A recent study has unveiled significant details about the interior of Mars, suggesting it is composed of large chunks of ancient crust embedded within its mantle. This discovery, based on seismic data collected by NASA’s InSight lander, indicates a tumultuous geological history akin to that of Earth, marked by violent collisions that shaped both planets during their formative years.
Understanding the structure of Mars has intrigued scientists for years. Unlike Earth, which features tectonic plates that shift and recycle, Mars possesses a singular, rigid crust. Additionally, the absence of a global magnetic field on Mars raises questions about its internal dynamics. Recent advancements in seismic analysis have begun to provide clarity.
From 2018 to 2022, NASA’s InSight lander operated on the Martian surface, detecting hundreds of marsquakes. This seismic activity serves as an acoustic X-ray, allowing scientists to map the planet’s internal composition. Led by Constantinos Charalambous from Imperial College London, researchers examined data from eight significant seismic events to reconstruct the composition of Mars’ mantle.
The findings revealed substantial fragments of material, some measuring up to 4 kilometers (approximately 2.5 miles) across, preserved in the Martian mantle since the planet’s formation approximately 4.5 billion years ago. This period in the Solar System was characterized by widespread chaos, with large bodies colliding and reshaping the young planets.
These colossal impacts, according to Charalambous, generated enough energy to melt portions of the nascent planet into vast magma oceans. As these oceans cooled, they left behind distinct geological fragments, which researchers believe are now detectable deep within Mars.
Remarkably, the crust of Mars reformed and sealed over the mantle, encasing these ancient remnants. On Earth, such features would have long been recycled due to constant tectonic movement. In contrast, Mars, with its stagnant geological processes, retains this material, serving as a time capsule from the early days of the Solar System.
“Most of this chaos likely unfolded in Mars’s first 100 million years,” Charalambous commented. “The fact that we can still detect its traces after four and a half billion years shows just how sluggishly Mars’s interior has been churning ever since.”
This research offers vital insights into the evolution of rocky planets. Earth is the only known planet with a crust divided into tectonic plates, making Mars a valuable point of comparison for understanding Mercury and Venus, whose interiors are still largely mysterious.
The study, published in the journal Science, emphasizes that the identification of preserved ancient mantle material on Mars provides an unprecedented view into the geological history and thermochemical evolution of a terrestrial planet under a stagnant lid. This evolution carries significant implications for understanding the conditions necessary for habitability on rocky bodies across the Solar System and beyond.
In conclusion, these findings not only deepen our understanding of Mars’ geological past but also enhance our knowledge of planetary formation and evolution, potentially guiding future explorations and studies of our neighboring planets.
