Back in August 2016, astronomers and other space enthusiasts got exciting news about the discovery by stargazers at the European Southern Observatory (ESA) of a potentially habitable exoplanet, Proxima b, located a mere 4.25 light-years from Earth. Now, the results of a new study from the University of Exeter suggest the world may indeed support liquid water and, possibly, life.
The researchers simulated various climate and atmospheric conditions using climate modeling software from the UK’s national weather service. The results are intriguing.
“Overall, our results are in agreement with previous studies in suggesting Proxima Centauri B may well have surface temperatures conducive to the presence of liquid water,” write the authors in the May 16, 2017, issue of Astronomy and Astrophysics.
Proxima b appears to be a rocky planet with a mass a little greater than that of Earth. It orbits Proxima Centauri, the smallest star in the system Alpha Centauri, within the ‘Goldilocks’ or habitable zone — where temperatures are just right for liquid water to exist. Proxima Centauri is the closest star to Earth, apart from the sun.
The researchers not only looked at Proxima b’s climate in light of different atmospheric compositions, they ran models for various orbital configurations.
“Our research team looked at a number of different scenarios for the planet’s likely orbital configuration using a set of simulations,” explained lead author Dr. Ian Boutle, in a statement. “As well as examining how the climate would behave if the planet was ‘tidally-locked’ (where one day is the same length as one year), we also looked at how an orbit similar to Mercury, which rotates three times on its axis for every two orbits around the sun (a 3:2 resonance), would affect the environment.”
Most configurations resulted in the potential for liquid water to exist.
Unlike Earth’s sun, the light from Proxima b’s star shines mostly in near infra-red frequencies. These frequencies react more robustly with carbon dioxide and water vapor, affecting the model climate scenarios, according to co-author Dr. James Manners.
Studying the climate of Proxima b may have relevance to concerns closer to home, says the team.
“With the project we have at Exeter we are trying to not only understand the somewhat bewildering diversity of exoplanets being discovered,” added co-author Dr Nathan Mayne, “but also exploit this to hopefully improve our understanding of how our own climate has and will evolve.”