Launch Pad, Day One: Kevin R. Grazier on Solar System/Cassini

How many solar systems are there in the galaxy? One. One star is called sol. There is one solar system. It is a proper noun and should be capitalized. Solar System.

It starts with an exploding star. Stars of very large size live by the credo "live fast, die young, live a good-looking black hole." A supernova can outshine the sum total of all other stars in its galaxy.

Fusion–fundamental energy creation process in our sun, a proton-proton chain. You slam hydrogen together, make helium and...