Date of discovery: April 2017
Location of discovery: Mars
Source NASA photograph:

Paranormal Crucible makes a speculation that this may very well be an historic tree stump on Mars. Its assumption since NASA themselves mentioned Mars was Earth-like when a photo voltaic explosion hit the planet, striping the ambiance and oceans from its floor. 
Scott C. Waring

Paranormal Crucible states: 
Intriguing object discovered by the curiosity rover, this time a potential tree stump. This object undoubtedly appears misplaced and for my part may very well be the petrified remnants of a Martian tree. Object is round three ft in peak, and with quite a few discoveries of plant and animal life on mars, it will be logical to imagine, that quite a lot of tree both existed, or nonetheless exists on this enigmatic planet.