... d) continental drift e) the hot core of the earth The earth's core is molten due to a) solar heating b) large scale meteoroid bombardment c) radioactivity d) heat left over from the earth's formation. $e) both d. and e. The Earth's magnetic dynamo is ...
... Besides making us more prone to collisions with comets and meteoroids (see Topic 4), it also means we get more of the brunt of the radiation from the Sun. ...