Astronomers in California, US, have found toxic fumes and gases make certain planets uninhabitable to advanced forms of alien life. The shocking revelation, presented this week by the University of California, Riverside, means most planets are unfit for advanced life. While microbes and simple bacteria can thrive in inhospitable environments, complex life needs very specific conditions to develop. The good news, however, is the alien discovery considerably narrows down the number of potential planets where alien life could exist.
Timothy Lyons, one of the study’s co-authors, said: “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 Lyons is an expert biogeochemist at UC Riverside and director of the Alternative Earths Astrobiology Center, which sponsored the study.
The researcher used powerful computer models to study the atmospheric conditions in distant planets outside of our solar system.
The results were published this week in a paper in the peer-reviewed The Astrophysical Journal.
READ MORE: Astronomer says look HERE for proof of alien life – ‘I’m hopeful’
Complex life on Earth exists because our planet sits in a so-called “habitable zone” where the conditions are right for liquid water to exist.
The habitable zone describes a region within a solar system, which is neither too close nor too far from its host star.
But not all planets within this zone have to be habitable themselves, and their individual climates and atmospherics play a crucial role in their habitability.
Professor Lyons said: “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.
READ MORE: We will never see aliens ‘because we’ll DESTROY them’, expert fears
“Our results indicate that complex ecosystems like our cannot exist on most regions of the habitable zone as traditionally defined.”
The researcher and his team studied distant exoplanets for carbon dioxide in their atmospheres.
The potent greenhouse gas here on Earth is one of the main culprits behind global warming and climate.
However, on planets too far away from their stars, high levels of carbon dioxide could be critical in keeping temperatures above freezing.
READ MORE: Aliens are HERE and they’re breeding with humans, claims Oxford University lecturer
Edward Schwieterman a NASA Postdoctoral Program fellow, who led the alien life study, said: “To sustain liquid water at the outer edge of the conventional habitable zone, a planet would need tens of thousands of times more carbon dioxide than Earth has today.
“That’s far beyond the levels known to be toxic to human and animal life on Earth.”
As a result of these findings, the toxicity of carbon dioxide concentrations in the atmosphere narrows down the safe habitable zone to less than one-third of that area.
And to further complicate matters, some stars like the nearby Proxima Centauri and TRAPPIST-1 do not have habitable zones for alien life at all.
READ MORE: Asteroid impacts could have created LIFE as key ingredients IDENTIFIED
According to space agency NASA, on June 12 this year, there were 3,972 confirmed exoplanets in distant systems and another 3,640 on the waiting list.
But the solar systems and their planets are simply too far away for any human or remote spacecraft to reach, meaning astronomers can only study the planets by looking at their atmospheres.
Christopher Reinhard, a UC Riverside graduate and assistant professor at the Georgia Institute of Technology, said: “Our discoveries provide one way to decide which of these myriad planets we should observe in more detail.
“We could identify otherwise habitable planets with carbon dioxide or carbon monoxide levels that are likely too high to support complex life.”