Science and Technology Daily on December 16, according to the latest report in The journal Nature and Science on December 15, NASA’s Insight probe has revealed that the earth’s crust on Mars may consist of three layers. This is the first time scientists have directly probed the interior of a planet other than Earth, and it will help researchers uncover how Mars formed and evolved over time.
This is a major discovery by the Insight Mars rover. The data show that the Martian crust is also layered, 20 kilometers or 37 kilometers thick, two or three layers, depending on whether seismic reflections accurately track the top of the mantle. On earth, the crust is about 5 to 10 km below the ocean and about 40 to 50 km below the continents, with a maximum average thickness of no more than 70 km. Amazingly, the Martian crust appears to be thinner than the Earth’s crust, the researchers say.
Insight landed on Mars in November 2018 with the goal of using a highly sensitive seismograph to listen for geological energy on the planet and glean clues about the red planet’s internal structure from the deep heat seeping from the Martian soil. But Mars has its temper: its sticky soil has hampered Insight’s thermal probes, and howling winds have deafened the probe’s sensitive seismometer. Most mysteriously, the planet was not rattled by a massive earthquake that could vividly reveal its deep structure.
Despite these obstacles, a series of small, clear earthquakes allowed the Insight team to see signs of rocky boundaries tens and hundreds of kilometers below. They are clues to how the planet formed billions of years ago, when Mars was a hot ball of magma, heavier elements such as iron sank to form a core, and lighter rocks rose from the mantle to form a crust cap.
The results, presented for the first time this month at an online meeting of the American Geophysical Union, show that Mars’ crust is surprisingly thin, its mantle is cooler than expected, and its giant liquid iron core is still melting. The findings suggest that Mars effectively dissipated its heat in its infancy — probably in a way that mantle rock, similar to earth’s plate tectonics, rose and subducted its crust. “This could be evidence of a dynamic crust forming early on Mars,” said planetary scientist Stephen Moises of the University of Colorado at Boulder.
So far, insight has detected more than 480 “Mars quakes,” said Bruce Bennett, lead investigator for the mission and a scientist at the Jet Propulsion Laboratory in Pasadena, Calif. Mars has less seismic activity than the Earth, but more than the moon. “Now we’re starting to have enough data to answer some of the big questions about how Mars formed.” “Said Bennett.
Over the next few months, Insight will continue to probe deeper underground, which will eventually reveal more about The planet’s core and mantle.