How small would the moon have to be to become a black hole?

A black hole the mass of the Moon would have an event horizon about the size of a sand grain. Specifically, according to one of my favorite charts, a black hole moon would be a grain of fine to medium-fine sand, and could pass through a sieve of size ASTM No. 70 or larger.

How small would the Earth have to be to be a black hole?

You can define a Schwarzschild Radius based solely on total mass, i.e. Rs=2GMc2. If you plug in the mass of the earth, the radius is about 9 mm — which is how small you would have to compress it to make a black-hole.

What size would a black hole be if it was the same mass as Earth?

A black hole with a Schwarzschild radius of about a centimeter, which would make it about the size of a coin, would have about the same mass as the Earth. The reason the Earth will be destroyed but not simply swallowed up is because the Earth will be resisting the black hole in at least two ways.

What if the Moon fell into a black hole?

If our moon were replaced with a black hole of 1 lunar mass, the only effect it would have on us is that we wouldn’t be able to see it. This black hole would continue to orbit the Earth in exactly the same orbit, causing exactly the same tides on Earth. It just wouldn’t reflect any light.

What would happen to the Moon if there was a black hole?

Black Hole Moon. When you’re floating outside a spherical mass, its pull on you is the same regardless of whether the mass is concentrated at the center of the sphere or spread out throughout it. If the Sun were replaced by a black hole of the same mass, the Earth’s orbit wouldn’t change, although life on Earth might.

Could a black hole stabilize the Earth’s orbit?

The Earth’s orbit is stabilized by the Moon, but the lunar-mass black hole would probably serve the same role. This black hole Moon would be pretty low-profile.

What would happen if we turned the Moon into a point?

With the Moon gathered into a point, there’d be no moonlight, which would affect the life cycles of all kinds of nocturnal animals. But compared to a lot of the other things we’ve done, that would be fairly minor. The Earth’s orbit is stabilized by the Moon, but the lunar-mass black hole would probably serve the same role.

What would happen if a black hole devour all matter?

A black hole can’t devour matter too fast, though, because at some point it would be producing so much radiation that it would blast its own “food” away. This is called the Eddington limit. If our black hole were devouring matter at the Eddington limit, it would be hot enough to sterilize the Earth.