NASA’s InSight probe reveals first detailed look inside Mars

NASA’s InSight lander arrived on Mars in 2018 to learn more about its interior while monitoring “marsquakes,” and now the project is starting to really pay off. NASA has announced that researchers have mapped the interior of the Red Planet and discovered big surprises and major differences with Earth.

The map is the very first from inside another planet. Compared to Earth, Mars has a thicker crust, a thinner mantle layer, and a larger, less dense, and more liquid core than expected. This in turn suggests that Mars may have formed millions of years before our planet, when the sun itself was not yet fully formed.

“This gives us our first sample of the interior of another rocky planet like Earth, built with the same materials but very, very different,” said University of Cambridge seismologist Sanne Cottaar (who didn’t was not involved in the project). the Wall Street newspaper. “It’s impressive.”

Building a map from the limited data provided by InSight has not been easy. The probe only recorded earthquakes in one location and has only one seismometer on the one hand. And Mars – although seismically active – had no earthquakes greater than about 4 on the Richter scale.

Yet by taking this data, along with the planet’s magnetism and orbital oscillations, scientists were able to create a detailed map. The innermost core of the planet turned out to be about 2,275 miles in diameter, larger than previously thought. Considering the mass of the planet as a whole, this implies that the iron / nickel core probably contains lighter elements like sulfur, oxygen, and carbon.

The crust, on the other hand, turned out to be very old. It was also thicker in the southern highlands of Mars and thinner in the northern lowlands, which may have hosted oceans long ago. On average, it is between 15 and 45 miles thick and divides into several layers of volcanic rock.

The mantle between the crust and the core extends approximately 970 miles below the surface. It is thinner than that of Earth and has a different makeup, suggesting that the two planets came from different materials when they formed. This “could be the simple explanation why we don’t see plate tectonics on Mars,” said Amir Khan, ETH Zurich geophysicist and co-author of the study. New York Times.

The results gave scientists new insight not only into the interior of Mars, but also into the formation of rocky planets in general. This will help them develop new theories about how planets were formed that could become particularly valuable in the near future, when new instruments like the James Webb Space Telescope allow astronomers to scan exoplanets around the galaxy. NASA will reveal more of its findings at a live event later today.