The Moon is the easiest thing to spot in the night sky. Even with the
naked eye, you can see quite a lot of detail on its surface. Through a
telescope it is a stunning sight, with craters, rays and dark regions
clearly visible.
An amateur astronomer may have found another moon of the Earth. Experts say it may have only just arrived.
Much uncertainty
surrounds the mysterious object, designated J002E3. It could be a
passing chunk of rock captured by the Earth's gravity, or it could be a
discarded rocket casing coming back to our region of space.
It was discovered by Bill Yeung, from his observatory in Arizona, US, and reported as a passing Near-Earth Object.
It was soon realised, however, that far from passing us, it was in fact in a 50-day orbit around the Earth.
Paul Chodas, of the
American space agency's Jet Propulsion Laboratory in California, says
it must have just arrived or it would have been easily detected long
ago.
Calculations suggest it may have been captured earlier this year.
