NASA’s InSights peers deep into Mars – layered interior?

NASA’s InSight mission eventually examined the interior of Mars and found that the planet’s crust could be made up of three layers. This emerges from a recorded lecture that was later repeated during the American Geophysical Union’s virtual meeting on December 15, and initially reported in nature.

This is the first time scientists have directly examined the interior of a planet next to Earth, helping researchers find out how the Red Planet originally formed and evolved over the centuries.


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

Before the InSight mission, researchers had only studied the internal structures of the earth and moon. “This information was previously missing on Mars,” said a seismologist from the University of Cologne, Brigitte Knapmeyer-Endrun, at the virtual meeting.

This is an important discovery for InSight, which landed on Mars in November 2018 to study the internal structure of the red planet.

Mars less seismically active than Earth, more than the Moon

At the time of this writing, InSight Lander sits near the Martian equator and rests on a smooth plain called the Elysium Planitia. The lander uses a highly sensitive seismometer to adjust to the geological energy swirling away inside the planet. So far, the mission has picked up the vibrations of 480 “Marsquakes,” said Principal Investigator Bruce Banerdt, who is also a scientist with NASA’s Jet Propulsion Laboratory.

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

InSight’s data shows that Mars is made up of two or three layers

Just like on earth with earthquakes, seismologists use marsquakes to map the internal structure of the red planet. Because seismic energy reverberates through the ground in two types of waves, it can measure the subtle differences in their motion and calculate where the core, mantle, and crust of the planet begin and end. They can also learn the composition of each layer.

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

The continental crust is generally divided into sub-layers of different types of rock. Researchers had assumed the Martian crust was similarly stratified, said Justin Filiberto, a planetary geologist at the Lunar and Planetary Institute in Houston, Texas nature. However, InSight’s new data shows that the Red Planet is made up of either two or three layers.

The Martian crust is likely 12 to 23 miles thick, depending on the layer

The three-layer model works best with geochemical models, in addition to Martian meteorites, said Julia Semprich, planetary researcher at the Open University in the UK nature.

The crust is either 20 or 37 km thick, depending on whether it consists of two or three layers, Knapmeyer-Endrun said during her lecture. This thickness will likely vary in different locations around the Red Planet, but it is unlikely to be more than 70 km on average, she added.

InSight could reveal information about Mars’ core, called the mantle

Here on earth, our crust thickness varies between 5 and 10 km under the oceans and between 40 and 50 km under the continents.

InSight scientists plan to report measurements from even deeper areas of Mars in the next few months, Banerdt said. And this could eventually provide new information about the core and mantle of the Red Planet and open the door to a new horizon of questions affecting the life of both the planet and the early solar system.