Video: Asteroid 2004 BL86 Has a Small Moon

Radar Reveals Asteroid 2004 BL86 Has a Small Moon

Published on Jan 26, 2015

Asteroid 2004 BL86 passed Earth on Jan. 26, 2015 at 16:19 UTC (11:19am EST). This "movie" of the asteroid was generated from radar data collected on that date by NASA's Deep Space Network antenna at Goldstone, California. Twenty individual images were used.
Radar observations allow scientists to better measure an asteroid's size, rotation and location. As a bonus, radar observations of 2004 BL86 detected a tiny moon orbiting the asteroid.

https://www.youtube.com/watch?v=1y7CYf4X3Lo