According to new research, a distant planet beyond the solar system could have a lot in common with Earth - including the prospect of life.
*Cues The X-Files theme tune*
The faraway exoplanet, which is known as K2-18b, could be a scaled-up version of Earth. The planet orbits within its star's habitable zone, which means it could hold liquid water on its surface - a key factor needed to sustain alien life.
The new study from researchers at the University of Texas discovered that the planet is either a mostly rocky planet with a gaseous atmosphere, just like Earth, or a mostly water planet with a thick layer of ice on top of it.
The planet could have water on it, like Earth. Credit: PA
Trying to find out whether the planet is more like a scaled-down version of Neptune made mostly of gas, or a scaled-up version of Earth made mostly of rock, the researchers used radial velocity measurements of its star, and a machine learning calculator.
"If you can get the mass and radius, you can measure the bulk density of the planet and that can tell you what the bulk of the planet is made of," said lead author Ryan Cloutier, of the University of Montreal, as reported in the Daily Mail.
The study also found that K2-18b even has a neighbour, K2-18c. However, while it also appears to be a super Earth and is closer to both planets' star (red-dwarf K2-18, which is located 111 light years from Earth) - it is likely to be too hot to be in the habitable zone. Probably no aliens here then.
They're clearly more interested in K2-18b, with researchers saying the planet will be a prime target for Nasa's James Webb Space telescope, which will launch in 2019.
"With the James Webb Space Telescope (JWST) we can probe the atmosphere and see whether it has an extensive atmosphere or it's a planet covered in water," Mr Cloutier said, which means they could determine if the planet is more like Neptune or the Earth that we know and love.
Study co-author Professor René Doyon, also from the University of Montreal, added: "There's a lot of demand to use this telescope, so you have to be meticulous in choosing which exoplanets to look at.
"K2-18b is now one of the best targets for atmospheric study, it's going to the near top of the list."
I'd just like to take this opportunity to give a friendly wave to potentially new pals over on K2-18b, in the hope that they will like us, and not want to death-ray us out of existence.
Featured Image Credit: PA