Lunar smackdown!

By Phil Plait | September 3, 2006 11:42 am

SMART-1 smacked into the Moon last night! as I wrote yesterday, the European probe SMART-1 crash landed (on purpose) onto the lunar surface last night. It made a flash that was visible to large telescopes, including the Canada-France-Hawaii Telescope, or CFHT:

These are before-and-after images of the area, and you can see pretty easily where the spacecraft hit (the black dots are noise in the detector, and are not real). I haven’t seen any numbers yet on how bright the flash was, or what science has been obtained by analyzing it. That might take some time. A good place for updates is the Moon Today website and of course The Planetary Society site.

Image credit: Canada-France-Hawaii Telescope / 2006

CATEGORIZED UNDER: Astronomy, Cool stuff, Science

Comments (34)

  1. I can only imagine what the conspiracy theorists are saying about this.

  2. KingNor

    its a preemtive strike by the government on the emerging peoples of the moon. that explosion is clearly from a maverick missle.

  3. Here is an animated GIF showing the SMART-1 impact imaged by Peter Lipscomb with an 8″ LX-90 and a TouCam:

  4. Pete

    I’m still in shock about a comment on the previous post. There are people who still think the earth is flat? How very odd indeed.

    Still, at least the moon know not to mess with us now.

  5. Daniel

    Shouldn’t it be just “crashed”? The “landed” part implies that something was left intact.

    Either way, a very neat event.

  6. Tukla in Iowa

    Oh, that’s the noise that woke me up.

  7. Max Fagin

    Yes, pete there really are people who think we are living on a flat disk, and what really suprised me is that none of them are biblical fundamentalists. Almost everyone on the forum belives in the FE for “scientific” reasons.

  8. Tom

    This article:,,13509-2341602,00.html

    Says that they crashed it on the dark side of the moon. Good planning!

  9. Ron S

    “noise in the detector” stays the same in different images? Wouldn’t those be (pixel) flaws in the detector rather than noise?

  10. I live in Austin, Texas. My girlfriend and I had given up on seeing the SMART-1 impact due to heavily overcast skies when something amazing happened. At app. 12:42am CST the moon broke through the clouds and we witnessed a huge tongue of red-orange flame erupt from the impact site. The whole event lasted no more than a few minutes and as the flash faded you could see that the clouds had not broken but had been overwhelmed by the flash.

    This was a truly awesome experience and we assumed many others had seen it and would report it. So far the images we’ve seen have been disappointing and nothing on the scale of what we saw.


    Brett & Mindy

  11. Mark Martin


    Notice that the reasoning for crashing the spacecraft on the night side of the Moon was for practical purposes.

    At the time of the impact, the planned impact site was on the Earth-side, but a few degrees inside the current night hemisphere. This allowed for maximum contrast between the impact-flash and the unilluminated surroundings, improving the signal/noise ratio in the flash. It was hoped the flash would contain enough spectral information to determine the chemical composition of the lunar soil in that region.

    Another thing potentially possible by targeting the crash just shortly inside the night region was that it allowed for the ejecta to rise above the shade and into sunlit space, where it’d then be visible against the darker background.

  12. CR

    I, too, was wondering why the “noise” stayed the same in both pics… I can just hear the CTs complaining about it being the same photo copied with a “flash” added in Photoshop.
    On the other hand, if anyone *cough* Hoagland *cough* sees a face in these pics, they’ll conveniently clean up all the “noise” dropouts EXCEPT for the one that happens to be right where a nostril would be on a real face.

    Anyhoo, would you care to enlighten us and head off the conspiracy claims at the same time?

  13. Troy

    Was it visible with the naked eye then? If it could penetrate clouds as Brett & Mindy are saying it must have been. But as Mr. Reagan used to say to Mr. Gorbachev, “trust but verify.”

  14. Not all noise has to change between shots:

    And the reason why the pixels would be dark, and not bright, is probably because the images have already gone through dark frame subtraction:

  15. Tom: There *IS NO* dark side of the moon!

    This is an all-too common misconception which was not helped by the release of the Pink Floyd album of the same name. The moon has a NEAR side and a FAR side (from the Earth’s point of view). However, each side receives the same amount of sunlight over a 29 1/2 day period (except for one point which receives permanent sunlight). I’m sure you probably already know this and your comment was an oversight, but I’m on a mission to clarify this issue every time I see the words “Dark side of the Moon” when not in a Pink Floyd context (and sometimes even then!)

  16. chris

    Brett, I don’t know what the magnitude of the impact flash was, but I know a lot of people with amatuer telescopes didn’t see it. Also, the impact flash lasted only a few seconds, so whatever you saw, it wasn’t SMART-1.

  17. Kaptain K

    “These are before-and-after images of the area…”

    More like “before and during”.

  18. Tom

    Hey, I was just quoting the article about the “dark side of the moon”:

    “The Lake of Excellence is a volcanic plain. It lies just on the dark side of the Moon, where it is not illuminated by the Sun, but where some dim light is provided by “Earthshine” — light reflected on to the Moon from Earth.”

    This is … ::looks up:: “Bad Astronomy”, right? 😀

  19. Troy

    If you’re talking about one instant of time there is a dark side of the moon, since only half of the moon is lit. As the reference indicates the part of the dark side was on the near side. (They probably should have said night side.) At the end of the song “eclipse” on the pink floyd album Dark side of the moon they say “there is no dark side of the moon, as a matter of fact it’s all dark” which I always thought meant that during an (lunar) eclipse (the name of the song) the moon is all dark.

  20. Rumour Mongerer

    You guys have, of course, read what the BA has to say about that phrase in his Bad Astonomy book, right?

  21. Luna 2, the Soviet Union’s lunar probe, impacted on the lunar surface on
    13 September 1959, 22:02:24 UTC. This probe also discovered the solar wind.
    What will Smart 1 reveal about the Moon?

  22. Pete

    Has anyone else seen the South Park episode with the Whale on the moon?

    For some reason this reminded me of it :o)

  23. CR

    “We’re whalers on the moon!” (Futurama)

  24. Jethro

    Don’t we know how the Moon was formed yet? You’d think that this would be a no-brainer considering how “our greatest minds” just demoted Pluto to Pluton.

  25. CR

    By the way, thanks, Elric for the info about “noise”.

  26. Why is it that hubble can show us full-color galaxies gazillions of light years away and when something happens on the moon it’s a boring pixelated white spot?

    Come to think of it, why do we know the composition of entities gazillions of miles away but we don’t know what’s in our own soil?

  27. Andy

    “…why do we know the composition of entities gazillions of miles away but we don’t know what’s in our own soil?”

    Actually, I’m certain we know more about our own soil then even whether there IS soil on other “entities” lol

    My Questions is:

    Is anyone else concerned that the moon might become our trash site?

    I mean, was this crash part of the science planned to be done by the SMART-1? Or was the crash just a “neat” ending to a spacecraft that finished it’s designed usefulness? And now we have to “make science” from the experience to feel justified in trashing the Moon.

    Not considering that this is one small hunk of metal on the millions of square miles of the lunar surface, how much junk can we throw on the moon before it just becomes “littered”. Is this the legacy we want to start accepting? That when humans explore space, we will be constantly leaving behind trash?

    Who would have thought Mount Everest would have become so littered with the O2 bottles and trash of hikers not willing to “hike out what the hiked in” that special expeditions have gone up just to clean up the mountain (not to mention some bodies of those that didn’t make it).

    I know you might all flame me as a tree hugger etc. But what’s wrong with a little consideration today for the generations of tomorrow. Why can’t my grandkids visit a moon without having to look at other’s trash?

    There is also a contamination issue. What happens when we find microbes on Mars just to learn that they were carried there by Spirit?

  28. NelC

    “As a matter of fact, it’s all dark.” I take that as a lead-in to the fact that the Moon — despite the impression our eyes give us at night — has a very low albedo, around 0.1. [Edit: Which in fact is what Phil says in his book, now that I go look.]

    Otherwise, you can take the phrase “dark side of the Moon” just to mean the nightside, wherever that happens to be at any particular time, so it’s still usable as a rhetorical flourish, just not so useful as an indication of location.

  29. NelC

    Andy, at a couple of klicks per second impact velocity, I doubt that there’s enough left of SMART-1 to distinguish it from the rest of the rubble. And it’s not as though the crater it leaves behind is going to be noticeable, you know, amongst all the other craters.

    If you want to go and clear it up, though, you go ahead and do it. Try to not leave too many boot-prints.

  30. M

    I know exactly what some conspiracy theorists will have to say about this experiment.

    [stupid]MOON ANTS! Look, you can see them right there in the picture it’s PROOF! What are you, brainwashed? Obviously now they’ll be angry that we dropped a satellite onto their colony and life will turn into Starship Troopers – the movie, not the book![/stupid]

  31. Irishman

    CafeenMan said:
    >Why is it that hubble can show us full-color galaxies gazillions of light years away and when something happens on the moon it’s a boring pixelated white spot?

    It’s a combination of size of the object, distance away, and resolution of the camera. There are some discussions around here somewhere discussing the resolution of Hubble on the moon, and IIRC it’s about 30 meters or so. That means the smallest items that show up as pixels are the size of a house. Those stunning “details” we see in images from light years away are HUGE.

    >Come to think of it, why do we know the composition of entities gazillions of miles away but we don’t know what’s in our own soil?

    Again, to what resolution are you trying to know? We know what stars are made of because they are burning, and burning produces light, and the characteristics of the light can identify the materials. But the level of detail is limited. We can analyze soil samples in numerous ways to find all sorts of things that we can’t study about stars. But without the tests, we can’t know what’s in our soil.

  32. Troy

    Regarding the issue of the moon being a junk yard. Any items from the 20 and 21st centuries that are found by future denizens of the moon would be priceless collector’s items. Considering the prohibitive cost of sending things to the moon it is unlikely to happen soon. A real issue for me though would be if some company/person/goverment decided to use the moon as a giant bill board. Debris or artifacts visible from earth would also be an issue.

  33. Andy Varga

    I agree that locations of lunar landings would be of historic interest and valued by future inhabitants (much as we cherish our Tall Ships etc). But a literal lump of metal from a high speed impact would have less value than a meteor. A meteor at least represents a foriegn (extra terestial) body and may hold something to be learned. SMART-1’s debri would hold no such “yet to be descovered” information.


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