It’s the first world discovered by NASA’s Transiting Exoplanet Survey Satellite (TESS) – a spacecraft that began surveying the galaxy only two months ago.
“This is one of the first objects we looked at,” says Chelsea Huang, a TESS scientist at the Massachusetts Institute of Technology (MIT).
“We were immediately saying ‘hey this is too good to be true!’”
Dubbed Pi Men C, the planet is around twice the size of Earth and 4.82 times its mass.
The planet also appears to be 50 times closer to its star than the first planet in our system, Mercury, is to our Sun.
NASA said it takes the planet only 6.3 days to complete a trip around the star.
Scientists analysing data collected by TESS have determined the alien world is most likely made up entirely of water – one of the fundamental building blocks of life.
However the chances of extraterrestrial life existing on this distant world are highly unlikely – due its proximity to its star.
Huang said the planet is “likely to have a rocky core and an extended atmosphere made of hydrogen and helium”, adding: “We also think this planet might be evaporating right now, given the intense irradiation it gets from its host star.”
NASA said: “This first-ever spaceborne all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances.
“No ground-based survey can achieve this feat.”
TESS is the successor to NASA’s Kepler Space Telescope which is currently nearing the end of its nearly 10 year lifespan.
The satellite works by watching thousands of nearby stars in the Milky Way, looking for signs of planets transiting them.
Tiny dips in the stars’ brightness can reveal the presence of an orbiting planet momentarily passing in front of them.