Natural Wonders: Dog Door on Mars

Reader Winston Stairs recently shared a peculiar image on our Facebook page taken by NASA’s Curiosity Rover. Since 2012, the vehicle has been scanning the red planet for signs of life. On May 7, the robot took a picture of the East Cliffs inside the Gale Crater. It showed what looked like a door cut into a cliff. It even has a lintel. The door seems purposefully carved into the rock.

The internet being the internet, theories and speculation abounded. However, its explanation is simpler than you’d think.

NASA nicknamed the formation the “dog door” because it is quite small, measuring 30cm tall by 40cm wide. If there are any Martians there, their appearance would be rather underwhelming. However, the door is by no means artificial. It resembles formations on our own planet.

Photo: NASA


Rocks can fracture at many different angles due to a variety of processes. Add erosion, and you have a natural ‘doorway’. Geologists credit Mars’s harsh winds with wearing away the rock strata, in combination with rock’s fracture angles. The chunk of rock in the foreground mostly likely broke off from that crevice. Alas, the pathway does not lead to an ancient Martian tomb.

The real question is; why are people so quick to jump on these far-fetched theories? There are formations in Antarctica, the Sahara, under our ocean and even on the Moon that also look suspiciously manmade.

We could be experiencing pareidolia. This is when we see patterns or meaningful images in our surroundings. For example, we all have seen faces and shapes in clouds. It’s a great kids’ game. The excitement suggests a strong ache for life outside our earthly borders.

The doorway in the Gale Crater from above. Photo: NASA


On the bright side, this doorway can provide us with insight into Mars’s geological processes, including earthquakes, wind and storm speeds, and heat. What did the red planet look like before so much erosion took place? For scientists, that is the exciting question.

Kristine De Abreu

Kristine De Abreu is a writer at ExplorersWeb.

Kristine has been writing about Science, Mysteries and History for 4+ years. Prior to that, Kristine studied at the University of Leicester in the UK.

Based in Port-of-Spain, Kristine is also a literature teacher, avid reader, hiker, occasional photographer, an animal lover and shameless ramen addict.