In a groundbreaking discovery, planetary scientists have uncovered the surprising thickness of Mars' crust, surpassing that of Earth. The revelation, facilitated by the strongest Marsquake ever observed, may shed light on the enigmatic elevation differences between the planet's northern and southern regions.

​

According to a forthcoming paper in Geophysical Research Letters, the Martian crust averages between 42 and 56 kilometers in thickness. Remarkably, this measurement represents a staggering 70 percent increase compared to Earth's average continental crust.

The data was derived from NASA's InSight lander, equipped with a stationary seismometer that meticulously recorded seismic waves traversing Mars' interior over the span of four Earth years. Last May, a magnitude 4.7 quake reverberated throughout the entire planet for over six hours, offering an extraordinary opportunity for analysis. Seismologist Doyeon Kim from ETH Zurich expressed their team's fortune, stating, "We were truly fortunate to have witnessed this quake." InSight captured seismic waves from the event, enabling Kim and colleagues to extrapolate the crust's thickness across the entire planet.

​

Significantly, the team's findings revealed not only the greater thickness of Mars' crust in comparison to Earth and the moon but also its inconsistencies throughout the Red Planet. This newfound knowledge may provide a potential explanation for the well-known disparity in elevations between Mars' northern and southern hemispheres.

​

Data from Mars orbiters, encompassing topological and gravity information, has previously indicated a substantial height difference between the planet's two hemispheres. Scientists hypothesized that differing densities of rocks might contribute to this contrast, with northern Mars potentially featuring distinct rock densities compared to the south.

However, Kim and colleagues discovered that the crust is, in fact, thinner in the northern hemisphere, indicating that rocks in both hemispheres likely possess similar average densities. This crucial revelation allows scientists to narrow down possible explanations for the elevation disparity.

​

Moreover, armed with knowledge of the crust's depth, the research team conducted calculations suggesting that a significant portion of Mars' internal heat originates from within the crust itself. Radioactive elements such as potassium, uranium, and thorium likely contribute to this heat generation. Computer simulations suggest that an estimated 50 to 70 percent of these elements reside in the crust, rather than the underlying mantle. These findings support the notion that volcanic activity may still persist in certain regions of Mars, contradicting the long-held belief that the Red Planet is devoid of life.

​

Through this seismic breakthrough, our understanding of Mars has taken a remarkable leap forward. The thicker crust, its uneven distribution, and the link to Martian geological activity may hold the keys to unraveling the planet's mysteries, opening up new avenues for future research and exploration.

April 15 2023.