A familiar couple that lives in our cosmic neighborhood will be buzzing by us this weekend. The Asteroid 1999 KW4 and its orbiting mini-moon will pass a safe 3,219,955 miles from Earth’s surface on their closest approach. Earthlings will be able to see the pair with a good telescope and some good timing, for the next few days.
1999 KW4 is technically a system, moving through space, since it is two objects. The two space rocks measure less than two miles across, combined. The asteroid is about 0.8 miles wide, according to NASA, and shaped like a spinning top. It’s moon is elongated and .35 miles long.
The two heavenly bodies aren’t new to our doorstep. This is the fourth time they will have passed by Earth since they were discovered in 1999. This is not the closest they’ve come, either. Though, they’ve never threatened to blow down our door. When they pass again in May, 2036 they’ll come 1,443,511 miles from the Earth’s surface. That’s still a distance no one has to worry about.
If you’re looking to find 1999 KW4, you’ll need some good equipment. EarthSky reports that during their closest approach at 7pm EDT (4pm PT) the rocks will be most visible in the Southern Hemisphere, “appearing as fast-moving shadows against stars in the constellation Puppis” – space.com. Northern Hemisphere sky watchers should look to the constellation Hydra on the evening of May 27.