What heats the earths core?

Question

Ok so i was just wondering... in science class today we learnt that mars used to have a heated core like earth but that eventually cooled and now we have mars like it is... What causes the earths core to stay heated to such high temperatures for the huge ammounts of time it does? Are we in any danger of the earths core cooling in the future? And last but no least, what caused mars' core to cool and earths to continue to heat?

Answer 1

The constant burning, melting, and heating of Iron, Copper and other metals and in the center a hot sphere of Iron,Copper, and other metals at high degrees.

Answer 2

ask your teacher, she is the one determining your grade. if she says she doesn't know it probably want be on the test.  my guess(uneducated guess) might be that whatever is burning is producing in some sort of cycle what it needs for fuel. sort of like rain,evaporation,...,

Answer 3

It's a combination of heat left over from the Earth's formation and radioactive decay in the core.

A smaller planet like Mars would lose its original heat faster, and would have less radioactive material. The Earth's core will eventually run out of radioactive material and cool down like Mars', but that won't be for around 2 billion years.

Answer 4

Radioactive decay.

Heavy elements like Uranium fall to the centre of the earth like other metals such as Iron.  When they decay they give of huge amounts of energy.  The half life of Uranium 238 is 4.5 billion years, about as long as the earth has existed so we have only used up half of our supply.

Mars is a lighter planet so would not have attracted so much Uranium initially, the Uranium would not have concentrated in the core to such an extent, and the smaller radius of the planet would have let the heat escape more quickly.