An artist’s illustration of the InSight lander on Mars.
NASA’s InSight lander just gave scientists a peek at the make-up of Mars’s core, crust, and mantle.
A trio of new studies reveal how the interior structure of Mars compares to that of Earth.
Evidence also suggests Mars had a strong, protective magnetic field like Earth does, then lost it.
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For the first time, we know what the interior of another planet similar to ours looks like.
In a trio of studies published Thursday in the journal Science, an international team of more than 40 scientists revealed how the Mars’s core, mantle, and crust contrast with Earth’s.
By analyzing seismic data collected by NASA’s InSight lander on the red planet, the researchers estimated of the size of Mars’s core, the thickness of its crust, and the composition of its mantle (the layer in between).
“We only have this kind of information for the Earth and moon,” Brigitte Knapmeyer-Endrun, a planetary seismologist at the University of Cologne and co-author of the new research, told Insider. “But the moon we can’t compare to Earth very well because it’s so much smaller.”
Mars, however, is our tinier, terrestrial twin. The new studies suggest its core is less dense than Earth’s but scaled to size.
Beaming seismic waves through Mars’s heart
The InSight lander’s seismometer, as photographed by the lander’s camera on September 23, 2020.
InSight, NASA’s $828 million robotic science station, landed on Mars in November 2018. Since then, the lander has used its seismometers – which detect and record earthquakes – to listen for similar quakes on Mars.
Seismic waves from 12 of these marsquakes, which travel right through the middle of the planet and bounce off the layers inside, helped Knapmeyer’s group to map the boundaries of the crust and core.
“Imagine you have a closed box and you want to find out what’s inside,” Knapmeyer said. “This method is like taking that box and putting it into an X-ray.”
Mars has a fatter core than scientists thought
An artist’s illustration of Mars’s interior.
InSight’s findings suggest Mars has a large liquid core that starts almost halfway to the planet’s center, nearly 1,000 miles beneath the surface.
Its 1,143-mile radius was “larger than expected,” Amir Khan, a seismologist from ETH Zurich in Switzerland and a study co-author, told Insider.
The boundary of Earth’s liquid outer core – which encircles a solid metal inner core – starts deeper than Mars’s does, at 1,800 feet.
That said, Earth is nearly twice as wide as Mars is, and its core is about twice as wide too.
Unlike Earth’s core which is dominated by nickel and iron, Mars’s less dense core contains lighter elements like hydrogen and oxygen.
The red planet appears to lack an inner core, according to Simon Stähler, another study co-author and Khan’s colleague at ETH.
“We don’t know, we’ll be looking for this,” Stähler told Insider, adding, “temperatures are likely too high for an inner core to form.”
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Source:: Business Insider