Ever since Italian astronomer Giovanni Schiaparelli described his discovery of canals on Mars in 1877 and American astronomer Percival Lowell started to map them, we humans have been fascinated with the Red Planet. Although the canals were nothing more than a case of mistaken identity and our technology has come a long way since Schiaparelli and Lowell's telescopes, Mars continues to serve up its fair share of illusions, hoaxes and misunderstandings.
For the most part, these illusions are triggered by a psychological quirk of our brains that creates familiar objects from apparently random shapes. This phenomenon is known as "pareidolia" -- the same phenomenon that makes some people see the face of Jesus in burnt toast and bunnies in clouds. In the case of Mars, pareidolia makes us see bigfoot, parrots, flowers and faces in the otherwise barren orange landscape. Most recently, the case of the "Mars rat" captivated the mainstream media, but how does it measure up against other examples?
Pictured here, an ancient lava flow Elysium Planitia was imaged by the High-Resolution Imaging Science Experiment (HiRISE) camera aboard NASA's Mars Reconnaissance Orbiter (MRO). To the HiRISE mission scientists, far from it being a barren landscape, the head of an elephant etched into the surface jumped out at them.