New type of ocean-covered exoplanet could support life

When it comes to looking for life elsewhere in the universe, we tend to be very Earth-centered: we look for planets similar to our own, assuming that life elsewhere will be similar to us and will require similar conditions. However, a new type of exoplanet has been identified by astronomers at the University of Cambridge, and although it is very different from Earth, it could still harbor life.

The new class of planets is called a “Hycean” planet, which means a world covered with oceans with hydrogen in abundance in its atmosphere. Researchers believe that this type of planet could be common and because they are potentially habitable, this greatly increases the possible locations to search for life outside of our solar system.

“The Hycean planets are opening up a whole new avenue in our search for life elsewhere,” lead researcher Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge said in a statement.

These planets are typically larger than Earth, up to 2.6 times its size, and can also be hotter, with air temperatures of up to 200 degrees Celsius. However, despite these high temperatures, their oceans could still harbor microbial life, as another recent study suggests on a large exoplanet with a hydrogen-rich atmosphere. This study revealed that there could be liquid water on the surface of the planet under its atmosphere. If this is also true for the Hycean planets, then the habitable zone – the area around a star where a planet must orbit in order for liquid water to exist on its surface – might be larger for these planets than for d ‘other types of planets.

“Essentially, when we researched these various molecular signatures, we focused on Earth-like planets, which is a reasonable starting point,” Madhusudhan said. “But we think the Hycean planets offer a better chance of finding more traces of biosignatures.”

Biosignatures are chemical indications of life and are one of the primary means by which researchers seek life elsewhere in the universe.

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

The research is published in The Astrophysical Journal.

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