NASA Image A Hole In Mars - Sparks Speculation About Hidden Alien Life

In 2011, an unusual hole on the side of Mars’ Pavonis Mons volcano was discovered by the Mars Reconnaissance Orbiter. Since then, scientists have been speculating about what the mysterious cavity could be hiding.

A photo of a mysterious hollowed-out mountain on Mars, which was published as the Astronomy Picture of the Day on NASA’s blog over the weekend.

What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole, shown in representative color, appears to be an opening to an underground cavern, partly illuminated on the image right.  Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers.  

A Hole in Mars  -  Image Credit:  NASA, JPL, U. Arizona