Scientists Take First Steps to Find Life on Proxima B

An artist’s impression of Proxima b, a planet in the Proxima Centauri system that scientists believe may be capable of supporting life. (European Southern Observatory)

(CN) – The quest to find life beyond Earth progressed Monday, with research that sheds light on the recently discovered – and potentially habitable – planet Proxima b.

First identified in August 2016, Proxima b is thought to be close in size to Earth, which suggests the mysterious planet could have a similar atmosphere.

Studies have estimated that Proxima b is in the habitable zone – a region where a planet would be capable of supporting liquid water on its surface, given an Earth-like atmosphere and an appropriate structure – of Proxima Centauri, the star closest to our solar system. Proxima Centauri is 4.2 light years, or 25 trillion miles, from Earth.

Now, a team of researchers from the University of Exeter has taken the first steps to explore Proxima b’s climate, doing so using the Unified Model – a sophisticated numerical template that’s been used to study Earth’s climate for decades. However, many aspects of the model are specific to Earth – such as the state of our ice caps and vegetation – which forced the researchers to focus on the basics, including primary climate drivers like heating and rainfall.

The Exeter team tested various atmospheric compositions, including one similar to Earth and one comprised of nitrogen with traces of carbon dioxide. The researchers also examined variations to Proxima b’s orbit.

Their simulations showed that Proxima b could be habitable, and could have a surprisingly stable climate pattern. The team cautions that much more research is needed to determine whether the planet can – or does – support life.

“One of the main features that distinguishes this planet from Earth is that the light from its star is mostly in the near-infrared,” said co-author James Manners. “These frequencies of light interact much more strongly with water vapor and carbon dioxide in the atmosphere which affects the climate that emerges in our model.”

Adjustments to the theoretical orbit of Proxima b also produced encouraging results. The team found configuring the planet as tidally locked – when one side of the planet always faces its host star – and giving it a 3:2 resonance orbit of three rotations for every two orbits around a star each showed that Proxima b could host liquid water. The 3:2 resonance example resulted in a larger portion of the planet falling within the necessary temperature range.

The team’s work is published in the journal Astronomy and Astrophysics.


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