Over the past few years the discovery of planets outside of our solar system has almost become routine. So many planets, and of such a wide variety of sizes, orbits and composition have been found that it now looks as though almost ever star comes with planets.
But the recent announcement in the journal nature ( http://www.nature.com/news/earth-sized-planet-around-nearby-star-is-astronomy-dream-come-true-1.20445) is something special. Not only does the planet orbit Proxima Centauri, the closest star to our own Sun, but the planet is similar to the Earth in size and orbits Proxima Centauri at a distance where liquid water could exist on its surface.
The newly discovered planet has been named Proxima B and has a mass estimated to be 30% greater than Earth’s. If it possesses an atmosphere and oceans it could easily be a home for life and astronomers are organized a coordinated effort to learn all we can with our present and future technology.
The sun our new planet orbits is very different from our own star. Proxima Centauri is a small red dwarf with a mass of only 12% that of our Sun and emits only 1.5% of the energy of our Sun. Notice that, while Proxima Centauri is smaller it emits much less energy. This means that the fuel powering Proxima Centauri could last almost ten times longer than the fuel remaining for our Sun. That’s true of stars in general, the larger they are the shorter their lifespan.
So here we have an interesting plot for a Science Fiction novel. It’s several billion years in the future and the Sun is running out of fuel so the inhabitants of the solar system, not necessarily Earth nor necessarily human, are striving to reach Proxima B as a new home.
Of course, that’s just fiction!