Over the last month, NASA’s InSight lander recorded the three largest “marsquakes” ever encountered, including one that lasted more than an hour.
The quakes each registered with just above 4.0 on the Richter scale, reports Richard A. Lovett of Cosmos. While earthquakes of that magnitude would be considered relatively minor, Mars is largely thought to be far less tectonically active than Earth, making these shakes a bigger deal.
Along with their relative intensity, another distinguishing feature of these marsquakes was their duration – one of the events was recorded as lasting for an hour and a half.
The InSight lander made its home on Mars in 2018 with a mission to learn more about the poorly understood interior of the planet through seismology. While previous Martian landers had detected vibrations from possible marsquakes, limited technology made it difficult to accurately isolate and scrutinize the data.
InSight brought new tools to the surface of the Red Planet, including a powerful seismometer that it placed directly on the Martian soil. Unlike previous landers’ instruments that were vulnerable to the planet’s powerful and unpredictable winds, the Seismic Experiment for Interior Structure (SEIS) is heavily shielded to allow the precise measurement of minor vibrations.
The lander detected its first marsquake in April 2019, and has since recorded many seismic waves shaking the planet, providing valuable information about what’s beneath the Martian soil, reports Amanda Kooser of CNET.
“The waves change as they travel through a planet’s crust, mantle, and core, providing scientists a way to peer deep below the surface,” NASA’s Jet Propulsion Laboratory noted in an article. Already, scientists have come to realize that Mars’ core is much larger than previously thought, while its crust is lighter than theorized, reports Mike Wall of Space.com.
These latest marsquake revelations and potential future ones would not have been possible without some creative thinking earlier this year to help keep the InSight lander powered, reports Alfredo Carpineti of IFLScience.
The lander uses large solar panels to power its scientific instruments and heaters to keep them from freezing over on the cold Martian surface. However, Mars’ famed red dust presents a major challenge when it comes to potentially blocking those solar panels. Generally, missions have hoped that gusts of Martian wind will occasionally brush off the panels to keep them clear enough to collect solar energy, but a long period of relatively weak wind let dust start to pile up on the craft.
Compounding the problem, this accumulation occurred as Mars’ elliptical orbit started to carry the planet further from the Sun, requiring the lander’s heaters to be used even more to preserve its instruments.
To help clear the dust and salvage the mission, NASA engineers thought up a seemingly counterintuitive solution – they ordered the lander to use its robotic arm to drop a pile of sand on the corner of one of its solar panels. The team hoped that the heavier sand particles would help brush the dust off the panels as they were moved by the wind.
Thankfully, the plan worked, and InSight soldiers on studying the shakes and quakes of Mars.