Nemesis star. Computer artwork of the star Nemesis,a hypothetical companion star to the Sun (upper left). It is thought that Nemesis is either a red or brown dwarf that moves in an elliptical orbit at a distance from the sun that varies between 90,000 astronomical units and 20,000 astronomical units. This path would lead it through the Oort cloud,a cloud of comet nuclei. One theory is that this would send some comets on a path to Earth and so would explain the periodic mass extinctions of life,such as that which wiped out the dinosaurs. However Nemesis has not been found despite extensive searches | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Dalhoff, Henning |
Taille de l’image : | 4383 px × 3992 px |
Model Release : | Non requis |
Restrictions : | - |