The way to dusty death

By Phil Plait | August 13, 2009 10:30 am

The Lunar Reconnaissance Orbiter continues to send back very cool imagery of the Moon. Check it:

[Click to embiggen]

This is a classic crater chain, a linearly laid-out set of craters about 4.5 km (3 miles) from end to end. These appear all over the solar system, pretty much whenever you have a large object with no atmosphere like a moon (or Mercury). There are two potential causes of these: an asteroid or comet that broke up due to gravity prior to impact, or material ejected from a large impact some distance away.

In the first case you usually need something big to break up the incoming object, like the way Jupiter’s tides tore apart comet Shoemaker Levy 9 which slammed repeatedly into the big planet back in 1994. It’s possible this could happen with the Moon, but unlikely because its gravity is weak (and while the Earth could do it, the object would then be more likely to hit the Earth and not the Moon).

Giordano Bruno crater on the Moon

So this chain seen by LRO is probably the second kind, material splashed out when crater formed nearby. It turns out that there is a likely suspect: Giordano Bruno. It’s a medium-sized crater about 20 km (14 miles) across, located just over the limb of the Moon on the far side. As you can see by this picture, it’s surrounded by bright rays, linear features from plumes of material arcing out of the crater when it formed. That’s encouraging; you’d expect to see this kind of ejected material if the event formed crater chains farther away.

Moreover, the bright material around Giordano Bruno, and lack of craters superimposed on it, means it’s young, probably less than a few hundred million years old (which is downright sprightly for a crater on the Moon). The same can be said for the crater chain; the craters making it up appear relatively fresh.

While this isn’t conclusive, it’s interesting, and pretty good evidence that the two features are related. Either way, the chain is pretty interesting. The largest crater at the bottom is about 340 meters (1100 feet) across, so it’s roughly the size of a big mall’s parking lot. The blur of material below the chain in the picture may be due to material splashed out and disturbing the lunar surface when the craters were formed themselves, meaning they probably hit at a low angle.

Interestingly, Giordano Bruno is located north of this chain, up past the top of this picture. That means this chain formed roughly perpendicular to the direction of the primary event. And since the largest crater is to the right, and they get smaller as you go left, I’m thinking that a big chunk of rock was pulverized when Bruno was made, and went flying south at a low angle along with a pile of debris. They all splashed down here, 500 km (300 miles) south of Bruno, making this weird formation.

One of the most amazing things about our Moon is how the geology is laid out; even millions or hundreds of millions of years after the fact, like forensic scientists we can trace back what happened and put together a story of the events. Is this particular story correct? Maybe, maybe not. But the best way to find out is to keep looking, find more evidence and build up more tales. LRO is doing just that, and more missions down the line will give us even more narrative voices. Eventually, we may have a novel with thousands of chapters, and — if I may contradict the Bard — it will be full of sound and fury, signifying everything.

Image credits… Crater chain: NASA/Goddard Space Flight Center/Arizona State University. Giordano Bruno: Wikipedia. Title of the post: Billy Shakespeare.


Comments (23)

  1. BUNNY

    Do think you can use some correct grammar?

  2. Kevin

    Wow, that’s just awesome-looking pictures. Can’t wait to see more from the LRO.

  3. Given the name of the post and comparative youth of the crater:

    “Out, out brief candle.”

  4. Dennis

    @Bunny: The irony of the poor grammar used in your question is delicious.

  5. BUNNY

    @ Dennis

    I was talking about that ’embiggen’ word.

  6. I don’t know why, it’s a perfectly cromulent word.

  7. Then don’t you mean vocabulary, and not grammar, which you don’t seem to use very well yourself?

  8. Rev. I. P. Freeley Rev.I

    @ BUNNY (or is it ZERO or QUASAR?)

    Matthew 7:3 And why beholdest thou the mote that is in thy brother’s eye, but considerest not the beam that is in thine own eye?
    Matthew 7:4 Or how wilt thou say to thy brother, Let me pull out the mote out of thine eye; and, behold, a beam is in thine own eye?
    Matthew 7:5 Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother’s eye.

  9. Gary Ansorge

    Ooh TechSkeptik, you extracted the lexicon from my verbiage and beat me to the oral assault.

    Ain’t this FUN?

    I wonder if Bunny is a Brit? If so, please remember, the language used here is American, not English,,,Y’All,,,we’ll masticate it as we please.

    My Ex used to correct my English all the time(that’ll teach me to marry a woman with an IQ 20 points higher than mine).

    Such impact chains should also be visible on earth but I can’t for the life of me recall any such. Guess they’re remnants of an earlier epoch and have all been subsumed by geological processes and weathering.

    Either that or the giant with the bowling ball gave up trying to get a strike,,,

    GAry 7

  10. Gadfly

    I am simply amazed at the creative genius of the special effects guys who developed the fake moon landing sets. They put lots of neat extras in there for us to enjoy years after the fact.

  11. zak

    I’m anispeptic, frasmotic, even compunctuous to have caused you such pericombobulation.

  12. Mark Hansen

    Bunny (or ZERO or QUASAR, the name change is not fooling anyone but yourself),
    It has been pointed out, ad nauseum, that embiggen is being used in a humourous fashion. If you can’t handle that, then go elsewhere.
    BTW, post 11 should have “correction”, not “corection”. Using bold face and large font exclusively in your posts is very annoying and childish. As I pointed out to you in your “ZERO” persona, perhaps you’ll be better behaved once you reach puberty or get through puberty, whichever applies in your particular case. Good luck with that.

  13. Mark Hansen

    Gary (post 9), it reminds me of Shaw’s comment on two countries being separated by a common language.

  14. Rob Glover

    Giordano Bruno is the crater the formation of which might, possibly, have been eyewitnessed from Canterbury, Kent in 1178 – although there are also arguments against – .
    It’s one of those stories which I do want to be true though!

  15. Duane

    Speaking of the Moon (and apologies for going slightly off-topic), I saw the Sam Rockwell movie MOON last weekend. A bit of “bad astronomy,” but the movie itself was deeply moving. Highly recommended.


  16. gruebait

    (channeling Stan Lee)

  17. Crux Australis

    Good grief, 500 km from the impact crater?! That’s amazing! I could imagine that happening on Earth. KA-frakking-BLAMMO!

  18. Chet Twarog

    LRO will continue to give us great pics and discoveries.
    While I am at it, I recommend the SF movie “Moon”. Well worth it.
    Has some minor science problems, reviewed in Cinefex 118, now in theatres.

  19. Russ

    Wow, Phil!
    Did you read that book too?
    I thought I must be the only one in the world who remembers it.

  20. bjgger

    Nice tip of the hat to Scottish author Alistair MacLean… or Shakespeare

  21. Alareth

    @Gary Ansorge

    Actually, the British form of English has evolved quite a bit.

    The American version is relatively unchanged in comparison from the original at the time of colonization which I find fascinating.

  22. Gary Ansorge

    14. Mark Hansen

    I expect it’s even worse when they’re separated by a common religion(See:Islam, or Christianity in Ireland or,,,) Hey, even in Israel there is contention between various sub sects, but they’re all the same fraking religion.

    22. Alareth:

    I worked with w/a Scotsman(Alex Gunn) in Saudi Arabia in the early ’80s who claimed only the Scots spoke the Queens English. When I asked him to which Queen he was referring he replied “Why, Mary, Queen of Scots, of course.”

    GAry 7

  23. Why is the moon’s gravity to weak to disrupt a comet? The tidal field (i.e. Weyl’s tensor) is proportional to the density of the source, which is higher for the moon than for jupiter. Or is the time spent inside the field relevant?


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