A quake on Mars confirmed its crust is thicker than Earth’s

Planetary scientists now know the way thick the Martian crust is, due to the strongest Marsquake ever noticed.

On common, the crust is between 42 and 56 kilometers thick, researchers report in a paper to look in Geophysical Analysis Letters. That’s roughly 70 p.c thicker than the typical continental crust on Earth.

The measurement was based mostly on information from NASA’s InSight lander, a stationary seismometer that recorded waves rippling by way of Mars’ inside for 4 Earth years. Final Could, your complete planet shook with a magnitude 4.7 quake that lasted greater than six hours (SN: 5/13/22). “We have been actually lucky that we acquired this quake,” says seismologist Doyeon Kim of ETH Zurich.

InSight recorded seismic waves from the quake that circled Mars as much as 3 times. That allow Kim and colleagues infer the crust thickness over the entire planet.

Not solely is the crust thicker than that of the Earth and the moon, but it surely’s additionally inconsistent throughout the Purple Planet, the group discovered. And that may clarify a recognized north-south elevation distinction on Mars.

Topological and gravity information from Mars orbiters have proven that the planet’s northern hemisphere is considerably decrease than the southern one. Researchers had suspected that density may play an element: Maybe the rocks that make up northern Mars have a unique density than these of southern Mars.

However the crust is thinner within the northern hemisphere, Kim and colleagues discovered, so the rocks in each hemispheres most likely have the identical common densities. That discovering helps scientists slim down the reasons for why the distinction exists within the first place.

Understanding the crust’s depth, the group additionally calculated that a lot of Mars’ inner warmth most likely originates within the crust. Most of this warmth comes from radioactive parts akin to potassium, uranium and thorium. An estimated 50 to 70 p.c of these parts are most likely within the crust somewhat than the underlying mantle, pc simulations recommend. That helps the concept that elements of Mars nonetheless have volcanic exercise, opposite to a long-held perception that the Purple Planet is lifeless (SN: 11/3/22).