New research shows that planets with high oxygen may have promoted the development of advanced … [+]
The search for oxygen may be critical to finding alien civilizations, but the reason isn’t as simple as you think, a new paper suggests. Meanwhile, a second new study suggests that planets with very little carbon dioxide in their atmospheres could be a sign of liquid water—and possibly life—on that planet’s surface.
Search for Oxygen
The fact that the Earth’s atmosphere contains oxygen makes it habitable for complex aerobic life, but the element is also characteristic for the development of technological civilization on Earth – fire.
A new paper sponsored by NASA published in Astronomy of Nature describes the links between atmospheric oxygen and the detection of alien technology on distant planets, suggesting that prioritizing the search for high oxygen levels on exoplanets could be an important clue to finding potential “technologies”.
Oxygen, Fire and “Technological Signatures”
Exoplanets are planets that orbit a star other than our sun—more than 5,200 of which have been found and whose atmospheres are now being studied by NASA’s James Webb Space Telescope. Technosignatures are scientific evidence of past or present technology, indicating the presence of life in another star system.
It has been argued that it may be easier to find technologies on distant planets that pinpoint signs of microbial life in the planets’ atmospheres – known as biosignatures. Examples of technical signatures include radio signals, artificial light, solar panels, clusters of satellites around a planet or megastructures of some kind, and industrial pollution in the atmosphere.
Motivating power
Researchers state that fire was the driving force behind industrial societies. Technology developed on Earth because open combustion—fire—is possible. Fire requires fuel and an oxidizer, usually oxygen. Fire makes it possible to cook, forge metals for construction, make materials for houses, and harness energy through burning fuel. They found that the controlled use of fire was possible only when oxygen levels in the atmosphere reached or exceeded 18 percent—much higher than what is needed to sustain biologically complex life. The air in Earth’s atmosphere is made up of about 78 percent nitrogen and 21 percent oxygen, according to NASA.
“Maybe you’ll be able to get biology—maybe even get intelligent creatures—in a world that doesn’t have oxygen. he said co-author Adam Frank, the Helen F. and Fred H. Gowen Professor of Physics and Astronomy at the University of Rochester, and the author of The Little Book of Aliens. “But without a ready source of fire, you’re never going to develop superior technology because [it] requires fuel and smelting’.
Search for coal
On separate paper published in Nature last week, scientists argue that the absence of carbon dioxide in the atmosphere of a rocky planet – relative to others in the same star system – may indicate the presence of liquid water on the planet’s surface. Earth’s lower carbon dioxide levels, compared to Venus and Mars, result from a water cycle that includes oceans. Researchers argue that a similar pattern on an exoplanet could mean oceans and life. “On Earth, much of the atmospheric carbon dioxide has been sequestered in seawater and solid rock over geologic time, which has helped regulate climate and habitability for billions of years,” said study co-author Frieder Klein. .
Distinctive Signature
Significantly, the characteristic signature of carbon dioxide can be obtained with NASA’s James Webb Infrared Space Telescope, the researchers argue, unlike many other biosignatures. Carbon dioxide is a strong infrared absorber and can easily be detected in the atmospheres of exoplanets. In July 2022, JWST detected carbon dioxide in the atmosphere of WASP-39b, a hot gas giant orbiting a sun-like star about 700 light-years from Earth. Biosignatures – such as oxygen and carbon dioxide – can be detected in an exoplanet’s atmosphere using spectroscopy, which analyzes light passing through the atmosphere.
“The Holy Grail in exoplanet science is the search for habitable worlds and the presence of life, but all the features that have been discussed so far have been beyond the newest observatories,” said Julien de Wit, assistant professor of planetary sciences. at MIT, in a press release. “Now we have a way to find out if liquid water exists on another planet. And it’s something we can get to in the next few years.”
I wish you clear skies and open eyes.
