NASA Can't Explain What Made This Strange, Deep Hole on Mars

You'd think NASA's Mars Reconnaissance Orbiter (MRO) has seen everything there is to see on the Martian surface in the 11 years it's orbited our nearest neighbour, but a snapshot taken over the planet's South Pole has revealed something we can't...
Read more: http://www.sciencealert.com/nasa-doesn-t-know-what-made-this-deep-hole-on-mars?source=Snapzu