Alien hunters should search for technological life on planets that possess a high oxygen abundance in their atmospheres, according to new research that aims to hone the search for technosignatures from extraterrestrial civilizations.
Amedeo Balbi, who is an associate professor of astronomy and astrophysics at University of Roma Tor Vergata in Italy, and Adam Frank, who is a professor of physics and astronomy at the University of Rochester in the U.S., argue that a planet's atmosphere needs to contain at least 18% oxygen to facilitate a technological civilization. The reason for this, they say, is a simple one: oxygen is needed for fire.
