When astronomers announced the discovery of an Earth-sized exoplanet 5 light-years away, the main question was - can we colonize it? We will not know if Prosima b is inhabited until we point very powerful telescopes at it, which will not happen until next year. Therefore, while scientists are testing various models - and one such attempt has recently revealed many new facts.
If Proxima b has an earth-like atmosphere, it could be a comfortable place to live, scientists have found. Most likely rocky, located at a distance of 40 trillion km from us, Proxima b is located just in the habitable zone of its star - a hot red dwarf named Proxima Centauri. This means that the planet can support liquid water and even life. The latter, however, is a big question, but while we await further information, a team of British scientists is trying to find out if Proxima b can have a stable climate and temperature necessary for life.
Proxima b as seen by the artist. ESO
Therefore, scientists turned to the United Kingdom Weather Service's Unified Model, one of the most advanced models for studying the climate on Earth. The team modified this model for extraterrestrial prediction, considering two types of potential atmospheres: an earth-like atmosphere rich in nitrogen and oxygen, and a simple nitrogen atmosphere containing traces of CO2. They then ran their simulations, considering several hypothetical orbits for Proxima b, including one in which the planet is in tidal lock on another, with constant day and night sides, and an orbit like Mercury. The researchers also looked at the difference in light output from a star that produces more infrared and less visible light than our sun.
In general, the results of the study, published this week in the journal Astronomy and Astrophysics, were encouraging. In tidal and Mercurial orbit, the models showed stable surface temperatures favorable for liquid water.
Although not all parts of Proxima b were inhabited in all simulations (the night side in the tidal capture scenario had a pleasant temperature of −129 degrees Celsius), the models showed regions warm enough to make the exoplanet a great vacation destination.
However, the models may fail to account for many factors. First of all, the modeling assumes that Proxima b has an atmosphere, which may not be true. Another study has shown that planets in orbits close to red dwarfs can lose their atmosphere from a huge number of high-energy solar storms. There is no atmosphere, no rivers, lakes and oceans, no life as we know it.
Also, the model did not take into account what the surface of Proxima b will be. As we have learned from studying the Earth, the mixture of land, water and ice that covers the planet has a huge impact on temperature.
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