"What surprised us, at the end, was how effective this type of impact could be in explaining Mercury's unusual structure ...

It is a world of extremes. Explore facts about our solar system's fastest planet. Mercury is slightly larger than our Moon - 15,329 kilometres around its equator. Its radius, the distance from the ...

Turns out, it's as tough to drop inward into the inner solar system, as it is to head outward. The problem stems from losing ...