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.