What is the Sun made of and why does it shine?
Sun's Generous Nightlight
What is the Sun made of and why does it shine?
Look up on a clear afternoon — there it is, our nearest star, shining like it has all the time in the universe. The Sun looks like a calm golden lamp hung in the sky. But here's the secret: it isn't a lamp at all. It's a furious, glowing ball of gas, and it has been pouring out light for about four and a half billion years.
So what is this ball actually made of? Mostly two of the lightest, simplest things in existence. About three-quarters of the Sun is hydrogen — the tiniest, most plentiful ingredient in the whole universe. Almost all the rest is helium, the same gas that makes party balloons float. A pinch of heavier stuff is sprinkled in too, but the Sun is essentially a colossal cloud of hydrogen and helium.
