The real science behind Moonfall.

The premise of Moonfall is simple, deranged, and delightful: Something has knocked the moon out of its orbit, and in a matter of weeks, the moon will collide with the Earth. “The moon is moving away from us an inch and a half a year,” James Greene, NASA’s former chief scientist and current senior advisor, told me. “As you’re squishing them in and out, you’re going to see cracks and earthquakes and landslides.” In fact, the Earth itself would be compressed and released with high tide and low tide. “If you move the moon inward, the days will speed up,” Greene explained, because the moon’s proximity would make the Earth spin faster. “The moon is currently 60 Earth radii away,” said Greene.. “When it’s at four Earth radii, the day on Earth will be five hours long.