Limited Habitable Zone for Complex Life In The Universe – New Study Shows

Eddie Gonzales Jr. – MessageToEagle.com – A new study conducted by researchers at UC Riverside shows that a buildup of toxic gases in the atmospheres of most planets makes them unfit for complex life as we know it.

It may be time to rethink their estimates for how many planets outside our solar system could host a rich diversity of life.

Traditionally, “habitable zone” is defined as the range of distances from a star warm enough that liquid water could exist on a planet’s surface. That description works for basic, single-celled microbes—but not for complex creatures like animals, which include everything from simple sponges to humans.

“This is the first time the physiological limits of life on Earth have been considered to predict the distribution of complex life elsewhere in the universe,” Professor Timothy Lyons of UC Riverside, said in a press release.

“Imagine a ‘habitable zone for complex life’ defined as a safe zone where it would be plausible to support rich ecosystems like we find on Earth today.

“Our results indicate that complex ecosystems like ours cannot exist in most regions of the habitable zone as traditionally defined.”

Using computer models to study atmospheric climate and photochemistry on a variety of planets, researchers concluded that carbon dioxide toxicity alone restricts simple animal life to no more than half of the traditional habitable zone. For humans and other higher order animals, which are more sensitive, the safe zone shrinks to less than one third of that area.

What is more, no safe zone at all exists for certain stars, including two of the sun’s nearest neighbors, Proxima Centauri and TRAPPIST-1.

The type and intensity of ultraviolet radiation that these cooler, dimmer stars emit can lead to high concentrations of carbon monoxide, another deadly gas.

Carbon monoxide binds to hemoglobin in animal blood—the compound that transports oxygen through the body. Even small amounts of it can cause the death of body cells due to lack of oxygen.

Microbes may be able to thrive on a planet with abundant carbon monoxide, but for humans and other complex organisms,  such environment would certainly not be good suitable place to  live.

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Written by Eddie Gonzales Jr. – MessageToEagle.com Staff