How can I tell if the rock I found is a moon rock?
The best way to tell if you have found a meteorite is to check with the websites listed under the previously asked question: How can I tell if the rock I found is a meteorite?
However, chances are that even if you have found a meteorite, the rock that you found is not a Moon rock. Although pieces of the Moon get ejected during impacts, very few of these pieces hit Earth and are collected as meteorites. We've found only 24 meteorites that have a composition that can be matched to the Moon, but there have been tens of thousands of meteorites discovered total. This is rather unfortunate since we'd love to have more samples of the Moon!
A great page on the lunar meteorites is available at the Washington University website. This site explains how we know that the lunar meteorites are from the Moon and how the meteorites got to Earth. They estimate that 0.08% of meteorites have a lunar origin, which is a very small number!
They also have a page describing what to do if you think you have a lunar rock.
Anyway, sorry to possibly disappoint you, but I hope this has at least been helpful!
Somewhat related P.S. added later by Lynn: I learned at a talk by another graduate student here that we have some measurement of how many meteorites impact the moon over time. During the period between 1972 and 1977, scientists studying data from the seismic network left by the Apollo astronauts say that there were around 1700 meteorite impacts on the Moon. But these are relatively small impacts, and most of them probably do not contribute much to the number of lunar rocks flying around in space.
This page was last updated on July 18, 2015.