c55c22b22845fceca0cf4ac8d7841359ed9622caAn unusually large asteroid that just skimmed by Earth had its own moon, NASA said Tuesday as the US space agency released its first radar images of the flyby. The asteroid known as 2004 BL86 made its closest approach late Monday at a distance about three times further than Earth’s own Moon. Radar images from NASA’s Deep Space Network antenna in Goldstone, California show that the asteroid itself was about 500 feet (150 meters) smaller than expected, and measured about 1,100 feet (325 meters) across. The asteroid’s small moon was approximately 230 feet (70 meters) across. Canadian astronaut Chris Hadfield called the discovery “strangely delightful,” and wondered on Twitter: “Who gets to name it?” The asteroid was already unusual because it was about 10 times bigger than most near-Earth objects, which range from 50 to 100 feet (15 to 30 meters) in diameter. NASA said that about 16 percent of asteroids in 2004 BL86’s size category — meaning those that are 655 feet (200 meters) or larger — are “binary,” meaning there is a primary asteroid with a smaller asteroid moon orbiting it. More