The leading explanation for all of these mysteries is known as the giant impact hypothesis. According to this story, when the solar system was just getting started, a Mars-size protoplanet named Theia ...

The total angular momentum of Earth's spin ... skywatching events and more! With an impact velocity of somewhere around 20,000 mph (32,000 km/h) — relatively slow as impacts go — what happened ...

The Blue Ghost spacecraft, named for a species of firefly, took eclipse chasing to new heights. Not only did it see the Earth block the Sun from an unexplored location on the Moon, but the lander fell ...

After hours: March 17 at 4:05:12 PM EDT Loading Chart for VEL ...