Is (Alien) life possible on Alpha Centauri ?

As an Earth similar planet, terrestrial planet, telluric planet or rocky planets are called in astronomy and planetology those celestial bodies, which are similar in structure of the earth: they consist entirely or almost entirely of solid ingredients, and usually have a shell structure: the center is one in iron core, over a thick layer, the so-called mantle of silicates and oxides, and on top a thin crust, which also consists of silicates and oxides, but enriched in elements that can not be incorporated into the mantle rock, and over time " sweat out "(for example potassium, rare earths, uranium). In some cases, is followed over the crust, the atmosphere, and the earth is still the hydrosphere (oceans, lakes ,etc) between. Furthermore, similar diameter and mass, but in particular, the average density, where the earth. The latter moves roughly between 4-6 g/cm3.Ausgehend of the similarity of the two stars, what the age, the type of star, the spectral type and affects the stability of the orbits, it is assumed that this star system is one of the best known conditions for extraterrestrial life could offer. Stars that are currently classified for the development of life as a useful include yellow G-star, late (cool) F-stars and early (hot) K-Stars.

A planet around Alpha Centauri A would have a spacing of about 1.2 to 1.3 AU have in order to have Earth-like temperatures. This would, based on the solar system, roughly correspond to an orbit between Earth and Mars. For the less bright, cooler Alpha Centauri B, should this distance about 0.73 to 0.74 AU (approximately the distance from Venus to the Sun) amount.

Alpha Centauri A and B are at the top of the top-one hundred list of the goals of NASA's planned Terrestrial Planet Finder. This list includes the most promising stars to the Earth-like planets are suspected. However, the construction of this World Space Telescope has been postponed due to budget cuts indefinitely.