<p>The gravitational binding energy of the Earth is $2×10^{32}  J $, so the same amount of energy must have been released during the Earth's history. </p>

<p>According to <a href="https://books.google.com.eg/books?id=rf419f-p4D8C&amp;pg=PA234&amp;lpg=PA234&amp;dq=earth%20internal%20energy%201031&amp;source=bl&amp;ots=vOBvhyjgZu&amp;sig=Fr63wbCRm-LdSSFFXilKoMplc9M&amp;hl=ar&amp;sa=X&amp;ei=fEuLVPrDNIb9Uo_MgpAB&amp;ved=0CCQQ6AEwAQ#v=onepage&amp;q=earth%20internal%20energy%201031&amp;f=false">this</a> and <a href="https://books.google.com.eg/books?id=qyN6_83vz2MC&amp;pg=PA109&amp;lpg=PA109&amp;dq=earth%20energy%201031&amp;source=bl&amp;ots=fFzkC7Jl2r&amp;sig=ey04DuzETjpfWDPHFRnmaEs4ew4&amp;hl=ar&amp;sa=X&amp;ei=mkuLVOSaJ4K0UYPfgqgF&amp;ved=0CD0Q6AEwBA#v=onepage&amp;q=earth%20energy%201031&amp;f=false">this</a>, the current internal energy of the Earth is ~ $1.5×10^{31} J$, and according to <a href="https://books.google.com.eg/books?id=4ey5BAAAQBAJ&amp;pg=PA23&amp;lpg=PA23&amp;dq=earth%20internal%20energy%201031&amp;source=bl&amp;ots=Zsqn2sk7sI&amp;sig=pKqC0LMcAHHJ7QpcjLxH0HW7oSM&amp;hl=ar&amp;sa=X&amp;ei=LUWLVP-NBcKvU4Lbg5AM&amp;ved=0CEYQ6AEwBg#v=onepage&amp;q=earth%20internal%20energy%201031&amp;f=false">this</a> source, the amount of heat loss due to outward radiation by the Earth during the entire lifetime of the planet is about $0.45×10^{31}  J $. </p>

<p>So, by adding those two numbers we get the Earth internal energy + energy radiated = ~ $2×10^{31}  J $, which is an order of magnitude less than what we should expect. 
We are also ignoring the fact that 50-90% of the current internal energy of the Earth is due to radioactive decay. So where did the rest of the energy go ?</p>

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2014-12-26T00:25:06.253Z
Please do not cross-post questions. Your question on physics.se already has answers. Closing for cross-posting.
casey
<geophysics><earth-history><geothermal-heat><planetary-formation>
Where did the energy released due to gravitational binding energy of the Earth go?
Abanob Ebrahim
# Where did the energy released due to gravitational binding energy of the Earth go?

(Asked by: username_0 on 2014-12-12)

The gravitational binding energy of the Earth is $2×10^{32} J $, so the same amount of energy must have been released during the Earth's history.

According to [this](https://books.google.com.eg/books?id=rf419f-p4D8C&pg=PA234&lpg=PA234&dq=earth%20internal%20energy%201031&source=bl&ots=vOBvhyjgZu&sig=Fr63wbCRm-LdSSFFXilKoMplc9M&hl=ar&sa=X&ei=fEuLVPrDNIb9Uo_MgpAB&ved=0CCQQ6AEwAQ#v=onepage&q=earth%20internal%20energy%201031&f=false) and [this](https://books.google.com.eg/books?id=qyN6_83vz2MC&pg=PA109&lpg=PA109&dq=earth%20energy%201031&source=bl&ots=fFzkC7Jl2r&sig=ey04DuzETjpfWDPHFRnmaEs4ew4&hl=ar&sa=X&ei=mkuLVOSaJ4K0UYPfgqgF&ved=0CD0Q6AEwBA#v=onepage&q=earth%20energy%201031&f=false), the current internal energy of the Earth is ~ $1.5×10^{31} J$, and according to [this](https://books.google.com.eg/books?id=4ey5BAAAQBAJ&pg=PA23&lpg=PA23&dq=earth%20internal%20energy%201031&source=bl&ots=Zsqn2sk7sI&sig=pKqC0LMcAHHJ7QpcjLxH0HW7oSM&hl=ar&sa=X&ei=LUWLVP-NBcKvU4Lbg5AM&ved=0CEYQ6AEwBg#v=onepage&q=earth%20internal%20energy%201031&f=false) source, the amount of heat loss due to outward radiation by the Earth during the entire lifetime of the planet is about $0.45×10^{31} J $.

So, by adding those two numbers we get the Earth internal energy + energy radiated = ~ $2×10^{31} J $, which is an order of magnitude less than what we should expect.
We are also ignoring the fact that 50-90% of the current internal energy of the Earth is due to radioactive decay. So where did the rest of the energy go ?

**Tags:** geophysics, earth-history, geothermal-heat, planetary-formation

> **Comments:**
> **username_1**: Please do not cross-post questions. Your question on physics.se already has answers. Closing for cross-posting.  

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