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Earth-class planet




Earthlike planet
A planet having a mass 0.5 to 10 times that of the Earth (Me) and a radius 0.8 to 2.2 times that of the Earth. Planets more massive than 10 Me have enough gravity to attract a large hydrogen-helium atmosphere and so become gas giants. Those less massive than 0.5 Me are likely to lose any potentially life-supporting atmosphere because of low gravity and lack of plate tectonics needed to recycle carbon dioxide back into the atmosphere.


Archived news

Plenty of Earths await discovery (Apr 5, 2004)
Smallest 'Earth-like' planet seen (Aug 25, 2004)
Galaxy teeming with Earths argues astrophysicist (Feb 19, 2001)


Related categories

   • EXTRASOLAR PLANETS AND SUBSTELLAR OBJECTS
   • PLANETS AND MOONS
   • ASTROBIOLOGY