Based on seismic data from NASA’s InSight mission and advanced first-principles simulations of liquid metal alloys, researchers have uncovered new characteristics of Mars’ liquid iron core. Contrary to earlier estimates, the core is encased in a 150-km thick layer of molten silicate. This discovery indicates that Mars’ core is not as large as once assumed, thereby suggesting a greater density that aligns with a metal core consisting of 9–15 weight percent of light elements such as sulfur, carbon, oxygen, and hydrogen. These findings are credited to Thibaut Roger, NCCR PlanetS, and ETH Zurich.
The ETH Zurich research team analyzed seismic data from the InSight lander, concluding that Mars’ core is not only smaller but also denser than originally estimated, and that it is enveloped by a layer of molten silicates.
Even after the InSight mission concluded one year ago, ongoing analysis of marsquake data and computer models continue to provide valuable insights. The initial marsquake data had implied a density of the Martian core that was substantially lower than that of pure liquid iron. The revised data has narrowed the core radius from the previously thought 1,800–1,850 kilometers to a new estimated range of 1,650–1,700 kilometers.
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Unveiling the Interior of Mars: Findings from the InSight Mission
Over a span of four years, the InSight lander captured seismic activities on Mars. Researchers at ETH Zurich subsequently scrutinized this data to understand the planet’s internal makeup. Amir Khan, a Senior Scientist at ETH Zurich, notes that although the mission concluded in December 2022, they continue to make new discoveries about Mars.
Mars’ Distinctive Silicate Layer
In addition to previously known layers, a new layer of liquid silicate approximately 150 kilometers thick has been identified between Mars’ liquid iron alloy core and its solid silicate mantle. Unlike Earth, Mars possesses this unique completely molten silicate layer, according to Khan.
This new information, published in the journal Nature, not only clarifies the size and composition of Mars’ core but also helps to resolve longstanding questions in planetary science.
Understanding Mars’ Core Elements
Earlier data had suggested that Mars’ core contained a large percentage of light elements—around 20% by weight. However, new calculations have revised this estimate to between 9 and 14 percent, making it more consistent with standard models of planetary formation, as pointed out by Paolo Sossi, Assistant Professor at ETH Zurich.
New Directions in Marsquake Analysis
Initially, analyses were based on quakes near the InSight lander. New seismic activity recorded on the opposite side of Mars, including one caused by a meteorite impact, has allowed a more comprehensive understanding of the core’s properties.
Advanced Computational Methods
Due to the lack of directly applicable experimental conditions for Mars, ETH Zurich researchers resorted to quantum-mechanical simulations at the Swiss National Supercomputing Centre to estimate the properties of various alloys, which helped them better understand Mars’ core composition.
A Revolutionary Model
The collective findings, including those published in Nature by Henri Samuel from the Institut de Physique de Globe de Paris, present a groundbreaking model of Mars’ internal structure, emphasizing the significance of a layer of molten silicates overlying the Martian core. This new model is transformative in understanding the internal structure and evolutionary path of the Red Planet.
The Ongoing Legacy of the InSight Mission
Managed by the Jet Propulsion Laboratory, NASA’s InSight Mission has had substantial international collaboration, including contributions from France’s CNES and Germany’s DLR. The mission, although concluded, will continue to impact the scientific community through the richness of the data gathered, as confirmed by Khan.
For further details, refer to the articles published in Nature on 25 October 2023.
References:
“New Data on a Liquid Silicate Layer Above Mars’s Core” by A. Khan, D. Huang, C. Durán, P. A. Sossi, D. Giardini, and M. Murakami, DOI: 10.1038/s41586-023-06586-4
“New Geophysical Indicators of Molten Silicate Layer over Mars’s Core” by Henri Samuel et al., DOI: 10.1038/s41586-023-06601-8
Frequently Asked Questions (FAQs) about Mars’ Core
What are the key findings about Mars’ core based on the InSight Mission?
The core of Mars is smaller and denser than previously estimated. Researchers at ETH Zurich have determined, through analysis of seismic data from the InSight lander, that the core is surrounded by a 150-km thick layer of molten silicate.
Who conducted the research and analysis on Mars’ seismic data?
The research and analysis were conducted by scientists at ETH Zurich, particularly those in the Department of Earth Sciences. They collaborated with NASA’s InSight Mission for the seismic data.
How does the new data change our understanding of Mars’ core?
The revised measurements imply a higher density for the Martian core than earlier estimates. The core is also smaller, with a radius falling within the range of 1,650 to 1,700 kilometers, contrasting with prior estimates of 1,800 to 1,850 kilometers.
What elements are believed to make up Mars’ core?
The Martian core is primarily composed of liquid iron. However, it also contains 9-15 wt% of light elements, chiefly sulfur, carbon, oxygen, and hydrogen.
What makes Mars’ internal structure unique compared to Earth’s?
Mars has a layer of molten silicate that is approximately 150 kilometers thick, sandwiched between its liquid iron core and solid silicate mantle. Earth does not possess such a completely molten silicate layer.
What methods were used to arrive at these new findings?
The ETH Zurich team used seismic data gathered from the InSight mission, along with first-principles simulations and quantum-mechanical supercomputer simulations. The data was further verified through comparison with laboratory measurements on synthetic iron alloys.
Is the research about Mars’ core published in any scientific journals?
Yes, the research findings have been published in the scientific journal Nature.
Are there any limitations to the study?
The study was unable to gather additional data due to the InSight lander’s dusty solar panels and resulting lack of power. However, the mission was still considered successful, providing valuable data for future analysis.
What is the next step in understanding Mars’ internal structure?
Further analysis of earlier marsquakes and additional computer simulations are planned. Ongoing study of the data collected by the InSight mission will continue to yield new insights into the composition and structure of Mars’ interior.
Who are the major collaborators in the InSight mission?
The InSight mission was managed by NASA’s Jet Propulsion Laboratory and included numerous European partners like France’s Centre National d’Études Spatiales (CNES) and the German Aerospace Center (DLR).
More about Mars’ Core
- ETH Zurich Department of Earth Sciences
- NASA’s InSight Mission Overview
- Nature Journal Mars Core Research Article
- InSight Mission Partners and Collaborators
- Seismic Data Analysis Methods
5 comments
Interesting how they had to rely on quantum-mechanical calcs. High-end tech for high-end science, huh.
Makes me wonder, what else dont we know bout other planets. The more we learn the less we seem to know.
Wow, never knew Mars had such a complex core. The science comin out of InSight is really next level.
So Mars has a molten silicate layer that Earth doesn’t? thats kinda cool and weird at the same time.
Anyone else excited for what other mysteries InSight could’ve solved if it hadn’t run outta power? Feels like a cliffhanger to me.