asking at each place how long its light takes to reach us here on Earth. The closest object to us is the Moon. Its average distance is about 240,000 miles, so light from the Moon takes (240,000 ...

"What I love most about geology is that it is a portal to the past," Stewart said. "You can look back 300,000 years through archaeology, but Earth is 4.6 billion years old and examining the rock ...

An explosion of particles arrived at Earth on Thursday, and could lead to visible northern lights in much of the country while also raising power grid concerns. By Kenneth Chang Kenneth Chang ...