Nasa confirms 5,000 exoplanets discovered beyond Solar System

Image source, NASA/Reuters

Image caption, This is an artist's impression of TESS, the Transiting Exoplanet Survey Satellite, one of the modern tools used to discover new planets

There are now more than 5,000 confirmed planets beyond our solar system, according to US space agency Nasa.

Sixty newly-discovered planets by the Nasa Exoplanet Archive and five more planets from other observatories brings the total number of exoplanets, as they are known, to 5,005.

These exoplanets vary in size and appearance - some are rocky worlds roughly the size of Earth with others giant gas planets, larger than Jupiter.

It's not only a huge milestone for astronomers but could also be important in the search for alien life.

"Each one of them is a new world, a brand-new planet. I get excited about every one because we don't know anything about them," said Nasa Exoplanet Science Institute (NESI) scientist Jessie Christiansen.

What is an exoplanet?

Image source, NASA

Image caption, The exoplanet Kepler-452b was discovered in 2014 and has very close similarities to Earth

Exoplanets are planets that orbit a different star than our Sun - so in a different solar system to the one we are in.

Even though scientists thought for a long time that they must exist, it was only in 1992 that the first exoplanet was discovered.

Further work to look for other ones has turned up some exciting results more recently too.

Video caption, The Big Question: How big is space?

In 2015, scientists discovered the exoplanet Kepler-452b, which was described as 'Earth's cousin' because of its close similarities to our planet.

Space experts say exoplanets are really important because they raise the possibility that other life could exist in other solar solar systems.

They believe we could discover many more exoplanets in the future as planet-finding technology improves, such as the recently launched James Webb Space Telescope.