Mars mantle holds ancient debris
InSight data shows fragments from early planetary impacts
Scientists have discovered a fragmented interior in Mars, revealing that the planet's mantle contains ancient debris from its tumultuous formation billions of years ago. This finding, based on data from NASA's InSight mission and published in the journal Science, challenges traditional models that depict rocky planets as having smooth, layered structures. Instead, Mars' mantle exhibits a fractal pattern, featuring large chunks up to 4 km wide surrounded by smaller fragments, indicative of the chaotic energy from early impacts.
Dr. Constantinos Charalambous from Imperial College London noted that the mantle is filled with primordial remnants at the kilometer scale, originating from massive collisions during Mars' first 100 million years, which melted parts of the planet into magma oceans and incorporated debris from impacting bodies. The term "marsquake" refers to any seismic activity on Mars, whether from tectonics, meteorite impacts, or thermal stress.
The InSight lander's detection of higher-frequency seismic waves revealed delays and interference, suggesting a heterogeneous mantle rather than a uniform one. Unlike Earth, where plate tectonics recycles materials, Mars' stagnant lid crust has preserved these features, creating a "geological time capsule" of its early history.
Researchers analyzed seismic waves from eight marsquakes, including two caused by recent meteorite impacts, using artificial intelligence to filter out non-seismic noise and identify genuine seismic signals. This approach allowed for a more comprehensive understanding of Mars' geological history.
The study not only enhances knowledge of stagnant-lid worlds like Venus and Mercury but also refines models of planetary formation across the solar system and beyond. It raises fundamental questions about the uniqueness of Earth and the possibility of extraterrestrial life, providing a second data point that highlights the distinctiveness of our planet in the broader context of the universe.
