A mile-wide asteroid that’s shaped like a walnut, and with a moon of its own, is expected to zip by Earth on Saturday, traveling at 48,000 mph. This double asteroid, designated as Asteroid (66391) 1999 KW4, is composed of one large asteroid orbited by a smaller moon, or one that’s about a third of a mile wide and orbits around the larger body about once every 16 hours. The Las Cumbres Observatory describes 1999 KW4 as “slightly squashed at the poles and with a mountain ridge around the equator, which runs all the way around the asteroid. This ridge gives the primary an appearance similar to a walnut or a spinning top.” Read more for two videos and additional information.
While 1999 KW4 is classified as a “Potentially Hazardous Asteroid” by the Minor Planet Center, it should clear Earth at a very safe distance of 3,219,955 miles. To put it in perspective, that’s more than 13 times the distance from the Earth to the moon. It will be the second-closest approach 1999 KW4 has made in the past two decades, and the nearest it will come to Earth until 2036. It’ll also be by far the largest object to come within about 20 lunar distances (4,647,790 miles) of us this year,” reports CBS.