Astronomer Humberto Saballos said the meteorite could have broken off from the 2014RC asteroid which passed Earth at the same time.
2014RC, which is the size of a house, came closest to earth at 18:18 GMT on Sunday, when it passed over New Zealand at a distance of about 40,000km (25,000 miles).
The asteroid was first discovered on 31 August and, at its closest approach, was about one-tenth of the distance from the centre of Earth to the Moon, Nasa said in a statement.
It is expected to orbit near Earth again in the future.
We’re doomed here!
