Discovery of an alien: scientists refine their research after a shocking discovery about extraterrestrials | Science | New


After discovering the composition of most planetary atmospheres, scientists looking for strangers focused more on fewer planets. As a general rule, alien hunting experts have analyzed the planets in their host star's habitable zone – a region of space where it is neither too cold nor too hot for life to exist. . However, experts at the University of California Riverside (UCR) believe that other scientists have ignored the buildup of toxic gases in the planet's atmosphere that would not allow for a complex life of evolve.

For example, using computer models, researchers have discovered that any planet on the periphery of the habitable zone with a liquid on the surface would need carbon dioxide – a greenhouse gas – at levels a thousand times higher than those of the Earth to maintain its liquid state and not freeze it. .

Edward Schwieterman, lead author of the study published in The Astrophysical Journal, and a postdoctoral program at NASA, said: "To conserve liquid water on the outskirts of the conventional habitable zone, a planet would need to tens of thousands of times more carbon dioxide than Earth has today.

"This far exceeds the known levels of toxicity to human and animal life on Earth."

Another example comes from the two closest extraterrestrial stars of our solar system – Proxima Centauri and TRAPPIST-1.

The intense ultraviolet radiation of these stars would hit all the planets in their habitable zones, which would lead to an accumulation of carbon monoxide, a poison.

Timothy Lyons, one of the co-authors of the study, distinguished professor of biogeochemistry at the Department of Earth Sciences and Planets of UCR and director of the Center for Alternative Earth Astrobiology, said: " This is the first time that the physiological limits of life on Earth have been considered to predict the distribution of complex life elsewhere in the universe.

"Imagine a" habitable zone for complex life "defined as a safe zone where it would be plausible to preserve ecosystems as rich as those currently found on Earth.

"Our results indicate that complex ecosystems like ours can not exist in most areas of the livelihood zone as traditionally defined."

Mr Schwieterman concluded: "I think that showing how rare and special our planet is only reinforces the case for its protection.

"As far as we know, the Earth is the only planet in the universe capable of sustaining human life."


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