The Medusae Fossae Formation rises near the equator of Mars. The soft rock has been carved by wind erosion into a collection of ridges, valleys and striking mesas. It's massive. It's strange. And scientists are now tracing its origin to explosive volcanic activity in Mars' deep past. NASA has referred to Medusae Fossae as "an enigmatic pile of eroding sediments." UFO enthusiasts once spotted what they believed to be a UFO there, which is mainly a testament to the exotic shapes formed in the wind-blasted area. A study published in the Journal of Geophysical Research: Planets now traces Medusae Fossae...