In the search for life elsewhere, astronomers have mostly looked for planets of a similar size, mass, temperature and atmospheric composition to Earth. However, astronomers from the University of Cambridge believe there are more promising possibilities out there.
The researchers have identified a new class of habitable planets, dubbed ‘Hycean’ planets – ocean-covered planets with hydrogen-rich atmospheres – which are more numerous and observable than Earth-like planets.
The researchers say the results, reported in The Astrophysical Journal, could mean that finding biosignatures of life outside our Solar System within the next few years is a real possibility.
“Hycean planets open a whole new avenue in our search for life elsewhere,” said Dr Nikku Madhusudhan from Cambridge’s Institute of Astronomy, who led the research.
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.
Image: Artist's impression of a Hycean planet
Credit: Amanda Smith
Reproduced courtesy of the University of Cambridge