Mind-Blowing Discovery: Molten Layer Found Deep Inside Mars

Exciting Mars Findings: Meteorite Impact Reveals Hidden Layers

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WASHINGTON, Oct 25 - A burst of seismic activity caused by a meteorite impact on the far side of Mars, a world apart from where NASA's InSight lander is stationed, has ignited fresh excitement among scientists, leading to a lively reevaluation of our understanding of the Red Planet's inner workings.

This new seismic data has unveiled a previously undiscovered layer of molten rock encircling a compact and denser liquid metallic core – the very heart of Mars, altering our perception of this celestial neighbor, as researchers shared on a bright Wednesday morning.

These seismic waves, born from quakes triggered by various factors, including meteorite impacts, take on varying speeds and shapes as they navigate through different materials within a planet. Thanks to the invaluable insights garnered from InSight's seismometer instrument, we're now peering deeper into the inner structure of this Martian world.

The meteorite's impact, which rocked a Martian highland named Tempe Terra on September 18, 2021, registered a magnitude 4.2 earthquake and left a striking 425-foot (130-meter) wide crater. Importantly, it occurred on the far side of Mars, diametrically opposite InSight's home in the plains of Elysium Planitia.

"The significance of this impact on the far side was its ability to generate seismic waves that traversed the planet's deep interior, including its core. Until now, we hadn't witnessed seismic waves traveling through the core; we had only detected reflections from its surface," shared Amir Khan, a planetary scientist from ETH Zürich in Switzerland, and the lead author of one of two groundbreaking studies published in the prestigious journal Nature.

The behavior of these seismic waves hinted at the absence of a vital component in our prior understanding of the Martian interior – a molten silicate layer, approximately 90 miles (150 km) thick, enveloping the core. This molten realm resides at the base of the planet's inner region, known as the mantle.

Additionally, researchers recalibrated the core's dimensions, revealing it to have a diameter of approximately 2,080 miles (3,350 km), a volume around 30% smaller than initially estimated.

In contrast to Mars, Earth lacks a molten layer encircling its core. In one of the two studies unveiled on this illuminating Wednesday, it's suggested that this Martian layer is entirely molten, while the other hints at a mostly molten composition, with a partially molten upper portion.

Henri Samuel, a planetary scientist with France's CNRS and affiliated with Institut de Physique du Globe de Paris, who led the second study, shed light on this molten and partially molten layer, explaining, "This region primarily consists of silicates, rock-forming minerals, enriched with iron and heat-producing radioactive elements when compared to the solid mantle above."

The core of Mars comprises primarily iron and nickel, albeit with traces of lighter elements like sulfur, oxygen, carbon, and hydrogen. Researchers have now determined that these lighter elements constitute roughly 9-15% of the core's weight, a finding diverging from previous estimations.

"This percentage of lighter elements bears resemblance to Earth's core, which is believed to be approximately 10% composed of them," Khan emphasized.

Mars, the fourth member of our solar family, boasts a diameter of about 4,220 miles (6,791 km), in contrast to Earth's broader span of around 7,926 miles (12,755 km). Earth's overall volume dwarfs Mars by nearly sevenfold.

NASA officially retired InSight in 2022, following a productive four-year mission.

As Samuel concluded, "Our exploration of Mars through the unique seismic data provided by the InSight mission has brought us rich insights. Planets are intricate and vibrant realms, where a multitude of processes interact across varying spatial and temporal scales, and Mars is no exception."

Source : Reuters (Reporting by Will Dunham)