A mile-wide asteroid traveling at 48,000 mph is set to pass close to Earth Saturday -- cosmically speaking. What makes this huge asteroid even more interesting is that it has its own moon.
Asteroid 1999 KW4 is actually designated a double asteroid or a binary asteroid. Its companion rock is 0.3-miles wide and orbits around the larger body about once every 16 hours.
The main asteroid -- which is just under one mile wide -- has been noted to have an unusual shape, similar to a walnut, according to CNET.
1999 KW4 has been designated a "Potentially Hazardous Asteroid" by the Minor Planet Center, according to NASA. But, it will safely pass the Earth at a distance of more than 3.2 million miles. That's about 13 1/2 times the distance from the Earth to the moon.
The closest approach will happen Saturday at 7:05 p.m. EDT, according to EarthSky. The bad news for people in the U.S. is that it will be best viewed from the southern hemisphere. The good news is people in the northern hemisphere should be able to see it two days later -- but you will need a telescope at least eight inches in diameter, according to EarthSky.