NASA has released new data from yesterday’s cosmic fly-past when asteroid 2004 BL86 zoomed past the Earth at a slightly greater distance than our Moon. Those observations appear to reveal the asteroid has a moon of its own.

The main asteroid is 325 metres across and its companion measures 70 metres. Click the image below to see an animated gif of the duo as they tumbled past Earth.


2004 BL86 and its companion passed by the Earth on January 26, 2015 [credit: NASA/JPL-Caltech]