Jupiter gives us a taste of Armageddon

By Phil Plait | June 3, 2010 11:05 am

Last year, in July, something smacked Jupiter. Hard.

It was discovered when an amateur astronomer found a black spot marring Jupiter’s cloud tops. Followup observations saw the spot glowing in the infrared, meaning it was hot, and therefore was not just a storm (which are common). For real and for sure, something impacted Jupiter and exploded – and I mean exploded, releasing the equivalent of hundreds of thousands of nuclear weapons.

But what was it?

hst_jupiter_impact

A new paper just published indicates that it was an asteroid that hit Jupiter. However, since it wasn’t seen beforehand, how do we know?

Because we’ve seen this sort of thing before. In 1994, the big planet was hit repeatedly by the comet Shoemaker-Levy 9. The comet had broken up into dozens of pieces, including several chunks a kilometer or so across, and they slammed into Jupiter one after another over the course of a week. That was one of the most well-observed astronomical events in history; every telescope on the planet was focused on Jupiter at the time.

And telescopes off the planet were too: Hubble took a lot of data, and found two key differences between the 1994 and 2009 events.

hst_jupiter_impactscarOne is that there was a halo of lighter debris around the comet impact points in 1994 (as seen in this image on the right), but no such halo around the 2009 impact site. That indicates that the impacting objects were different.

Also, Hubble observed Jupiter both times in the ultraviolet. Images like that show where small, lighter-weight particles fell from the impact because those particles absorb UV light, leaving dark spots. Even nearly two weeks later, dark spots on Jupiter were evident around the 1994 impact sites. Since comets have a lot of ices in them — what you might call frozen gases like ammonia, methane, and so on — that’s expected. The lighter particles floated around in Jupiter’s clouds, absorbing the UV for quite some time.

But observations from last year’s impact don’t show that behavior! As you can see in big the image above, the dark spot fades rapidly. That’s most likely due to the impact debris (made up of vaporized impactor plus material from Jupiter’s atmosphere that got heated and chemically altered) to sink beneath the clouds. That indicates the particles were heavier than the SL9 impact in 1994, pointing toward the impacting object being an asteroid, not a comet. This is also consistent with the lack of a halo as mentioned above; halos are also made by finer particles. The 2009 impact site lacking a halo means the particles were heavier, as you’d expect from an asteroid.

So even though we didn’t see the object before it hit, it left — haha! — a smoking gun pointing toward its origin.

And here’s a funny thing: this impact occurred 15 years to the week after the SL9 onslaught. I remember getting a lot of email asking me if that meant they were related, but if you think about it you’ll realize it has to be a coincidence: after all, why would Earth’s orbital period have to do with anything hitting Jupiter? And now we see that the object that hit was not comet-like, proving the point.

Asteroid and comet impacts are a real threat to us on Earth. Jupiter, being so much more massive than the Earth, is a bigger target; its gravity draws in more debris. By observing it we can get a better idea of just how much stuff is out there in the solar system, waiting to put the hurt on a planet, including our planet. Just in case you have any lingering doubts, astronomy is important. It is no exaggeration at all to say that learning about astronomy and astronomical events may very well save the human race one day.

Image credits: NASA, ESA, M. H. Wong (University of California, Berkeley), H. B. Hammel (Space Science Institute, Boulder, Colo.), I. de Pater (University of California, Berkeley), and the Jupiter Impact Team; HST Comet Team and NASA


Related posts:

New black spot on Jupiter
Hubble pix at Jupiter’s scar
Jupiter: bringing the hammer down


Comments (45)

  1. It is no exaggeration at all to say that learning about astronomy and astronomical events may very well save the human race one day.

    Meh.

    Bring on the asteroids.

    //gulping flu medicine, going back to bed

  2. Noah

    Would it be safe to say that Earth is safer to have such a massive planet in our solar system to attract large bodies like this away from us?

  3. David

    I love jupiter, Not only does it look Amazing through my telescope. Its also like our big brother that keeps the bullies from beating on us…..At least some of the time.

  4. Ray

    Astronomy is important, but when it comes time to divert the asteroid bearing down on us I’ll take Bruce Willis for the win.

  5. Number 6

    “And here’s a funny thing: this impact occurred 15 years to the week after the SL9 onslaught. I remember getting a lot of email asking me if that meant they were related, but if you think about you’ll realize it has to be a coincidence: after all, why would Earth’s orbital period have to do with anything hitting Jupiter?”

    Because most things in the solar system are locked into orbital resonances with Jupiter?

    “And now we see that the object that hit was not comet-like, proving the point.”

  6. Gary Ansorge

    To me, the July 23 impact looks like a belly button. Perhaps Jup was just showing off its robust girth.

    I love the forensic work. Might even make Bones jealous.

    Great pics.

    GAry 7

  7. Derek

    The human race is hardly worth saving. Do it for the grasshoppers or the panda bears and you’ll have me sold.

  8. GA

    So I’ve heard this many times – that Jupiter is a cosmic vacuum cleaner, sucking up bodies that might be heading towards a collision with the Earth.

    However, wouldn’t the flip side of this be true as well, in that Jupiter might alter the orbit of a comet or an asteroid towards an impact with the Earth?

  9. Asteroid impacts? Bring ‘em on! I’d prefer a straight fight to all this sneaking around!

  10. Derek @7:

    “An asteroid impact could kill millions of kittens and puppies, not to mention Pandas and the endangered Mountain Gorillas, an instant! We must do something about this!”

    Perhaps another approach? “An asteroid impact could destroy half the world’s oil wells in an instant! We must do something about this!”

    ;-)

  11. Levi in NY

    Maybe if an asteroid comes in at just the right angle and is just the right shape, it could plug the broken pipe in the Gulf.

  12. GA #8: “However, wouldn’t the flip side of this be true as well, in that Jupiter might alter the orbit of a comet or an asteroid towards an impact with the Earth?”

    Seat-belts and airbags cause some deaths in auto accidents, but they save many more. I’m willing to bet that Jupiter has a net benefit for us.

  13. EasyAstronomer #12:”Seat-belts and airbags cause some deaths in auto accidents, but they save many more. I’m willing to bet that Jupiter has a net benefit for us.”

    Well I’m not! I demand the government removes Jupiter now. Do we really want to take the chance it might fling something our way before we’re ready?

  14. MoonShark

    “Bring on the asteroids”? — If it’s cowardly to think we lack the tech to fight a many-megaton rock zipping through space at tens of thousands of kmph… then I’m a pansy.

    Go hang around Jupiter if you wanna play cosmic dodgeball ;)

    (FWIW I wish ‘cosmic dodgeball’ was the theme of my birthday party at age 9)

  15. Josh

    we need to replace “amateur astronomer” with underfunded ill equipped volunteer

  16. One of the things that made the SL9 event so exciting is that we had a little warning of its occurrence. I saw the after effects in a large (to me, anyway) telescope, which was another layer of interesting. I was able to see a major astronomical event for myself, not just via the news, and not merely an interesting event from history. I was seeing it live(-ish). I think if we had spotted the asteroid first, that would have added some cache. But this is cool too :-)

  17. GA: “However, wouldn’t the flip side of this be true as well, in that Jupiter might alter the orbit of a comet or an asteroid towards an impact with the Earth? “

    Yes. It’s entirely possible it could also pull something into a collision course, if it doesn’t get too close to Jupiter. But as we’ve seen, Jupiter’s still sucking up more objects than it’s been sending our way.

    Ken: An asteroid impact could kill us all and turn us into fossil fuels for the next civilized race, so bring it on. Now that’s thinking for the future. ;)

    Personally, I wish we got some warning and it was caught on camera. That would have been some great imagery. Maybe in the next 15 years.

    He Who is Currently Working On Some Animations Of This Very Event.

  18. Mark Hansen

    All these worlds are yours except Europa. Attempt no landings there.

  19. Charon

    “Because most things in the solar system are locked into orbital resonances with Jupiter?”

    If by “most things” you mean “almost nothing”, then you would be correct. The asteroid belt has density peaks in resonances with Jupiter. That’s it. None of the planets, comets, Kuiper Belt objects, Oort Cloud objects…

  20. Chas, PE SE

    “Would it be safe to say that Earth is safer to have such a massive planet in our solar system to attract large bodies like this away from us”

    I understood that one of the causes of the asteroid belt was purturbations caused by Jupiter’s gravity. No Jupiter = no asteroids, less pieces to smack into us. (maybe) Have to build an alt. universe with no Jupe.

  21. NobodyOfNote

    Judging by the time lapse photos, the damage looks like it is being erased pretty quickly. Is it just luck that people have seen the impact after effects? Do comets or asteroids hit Jupiter relatively (cosmic-wise) frequently and we are just not seeing the impact or it’s damage?

  22. An enduring disappointment from the 1994 event was that the Galileo spacecraft would have had a front row seat in orbit around Jupiter had it not been delayed by the knock on effect from the Challenger disaster.

    Ah well.

  23. Maybe we could get some movement on the Earth DefensE Network (EDEN! ) if we reminded all the geeks that they will no longer be able to purchase Apple products and blog about them on the internets.

  24. Harry

    If you look closely at the picture…we can see its obvious proof that Black Mesa is still at work!

  25. I’m not sure I would even want to know if an asteroid was heading to Earth that could wipe out all life, or a good chunk of it. What would be the point of us knowing? I’d rather be blissfully ignorant, and be vaporized in an instant, than know what was coming.

  26. Michael, that’s very unlikely to happen now. The vast majority of all civilization-ending capable asteroids have already been located, and none of them is going to hit us any time soon. You might be unlucky enough to be underneath a much smaller asteroid that sneaks though undetected, but I suspect you would prefer to have enough warning to get out of the way before it struck.

    Of all the potential disasters that could face Earth, asteroid/comet strikes are probably the one we should be least worried about. We’re almost to the point where nothing can sneak up on us, and I have every confidence that when a dangerous rock is spotted, we will have ample time to devote the resources necessary to thwart the threat.

    We should be more concerned about what might happen beneath our feet. If a caldera volcano like the one at Yellowstone has a major eruption, it could destroy the world’s economy and wipe out thousands of square miles of habitat. And a major underwater landslide at either Hawaii or the Canary Islands could easily wipe out tens of millions of people and destroy thousands of miles of coastline, with almost no warning at all.

    At least we have a plan for those pesky asteroids. We haven’t a clue what to do with the dangers lurking below our feet, and it’s entirely possible there is nothing we can do.

  27. Jeffersonian

    One thing that’s still not quite clear to me:
    Jupiter’s a gas giant, mostly hydrogen, right?
    So an impact isn’t the same as on Earth (Mars, etc.).
    What IS an impact like, then?
    Aren’t there just succeeding layers of density?
    Maybe a future post topic, Dr. Phil?

  28. Phil, nice use of a Star Trek episode title for this one.

  29. #27: Dreamer:
    I suppose that is true.

  30. Pi-needles

    @4. Ray Says:

    Astronomy is important, but when it comes time to divert the asteroid bearing down on us I’ll take Bruce Willis for the win.

    Um, .. you do know he’s just an actor and can’t actually fly spacecraft, drill into & place bombs on asteroids /comets etc … right? ;-)

    @ 28. Jeffersonian Says:

    One thing that’s still not quite clear to me: Jupiter’s a gas giant, mostly hydrogen, right? So an impact isn’t the same as on Earth (Mars, etc.). What IS an impact like, then?

    Ever done or seen a belly-flop into a swimming pool? ;-)

    Or seen (in movies etc ..) a mine or torpedo or other explosion in water?

    It’s a bit like that.

    You can definitely still get “impacts” & explosions without necessarily having a solid surface.

  31. Messier Tidy Upper

    And here’s a funny thing: this impact occurred 15 years to the week after the SL9 onslaught.

    Here’s a funnier co-incidence (or as funny anyhow) on the same day as you post this, we discover *another* Jovian impact :

    http://blogs.discovermagazine.com/badastronomy/2010/06/03/breaking-another-jupiter-impact/

    Jupiter is induitably the Planet de Jour non? ;-)

    Its almost like Jupiter is celebrating a “birthday” (or Comet SL-9 “death-day”?) bash or roast isn’t it? ;-)

  32. Larry Hotchkiss

    Dreamer gives a few samples of disaster scenarios, but fails to mention the worst and most continuous disaster areas.
    Those are the ones between the ears of the politicians and religeous leaders (There is no real difference).
    Not a single one of these has shown any inclination to common sense, although the current coalition between Conservatives and Lib Dems in UK could be a small move in the right direction. See the Venus Project.

  33. dmlex1

    #27 → “Michael, that’s very unlikely to happen now. The vast majority of all civilization-ending capable asteroids have already been located, and none of them is going to hit us any time soon.”

    How does one know that the majority of an unknown number…is known?

  34. tril

    Demons live on jupiter! i think the planet we cant reach are afterlife vacations!! lol

  35. Bush

    I am sure President Bush will be blamed for the impact.

  36. Donald

    Reminds me of Revelation chapter 6 verse 13. I believe we will be hit too.

  37. I can be the equal of the largest planet in the solar system. Ahem.

    “I DON’T WANT TO CLOSE MY EEEEEEEEEYES, I DON’T WANT TO FALL TO PIECES, BECAUSE I MISS YOU BABE, AND I DON’T WANT TO MISS A THING!!!!!”

    See? I gave you all a little taste of Armageddon.

    Thank you.

  38. Justin Wolf

    Hmmm… We have astroids and comets that may hit Earth… Yet all you see on t.v. is Tiger Woods and Megan Foxx’s problems. Plus with our new generation coming in (which I am part of) the world will be even worse with all the girls (and some boys) who think it’s funny to fail school. I guess my dream of flying cars will never happen.

  39. Travis Porco

    Do you remember that movie some few years ago where a 500 km asteroid hit the earth, creating a “total evaporation impact” and a “rock vapor atmosphere”? I can’t find it, only hundreds of copies of snippets from it set to Pink Floyd. Who remembers the name of that film? Thanks!

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