Breezing through the space environment of Barnard`s Star b
(PHYSorg.com Space & Earth)

The closest exoplanet to us, if we include only single stars like the Sun, is the planet around Barnard`s Star, Barnard`s Star-b (`BSb`). (The planet Promixa Centauri-b is closer, but Proxima Cen is part of a triple-star system with Alpha and Beta Centauri, and understanding the evolutionary development of the planet is more complicated.) BSb orbits at a distance similar to that of Mercury around the Sun, but Barnard`s Star is a cool M-dwarf star and so despite the planet being close to the star it probably resides near the snow line - the distance where stellar irradiation is weak enough to allow volatile elements to condense onto the planet`s surface. This makes BSb an especially interesting planet and possibly a keystone for future progress understanding planet formation and atmospheric evolution.