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Exoplanets IV

September 15, 2016

The giant planets Jupiter and Saturn are unlikely homes for life. They don’t have solid surfaces, and conditions in their atmospheres aren’t good for the kind of life we have here on Earth. Yet both planets have moons that are considered much more likely abodes for life. The moons have liquid water below their icy crusts, along with sources of energy and the right chemistry for life. That’s inspired astronomers to look for moons orbiting planets in other star systems.

They’ve already discovered several giant planets that are in the habitable zone — the distance from the star where temperatures are just right for liquid water. The planets are too much like Jupiter and Saturn for Earth-like life. But if they have big moons, those worlds could be good abodes for life — small, rocky worlds with lots of water.

Recent simulations by researchers at McMasters University found that such “exomoons” could grow to about twice the mass of Mars — bigger than any moon in the solar system. Such a heavy world could hold on to its water and atmosphere for billions of years — providing plenty of time for life to develop.

So far, no one has seen any exomoons. They’re quite hard to detect with current technology. But new telescopes on the ground and in space should have the ability to pluck them from the observations of exoplanets — perhaps revealing some distant homes for life.

We’ll talk about how we might find evidence of life on other worlds tomorrow.


Script by Damond Benningfield

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