Astronomers from the Cornell University suggest that looking for hydrogen from volcanic sources can help locating life in the universe.
“On frozen planets, any potential life would be buried under layers of ice, which would make it really hard to spot with telescopes,” said lead author Ramses Ramirez. “But if the surface is warm enough — thanks to volcanic hydrogen and atmospheric warming — you could have life on the surface, generating a slew of detectable signatures.”
According to this new research, the greenhouse effect of gases like hydrogen, water vapor and carbon dioxde may expand the habitable zones by 30-60%. “Where we thought you would only find icy wastelands, planets can be nice and warm — as long as volcanoes are in view,” said Lisa Kaltenegger, Cornell professor of astronomy.
An Earth-sized planet can’t hold its hydrogen for more than a few million years, but volcanoes change that. “You get a nice big warming effect from volcanic hydrogen, which is sustainable as long as the volcanoes are intense enough.”- said Ramirez, the researcher that suggested that hydrogen may help finding life on distant planets.
Because hydrogen is a very light gas, it puffs the planetary atmospheres, making life easier to detect.
“Adding hydrogen to the air of an exoplanet is a good thing if you’re an astronomer trying to observe potential life from a telescope or a space mission. It increases your signal, making it easier to spot the makeup of the atmosphere as compared to planets without hydrogen,” said Ramirez.
The habitable zone in our Solar system is around 1,67 the Earth orbit, just outside Mars. With the hydrogen from volcanoes this can be extended to 2.4 times – which is at the same place as the asteroid belt.
“We just increased the width of the habitable zone by about half, adding a lot more planets to our ‘search here’ target list,” said Ramirez.
Soon, atmospheric biosignatures like methane with ozone can be detected by the coming James Webb Space Telescope, that launches in 2018 and the European Extremely Large Telescope,which is scheduled for 2024.
The evidence of seven planet in the TRAPPIST-1 system was reported by NASA last week.”Finding multiple planets in the habitable zone of their host star is a great discovery because it means that there can be even more potentially habitable planets per star than we thought,” said Kaltenegger. “Finding more rocky planets in the habitable zone — per star — increases our odds of finding life.”
With the latest research from Ramirez and Kaltenegger, planets believed to be too cold may now support life. The TRAPPIST-1 system extended habitable zone now counts four planets, instead of three. “Although uncertainties with the orbit of the outermost Trappist-1 planet ‘h’ means that we’ll have to wait and see on that one,” said Kaltenegger.