NASA’s InSight Scans the Depths of Mars: Layered Interior?

NASA’s InSight mission finally examined the interior of Mars and found that the planet’s crust could consist of three layers, according to a pre-recorded speech later played during the virtual meeting of the American Geophysical Union on December 15, and initially reported in Nature.

This marks the first time scientists have directly probed the interior of a planet other than Earth, and will also help researchers discover how the Red Planet initially formed and evolved over the centuries.


NASA’s InSight mission reveals “cake-like” layers of Mars

Prior to the InSight mission, researchers had only studied the internal structures of the Earth and the Moon. “This information was missing, until now, from Mars,” said a seismologist from the University of Cologne in Germany, Brigitte Knapmeyer-Endrun, at the virtual meeting.

This represents an important discovery for InSight, which made its landing on Mars in November 2018, with the aim of probing the internal structure of the Red Planet.

Mars less seismically active than Earth, more than the Moon

At the time of writing, the InSight lander is sitting near the Martian equator, resting on a smooth plain called Elysium Planitia. The lander uses a highly sensitive seismometer to tune into the geological energy pulsing within the planet, and so far the mission has collected the vibrations of 480 “ earthquakes, ” said principal investigator Bruce Banerdt, who is also a scientist. of NASA Jet Propulsion Laboratory.

Mars is not as seismically active as Earth, but it vibrates more than the moon.

InSight data shows that Mars is made up of two, three layers

Just as they do on Earth with earthquakes, seismologists use earthquakes to map the internal structure of the Red Planet. Because seismic energy reverberates through the ground in two types of waves, they can measure the subtle differences in how they move and calculate where the planet’s core, mantle, and crust begin and end, as well as learn the composition of each. layer.

These basic geological layers help scientists study how Mars initially cooled and formed billions of years ago when the solar system was young. According to Banerdt, “we have enough data to start answering some of these big questions.”

The Earth’s continental crust is generally separated into sub-levels of various rock types. The researchers speculated that the Martian crust was similarly layered, a planetary geologist at the Lunar and Planetary Institute in Houston, Texas, Justin Filiberto, said. Nature. But new data from InSight shows that the red planet is made up of two or three layers.

The crust of Mars is likely 12 to 23 miles thick, depending on the layers

The three-layered model fits better with geochemical models, in addition to Martian meteorites, said Julia Semprich, a planetary scientist at the Open University in the UK, at Nature.

The crust is 12.4 or 23 miles (20 or 37 km) thick, depending on whether it is made up of two or three layers, respectively, Knapmeyer-Endrun said during his speech. This thickness likely varies in different locations on the Red Planet, but is unlikely to be more than 43.5 miles (70 km) on average, he added.

InSight could reveal information about the core of Mars, the mantle

Here on Earth, the thickness of our crust fluctuates between 3 and 6.2 miles (5-10 km) under the oceans and about 24.85-31 miles (40-50 km) under the continents.

In the coming months, InSight scientists aim to report even deeper measurements inside Mars, Banerdt said. And this could eventually provide new insights into the Red Planet’s core and mantle, opening the door to a new horizon of questions surrounding the life of both the planet and the early solar system.