For the first time, researchers at Northwestern University have combined atmospheric chemistry with three-dimensional climate models to help identify planets that may be alive outside the solar system. The study could help astronomers make progress in finding extraterrestrial life, it said, and could help them reduce the number of telescope objects.
The researchers focused on the planets orbiting the M star. These are the most common types of stars, accounting for about 70 percent of the milky galaxy’s population. M dwarfs generally refer to red dwarfs, although some definitions of red dwarfs also include larger K dwarfs. The findings further reveal the so-called Goldilocks region, which could theoretically have life in the solar system. It is currently understood that liquid water evaporates on planets that are too close to the star. On planets too far from the star, liquid water freezes, and at Earth-like distances, life can exist when liquid water is sustained.
However, the researchers found that if a star is active and emits a lot of ultraviolet light, its planets lose moisture as a result of evaporation, and so-called inactive or quiet stars are more likely to maintain liquid water, which is essential for livability. Using 3D climate modeling and chemistry, the researchers found that stellar activity, not just distance from planets, was an important factor in sustaining the planet’s ability to live.
They also found that if the Earth’s ozone layer is too thin, it could pose a risk to the living environment, and high ultraviolet levels could seriously threaten the survival of any advanced life on the planet’s surface.