There may be life in “terminator zones”
For example, imagine that the Earth is orbitally locked to the Sun, and the same face is constantly facing the star. While the part of such planets facing their star becomes barren with scorching temperatures, the parts that are constantly in darkness become frozen to unbearable cold.
In a new study, astronomers suggest that extraterrestrial life may exist in “terminator zones” that lie between the light and dark areas of an exoplanet. Temperatures are not expected to be extreme, as there is a constant state of twilight in these areas. These “terminator zones” of a planet closest to its star can create conditions in which water can remain liquid. Previous studies have not looked at the possibility that such close-to-star, gravitationally locked planets could harbor life.
This strange-looking type of planet is actually quite common, especially around faint small M dwarf stars that make up about 70 percent of all stars in our galaxy, the Milky Way. Astrobiologists often focus on oceanic worlds because water is a crucial ingredient for life. But Lobo and team members wanted to find new niches where life could survive.
“We’re trying to draw attention to water-limited planets that may not have extensive oceans but may have lakes or other small bodies of liquid water. These climates can actually be very promising,” Lobo said. A range of planet-hunting telescopes can now also study such planets, from the James Webb Space Telescope to the Habitable Worlds Observatory, scheduled for launch in the 2040s. The study was published in The Astrophysical Journal last month.