Mad, gibbering, armchair Mars nerd that I am, I can’t get enough about these supposed cave/sinkhole entrances on the surface of Mars. Apparently, there’s a bunch of them around the Arsia Mons volcano.

“Images from the Thermal Emission Imaging System (THEMIS) aboard NASA’s Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the Arsia Mons volcano. The caves, named Dena, Chloe, Wendy, Annie, Abbey, Nikki and Jeanne after loved ones of their discoverers, are collectively known as the “seven sisters.” Cave entrances measure from 100m to 252m wide and they are believed to be at least 73m to 96m deep. Because light does not reach the floor of most of the caves, it is likely that they extend much deeper than these lower estimates and widen below the surface. Dena is the only exception, its floor is visible and was measured to be 130m deep. The interior of these caverns is possibly protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet’s surface. Some researchers have suggested that this protection makes the caves good candidates for future efforts to find liquid water and signs of life.”

Caves beneath the surface of Mars. Very sweet.