Alien life hunt BOOST after major NASA announcement

In their research, they discovered that three billion years ago, when oceans were teeming with microbial life, the Earth was almost completely void of oxygen, and the sun was much dimmer.

As a result, Earth’s earliest life forms were able to survive on carbon monoxide levels of roughly 100 parts per million – significantly higher than the levels today which registers in parts per billion.

Timothy Lyons, one of the study’s co-authors, a professor of biogeochemistry in UCR’s Department of Earth Science, and director of the UCR Alternative Earths Astrobiology Center, said: “That means we could expect high carbon monoxide abundances in the atmospheres of inhabited but oxygen-poor exoplanets orbiting stars like our own sun.