# Formation of Black holes from smaller bodies

Black holes are formed when the supermassive stars collapse under their own gravitational force. But why they should be supermassive. The gravitational force is also present in smaller bodies like earth and moon etc. Why they dont get compressed by their own gravity to form a very small black hole?

We all are familiar that squeezing or squashing an object by putting it between our palms and pressing is quite difficult (unless its elastic). And so is the case for smaller bodies. Think about the Earth. It will have to be compressed to about $9\ mm$ for it to become a black hole! You would require an enormous force to squash earth to so small a volume.