Question: Does the hotness of a planet's/star's core affect its temperature on the top?

Rebecca Williams answered on 25 Jun 2014:

Hi Alberteinstein,
This was quite a tricky question so I had to double check a few things before answering you.

So, the core is super hot – you know that which is why I guess you asked the question. The core is over 6000 deg C, which is hotter than the sun. So, you’d expect it to have a huge effect on the surface temperature that we feel, right?

The answer lies in those layers I’ve talked about in my other answers. Here is a picture of the earths layers: Around the core is a layer called the mantle. The mantle is thicker than the inner core (the really hot bit) and almost thicker than both the inner and the outer core together. On top of that, there is the Earths crust.

Both the crust and the mantle act like a blanket – they don’t transport heat very well. So, all the heat that comes out of the core has a really hard time getting through the mantle. If you look at this picture here the boxes represent how much heat the Earth’s surface receives from different sources. The big yellow box is the sun -so you can see that most of the heat at the Earth’s surface comes from the sun. Heat from the core is the purple box – so you can see it is tiny in comparison.