The rusty world is full of mysteries—and some of the solar system's most extreme geology. Learn more about Earth's smaller, colder neighbor.

How far it is from the sun: 886 million miles (1.4 billion kilometers), on average How big it is: 72,400 miles (116,500 km) across, or almost 10 times the size of Earth. How many moons it has: At ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. The moon's orbit isn't a ...

Currently, the closest exoplanet to Earth is Proxima Centauri b, which orbits the star Proxima Centauri, located 4 ...

1. Earth is not a perfect sphere. Yes, we've all been taught that the Earth is not flat, but it may shock you to learn that it's not perfectly spherical either. As the National Oceanic and Atmospheric ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Sky-watchers who saw the Venus-Jupiter conjunction on ...

Ah, Earth. We may not think about our planet on a day-to-day basis, but the world we live in is a pretty interesting place. The third rock from the Sun—and to this day, the only one with known ...

The moon is our constant companion and the only natural object that always orbits Earth. It's about four times smaller than Earth and its gravity is much weaker, which is why astronauts bounce around ...