Which molecules, whose absorption lines appear in the infrared, are considered most likely to indicate the presence of life if they were detected on any planet orbiting another star?

Question

Quizplus · Accepted Answer

Carbon dioxide, ozone, and water vapor are the molecules that are most likely to indicate the presence of life if they were detected on any planet orbiting another star. This is because these molecules are produced by life processes, and their presence in an exoplanet's atmosphere would therefore suggest the presence of living organisms. Methane and ammonia are also often associated with life, but they can also be produced through non-biological processes, so their detection alone would not necessarily imply the presence of life. Hydrogen and helium are unlikely to be associated with life processes, so their detection would not be a strong indicator of the presence of life.

Which Molecules, Whose Absorption Lines Appear in the Infrared, Are