MASHABLE - Considering humans don't have a spacecraft capable of traveling to planets beyond the solar system, scientists have to get creative if they want to find clues of life existing light-years away.
Now a group of scientists is proposing a new way for astronomers to look for signs of aliens using the James Webb Space Telescope, a collaboration of NASA and the European and Canadian space agencies: look for methyl halides.
These gases — composed of carbon, hydrogen, and a halogen, like chlorine — are mostly made by bacteria, algae, fungi, and plants. The chemicals are particularly intriguing as a potential sign of life because they can be detected in infrared light, which is Webb's viewing specialty.
Furthermore, scientists think the gases may show up in higher concentrations around worlds with hydrogen-thick atmospheres, a type of planet Webb scientists are hunting for. These worlds, thought to have seas, are called "Hycean," combining the words "hydrogen" and "ocean." They would be among a class of planets called sub-Neptunes: smaller than Neptune but larger than Earth.
Their larger size is what makes them easier targets to observe than small rocky worlds like Earth.
"One of the great benefits of looking for methyl halides is you could potentially find them in as few as 13 hours with James Webb. That is similar or lower, by a lot, to how much telescope time you’d need to find gases like oxygen or methane," said Michaela Leung, a planetary scientist at the University of California in Riverside, in a statement. "Less time with the telescope means it’s less expensive."