Proxima Centauri b
Dear Reader,
The discovery of Proxima Centauri b is nothing short of extraordinary: A planet with a mass that appears similar to that of the Earth is orbiting in the habitable zone of our nearest star! We could not have hoped for anything better! The star is sufficiently close that within the next decade instruments on the largest Earth-based telescopes will be able to directly study this planet and looking for signatures of life.
Professor Willy Benz, Director of NCCR PlanetS. (Photo: Alessandro Della Bella)
Should we mind that the host star, Proxima Centauri, is only 10% of the mass of the sun, that the planet’s radiation environment might be much harsher, that the same side of the planet might be continuously facing the star, that there might be no water on its surface even though the temperature is mild?
The answer is a clear resounding no! Investigating these issues is precisely what will help us understanding the formation of planets, their evolution, and their ability to harbour life. In the laboratory, understanding is gained by repeating experiments under different conditions. In astronomy, we cannot change anything, we are condemned to just observe. But, we can be smart and circumvent this problem by observing the different experiments Nature has realised for us! Proxima Centauri b is precisely one of these other experiments.
This planet might not be inhabited or even be habitable… but it is the one planet, out of all the many we know so far outside the solar system, that shares with the Earth some key characteristics defining habitability (for life as we know it on Earth) and it happens to be our closest neighbour… An opportunity that simply cannot be ignored. Let us look under the hood and find out what is really there!
Willy Benz,
Director NCCR PlanetS
