Do Exoplanets with Oxygen Mean Alien Life? Not so Fast. - The Cosmic Companion - April 14, 2021
Oxygen is one sign of lifeforms on other worlds, but simulations show several ways exoplanets could have a lot of oxygen without life.
Exoplanets with oxygen might be a sign of life — or not. Here’s a look at how worlds can build oxygen-rich atmospheres without life.
Just because an exoplanet has a lot of oxygen, it doesn’t mean it has life. Image credit: The Cosmic Companion / Created in Universe Sandbox
The discovery of life on another world would be a monumental moment in the history of human civilization. The most likely way we will, one day, find alien life will be discovering chemical markers of life in the atmosphere of planets orbiting distant stars.
One of these markers is oxygen, which currently makes up a little over 20 percent of the atmosphere of our own world. However, our own world held onto relatively little oxygen until 2.4 billion years ago, when oxygen-producing cyanobacteria filled the atmosphere with the gas, leading to the first widespread extinction — the Great Oxidation event. Many lifeforms on Earth today, including human beings, are now dependent on this life-giving gas.
“Oxygen is a promising exoplanet biosignature due to the evolutionary advantage conferred by harnessing starlight for photosynthesis, and the apparent low likelihood of maintaining oxygen‐rich atmospheres without life,” researchers explained in an article published in the journal AGU Advances.
Read more: https://thecosmiccompanion.net/do-exoplanets-with-oxygen-mean-alien-life-not-so-fast
April is going to be an exciting month on Astronomy News with The Cosmic Companion! Here’s a look at our guests:
THIS WEEK! April 13 (s4/e15): Affelia Wibisono of University College London, discussing the recent discovery of X-rays from Uranus.
April 20 (s4/e16): Andrew Fazekas, National Geographic’s “Night Sky Guy,” talking about his National Geographic Backyard Guide to the Night Sky.
Plus – just added - NASA’s Joshua Ravich, mechanical engineering lead for the Ingenuity helicopter on Mars.
April 27 (s4/e17): Ohad Harlev, CEO of Lyteloop, discussing new technology for storing data in space.
Wacky Wednesday in our new comic series, Cosmix!
Tell us in the comsmix section what you think about our new series!
Written by James Maynard, and illustrated by Florencia Vidal, the same team that brings you Max on Mars!
For more details on space and astronomy news, please visit: thecosmiccompanion.net or thecosmiccompanion.com.
Thanks for reading, donating, and sharing!
- James