'Mini-Neptunes' beyond solar system may soon yield signs of life

Cambridge astronomers identify new hycean class of habitable exoplanets, which could accelerate search for life

Nicola Davis Science correspondent
@NicolaKSDavis
Wed 25 Aug 2021 19.01 EDT

Signs of life beyond our solar system may be detectable within two to three years, experts have said after rethinking the kinds of planets that may be habitable.

Researchers have mostly looked for planets of a similar size, mass, temperature and atmospheric composition to Earth. But University of Cambridge astronomers believe there may be more promising possibilities after recent work suggested that a “mini-Neptune” more than twice the radius of Earth and more than eight times as massive may also be habitable.

They have now identified a new class of habitable exoplanets, called hycean planets – hot, ocean-covered and with hydrogen-rich atmospheres – which are more numerous and observable than Earth-like planets. The mini-Neptune, known as K2-18b, is one and there could be many more in existence.

“Hyceans are basically water worlds with hydrogen-rich atmospheres,” said Dr Nikku Madhusudhan, the lead author of the research from the University of Cambridge. He said focusing on hyceans could accelerate efforts to find life beyond Earth.

More:
https://www.theguardian.com/science/2021/aug/26/mini-neptune-beyond-solar-system-may-soon-yield-sign-life-hycean-exoplanet-cambridge-astronomer