Alien life might flourish on an exotic kind of carbon dioxide, according to a new study co-authored by Dirk Schulze-Makuch, professor at Washington State University’s School of the Environment. This “supercritical” carbon dioxide, which has features of both liquids and gases, could be key to extraterrestrial organisms much as water is to biology on Earth.
Ordinarily, carbon dioxide is not considered a viable solvent to host the chemical reactions for life, but the properties of super critical fluids can differ quite significantly from the regular versions of those fluids — for instance, while regular water is not acid, supercritical water is acidic. Given how substantially different supercritical carbon dioxide is from regular carbon dioxide in terms of physical and chemical properties, scientists explored whether it could be suitable for life.
“I always have been interested in possibly exotic life and creative adaptations of organisms to extreme environments,” said Schulze-Makuch. “Supercritical CO2 is often overlooked, so I felt that someone had to put together something on its biological potential.”
Beyond the solar system, Schulze-Makuch noted that many newfound planets orbiting distant stars are so-called super-Earths, worlds up to 10 or more times the mass of Earth. Under the stronger gravitational pulls and correspondingly higher atmospheric pressures of those planets, supercritical carbon dioxide might be common, he said.
Although Schulze-Makuch noted there is no proof that life that does not depend on water is possible, “there are good reasons to hypothesize that this is so,” he told Space.com.