How to find life on distant planets: maybe try looking for carbon dioxide and methane
One way to find life outside our Solar System is to peer into the atmospheres of distant planets, looking for gases that may be produced by living organisms. A group of scientists thinks we should look for two gases in particular: carbon dioxide and methane.
Most astronomers advocate looking for oxygen as a sign of extraterrestrial life. Oxygen is abundant in Earth’s atmosphere because there are many plants and other organisms that constantly pump out the gas. Without life on Earth, oxygen would eventually disappear.
But in a new study published in Science Advances, scientists suggest oxygen may not be the best target since the gas didn’t always exist in large quantities here on Earth — even when life was present. Billions of years…
