Celestia Forums

I'm just wondering, a question if you will, why it is that we don't see spectacular lunar meteroid impacts with a display such was seen with the Deep Impact project? I understand the moon is much larger and brighter, and the apparent majority of meteorites are small... but still, some of the indications in the past have been that some strikes were quite major, and with the moon being so "dusty" and of low gravity, why is it we've not seen anything like an enormus ejecta cloud? As far as I know, never in recorded history has man ever looked to the moon and seen such a thing with the naked eye.

Some of the links I've seen on the subject -
http://www.nasa.gov/centers/marshall/news/lunar/index.html
http://science.nasa.gov/headlines/y2006/13jun_lunarsporadic.htm
http://www.gvarros.com/
http://www.lpl.arizona.edu/~rhill/alpo/lunarstuff/lunimpacts.html

There's a big difference between a light fluffy comet that's 8.7 by 2.5 miles and a 3,474 km diameter moon. There's a difference of scale, not to mention that the moon has quite a bit more gravity, which will not allow ejecta to travel as far as it would on the comet.

Thanks for the reply. I understand there's a large difference in size/scale and gravity involved. But still I'll ask the question. Like I said, there's much indication in the past that large scale impacts have occured on the moon according to some lunar seismological articles I've read. When I see in Discovery Channel presentations of how killer asteroids could hit the Earth, and of course the depiction shows a huge ejecta cloud hurling itself to the upper atmosphere (and quite visable from their given bird's-eye view in space), it brings this question of mine to mind. Perhaps it's just a "significant" event hasn't occured (yet)? Sorry, it just has had me wondering for some time and I was looking for other opinions/views.

I'm probably gonna be sorry I mentioned this, but...

I thought that I actually saw an impact on the moon in my youth. I
simply saw a very bright flash in the shadowed portion of the Moon,
and it didn't last very long at all. Maybe 1.0 to 1.5 seconds?

Go ahead now. You can all just tell me to lay off of the moonshine if
you like.

The thing is though, that I still remember seeing it. The event was so
unexpected - and so visible - that I was sure that someone else had
seen it. Don't recall ever hearing about though, so I guess it was just
the moonshine.

Thanks, Brain-Dead

Lay off of the moonshine, Bob.

Flashes on the moon have been reported by quite a few amateur astronomers. The common explanation (when they aren't dismissed out of hand) is that they are indeed meteor impacts. Considering how many meteors are seen during the various meteor showers, obviously some of them have to be hitting the moon.

Among those links I posted are one or two sites which actually deal with that, they even have some images and movies showing suspected impacts.

selden wrote:Flashes on the moon have been reported by quite a few amateur astronomers. The common explanation (when they aren't dismissed out of hand) is that they are indeed meteor impacts. Considering how many meteors are seen during the various meteor showers, obviously some of them have to be hitting the moon.

Ah, thanks again, Selden. A never ending source for reason and
sanity amongst a bunch of car crazy Celestial Lunatics. You are the
glue that holds this place together my friend.

I DO have some nice moonshine on occasion though. (Hic!)