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