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

http://www.irishastronomy.org/cms/forum?fu...;id=79644#79647

More info: http://www.acquerra.com.au/astro/ObsReport...ter-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

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



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.

Now picked up by astronomy.

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.

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!

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.

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

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.

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

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!



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

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.

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.

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.

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

JPL new release 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.

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

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/dn1749...rom-impact.html

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

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...

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