Researchers at the Europlanet Science Congress have identified massive, dense structures beneath the remains of an ancient Martian ocean, possibly formed by volcanic activity or space rock impacts.

Detected through Mars’ gravity data from NASA’s Insight mission and other satellites, these structures, including one shaped like a dog, are located in the northern polar plains.

They are about 300-400 kg/m³ denser than surrounding rock and likely buried under sediment, Newsweek has reported.

The study also suggests that Mars’ mantle may be causing the Tharsis Rise to uplift, potentially affecting volcanic activity on the planet.

Written by B.C. Begley