In the tidal confinement of the stars, there may be life near the exoplanet terminator line. This has been reported by the University of California at Irvine.
Planets close to a star are often caught in a tidal lock and remain turned to one side forever. An example of this is that Mercury, as well as the Moon, is always facing one side towards the Earth. There is a huge temperature difference between the day and night sides of such planets – for example, on Mercury it is from -170 to 400 degrees. Extreme heat and extreme cold are unfavorable for life, and therefore it was traditionally believed that the emergence of life on such planets is unlikely.
Lucas Van Wyck and colleagues have described a scenario where such planets could support life. According to them, it can be concentrated along the terminating line that separates night and day. The scientists modeled the climate of the planets in tide capture, using software commonly used to model Earth’s climate, but with some adjustments. The model showed that for certain combinations of the star’s spectral class, the planet’s orbit and mass, as well as its elemental composition, conditions suitable for life would emerge in the terminating region.
The amount of water on the planet plays an important role. If it is covered by an ocean, it will evaporate on the day side and cover the planet with a thick layer of vapor. If there is too much land on the planet, this will not happen.
According to the study’s authors, the theoretical prediction of the existence of such exotic habitats along the line of eternal “evening” forces us to rethink the policy of searching for habitable planets.