Sun & SpaceWhat is a star?
On a clear night the sky sparkles with stars. They look like tiny silver dots. But each one is really a giant, far-away ball of glowing gas — a lot like our own Sun.
Stars are giant balls of gas
A star is an enormous ball of hot, glowing gas. Deep inside, a star makes a huge amount of energy, and that energy pours out as light and heat. That is why a star shines. Stars are so big that a million Earths could fit inside one!
Our Sun is a star
Here is a surprise: the Sun is a star too! It only looks different because it is so much closer to us than all the others. The night-time stars are millions upon millions of times farther away, which is why they look like tiny pinpricks instead of one big, bright Sun.
Why stars twinkle
When starlight finally reaches us, it passes through the moving air above your head. The air wobbles the light this way and that, so the star seems to flicker and twinkle. Out in space, above the air, stars shine with a steady, calm glow and do not twinkle at all.
Wonder fact: Stars come in different colours! The cooler ones glow red or orange, and the very hottest ones shine blue-white. Our Sun is a warm, friendly yellow.