Graphing variables is a critical skill in science. If something depends on something else – like the speed of sounds depends on air density, or the surface gravity of an object depends on its size – ...

Stars come in different types, and most stars will change types throughout their lifetimes. Stars are often organized using what's known as the Hertzsprung-Russell (H-R) diagram. Stars like Earth’s ...

A: To determine the age of a globular cluster, astronomers rely on the assumption that all the stars in the cluster formed at the same time and are the same distance from us. But the stars don’t all ...

Phil explains stars and how they can be categorized using their spectra. Today Phil's explaining the stars and how they can be categorized using their spectra. Together with their distance, this ...