Lunar meteor impact on video

By Phil Plait | March 19, 2008 8:30 am

Go outside, look up at night, wait long enough, and zip! You’ll see a tiny bit of rock burn up in our atmosphere: a meteor.

But other objects get hit too, including the Moon. It happens more rarely; the Moon presents a smaller cross-section to get hit, and its gravity is lower so it cannot draw in material as well as Earth. But hit it does get, and if you watch long enough you’ll see one.

Amateur astronomer George Varros did just that on March 13, and better yet, he had a video camera hooked up to his telescope! He captured an impact, and has an animation on his site of it; the image above is a still from it.

These are notoriously hard to get on video, and even then they are harder to confirm; it might be something else like a flaw in the camera. But in this case, other cameras caught it, so this has been confirmed; it was the equivalent of about 100 kilograms of TNT exploding on the lunar surface. Assuming an impact speed of 30 km/sec (that’s a complete guess, but about the speed of an orbiting object near the Earth’s distance from the Sun) the object itself would have massed about a ton kilogram. If it were a rocky sphere it would have been about a meter across 10 centimeters across, roughly the size of a baseball. Not something you want hitting your house!

Varros has a page listing other impacts he’s caught as well. Very cool, and very useful! Eventually, when we go back to the Moon, the number and size of impacts on the surface will determine how we build structures on — or below — the lunar surface.

CATEGORIZED UNDER: Astronomy, Pretty pictures, Science

Comments (33)

Links to this Post

  1. Virtual Dave » Metor on the moon | March 19, 2008
  2. GIF loop of lunar impact « David Kirkpatrick | March 20, 2008
  1. firemancarl

    Frackin awesome!

  2. Carey

    That is the coolest thing I’ve ever seen.

  3. Ken Youngstrom

    Back in the early 60′s I worked on a project to detect micrometeorite impacts on the lunar surface using the 61″ Fecker ‘scope at Harvard. Question was would the astronauts get punctured by hypervelocity sand grains. Spent many long cold nights up on the drive platform tracking the moon (no lunar rate drive!) in my electric suit with a fast cooling pizza and an FM radio. We used a PMT looking through a hole in an angled mirror focussed on a second PMT to discard earthly atmospheric events with coincidence counting techniques familiar to nuclear experimenters. We never did see any verifiable events. Lots of fun though, including playing with the wonderful old Alvan Clark scopes located in various outbuildings.

  4. Michael Lonergan

    Very cool. I am wondering if these type of events are the cause of what is termed “Lunar Transient Phenomenon”? Also, what steps is NASA taking to protect future Astronauts? It would seem awfully cost prohibitive to build underground, and I don’t know of too many structures that would survive a one ton object smashing into it unscathed unless it was some kind of reinforced structure. Again, the cost seems far to prohibitive.

    On a side note, I watched the silliest conspiracy video last night, “Secret Space – The Illuminati Conquest of Space” – AKA “Almost 2 Hours of my Life I Will Never Get Back.” This is so full of holes that I do not even know where to begin! Keep up the good work debunking this nonsense.

  5. Michael Lonergan

    Ken, was the operating manual for that telescope titled, “Meet the Fecker.”?

    Sorry, couldn’t resist that one! :)

  6. Mang

    Ah Phil, either you mistyped or I goofed.

    1 ton at 30km/s is on the close order of 4×10^12 J using (1/2mv^2)
    1 kg of TNT is on the close order of 4×10^6 J

    Either 100kg TNT is too small, or the rock is much smaller

    Either way its impressive

  7. Yoshi_3up

    Cool. It’s nice to see this stuff happening once in a while.

  8. rhr

    How big a crater would that leave?

  9. Dagnabbit, I hate it when I make unit conversion errors! I should have known a ton was too much. I got a mass of about 1000, and for some reason though that was kilos, but it’s actually grams! I fixed it, thanks!

  10. dziban

    It’d be a larger crater than the universe is wide, rhr, using the BA’s math.

  11. Mang

    Thanks for the correction. Holy smoke that is IMPRESSIVE!

    A meter rock would be really spectacular!

  12. Chip

    I wonder what it looks like to be close (not too close!) to the impact site at the moment of impact?

    I imagine the craters or fresh lunar features made by these impacts are way too small to be seen from Earth, but those flashes are quite bright.

  13. terry

    Maybe this is a dumb question, but what exactly is “lighting up” when this happens? With no oxygen, I thought nothing can burn.

  14. Bouch

    Seems Cool. But, I have a question. What causes the flash? The moon has no atmosphere, so no oxygen, so no fire, so no flash… I thought it might be the dust kicked up reflecting the light of the sun, but this is pretty far away from the terminator, so that isn’t likely.

  15. chris

    ASTRONOMER: come on man, Phil has done more to put cool astro into the heads of kids then you’ve ever done. human’s make errors, phil is just as likely as you to forget to carry the 1, suck it up and don’t read badastronomy if you disagree.

  16. Nick

    The flashes are not caused by combustion, rather, the kinetic energy from the impact gets converted to heat. Heat makes things hot, and hot thinks get bright.

  17. Arthur Maruyama

    terry and Bouch:

    Part of the energy of the impact becomes light with the heat of impact. It is similar to what happens when a meteor flashes through the Earth’s atmosphere: while the term “burns up” is often used, this isn’t due to the meteor being oxidized. The meteor is worn away by impacts with molecules in the atmosphere–there is so much heat generated that it glows visibly.

    Instead of being spread across the sky imagine all of these impacts happening nearly at once when a meteor hits the surface of the moon.

  18. Saturn8

    ASTRONOMER – Ugh! Can you please learn the difference between “your” and “you’re”. Sheesh!

  19. tony873004

    Isn’t 30 km/s a bit high? Sure, that’s the orbital velocity (wrt the Sun) of stuff in Earth’s neighborhood. But Earth is also traveling at 30 km/s, negating much of velocity. Off the top of my head, I would guess that objects in Earth’s vicinity are moving ~0-5 km/s relative to Earth, and then the Moon accelerates it about another 2 km/s with its own gravity. Since velocity gets squared in the KE formula, its important not to overestimate it too much.

  20. Kaptain K

    I thought it was a given that any long-term habitats would be under the surface for protection from radiation, if nothing else!

  21. tomr

    Tony873004–as far as I know, most meteors are in elliptical or highly elliptical orbits, and so are going to cross the earth’s orbit at a nearly perpendicular angle.

    Objects that shared the earth’s orbit would have been ‘cleared’ by now (that’s the new definition of planet!).

    From the video, the impact is near the center of the night side. This doesn’t tell us anything for sure, but suggests that it was travelling more-or-less towards the sun.

  22. Grr…

    Connection to server gvarros.com failed (Connection actively refused by the server.)

    Perhaps his server got bombarded with everyone wanting to see it? Anyone know of another site it’s available on?

  23. Torbjörn Larsson, OM

    Bad Astronomer: conversion error.

    Bad ASTRONOMER:

    your degrading astronomy

    conversation error.

    You’ll be the judge …

  24. Can someone please tell me how to get quotes like in Torbjörn Larsson’s post?

    Perhaps BA can include a “posting FAQ”-type link next to the comment form?

  25. Joe Meils

    Okay, so… obvious question. How big of a rock was it? Also, was anyone else photographing the sky at the time this rock hit the moon? Perhaps it had some companions that were also caught burning up in the earth’s atmo? Might be interesting if there were evidence for a spike in meteors around the time of this lunar impact….

  26. Mark Hansen

    At the risk of feeding a troll…

    Astronomer: Yes, Phil can and does make mistakes. However the difference between him and the woowoo’s is that he will correct his mistakes and point out the corrections to show where he went wrong. The woowoo crowd 1) change what is displayed on their EOTW websites without admitting they were wrong or 2) claim that their EOTW predictions were misinterpreted or 3) move on to the next EOTW woowoo scenario and hope that no-one notices. Phil also knows the difference between “your” and “you’re” (and “yaw” and “yore” as well) which is something that you, with your cut-&-paste posting method, seem unable to do. Your best bet would be to get a little education because you’re getting very tedious.

  27. Ian Menzies

    Can someone please tell me how to get quotes like in Torbjörn Larsson’s post?

    I believe (and if this works I will be right) that you want to use <blockquote></blockquote> to make them.

  28. chris says: “ASTRONOMER: come on man, Phil has done more to put cool astro into the heads of kids then you’ve ever done. humans make errors, phil is just as likely as you to forget to carry the 1, suck it up and don’t read badastronomy if you disagree.”

    Chris (and others who responded), forget it. This is a troll. It’s word-for-word identical to the post a few weeks ago. There probably wasn’t an earlier message deleted. That’s a technique to get you to start thinking about the troll. Notice there is not a single specific about what the message (or this topic) was about?

    - Jack

  29. Will any of the vechicles currently orbiting the moon be able to image the impact site?

    - Jack

  30. tony873004

    “Tony873004–as far as I know, most meteors are in elliptical or highly elliptical orbits, and so are going to cross the earth’s orbit at a nearly perpendicular angle. ”

    That makes sense, since we’re probably talking about particles shed from comets.

  31. Michael Lonergan

    Ahhh, grams! However, wouldn’t it be more likely that larger meteorites would impact the moon because of the lack of atmosphere? Also didn’t the Apollo crews leave behind seismic instruments that detected impacts on the Lunar surface?

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