"The Moon, I'm Over It"

Written by Paul Sutter on Tuesday, 10 May 2016. Posted in From The Desk of...The Chief Scientist

The moon. Huh. What is it good for? Absolutely nothing.

At least, not any more.

Before I really get going, let's take a moment and appreciate how special our moon is. Look at all the other inner planets. How many moons does Mercury have? Zero. Venus? Nada. Mars? Two, but come on, they're just rinky-dink captured asteroids and don't count for nothing.

But Earth? A big fat moon, a whopping 27% of the width of our planet! You don't get a moon like that by accident. No, wait, that's exactly how you get one: models suggest that in the early solar system a Mars-sized planetoid slammed into a baby Earth, tearing a chunk out of it and making our gorgeously big satellite.

Back in the day, our moon served as the Earth's galactic goalkeeper. See all those giant craters on the surface? Be glad all that space stuff slammed over there instead of over here. But nowadays the solar system is much quieter, and the need for an orbiting defense platform isn't so urgent.

Take away the moon, and what would happen? The tides - a very visible reminder of the weak but relentless tug of gravity - would get cut in half (the other half comes from the sun). The interaction of the Earth and the moon via the tides also causes something imperceptible: over millions of years, the moon steadily moves further away while the Earth's spin slows. After eons the Earth would be tidally locked - one side permanently facing our satellite. So take away the moon and that problem sorts itself out.

Oh, yeah, and no more eclipses, which would be a bummer.

About the Author

Paul Sutter

Paul Sutter

Paul Sutter is COSI's Chief Scientist. He is an astrophysicist and offers a wealth of knowledge about our universe. In addition to his COSI position, Paul Sutter is a Cosmological Researcher and Community Outreach Coordinator at The Ohio State University's Center for Cosmology and AstroParticle Physics (CCAPP).