The mission to discover whether Proxima B has the potential to support life has taken a new and exciting twist. Researchers have embarked on the first steps to explore the potential climate of the exoplanet, which has been dubbed 'Earth 2.0.'
Their findings indicate that the planet has a climate that could be habitable, reinforcing the idea that it could host alien life. Proxima B was discovered in August last year orbiting our closest neighbouring star, Proxima Centauri, which is just 4.2 light years (25 trillion miles) away from Earth.
Its nickname of 'second Earth' arose due to the fact that it is of similar size to our planet, and was thought to have an atmosphere like our own. Early studies suggested that the planet is in the habitable zone of Proxima Centauri - the region where, given an Earth-like atmosphere and suitable structure, it would receive the right amount of light to sustain liquid water on its surface.
Now, researchers from the University of Exeter, have undertaken new research to explore the potential climate of the planet. Using the Met Office's Unified Model, which has been used to study the Earth's climate for several decades, the team simulated the climate of Proxima B if it were to have a similar atmospheric composition to our own Earth.
The team also looked at a much simpler atmosphere, made up of nitrogen with small traces of carbon dioxide, as well as variations of the planets orbit. The results showed that Proxima B has the potential to be habitable, and could exist in a stable climate regime.
Dr Ian Boutle, lead author of the study, said:
“Our research team looked at a number of different scenarios for the planet's likely orbital configuration using a set of simulations. 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.”
Dr James Manners, another author on the study, added:
“One of the main features that distinguishes this planet from Earth is that the light from its star is mostly in the near infra-red. These frequencies of light interact much more strongly with water vapour and carbon dioxide in the atmosphere which affects the climate that emerges in our model.”
Using the Unified Model, the researchers found that both the tidally-locked and 3:2 resonance configurations result in regions of the planet able to host liquid water. But the 3:2 resonance example resulted in more substantial areas of the planet falling within this temperature range. They also found that a circular orbit could lead to a further increase in the 'habitability' of this world.
Dr Nathan Mayne, an author of the study, added:
“With the project we have at Exeter we are trying to not only understand the somewhat bewildering diversity of exoplanets being discovered, but also exploit this to hopefully improve our understanding of how our own climate has and will evolve.