What Would Happen If the Earth’s Moon Transformed Into a Black Hole of Equal Mass

As part of their ongoing “What If?” series, Randall Munroe of xkcd and Henry Reich of MinutePhysics answered a viewer’s query as to what would happen if the Earth’s moon transformed into a black hole of equal mass.

This question comes from Matt, who asks: what would happen if the Moon were replaced with an equivalently-massed black hole? And what would a lunar (“holar”?) eclipse look like?

The narrator further explains that a black hole equal to the mass of the moon would be smaller than a grain of sand. This would have only a slight effect upon light, darkness, and temperature, but nothing too extreme. However, if the black hole were the exact size of the moon, then it would be lights out for good.

You might now be wondering what would happen if the moon were replaced by a black hole of the same size, not the same mass. Well, a moon-sized black hole would have around 600 times the mass of the sun, so we would definitely fall into it. A total final lunar eclipse.