Alien could be discovered on this new class of 'Hycean' exoplanet.

In the discovery for Alien life, astronomers have mostly looked for planets of a similar size, mass, temperature, and atmospheric composition to Earth. Recently, the team of astronomers find a class of planets that may prove the existence of Alien Life. Such exoplanets are more numerous in planetary surveys than rocky ones, which means they could be fertile territory in the search for alien life. The researchers have dubbed them 'Hycean' worlds. 

In the new study, researchers identify one such class of alien worlds "Hycean" planets, which are up to 2.5 times larger than Earth and feature huge oceans of liquid water beneath hydrogen-rich atmospheres. Hycean planets appear to be incredibly abundant throughout the Milky Way galaxy, and they could host microbial life similar to the "extremophiles" that thrive in some of Earth's harshest environments, study team members said. "Hycean planets open a whole new avenue in our search for life elsewhere," lead author Nikku Madhusudhan, of the Institute of Astronomy at the University of Cambridge in England, said in a statement. 

Many of the prime Hycean candidates identified by the researchers are bigger and hotter than Earth, but still have the characteristics to host large oceans that could support microbial life similar to that found in some of Earth’s most extreme aquatic environments. These planets also allow for a far wider habitable zone, or ‘Goldilocks zone’, compared to Earth-like planets. This means that they could still support life even though they lie outside the range where a planet similar to Earth would need to be in order to be habitable. 

The team have already identified a sample of potential Hycean worlds which could be prime candidates for future study. These planets all orbit red dwarf stars between 35-150 light-years away which, by astronomical standards, is practically in our backyard. The James Webb Space Telescope, due to launch this year, will observe the most promising candidate – K2-18b – once it becomes operational.

“A biosignature detection would transform our understanding of life in the universe,” says Madhusudhan. “We need to be open about where we expect to find life and what form that life could take, as nature continues to surprise us in often unimaginable ways.” .”