Methane and Life on Other Planets

Astronomers are constantly looking for signs of life on other planets or moons. One of the potential clues they seek is methane, a hydrocarbon gas consisting of one carbon atom and four hydrogen atoms. It is classified as a “greenhouse gas” because it can trap heat on Earth’s surface resulting in “global warming.” It’s a more effective greenhouse gas than the much-discussed carbon dioxide. Methane is produced by organic decomposition and in the digestion process of ruminants such as cows and other animals. Scientists seek to learn more about a possible connection between methane and life on other planets.

Since living things create methane, scientists regard it as a potential “biosignature” indicating life on an astronomical body. For that reason, astronomers are searching for methane on planetary bodies. News reports have sometimes gone overboard with stories about methane and life on other planets. However, not all methane is created biologically. Volcanic eruptions can release methane gas, and even asteroid impacts can add methane to a planet’s atmosphere. So how can scientists tell if the methane is a sign of life on a body far out in space?

For one thing, gasses from a volcano would contain not only methane but also carbon monoxide. The biological creation of methane would consume carbon monoxide. When examining the gasses in a planet’s atmosphere, a large amount of BOTH methane and carbon monoxide would probably indicate that the methane was not a biosignature. Methane alone would be a more likely indicator of the possibility of life.

However, an abundance of methane without carbon monoxide would not prove the existence of life on a planet. As we have said before, many factors are required to make a planet suitable for any kind of life, especially advanced life. NASA’s James Webb telescope, launched in December, is still working to reach full functionality. When it does, a significant part of its purpose will be to look for methane in the atmosphere of exoplanets.

When results indicate that the Webb telescope has detected methane on a planet, news reporters may sensationalize the facts to suggest more than they deserve. Reputable scientists are more cautious in their predictions about methane and life on other planets. Nevertheless, we are excited about the possibility of learning more about the universe with the new Webb space telescope.

As we have said before, the Bible doesn’t tell us if there is life on any other object in space. If there is, we believe that God put it there. We are not afraid of scientific investigation because the more we learn about the creation, the more we stand in awe of the Creator.

— Roland Earnst © 2022