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
Precisely 15 years after Shoemaker-Levy 9 barrage. If only we had advance notice, maybe this time it was a dayside impact...
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
Now picked up by http://cs.astronomy.com/asycs/forums/t/41364.aspx.
Maybe we are getting another Venus ??
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.)
Very cool. Given how much Jupiter eats comets and asteroids, wouldn't be all that surprising. Now if only this would happen on Saturn
Otherwise, the monolith seems to be a year early
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.
No problem. This topic belongs in the Telescope Observations sub-forum anyway, so I'm moving this there.
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.
Universe Today... Bad Astronomer... sites like that.
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
I think the forum might enjoy this, one of my favourite bits from Terry Pratchett's Discworld series:
Some more pix here...
http://jupiter.samba.org/jupiter-impact.html
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.
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.
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.
Yes, the ALPO Japan Planetary Section it's full of great stuff. For example, there are updated planetary maps and the "database" goes back some years. All amateur work but very organized and well documented.
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!!"
can you give me the link the the twitter sites your using?
Die! Die! Watch them die!
Too bad it wasn't Saturn.
EGD: "Too bad it wasn't Saturn. "
Very good point!
Phil
Interesting Twitter site to follow re this story...
http://twitter.com/LeighFletcher
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.
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.
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.
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.
http://photojournal.jpl.nasa.gov/catalog/PIA12148
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.
Agreed.
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!
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
It may be that the public relations office nazis are waiting to get some privacy release consent...
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.
I just e-mailed her
Thanks, Sunspot. I just left her a very polite voicemail with a callback number & everything; hopefully it'll do some good...(?)
Just name the deceased impactor after him. Heck, if they do find it in old images... would they?
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
Wow, the Keck image really shows some interesting structure in the infrared. Almost looks like two discrete impacts.
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.
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
Well done, Floyd!!!!!
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...
Problem is that it's extremely transient, Rogelio. It'll probably be completely gone in a few weeks, a few months at most.
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.
Saw a mention of this on SpaceWeather this morning:
http://www.nasa.gov/topics/solarsystem/features/jup-20090720.html
-- Pertinax
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/
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.
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
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.
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.
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.)
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
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?
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.
Also shows how damn good the amateurs have got using the webcam techniques.
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.
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.
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.
Is that a restricted-access page, Ted? I get nothing but the frame.
Surprisingly good news, in any case!
It did that for me on the first few tries.
BTW, Gemini has also looked http://www.gemini.edu/node/11300
Definitely looking forward to this first example of the improved capabilities with WFP3.
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.
OK, I see that now, I didn't realize the HRC had further problems (although they are still trying to find a work-around).
Good http://www.spaceflightnow.com/news/n0907/24hubble/ re yesterday's Hubble obs; images may be released later today!
Yup! http://hubblesite.org/newscenter/archive/releases/2009/23/
YESSSSS!!!
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!
Man, I love the Hubble! That picture is incredible
Sweet Fancy Moses!!!!!
Also, http://www.gemini.edu/node/11300
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.
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?
I sharpened the BW image slightly... this new camera is going to be amazing.
Just don't put ME in charge of that...doubt that many (if any) of my terms would be printable!
Ordinary adjectives just aren't sufficient to describe these titanic events.
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
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.
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
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.
The new images from Hubble are going to be incredible -- does anyone have an idea of how frequently they will be updating?
The impact feature is easily visible on small telescopes.
Here's an image I got last night:
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
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.
Another overview site:
http://planets.ucf.edu/resources/jupiter-impact
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
This Friday 14th August, the planet Jupiter will be in opposition = best moment to observe it in binoculars or telescopes!
on arXiv today http://arxiv.org/abs/1005.2312
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.
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