Recently, scientists from Harvard University succeeded in exploring more the exoplanets and their chance to be habitable. They found how even very small rocky exoplanets which orbit other stars, can maintain water, necessary for living. The research involved the area around a star and its temperature that has to reach the right levels to allow liquid water to develop.
Moreover, scientists’ study recalculates the lower limit in mass for possible habitable exoplanets.
How Small Could an Exoplanet Be?
The critical limit level seems to be almost 2,7 % of the mass of Earth. If other exoplanets overreached that limit, the chance to be habitable would decrease. They would lose their atmosphere into outer space before water could develop in their areas. Any quantity of water would also freeze or vaporize.
Constantin Arnscheidt, astronomer and author of the study, explained that “setting a lower bound for habitability in terms of planet size gives us an important constraint in our ongoing hunt for habitable exoplanets and exomoons.” Furthermore, co-author, Robin Wordsworth, detailed that “…this paper shows just how different their behavior is likely to be compared to that of Earth-like planets. ”
According to current theories and studies, if a planet is too close to its star, it would lose all its water due to the runaway greenhouse effect. Venus, for example, is now dry and hot, but it might have had a long time ago an ocean. The planet suffered a runaway greenhouse effect.
New Study Ideas and Goals
The study explains how the small exoplanets, but not very small, starts to get hotter due to the greenhouse effect. This process allows them to expand much more. The planet would reach then, an equilibrium, because of the increase of radiation and absorption of heat. The process would lead to a smart way of preventing the runaway greenhouse effect, and the planet will succeed in maintaining its water.
Scientists discovered that their theories could apply to red dwarf stars and G-type sun, as well.