A LUNAR METEORITE FOUND OUTSIDE THE ANTARCTIC

OUR knowledge of the Moon's surface composition has come from samples returned by the Apollo and Luna missions, and from eleven lunar meteorites, all of which were discovered in Antarctica 1,2. Here we report the discovery of a new lunar meteorite, Calcalong Creek, in a desert region of Australia which is analogous to Antarctica in its ability to preserve meteorites of different types 3. On the basis of a diagnostic Fe/Mn ratio of 73-78, and other element abundances, we conclude that Calcalong Creek is a lunar breccia, containing both highland and mare materials. Whereas the Apollo and Luna missions selectively sampled only 5% of the lunar crust, lunar meteorites should provide a random sample 4; nevertheless there has been some concern that the Antarctic meteorite population may be biased in some way 5. Calcalong Creek will add to our understanding of lunar petrology, and as the first non-Antarctic lunar meteorite, may also shed new light on the transfer of impact ejecta from the Moon to the Earth.