1 AU is the average distance between the Earth and the Sun and is approximately equal to 150,000,000 km (or 1.5 × 10 11 m). Distances between the Earth and other stars and galaxies are measured ...

planets in our Solar System and other planets far off in outer space. From up here on the International Space Station I get a great view of Earth. Our planet is just the right distance from the ...

Most of the long-period comets in the Solar System come from the outer Oort Cloud. The inner region is much more stable. It's ...

A NASA spacecraft far from Earth has made an unexpected discovery, after turning its instruments towards a dark patch of sky at the galactic poles for over 200 hours. Studying the background light ...