In an unprecedented discovery, astronomers have detected a rare exoplanet located at the very edge of the Milky Way galaxy, using a method grounded in Albert Einstein’s theory of general relativity.

Stargazers will be treated to a rare alignment of seven planets on 28 February when Mercury joins six other planets that are already visible in the night sky. Here's why it matters to scientists. Peer ...

While most planets that we are familiar with stick relatively close to their host star in a predictable orbit, some planets seem to have been knocked out of their orbits, floating through space free ...