>>12108175The whole planet is made of space rocks. Natural uranium is just around, all over the place. It's in the crust, it's in the ocean. All over. Natural uranium is mostly U-238, which is technically unstable but has a half life of over four billion years. A bit under 1% of natural uranium is U-235, which has a half life of 700 million years and is directly useful for the production of nuclear fuel. U-238 must first be transmuted into plutonium to be useful as a fissile material.
Natural uranium was made in supernovae, just like every other heavy element. The two isotopes described above are stable enough that they've been sittings around since the Earth formed.
Story on the webm please.
