Its broad, gently sloping profile is a result of millions of years of fluid lava flows typical of shield volcanoes. Located ...

Under certain conditions, the fluid even began to bounce. The mucky gunge resembled a certain type of lava referred to as "pahoehoe", which is observed at Hawaii's famous Kīlauea volcano.

Olympus Mons, Mars' immense shield volcano, towers 21 kilometers above its surface, dwarfing Earth's Mount Everest. Covering an area akin to Italy, it ...