Meanwhile in the Future: A Second Moon for Earth

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This week on Meanwhile in the Future, we ask what would happen if Earth had a second moon. How exactly that happens I won’t reveal — you’ll have to listen! But once it does, there are some really interesting things that we might notice on Earth, from tides and the night sky, to the potential destruction of Earth.

This week we talked to Lucianne Walkowicz, an astronomer at Adler Planetarium in Chicago and Jeff Oishi, an Assistant Professor of Physics at Farmingdale State College. They walked me through a whole bunch of things that might happen should we Earthlings get a second moon in the sky. For even more on how a second moon might impact Earth, check out this book by Neil Comins who describes the possibilities, along with other space-based scenarios.


The chances of Earth acquiring a large, second moon, are pretty slim. But scientists are working on a few different asteroid-capturing ideas. The Asteroid Redirect Mission, for example, is, according to NASA, the “first-ever robotic mission to visit a large near-Earth asteroid, collect a multi-ton boulder from its surface, and redirect it into a stable orbit around the moon.” And companies like Planetary Resources have talked about dragging asteroids closer to Earth for mining.

These plans all involve asteroids far smaller than the moon we considered in this episode, of course. But should Earth snag a large second moon, it certainly wouldn’t be the first planet in the solar system to have multiple satellites. There are, in fact, 146 moons orbiting planets in our solar system alone. Mars has two, Jupiter has fifty, and Saturn has 53. So Earth actually has some catching up to do.


There are a bunch of things we didn’t get into, too—how brighter nights could change migration patterns of animals, the panic that a second moon would likely cause, and what it might do to religious and cultural rituals that rely on the lunar cycle. Will this second moon also hit your eye like a big pizza pie, or is it a different food item? Is this new moon made of cheese? Is there a man in this one too?

What else didn’t we get talk about? What would you name the moon? Let us know down in the comments.


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Thanks for listening, and we’ll see you next week.