© YouTubeAsteroid 2004 BL86
Radar images revealed an asteroid that passed by Earth this week has its own small moon.

Asteroid 2004 BL86 made its closest approach Monday morning at about 745,000 miles - more than three times the distance from Earth to the moon.

Scientists working with NASA's Deep Space Network antenna released the first radar images of the 1,100-foot-wide asteroid - which is orbited by a 230-foot-wide moon.

About 16 percent of asteroids that are at least 650 feet wide are binary or triple systems, meaning they are orbited by one or two satellites.

The asteroid won't come this close to Earth for at least 200 years, and the next asteroid of its size won't fly past Earth until 2027.

Watch radar video of the asteroid posted online by NASA Jet Propulsion Laboratory: