Alien planetary system. Computer artwork of an Earth-like moon orbiting a ringed gas giant planet that is orbiting the star at lower right. An alien (or extrasolar) planet has to fit a narrow range of sizes and distances from its star,if it is to have a surface temperature suitable for liquid water,and to retain an atmosphere. The number of other habitable planets in the Milky Way galaxy is not known,but has been estimated at anything between 1 (just Earth) and as many as 10 billion. Many planets have already been discovered orbiting nearby stars | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Van Ravenswaay, Detlev |
Bildgröße: | 4724 px × 2756 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |