Science & Technology

Underwater InSight Pier on Mars

The InSight lander is on Mars, collecting data for 1000 days and working to better understand the interior of the planet.Is in Elysium Planitia, The second largest volcanic region on Mars. A newly published paper based on seismic data from landers shows something unexpected underground, a layer of sediment sandwiched between layers of lava flow.

Much of InSight’s media coverage is centered around landers. Heat flow and physics package (HP3), Also called mole. Its job was to measure the heat coming from inside the planet to the surface.After a spectacular struggle to make the instrument work, NASA and DLR (German Aerospace Center) in January 2021 of Mole The mission is over Before it starts.

But Mole is not the only instrument in InSight. Other major scientific instruments are Seismic experiment of internal structure (SEIS.) SEIS is functioning normally and already offers some solid science. This new paper is based on seismic data from SEIS.

InSight Lander seismograph under protective wind and heat shield. Image Credit: NASA / JPL-Caltech

The title of the new paper is “Shallow structure of Mars at InSight landing point due to reversal of ambient vibration.. It is published in the journal Nature Communications and the author is an international team of scientists.

The team used seismic data from InSight’s SEIS lander, Elysium Planitia Up to a depth of 200 meters. Just below the lander, they found a 3 meter layer of sandy material. Regolith.. Below that is a layer of material called a coarse rock ejecta, which is 15 meters long. The material is a meteorite impact fragment that is thrown into the air before returning to Mars.

Then it gets interesting.

InSight has discovered a 150-meter layered basaltic material area of ​​solidified lava beneath the ejecta layer. That layer is in line with expectations. But there is something unexpected between the basalts. Between 30 and 75 meters, there is a “slow seismic zone” that the team interprets as a layer of dense sediment.

This figure from paper shows the area near the surface under the InSight Lander. The left and center panels show what the various models predicted. Reference models 1 and 2 are pre-landing models. ML and MAP represent maximum likelihood and maximum a posteriori models, and the gray line is an ensemble of all models. On the right is the author's interpretation of the seismic data. See Surveys for more information. Image credit: Hobiger et al 2021.
This figure from paper shows the area near the surface under the InSight Lander. The left and center panels show what the various models predicted. Reference models 1 and 2 are pre-landing models. The ML and MAP represent the maximum likelihood model and the maximum a posteriori model, and the gray line is the ensemble of all models. On the right is the author’s interpretation of the seismic data. See Surveys for more information. Image credit: Hobiger et al 2021.

InSight is exploring the deeper planetary structures of Mars, studying shallow underground to a depth of 10 to 20 meters. But it hasn’t been studied tens or hundreds of meters before the first. This data will help build a detailed model of the region near the surface that will help explain the formation of the Elysium Planitia.

Since InSight’s mission focuses on the underground of Mars, it landed on the relatively flat and featureless Elysium Planitia. Landing a spacecraft on Mars is not easy, making it a safe place to land. Still, the lander is near the border between the two regions. The heavy cratered highlands of the southern part of ancient times and the young, smooth northern plains that stand low.

There is a clear difference between the young northern plains of Mars and the much older southern highlands. This distinction is Martian dichotomy, And it is one of the permanent mysteries of the planet. The area between the two geographies is also very complex, and scientists want to help InSight gain a deeper understanding of what’s happening there. Three competing hypotheses that explain the dichotomy of Mars: the single impact hypothesis, the multiple impact hypothesis, and the plate tectonics hypothesis.

InSight Lander is located on the Elysium Planitia, on the border between the young Northern Lowlands and the old Southern Highlands. Image credit: MOLA Map: NASA / JPL / GSFC. Map by Emily Camel Straw.
InSight Lander is located on the Elysium Planitia, on the border between the young Northern Lowlands and the old Southern Highlands. Image credit: MOLA Map: NASA / JPL / GSFC. Map by Emily Camel Straw.

InSight should help scientists “… understand the role of strata and volcanic activity, and sedimentation in the transition …” by studying areas near the surface.

Researchers wanted to dating shallow lava flows, which is why they turned to crater counting. At the basic level, the more craters, the older the surface area. Areas with few craters must be young. Scientists use this basic fact to dating rocks. Also, as the crater gets deeper, scientists can dating deeper rocks, and vice versa.

The team was able to dating a pair of solidified lava flows across the sedimentary layer. They discovered that when Mars was in the Amazon era, the shallower lava layers were about 1.7 billion years old. The deeper layers are about 3.6 billion years ago from the Hesperian period on Mars, where the planet was subject to extensive volcanic activity. The authors believe that the sedimentary layers are between the basalt layers or are buried deeper and older.

Artist Impressions: The InSight lander is located at Homestead Hollow, a small collision crater. The seismograph SEIS used in this study is a brightly colored hemisphere on the ground in front of the lander. The ground beneath it consists of a layer of sand regolith above alternating layers of sediment (yellow-orange) and basalt, the original lava flow (brown). Image Credit: University of Cologne.

This study is the first time scientists have compared areas near the surface of Mars with models based primarily on remote data. InSight data show that there are additional layers and more porous rocks.

One of the authors of this paper is Dr. Knapmeyer-Endrun of the Institute of Geological Mineralogy, University of Cologne. In a press release, she said, “The results will help us better understand the geological process of the Elysium Planitia, but comparisons with pre-landing models will help refine our predictions for future landing missions. Is also useful. ” A better understanding of rover load-bearing and driving conditions will help in planning. It may also help you find underground water ice.

Mars seismology is different from Earth. Scientists can study structures here on Earth by sending seismic signals to the ground and reading how they bounce off sensors. But on Mars, SEIS equipment reads ambient vibrations. These ambient vibrations result from the interaction between the wind and the surface of the planet. But the thin atmosphere, low solar radiation, and lack of ocean make the surrounding vibrations much weaker than here on Earth.

The Insight lander has been on Mars since November 26, 2018. The mission length was set at 709 sol, but reached 1070 sol. Since the lander is solar powered, it could probably last much longer. InSight stands for Internal Exploration Using Seismic Exploration, Geodesy, and Heat Transport. This is a joint mission between NASA and the European Space Agency, especially the German DLR.

more:

Underwater InSight Pier on Mars

https://www.universetoday.com/153477/insight-peers-deep-below-the-surface-on-mars/ Underwater InSight Pier on Mars

Back to top button