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Q & A: Hot Sun

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Most recent answer: 10/22/2007
Why does the sun give out heat?
- Sia Heng Guang (age 8)
Tampines North Primary School, SIngapore

Nice question. I'm not sure whether you are mainly wondering why the Sun is very hot or how the Sun gives off its heat. I'll try answering that question first.

Anything that is hot gives out heat. For instance, if you've ever stood near a bonfire, you certainly noticed that it was really warm - even if you weren't actually touching the flames. The same thing happens with the sun. The sun is basically just a giant ball of hot gas that is incredibly hot. Its heat is radiated out in all directions and since it's so big and hot, we can feel it all the way on Earth. For more information on how heat travels, check out this answer about the ways of .

If you are wondering what keeps the Sun so hot, it turns out that the source isn't a chemical fire like in a stove or a gas heater. It's a type of nuclear reaction called fusion. We wrote about that in the answer to .


(published on 10/22/2007)

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