A new “gravity map” of Mars has revealed 20 mysteriously dense blobs, including a dog-shaped structure, buried beneath the planet’s north pole. The first-of-its-kind atlas combines data from NASA’s InSight lander and satellite orbits to create a true global density map of Mars.
The standout features in the new map are the underground blobs in the Borealis Basin, which was an ancient seabed over 3 billion years ago. These blobs have densities between 300 and 400 kilograms per cubic meter higher than the surrounding ground, but it is currently unclear what they are, why they are so dense, or how they were created.
Researchers suggest that these dense structures could be volcanic in origin or compacted material due to ancient meteor impacts. However, there seems to be no trace of them at the surface.
The new map also confirmed the presence of a massive blob under Olympus Mons, a dormant volcano near Mars’ equator. This gigantic blob is less dense than its surroundings and is most likely a massive plume of cooled lava, hinting that Mars’ volcanism may have ended only recently or could be ongoing.
This discovery adds to the list of intriguing geological structures found under Mars’ surface, including an enormous hidden ocean and a 2-mile-thick layer of ice buried beneath the equator.
Source: https://www.livescience.com/space/mars/martian-dog-and-dozens-of-other-mysterious-blobs-found-hiding-under-mars-north-pole-in-new-gravity-map