Alien water world: Astronomers spot exoplanet that may be entirely covered by ocean

Astronomers have discovered what they believe could be a real-life "water world" – a planet completely covered by ocean.

Orbiting a star some 100 light years from Earth, the planet is in the so-called "Goldilocks zone" or "habitable zone” where its temperature would be just right for liquid water to exist on the surface.

Just like Earth, it would retain its liquid water, as the distance from its star means it isn’t too hot or too cold.

Named TOI-1452 b, the planet is slightly greater in size and mass than Earth, but due to its lower density compared to Earth, scientists think it may be covered by a thick layer of water.

Ocean planets are of particular interest to astronomers and space enthusiasts alike, as they are thought to be strong candidates for planets where life could originate or survive.

Astronomers working on the study have called TOI-1452 b one of the best ocean planet candidates discovered so far.

It was first spotted by NASA’s space telescope the Transiting Exoplanet Survey Satellite (TESS), which surveys the entire sky to find exoplanets around nearby bright stars.

TESS saw a slight decrease in brightness of a star in a binary star system every 11 days, with astronomers predicting from this data a planet about 70 per cent larger than Earth.

Astronomers from the Université de Montréal conducted follow-up observations from a telescope on the ground to confirm the planet type and its characteristics.

"This was no routine check," said Charles Cadieux, a PhD student at the Université de Montréal and member of the Institute for Research on Exoplanets.

"We had to make sure the signal detected by TESS was really caused by an exoplanet circling TOI-1452, the largest of the two stars in that binary system".

To work out the mass