As a big asteroid flies by at a close but safe distance from Earth on Saturday (Oct. 31), astronomers will likely get a better radar view of the surface than ever before.
Asteroid 2015 TB145—discovered earlier this month, on Oct. 10—will fly by slightly outside the moon's orbit. In celestial terms, this is rather close, especially considering the asteroid's size; at an estimated 1,300 feet (400 meters) wide, this is the closest known flyby by a large asteroid until 2027. TB145 will fly by at 300,000 miles (480,000 kilometers) from Earth, but poses no threat to our planet.
