Asteroid 1999 KW4 was first discovered by astronomers in 1999. When it got closer, in 2001, astronomers realized it wasn’t a single asteroid, but two clusters of rubble orbiting each other. It’s been classified as a Potentially Hazardous Asteroid, but astronomers have calculated a safe trajectory out for at least 1,000 years. Since it’s a … Continue reading Detailed Look at Twin Asteroid 1999 KW4