Mars' Interior Holds Evidence Of Violent Early History, NASA Scientists Confirm

In a significant new finding, NASA scientists have uncovered massive, buried remnants of ancient planetary collisions deep within the mantle of Mars. Using data from the now-retired **InSight lander**, researchers found large lumps of rocky debris, some up to 2.5 miles across, scattered inside the planet. This discovery provides new insights into Mars' tumultuous early history, over four billion years ago.

The study, published in the journal Science recently, is based on seismic data from eight powerful marsquakes. These quakes allowed scientists to map the Martian interior with unprecedented detail, revealing anomalies that appear to be preserved scars from a period of heavy bombardment.

This finding is particularly significant because, unlike Earth, Mars lacks the geological activity of plate tectonics. On Earth, this process continuously recycles crustal and mantle material, erasing evidence of ancient impacts. The lack of this process on Mars has left its interior largely unchanged since its formation, acting as a time capsule of the planet's early history.

The InSight mission, which operated from 2018 to 2022, recorded more than 1,300 marsquakes. By analyzing how seismic waves from these quakes and impacts traveled through the planet's interior, scientists were able to detect localized regions where the waves were delayed. These delays indicated a change in material density and composition, pinpointing the locations of the buried debris. The seismic signals traveled deep into the Martian mantle, a solid rock layer that extends nearly 960 miles below the surface.

"We've never seen the inside of a planet in such fine detail and clarity before," said the paper's lead author, Constantinos Charalambous of Imperial College London. "What we're seeing is a mantle studded with ancient fragments. Their survival to this day tells us Mars' mantle has evolved sluggishly over billions of years. On Earth, features like these may well have been largely erased."

"We knew Mars was a time capsule bearing records of its early formation, but we didn't anticipate just how clearly we'd be able to see with InSight," said Tom Pike of Imperial College London, coauthor of the paper.