Last year, astronomers announced that they had found water vapor in the atmosphere of an exoplanet called K2-18b, which has a temperature suitable for life,media reported. But the planet’s sheer size makes it impossible to determine whether it is really fit for human habitation. Now, new research suggests that this super-sized world and other similar worlds may still be active.
It is understood that K2-18b orbits a dwarf star 124 light-years away, estimated to be larger than Earth — 8.6 times the mass of the Earth, but smaller than Neptune. It has long been thought that larger planets tend to be gas giants, and that their atmospheric pressure sits not suitable for habitability.
Researchers from the University of Cambridge have fed the planet’s latest mass, radius and atmospheric data into different models and concluded that K2-18b is more likely to be more Earth than Neptune.
“Water vapor has been found in the atmospheres of many exoplanets, but even if the planet is in the habitable zone, it does not necessarily mean that there is a habitable condition on its surface,” study leader Nikku Madhusudhan explained in a press release. To establish the prospect of livability, it is important to have a unified understanding of the inner and atmospheric conditions of the planet — in particular whether liquid water can exist in the atmosphere. “