The distant Whirlpool galaxy as seen from the Hubble Space Telescope in 2005. Two McMaster professors think the large moons of exoplanets — planets outside our solar system — could harbour conditions in which forms of life could evolve.
For many die-hard, downtown Toronto residents, this question refers to whether there’s life as they know it in the 905 area or even beyond.
For McMaster University scientist René Heller, it refers to whether there’s life beyond Earth. Heller, a post-doctoral fellow at McMaster’s Origins Institute, thinks that’s quite possible. “It’s not completely weird to assume that life on other planets has evolved to other stages that are equal to or more advanced than us,” Heller said in an interview.
Heller and fellow McMaster astrophysicist Ralph Pudritz, argue that giant moons of exoplanets — planets which are far outside our solar system — could support life. They’re presenting their findings on Wednesday at the annual conference of the Canadian Astronomical Society in Hamilton.
“We could be just a few decades from proving if there is life elsewhere,” said Heller, 32. “For all this time, we have been looking on other planets, when the answer could be on a moon.”
Their work is also supported by papers they have published in the current issues of Astrophysical Journal. Their writing contributes to debates on exomoon detection, habitability and the search for extraterrestrial intelligence.
The McMaster profs postulate that moons of some exoplanets could have enough water, as well as the correct size and position to support some form of life. Although exoplanets are beyond the range of existing telescopes, they can be detected by measuring light patterns, and how they dim just a little when planets pass them. Proof of giant exomoons might already be present in data found by NASA’s Kepler space telescope, Heller said. The giant moons could also be found by the European Space Agency’s upcoming PLATO space mission and the ground-based European Extremely Large Telescope of the European Southern Observatory.
There are some 4,000 exoplanets that are currently known to exist and Heller is excited about the day when an exomoon is also proven to exist. “I’m pretty confident that in the next few years an exomoon detection could actually happen,” Heller said. “Once we have found those moons . . . ” He thinks it’s quite possible life could be detected somewhere way up there in the next 20 to 40 years.
He supports his idea with simple math. If there are a billion stars in a galaxy, and plenty of them are far older than our sun, then a huge amount of exomoons have had time for some life form to evolve. Some moons of exoplanets might have the proper conditions for water to exist on their surfaces, which could allow for life forms to evolve.
Heller also wonders if, sometime during his career, some type of signal will come down from a faraway life form. “Maybe they have what we call leakage signals,” he said. The enthusiasm in his voice is easy to detect now. “From an interest point of view, I’m in exactly the type of field I want to work in,” he said.
