YR4 has a 2% chance of hitting Earth in 2032. Astronomers are tracking it to refine estimates of its size and orbit to see how much of a risk the space rock poses.

It measures 130 to 300 feet across, a pebble compared to the asteroid that killed the dinosaurs, which is estimated to have been six to nine miles in length. On the other hand, on Feb. 15, 2013, an ...

Firefly Aerospace's moon-bound spacecraft has provided the closest thing to a reflecting pool in space, showing Earth as an ...