New Class of Exoplanets Called ‘Hycean’ Planets Could Support Life

Astronomers found a new type of 'Waterworld exoplanets that might host life despite being hot, ocean-covered, and hydrogen-rich.

The team from the University of Cambridge has named them 'Hycean' worlds, claiming that they 'greatly improve our chances of finding life.'

Scientists have primarily sought planets comparable to Earth in atmospheric composition, mass, size, and temperature to hunt for life.

Researchers published their study, titled "Hycean Worlds Habitability and Bio-Signature," in The Astrophysical Journal.

Hycean Worlds More Frequent Than Other Earth-Like Exoplanets

Astronomers say, per Forbes, there might be more good possibilities because Hycean worlds are much easier to find and examine.

Liveable exoplanets are ocean-covered planets with hot, hydrogen-rich environments. Their warmth makes them more visible than Earth-like planets, making them simpler to discover with existing telescopes.

Scientists say the findings might show that the development of life outside our home galaxy is possible within the next few years.

The study's lead author, Cambridge's Institute of Astronomy's Dr. Nikku Madhusudhan, said the findings open up a whole new line of exploration for life somewhere else.

Mini Neptunes, Super-Earths

The Evening Standard said many exoplanets identified as good possibilities by the researchers are larger and hotter than Earth,

According to experts, they still have the qualities to host vast seas that may maintain microbial life akin to that found in some of the world's most severe aquatic settings.

In comparison to Earth-like planets, the planets have a much larger habitable zone, or Goldilocks zone.

This indicates that even if they are outside the range where Earth would need to be to be habitable, they might still host life.

Thousands of additional planets have been discovered outside our Solar System since the first exoplanet was identified 30 years ago.

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The majority are super-Earths or mini-Neptunes, planets that are between the sizes of Earth and Neptune.

They can be mostly rocky or ice giants with hydrogen-rich atmospheres or anything in the between.

Previous research on such planets discovered that the pressure and temperature underneath their hydrogen-rich atmospheres were too great to host life.

Welcome to K2-18b!

PA Media (via Yahoo! Sport) said Dr. Madhusudhan's team discovered that these planets might host life under specific conditions in recent research on the mini-Neptune K2-18b.

This sparked thorough research of the complete spectrum of planetary and stellar characteristics that may result in these situations.

It also looked at whether known exoplanets may meet those criteria and if their biosignatures could be detected soon.

Researchers discovered a new type of worlds called Hycean planets, with huge planet-wide seas under hydrogen-rich atmospheres.

Hycean planets could be more than twice times bigger the size of Earth, with temperatures approaching 392ºF (200º C) in their atmospheres.

Astronomers say tidally locked 'black' Hycean worlds may have livable circumstances only on their permanent night sides. Meanwhile, 'cold' Hycean worlds get minimal radiation from their stars.

Size alone is insufficient to establish if a planet is Hycean; additional factors like mass, temperature, and atmospheric characteristics must be considered.

The team has discovered many possible Hycean worlds that are ideal candidates for comprehensive investigation with the new observatories like the James Webb Space Telescope (JWST), which is scheduled to launch later this year.

These planets are all nearby astronomical standards, orbiting red dwarf stars between 35 and 150 light-years distant.

It's possible that future JWST observations of the most intriguing candidate, K2-18b, will reveal one or more biosignature chemicals.