 30 2009, 03:22 PM

Another overview site:

http://planets.ucf.edu/resources/jupiter-impact

Posted by: tedstryk Aug 9 2009, 12:22 AM

Hubble has just wrapped up its next look.


___________________________________________

Visit Status Report for 12003
Sat Aug 08 20:18:57 EDT 2009

Visit Status Targets Configs Start Time End Time
21 Archived JUPITER-IMPACT-SITE WFC3/UVIS Jul 23 2009 18:05:50 Jul 23 2009 20:36:33
22 Archived JUPITER-IMPACT-SITE-V3 WFC3/UVIS Aug 3 2009 12:59:46 Aug 3 2009 13:52:21
23 Scheduled JUPITER-IMPACT-SITE-V3 WFC3/UVIS Aug 8 2009 22:24:37 Aug 8 2009 23:20:28

Posted by: PhilCo126 Aug 9 2009, 10:13 AM

This Friday 14th August, the planet Jupiter will be in opposition = best moment to observe it in binoculars or telescopes!

Posted by: stevesliva Aug 10 2009, 07:57 PM

QUOTE (PhilCo126 @ Aug 9 2009, 06:13 AM) *
This Friday 14th August, the planet Jupiter will be in opposition = best moment to observe it in binoculars or telescopes!


Is that why there are so many fantastic images of this?

Someone has contributed an amazing polar-projection animation to spaceweather.com. Hopefully this is a permalink:
http://spaceweather.com/archive.php?view=1&day=09&month=08&year=2009

The "zoom" version appears to show a wisp (yeah, a continent-sized "wisp) torn off into the more northerly band of weather. Very very cool.

Posted by: Paolo May 14 2010, 07:35 AM

on arXiv today http://arxiv.org/abs/1005.2312

Posted by: Sunspot Jun 3 2010, 04:15 PM

http://hubblesite.org/newscenter/archive/releases/2010/16/full/

More from Hubble on lasts years impact.

Again, Anthony Wesley is not credited with the discovery by name.

Posted by: Tom Tamlyn Jun 5 2010, 06:26 AM

QUOTE (Sunspot @ Jun 3 2010, 11:15 AM) *
Again, Anthony Wesley is not credited with the discovery by name.

The omission is especially striking in light of the press release's comments about the value of cooperation between professional and amateur astronomers.

>>"This solitary event caught us by surprise, and we can only see the aftermath of the impact, ....
>>...
>>The recent impact underscores the important work performed by amateur astronomers.
>>"This event beautifully illustrates how amateur and professional astronomers can work together..."

It's interesting that the paper http://www.unmannedspaceflight.com/index.php?s=&showtopic=6118&view=findpost&p=159712 several messages up thread, which looks as though it might be the standard scholarly account of the impact discovered by Wesley, and which is cited in the Hubble paper, includes Wesley as second author. And it's also pleasing that http://en.wikipedia.org/wiki/2009_Jupiter_impact_event says that the 2009 Jupiter impact event is "occasionally referred to as the Wesley impact."

TTT

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