Dark Side of the Earth: What would happen if our planet became tidally locked?

Esther Inglis-Arkell

There’s a reason we only ever see one side of the Moon. It’s tidally locked to the Earth, presenting only one side to us as it orbits around the planet. Tidal locking is a fate that befalls lots of planetary bodies, and it can wreak havoc on the surface.

Why does tidal locking happen? And more importantly, why hasn’t Earth become a tidally locked planet? And are we doomed to go that way eventually?

When the planet Zarmina was first reported as having been discovered, people got all excited about the idea of a planet existing in its star’s habitable zone — only to have their excitement fade a little when they learned that Zarmina was tidally locked to its star. This reduced the chances of life, in any complex form, existing on the surface. Tidal locking does a number on a planet, and not just its surface temperature. Everything from water composition to geography changes as one side starts getting all the sunlight, and the other slowly freezes.

Read more: Dark Side of the Earth: What would happen if our planet became tidally locked? — io9.

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