Alien Worlds Rich in Oxygen Still Might Not Harbor Life
Oxygen may not be quite as compelling a sign of alien life as astrobiologists had thought, a new study suggests. Researchers running laboratory experiments with various types of simulated exoplanet atmospheres managed to generate oxygen, as well as carbon-containing organic molecules, the chemical building blocks of life as we know it.
"People used to suggest that oxygen and organics being present together indicates life, but we produced them abiotically in multiple simulations," study lead author Chao He, of the Department of Earth and Planetary Sciences at Johns Hopkins University in Baltimore, said in a statement. "This suggests that even the co-presence of commonly accepted biosignatures could be a false positive for life." [10 Exoplanets That Could Host Alien Life]