Starship Asterisk*

The quest to discover whether a planet orbiting our closest neighbouring star, Proxima Centauri (4.2 light years or 25 trillion miles from Earth), has the potential to support life has taken a new, exhilarating twist.

The planet was only discovered in August 2016, and is thought to be of similar size to Earth, creating the possibility that it could have an 'Earth-like’ atmosphere. Scientists from the University of Exeter and Met Office have embarked on their first, tentative steps to explore the potential climate of the exoplanet, known as Proxima B.

Early studies have suggested that the planet is in the habitable zone of its star 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, the team of astrophysics and meteorology experts have undertaken new research to explore the potential climate of the planet, towards the longer term goal of revealing whether it has the potential to support life.

Using the state-of-the-art Met Office Unified Model, which has been successfully 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 explored a much simpler atmosphere, comprising of nitrogen with traces of carbon dioxide, as well as variations of the planet's orbit. This allowed them to both compare with, and extend beyond, previous studies.

Crucially, the results of the simulations showed that Proxima B could have the potential to be habitable, and could exist in a remarkably stable climate regime. However, much more work must be done to truly understand whether this planet can support, or indeed does support, life of some form. ...

• Astronomy & Astrophysics (online 16 May 2017) DOI: 10.1051/0004-6361/201630020
  arXiv.org > astro-ph > arXiv:1702.08463 > 27 Feb 2017