NASA Mars lander prepares its 1st map of Red Planet underground by hearing to wind sound
Designing the 1st Map
Researchers listened to the sound of wind resonating through the layers of soil and rock near Mars’ equator to generate the first-ever map of the Martian underworld.
NASA’s InSight mission, which landed in the flat Elysium Planitia in 2018 to examine mild “marsquakes” rippling across the planet, was employed by the researchers. The data from InSights previously allowed scientists to gain a good understanding of the size and composition of Mars’ core, as well as the nature of the mantle and the thickness of the crust.
For the first time, a team led by Swiss geophysicists was able to use a new approach developed and fine-tuned on Earth. The goal was to utilise the lander’s equipment to peer beneath the planet’s arid surface and see what lies beneath the first 660 feet (200 metres) of its crust.
“To define regions for earthquake risk and investigate the subsurface structure, we employed a technique that was established here on Earth,” Cedric Schmelzbach said.
“It’s based on environmental vibration,” Schmelzbach explained. “On Earth, there are oceans and winds that cause the ground to shake all the time, and the shaking you measure at a particular spot bears an imprint of the subsurface.”
The earth vibrates as a result of the commotion on the surface. Sensitive sensors can detect these small vibrations that travel deep into the ground.
“As we go deeper, the resolution gets coarser,” Schmelzbach explained. “We can resolve layers that are one metre [three feet] thick close to the surface. However, it is only a few tens of metres [10 metres = 33 feet] at deeper depths.”
What does the map offer?
The map gives a fascinating peek into Martian evolution over the last several billion years. It displays a layer of deep sediments as well as large deposits of solidified lava, all of which are covered by a 10-foot-thick (3-meter) blanket of sandy regolith.
The mysterious sedimentary layer, which lies 100 to 230 feet (30 to 70 metres) below the Martian surface and wedged between two solidified layers of old lava, is located 100 to 230 feet (30 to 70 metres) below the Martian surface.
“We’re still trying to figure out how to interpret that and determine how old this layer is,” he said. “However, it indicates that the geological history of that location is likely to be more intricate.”
The researchers compared the geology of adjacent craters to the two lava levels that encompassed this silt. They were able to date the origins of those layers to two key times in Mars’ geological history, roughly 1.7 billion and 3.6 billion years ago, using this information.
Previous InSight-based examinations of the planet’s core, mantle, and crust showed startling variations between Mars and Earth. The two planets are commonly regarded as solar system twins who shared their evolutionary paths up to a point.