A kind of planet considered able to supporting life may very well be coated in scorching magma. The chemical properties of those so-called hycean exoplanets – which have been beforehand thought to host liquid water oceans – might as an alternative point out magma seas.

Oliver Shorttle on the College of Cambridge and his colleagues got here to this conclusion utilizing observations from the James Webb House Telescope (JWST) of the exoplanet K2-18b. This world is archetypically hycean – a reputation given to planets with a hydrogen-rich ambiance above a liquid ocean. These planets additionally are typically between the scale of Earth and Neptune, with chemistry of their atmospheres that means liquid water exists on the floor – making them prime targets within the hunt for all times past Earth.

Nevertheless, current fashions of K2-18b’s local weather point out that it might be hotter than beforehand thought, sweltering sufficient that any water oceans would have boiled away way back. “The bottom is form of transferring beneath our ft, from a theoretical perspective, as to the circumstances on this planet,” says Shorttle.

The researchers investigated how it might have an effect on the planet’s atmospheric chemistry if these oceans have been manufactured from magma relatively than water, which might be in line with the warmer predicted temperatures. They discovered that this matched the JWST observations simply in addition to water oceans.

“These two radically totally different regimes look very comparable,” says Shorttle. “It makes the detection of liveable circumstances on an excellent Earth or sub-Neptune-sized planet extra sophisticated than we’d have hoped.”

Because of this we most likely want extra detailed knowledge to inform the distinction between a doubtlessly liveable world with water oceans and a broiling, inhospitable magma world. For K2-18b, Shorttle says the query ought to be resolved by further JWST observations within the coming years. And in the case of different hycean worlds, we might should develop new concepts of how one can seek for liquid water.