December 16th, based on the latest report of Nature and Science magazine on the 15th, NASA’s InSight probe sent “intelligence” from Mars’ internal: Mars’ crust may be composed of three layers.
This is the first time that scientists have directly explored the interior of a planet outside Earth, which will help researchers reveal how Mars formed and evolved over time.
This is a major discovery of the Insight Mars rover. The data shows that the crust of Mars is also layered, 20 kilometers or 37 kilometers thick, whether it is two or three layers, depending on whether the reflection of seismic waves accurately traces to the top of the mantle.
On Earth, the crust thickness ranges from about 5 to 10 kilometers below the ocean to about 40 to 50 kilometers below the continents, with a maximum average thickness of no more than 70 kilometers. Researchers believe that the thickness of the Martian crust seems to be thinner than the earth’s crust, which is very surprising.
In November 2018, Insight landed on Mars with the goal of using a highly sensitive seismograph to monitor geological energy on Mars and collect clues to the internal structure of the red planet from the deep heat seeping from the soil of Mars.
But Mars has its “temper”: its sticky soil hinders InSight’s thermal exploration, and the roaring wind makes the detector’s sensitive seismograph sound deafeningly. Most mysteriously, the planet is not panicked by a large earthquake that vividly reveals its deep structure.
Despite these obstacles, a series of small and clear earthquakes allowed the Insight team to see signs of rock boundaries tens of kilometers and hundreds of kilometers below. They are clues to the formation of the planet billions of years ago, when Mars was a hot ball composed of magma. Heavy elements such as iron sank to form a nucleus, while lighter rocks rose from the mantle to form a crustal cover.
These results, which were unveiled at an online conference of the American Geophysical Union this month, showed that the crust of Mars was unexpectedly thin, the mantle temperature was lower than expected, and the huge liquid iron core was still melting.
These findings suggest that Mars has effectively released heat in its infancy—perhaps through a way of raising and subducting the crust through mantle rocks similar to the structure of the Earth’s plate.
“This may be evidence of the early formation of a dynamic crust on Mars,” said Stephen Moyzis, a planetary scientist at the University of Colorado Boulder.
Bruce Bennett, chief investigator of the InSight Mars exploration mission and scientist at the Jet Propulsion Laboratory in Pasadena, California, said that the mission has detected more than 480 “Mars earthquakes” so far.
Mars has less seismic activity than Earth, but more than the Moon.” Now, we are beginning to have enough data to answer some of the major questions about the formation of Mars.” Bennet said.
It is understood that in the next few months, InSight will continue to explore deeper underground Mars, which will eventually reveal more information about the core and mantle of Mars.
