Researchers are now focusing on how could diverse forms of life survive or come into being outside our Solar System. In the present research, a UC Riverside-headed team found that the amassing of toxic gases in the atmospheres of various planets renders them unfit for complex life. The scientists have been since years trying to look for extraterrestrial life or habitable zone, which is a definite range of distance from a warm star that helps retain liquid water on the planet’s surface. The single-celled microbes could possibly survive in such conditions but not complex creatures like animals. The toxic gases decline the chances of a safe zone for the survival of complex life.
It is for the first time that the lives physiological limits on Earth are being considered to foretell the distribution of complex life anywhere else in the Universe. The habitable zone for complex life is a safe zone that provides a rich ecosystem just like the ones found the Earth today. The complex ecosystems like ours are believed to not exist anywhere in the entire Universe. The computer models are used to understand the photochemistry and atmospheric climate of various planets so as to study the gases including carbon dioxide. The planets away from their host star tend to require more carbon dioxide so as to retain the temperatures above freezing.
For sustaining the water on the surface, the planets will need more carbon dioxide compared to that on the Earth for creating a conventional habitable zone. The carbon dioxide toxicity is enough to restrict the survival of life forms. The Sun’s closest neighbors, TRAPPIST-1 and Proxima Centauri, have no safe zone. The UV rays emitted by the cooler and dimmer stars can increase the concentration of carbon monoxide. On the Earth, the Sun uses its heat to cause a chemical reaction that can destroy carbon monoxide. The microbial biospheres’ survival in such harmful gases may seem possible but not for humans. The exoplanets have shown abundances of certain gases in the surroundings and the NASA’s proposed Habitable Exoplanet Observatory is a future mission that can help find habitable exoplanets or other bodies.