Chapter 1: The Journey to Mars' Core

The latest advancements from NASA's InSight mission are shedding light on the Red Planet's internal structure for the first time. Through three new research studies, scientists have started to unravel the depths and composition of Mars' crust, mantle, and core, which will be crucial for future human exploration.

The mission has significantly enhanced our understanding of Mars' geography and atmosphere, primarily due to the advanced technology deployed on its surface. Following a historic "Wright Brothers moment" with a successful helicopter flight, the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) has also demonstrated the ability to generate small quantities of oxygen.

While previous efforts focused mainly on mapping Mars' surface, the recent findings from the InSight mission provide a comprehensive view of its internal layers. An international collaboration involving CNRS, the Institut de Physique du Globe de Paris, and Université de Paris, with support from the French space agency CNES and the National Research Agency (ANR), has estimated the core's size, the crust's thickness, and the mantle's structure.

Section 1.1: Unveiling Mars' Internal Layers

Historically, our grasp of Mars' internal makeup has been limited, with most data gathered from orbit or surface observations. However, the seismometer aboard InSight has transformed our knowledge by delivering crucial information about the depths and composition of the planet's interior. One of the most intriguing discoveries is that Mars' core is molten, paralleling Earth's outer core.

“This study is a once-in-a-lifetime opportunity. It took scientists centuries to measure Earth's core; after the Apollo missions, it took 40 years to assess the Moon's core. InSight achieved this in just two years.”

~ Simon Stähler, Lead Author of the Core Study

Section 1.2: Seismic Discoveries and Their Implications

InSight's seismometer, known as SEIS (Seismic Experiment for Interior Structure), has detected 733 unique marsquakes. Out of these, 35 registered magnitudes between 3.0 and 4.0, forming the basis for recent research papers. The crust's thickness is now estimated to range from 30 to 100 km, while the core's radius is believed to be between 1,400 and 2,000 km. However, the exact depth of the boundaries separating the crust, mantle, and core remains uncertain.

Collaboration among French researchers and their colleagues from ETH Zurich, the University of Cologne, and the Jet Propulsion Laboratory in Pasadena has allowed for a comprehensive analysis of the data collected over one Martian year (equivalent to two Earth years). By integrating mineralogical and thermal modeling, the team overcame the challenge of having a single measurement station.

Another obstacle stemmed from Mars' low seismic activity, which necessitated filtering out atmospheric noise to obtain precise readings. The international Mars Quake Service team (MQS) diligently documented seismic events daily, successfully cataloging around 600 of them, ten of which provided insights into the planet’s deep structure.

Chapter 2: The Road Ahead

By analyzing the seismic waves that traveled through the crust before reaching the InSight station, researchers identified several distinct layers within the crust. The first discontinuity occurs at a depth of approximately 10 km, distinguishing a highly altered structure resulting from ancient fluid circulation from a less altered crust. Additional discontinuities were noted at around 20 km and 35 km depths.

Over two years of seismic monitoring has culminated in the first-ever model of Mars' internal structure, extending to the core. This accomplishment aligns Mars with Earth and the Moon, which have also been explored seismically. Such discoveries significantly enhance our understanding of Mars' thermal evolution and its similarities to our own planet.

The video "NASA's InSight Mars landing: what it really took" provides a deeper understanding of the mission's challenges and successes.

The video "Mars Insight - Digging Into The Martian Interior" further explores the implications of the findings from the InSight mission.

Complete research studies can be found in the Journal of Science [1] [2] [3].

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