Dhaka, Sept. 28 -- A space rock that once had scientists concerned about a possible collision with Earth has a new potential target: the moon.

Asteroid 2024 YR4, estimated to be around 60 metres wide, at one point carried a 3.1 percent chance of striking Earth in December 2032, CNN reports.

Further observations effectively ruled out an Earth impact, but calculations also indicated a 4.3 percent chance that the asteroid could instead strike the moon.

If that happens, researchers say the impact could be the largest on the lunar surface in thousands of years, carving out a crater about a kilometre wide and throwing vast amounts of rock and dust into space.

Some of that debris could reach Earth within days or months, potentially producing...