<p>Yes. It's kept warm by slowly  decaying primordial radioactive elements. They are: Uranium (238) and Thorium (232). The half life of the first is 4.4 billion years, the second around 14 billion years.</p>

<p>They heat the surface even to this date, and it's around 0.2K warmer than if they were absent.</p>

<p>Owing to their continued decay, this temperature differential will decrease .</p>

<hr>

<p><strong>Extension:</strong> On the most popular <a href="http://www.thenakedscientists.com/forum/index.php?topic=44643.5;wap2" rel="nofollow noreferrer">models</a> (and David Hammen's comment :-) ), Uranium and Thorium are in the crust and   mantle, and not in the core. Despite that, their radioactive decay heats the Earth.</p>

CC BY-SA 3.0
2016-05-25T15:18:48.203Z
Most geophysicists think there is very little uranium and thorium in the Earth's core. Both are [incompatible](https://en.wikipedia.org/wiki/Incompatible_element) [lithophile](https://en.wikipedia.org/wiki/Goldschmidt_classification#Lithophile_elements) elements.
David Hammen
CC BY-SA 3.0
2016-05-25T21:55:43.687Z
@DavidHammen 1) Ok, but chemistry in 6000K and some 100000 bar isn't a little bit different? 2) Any idea, what heats the core then? 3) They are also the heaviest elements, any idea where could they are? 4) What is with their ores? They are mined in large quantities. They are not incompatible?
peterh
CC BY-SA 4.0
2016-05-24T05:37:44.827Z
2020-05-07T04:11:02.467Z
2020-05-07T04:11:02.467Z
peterh
<p>I am doing a school project and need to know...</p>

<p>Will the Earth's mantle or core ever cool? If so, how? </p>

<p>Thank you!</p>

CC BY-SA 3.0
2016-05-24T03:04:35.740Z
Does [Could earth's core lose its heat?](http://earthscience.stackexchange.com/questions/428/could-earths-core-lose-its-heat) answer your question? Or do you need to also know about the mantle cooling too? (although that's likely a similar answer)
hichris123
CC BY-SA 3.0
2016-05-24T03:20:44.537Z
It's absolutely answered in the question you've linked, but the question isn't exactly the same. Flagged anyway for review by mods.
Ben MS
CC BY-SA 3.0
2016-05-25T15:23:34.467Z
The Earth's core is cooling, and has been cooling for a long, long time. Evidence: The Earth has a solid inner core (which couldn't exist if the core wasn't cooling), and it has a magnetic field (which couldn't exist without a high heat flux through the outer core).
David Hammen
<geophysics><temperature>
Will the Earth's core cool?
PinkSheep5218
# Will the Earth's core cool?

(Asked by: username_0 on 2016-05-24)

I am doing a school project and need to know...

Will the Earth's mantle or core ever cool? If so, how?

Thank you!

**Tags:** geophysics, temperature

> **Comments:**
> **username_1**: Does [Could earth's core lose its heat?](http://earthscience.stackexchange.com/questions/428/could-earths-core-lose-its-heat) answer your question? Or do you need to also know about the mantle cooling too? (although that's likely a similar answer)  
> **username_2**: It's absolutely answered in the question you've linked, but the question isn't exactly the same. Flagged anyway for review by mods.  
> **username_3**: The Earth's core is cooling, and has been cooling for a long, long time. Evidence: The Earth has a solid inner core (which couldn't exist if the core wasn't cooling), and it has a magnetic field (which couldn't exist without a high heat flux through the outer core).  

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## 1 answers

### Answer by username_4 on 2016-05-24. Score: 1

Yes. It's kept warm by slowly decaying primordial radioactive elements. They are: Uranium (238) and Thorium (232). The half life of the first is 4.4 billion years, the second around 14 billion years.

They heat the surface even to this date, and it's around 0.2K warmer than if they were absent.

Owing to their continued decay, this temperature differential will decrease .

---

**Extension:** On the most popular [models](http://www.thenakedscientists.com/forum/index.php?topic=44643.5;wap2) (and username_3 username_3's comment :-) ), Uranium and Thorium are in the crust and mantle, and not in the core. Despite that, their radioactive decay heats the Earth.

> **Comments:**
> **username_3**: Most geophysicists think there is very little uranium and thorium in the Earth's core. Both are [incompatible](https://en.wikipedia.org/wiki/Incompatible_element) [lithophile](https://en.wikipedia.org/wiki/Goldschmidt_classification#Lithophile_elements) elements.  
> **username_4**: @username_3 1) Ok, but chemistry in 6000K and some 100000 bar isn't a little bit different? 2) Any idea, what heats the core then? 3) They are also the heaviest elements, any idea where could they are? 4) What is with their ores? They are mined in large quantities. They are not incompatible?  

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