NASA’s InSight robotic lander has just given us the first sight of the depths of planets beyond Earth.
More than two years after launch, the seismic data collected by InSight has provided researchers with clues about how Mars formed, how it has evolved over 4.6 billion years, and how it differs from Earth.A set of three new studies, published In scienceelectronic This week, this shows that Mars has a thicker crust than expected, and a molten liquid core larger than we thought.
In the early days of the solar system, Mars was very similar to Earth, and each surface was covered by an ocean. But in the next 4 billion years, the earth became mild and very suitable for life, and Mars lost its atmosphere and water and became the barren wasteland we know today. A better understanding of the conditions inside Mars may help us figure out why the fates of the two planets are so different.
“By [a] Cartoon understands what the inside of Mars looks like and puts real numbers on it,” said Mark PenningThe project scientist of the InSight mission, at a NASA press conference, “we can really expand our understanding of how these rocky planets formed and how they are similar and different in their genealogy.”
Since InSight landed on Mars in 2018, its seismometer on the surface of Mars has detected thousands of different earthquakes. Most are so small that people standing on the surface of Mars will not notice them. But some are large enough to help the team really understand what’s going on at the bottom for the first time.
An earthquake on Mars generates seismic waves detected by seismographs. Researchers used data from two different seismic waves to create a 3D map of Mars: shear waves and pressure waves. Shear waves that can only pass through solids are reflected by the planet’s surface.
Pressure waves are faster and can pass through solids, liquids and gases. Measuring the difference between the arrival times of these waves allows researchers to locate earthquakes and provide clues to the internal composition.
A team by Simon StreetwhatreadSeismologists at ETH Zurich used data from 11 major earthquakes to study the core of the planet. Based on the way the seismic waves were reflected from the core, they concluded that it was made of liquid nickel-iron, which was much larger than previously estimated (2,230 to 2,320 miles wide) and may be less dense.