Fluid magma that flows onto the surface of a planet or moon; erupted from a volcano or fissure. Also, the rock formed by solidification of this material.
An element with atomic number 8; symbol: O. It is actually the most common element in the crusts and mantles of the inner planets and rocky moons, making up all silicate minerals. ...
An enormously bright, energetic, catastrophic explosion that occurs at the end of the lifetime of a massive star whose core collapses. A star must have at least nine times the ...