Sweet Surprise: NASA Insight Lander’s First Look Inside Mars Reveals The Red Planet’s Crust Resembles A Three-Layer Cake
The lander’s seismometer has recorded more than 480 earthquakes since April 2019
Differences in the way seismic waves move allow scientists to assess the size and composition of the crust
They believe that the crust of Mars is about 23 miles thick, much thicker than Earth’s.
Seismic activity has practically stopped, with only four earthquakes since June.
Data transmitted to Earth by NASA’s InSight lander suggests that the crust of Mars is made up of three layers in the shape of a cake.
Anchored near the equator of Mars, the robotic lander’s super-sensitive seismometer, known as SEIS, has recorded hundreds of “earthquakes” in the past two years.
Each earthquake emits two sets of seismic waves, and analyzing the differences in how these waves move allowed the researchers to begin calculating the size and composition of the planet’s crust, mantle and core.
“We have enough data to start answering some of these big questions,” said Bruce Banerdt, a scientist at the Jet Propulsion Laboratory. Nature .
Launched in 2018, the InSight mission marks the first time scientists have looked at a planet other than Earth.
Analysis of the primary and secondary waves caused by hundreds of earthquakes suggests that the crust of the red planet is made up of three layers of “cake”
The earth’s crust is divided into three rock sublevels: metamorphic, igneous, and sedimentary. Scientists had theorized that the crust of Mars had a similar structure but, until now, they had no data to work on.
According to the Nature report, Mars may have only two layers, but a three-layer crust aligns with the analysis of Martian meteorites.
By comparing the primary and secondary waves of the marsquakes, they deduced that the crust is about 23 miles thick on average and about 42 miles thick at the thickest point.
InSight’s super sensitive seismometer, known as SEIS, has recorded more than 480 earthquakes. By analyzing the primary and secondary waves from these earthquakes, the researchers believe that the crust of Mars is approximately 23 miles thick.
It is considerably thicker than Earth, which has a crust that ranges from about 3 miles under the oceans to 18 miles under the continents.
InSight (short for interior exploration using seismic investigations, geodesy, and heat transport) arrived on Mars in November 2018.
Their probe, dubbed the “Mole,” was designed to dig below the surface and measure the planet’s temperature, but unexpected properties of the Martian soil hampered progress.
Fortunately, other equipment on the lander is in perfect working order, including the seismometer, supplied by the French space agency, Center National d’Études Spatiales.
Since April 2019, SIX has recorded more than 480 earthquakes. The tremors are relatively mild, none greater than a magnitude of 3.7.
“It’s a bit surprising that we haven’t seen a larger event,” said seismologist Mark Panning of NASA’s Jet Propulsion Laboratory.
Panning says that it is not yet clear if Mars is more static than Earth or if InSight landed during an interval of silence.
Earthquakes had been daily for some time, but stopped abruptly in late June, just as the planet entered the windiest season of the year.
The seismometer is protected, but the wind may be strong enough to shake the ground and mask legitimate tremors.
The researchers hope other major earthquakes will follow, providing a deeper insight into the inner layers of the planet.
“Sometimes you get big flashes of surprising information, but most of the time you scoff at what nature has to tell you,” Banerdt said.
“It’s more like trying to follow a trail of complicated clues than receiving the answers in a well-packaged package.”
The lander that could reveal how Earth was formed: The InSight lander is ready to land on Mars on November 26
Three key tools will allow the InSight lander to “take the pulse” of the red planet:
Seismometer : The InSight lander carries a seismometer , SIX, listening to the pulse of Mars.
The seismometer records the waves that travel through the internal structure of a planet.
The study of seismic waves tells us what might create the waves.
On Mars, scientists suspect that the culprits may be earthquakes or meteorites hitting the surface.
Thermal probe : InSight’s HP3 heat flux probe digs deeper than any other shovel, drill or probe on Mars before it.
It will investigate how much heat is still coming out of Mars.
Radio antennas: Like Earth, Mars oscillates slightly as it rotates around its axis.
To study it, two radio antennas, part of the RISE instrument, track the position of the lander very precisely.
This helps scientists test the reflections of the planet and explains how the deep internal structure affects the movement of the planet around the sun.