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.

Astronomers have revealed new evidence that there are not just one but four tiny planets circling around Barnard's Star, the second-nearest star system to Earth.

Beginning in late February, seven planets will align in the night sky. But Uranus and Neptune may require a telescope to see. Mars SKY AT Viewed from above the solar system, the seven planets will ...

Everyone knows about the Solar System, and the planets that make it up. They’re in space, orbiting the Sun, in an order we all at least used to be able to recite. But it was not always so.