Moon may harbour alien minerals
FRANCE: Minerals found in craters on the Moon may be remnants
of asteroids that slammed into it and not, as long believed, the
satellite’s innards exposed by such impacts, a study said Sunday. The
findings, published in the journal Nature Geoscience, cast doubt on the
little we knew of what the Moon is actually composed of.
It had long been thought that meteoroids vaporise on impact with
large celestial bodies. Unusual minerals like spinel and olivine found
in many lunar craters, but rarely on the Moon’s surface, were therefore
attributed to the excavation of sub-surface lunar layers by asteroid
hits. Olivine and spinel are common components of asteroids and
meteorites, and have been found on the floors and around the central
peaks of lunar craters like Copernicus, Theophilus and Tycho that are
around 100 kilometres (63 miles) in diameter.
A team from China and the United States simulated the formation of
Moon craters and found that at impact velocities under 12 kilometres per
second a projectile may survive the impact, though fragmented and
deformed.
“We conclude that some unusual minerals observed in the central peaks
of many lunar impact craters could be exogenic (external) in origin and
may not be indigenous to the Moon,” they wrote.
AFP |