We measure the extremely long distances between things in space by light years. A light year is the distance that light travels in one Earth year. Light travels at about 300,000 kilometres per second.

Proxima Centauri b is the closest known exoplanet to our solar system that is thought to be within the habitable zone of its star.

Some exoplanets in their stars' habitable zones may be distinctly uninhabitable due to solar flaring. Red dwarfs are known for powerful flaring, and since they're dim and their habitable zones are ...

Sedna, a distant dwarf planet three-quarters the size of Pluto, is inching toward the brightest star in our sky — and in 2076 ...

On October 9, 2008, the State Space Agency of Ukraine sent a message towards Gliese 581c. Unlike the Voyager records, whose messages were chosen by a committee chaired by renowned physicist Carl Sagan ...

A giant gas planet comparable in size to Saturn exists around a small red dwarf star. The discovery is beyond the scope of conventional astronomy theory, and is making experts reconsider conventional ...

The unexpected discovery of the real-life celestial body Pluto in No Man's Sky by one explorer astonishes and impresses the player community.

Dark matter is one of Nature’s most confounding mysteries. It keeps particle physicists up at night and cosmologists glued to their supercomputer simulations. We know it’s real because its mass ...

While for most people Pluto is the most distant planet in the Solar System, things get a lot more fuzzy once you pass Neptune ...

How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between ...

The planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. If you include the ...