Wednesday, April 18, 2012

Red Dwarf Habitable Zone Earth Size Planets are Venus Like

The Earth is located within the sun’s habitable zone that is the distance range around a star where planets can have liquid water on their surface. Astronomers have found that about 40% of red dwarfs have approximately Earth size planets orbiting them many of which are in the stars habitable zone leading to the suggestion that these planet could have life on them. Howevere a new study shows that tidal forces may dry out Earth size planets orbiting within a red dwarf “habitable zones” making them more like Venus than Earth and therefore hostile to life.

Red dwarfs are fainter and cooler than the sun, a planet orbiting within a red dwarf's “habitable zones” much closer to the star than the Earth is to the Sun. As a result such planets would have a very strong tidal force with the star. A planet not in a perfectly circular orbit would get stretched and squeezed as this pull changes during the planets orbit, such tidal stretching and squeezing heats the planet up. As result a planet with liquid water orbiting a star whose mass is less than 1/3 that of the sun would get so hot that its water would evaporate. The light from the star would split the water vapor into hydrogen and oxygen. The Hydrogen would escape into space and the oxygen would combine with carbon to form carbon dioxide thus producing a Venus like planet

The result is that so called Earth like planets orbiting red dwarf stars are hardly Earth like. These planets are more like Venus and totally hostile to life. This study showsfurther evidience of how unique our solar system and the Earth are.

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