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The fate of almost everything on the earth’s surface is determined by the engines of hell in the deep. The situation is no different on Mars. Now, thanks to a daring robot parked on the Martian surface by NASA in November 2018, scientists have a map of our neighboring world’s geological cliffs, the first ever made from another planet.
NASA’s InSight instrument listens for marsquakes and tracks their seismic waves as they travel the planet. triple your papers Published Thursday Using data collected by InSight in the journal Science, he reveals that the red planet is something like a giant candy floss dreamed up by a greedy god. Her shell It is divided into two or three layers of volcanic chocolate. cover The following has a surprisingly large and hard toffee-like filling. and the planet core surprisingly light – less nougat center, more syrupy heart.
Paired with recent activity on the surface by new NASA and Chinese robot rovers, these missions highlight the stark differences between our blue world and the red world to the side.
This research into the interior of Mars has been a long time coming. Earth’s tough yet soft mantle first seen in 1889When seismic waves from an earthquake in Japan enter and exit the layer before appearing in Germany. Earth’s liquid outer core was discovered in 1914, and the solid inner core appeared in 1936. Similar measurements of the moon were made when the Apollo astronauts left seismometers on its surface.
Now the same fundamental and fundamental measurements have been made on Mars. Conducted with one of the most technologically advanced seismometers ever made, this work represents “a major leap forward in planetary seismology.” Paula Koelemeijer, a seismologist at Royal Holloway, University of London, who was not involved in the research but is a co-author A perspective article in Science.
Previous missions to Mars have provided rough estimates of the dimensions and properties of its interior. However, InSight’s seismological surveys provide certainty. Models used to simulate the evolution of Mars can now be built on the foundations of these fundamental facts.
Reveals from the InSight mission will also be useful for studying other worlds, providing scientists with a different example from Earth.
“If you’re a doctor and you’re only working on one patient, you’re not going to be a very good doctor,” he said. Mark Scrollis a planetary seismologist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and co-author on all three papers.
Mars is more like a cousin of our planet than a sibling. It’s oddly small—six times less bulky—and geochemical evidence suggests it’s “this really ancient remnant of the early solar system.” Christine Houser, a seismologist at the Earth-Life Sciences Institute in Tokyo, who was not involved in the research.
Why is tiny Mars so physically different from Earth and Venus? Earth’s geological twin? InSight’s forensic examination improves scientists’ chances of finding an answer, and in the process better understands our planet’s place in the solar system.
Over the past two years, the InSight spacecraft has studied the red planet’s magnetism, its shaking as it orbits the Sun, and the seismic waves created by its marsquakes.
Most Martian earthquakes occur at shallow depths. However, a handful of them bounce off the planet before reaching InSight, radiating from deeper places. Seismic waves change speed and direction as they pass different materials, so scientists can use these deep earthquakes to see what’s going on on Mars.
It hasn’t been easy. Working with a single seismometer means scientists get a good look at just one region of Mars, rather than the entire planet. And to create a detailed picture of the underground, plenty of strong earthquakes that go through most of the depths of the planet would be ideal. Unfortunately, Mars’ seemingly infrequent earthquakes are never stronger than magnitude 4.0.
“We just needed to move forward and see what we could do with this data,” he said. Brigitte Knapmeyer – Endrun, a planetary seismologist at the University of Cologne and lead author of the paper on the Martian crust. Despite the difficulties, the team was able to take a detailed X-ray of the bowels of Mars.
Scientists have confirmed that the crust is thicker in the southern highlands and thinner in the northern plains. temporary oceans It may have been collected a long time ago. On average, the planetary crust is between 15 and 45 miles thick. It is also divided into an upper layer of volcanic rock, mostly fragmented by meteorites, a middle layer of more compatible volcanic rock, and perhaps a lower layer whose characteristics are currently undetermined.
Like Earth’s, Mars’ mantle is much thicker than its crust. But the hard part of the upper mantle that forms the Earth’s floor ever-changing tectonic plates, on Mars maybe twice as thick, maybe more.
“This may be the simple explanation that we don’t see plate tectonics on Mars,” he said. Emir Khan, geophysicist at ETH Zurich, Switzerland, and co-author of all three studies. Such rigidity may have prevented the upper layers of Mars from separating into individual tectonic plates and stole it from the sculptor who gave Earth such a variety of mountains, ocean basins, volcanoes, and continents.
The mantle of Mars gives us clues as to why a planet that once built volcanoes as large as Arizona and frequently spews lava flows that may have covered Great Britain is now so geologically dormant.
A planet’s primary volcanic and tectonic activity is driven primarily by the movement of heat from a planet’s inner sanctuary to its outermost crust. Seismic waves reaching InSight show that Mars’ mantle is relatively cold, impeding significant geological activity above.
InSight also found that its mantle is half as thick as Earth’s as a whole – a lack of insulation that would exacerbate Mars’ heat loss as it erupted heavily in its youth. (Mars’ small size also allowed plenty of its primordial heat to radiate into space.)
This thin mantle may also partly explain why Mars lost its protective magnetic field during the first 700 million years of its history. Earth’s magnetic field is powered by the circulation of iron-nickel currents in its liquid outer core. Probably Mars had a similar circulation, but the rapid cooling of its internal organs caused these currents to be caught and its magnetic dynamo shut down.
Since there was no magnetic bubble to protect Mars from the sun’s radiation, its atmosphere flew away like confetti. The water that once came upon its surface – had it not been so wet by rocks below – escaped into space, turning it into a cold, irradiated desert.
InSight also saw the core of Mars. Larger than expected with a radius of 1,140 miles. Dr. It’s not very intense either, which is “one of the most compelling results we’ve ever found,” Khan said.
Earth’s core is quite dense because the planet Much bigger than Mars, so all that weight is crushing the core together. The smaller Mars was expected to have a slightly less compressed core. But InSight has found that this is half the density of Earth, something planetary compression cannot explain.
This means that the core of Mars must have been made of different materials. Like Earth, it is still predominantly iron and nickel, but also contains a sizable portion of lighter elements such as oxygen, carbon, sulfur and hydrogen. The unusual chemistry of the Martian core is another clue to the distinctive formation history of the red planet.
Despite the achievements of humanity’s first interplanetary seismic survey, many questions remain to be answered. None of the Martian earthquakes detected were strong enough to reach the very center of the planet, so scientists don’t know if Mars, like Earth, has a solid inner core. All that can be said for now is that it has a liquid outer core – albeit a more slurry-like, slow-moving core compared to Earth’s.
The Martian earthquakes themselves remain confusing. They may be the key to seeing the inside of the planet, but Its origins are much debated.. Many shallow earthquakes, for example, are more intense and more frequent during Martian winters. “This is strange because there are no clear seasonal earthquakes on Earth,” he said. Simon Stahler, a seismologist at ETH Zurich, Switzerland, and co-author of all three papers.
InSight’s scientific expedition has been extended until December 2022, so these puzzles may be solved as more marsquakes arrive. But dust accumulation in the solar arrays of the all-terrain vehicle can kill the robot within a year.
Sooner or later, InSight is already a Mars veteran. Newer robotic visitors are just getting started. of china zhurong navigatorLanding in May, he explores another region, Utopia Planitia, and taking pictures of the parachute It helped him land safely.
NASA’s Perseverance rover, landed in jezero — a 30-mile crater that once housed a river delta-filled lake — in February, warming up for its main action: quest ancient signs of microbial life.
Wednesday, Jennifer TrosperThe Perseverance project manager announced that the mission is testing one of the rover’s most important functions: the ability to open one of the finger-sized sample tubes, seal and save inside the rover.
Perseverance’s primary purpose is to pierce Jezero and at least 20 different rock cores. These pristine Mars samples They will be delivered to Earth in 2031, where they will be subjected to intense scientific scrutiny. The team is now preparing to retrieve and store the mission’s first rock sample in August.
Perseverance is poised to revolutionize the scientific understanding of the Martian surface. InSight has provided descriptive access to the Martian underworld. The paradigm-shifting efforts of these missions mean we may one day claim to know not one but two planets, inside and out.
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