First direct evidence of Marsquakes discovered by InSight mission

According to first reports, Mars has been found to have a moderate level of seismic activity and ground vibrations, intermediate between Earth and Moon. findings are based on preliminary results from InSight mission, which landed a probe on Mars on vember 26, 2018. This mission is scheduled to continue collecting data through 2020.

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first direct seismic measurements of Martian subsurface and upper crust- rocky outermost layer of planet were provided by an international team which includes University of Maryland geologists that released data from mission's Seismic Experiment for Interior Structure (SEIS). results were published in a special issue of journal Nature Geoscience on Monday, February 24. 

Nicholas Schmerr, an assistant professor of geology at UMD and a co-author of study said, "This is first mission focused on taking direct geophysical measurements of any planet besides Earth, and it's given us our first real understanding of Mars' interior structure and geological processes". "se data are helping us understand how planet works, its rate of seismicity, how active it is and where it's active", he added.

Seismic data acquired from 235 Martian days

seismic data was acquired from over 235 Martian days showed 174 seismic events or marsquakes. Of those, 150 were high-frequency events that produce ground-shaking similar to that recorded on Moon by Apollo program. ir waveforms show that seismic waves bounce around as y travel through heterogeneous and fractured Martian crust. or 24 quakes observed by SEIS were predominantly low-frequency events. Three showed two distinct wave patterns similar to quakes on Earth caused by movement of tectonic plates.

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"se low-frequency events were really exciting because we kw how to analyze m and extract information about subsurface structure," said Vedran Lekic, an associate professor of geology at UMD and a co-author of study. "Based on how different waves propagate through crust, we can identify geologic layers within planet and determine distance and location to source of quakes."

Researchers identified source location and magnitude of three of low-frequency marsquakes, and believe that 10 more are strong eugh to reveal ir source and magnitude once y are analysed.

"Understanding se processes is part of a bigger question about planet itself," Schmerr said. "Can it support life, or did it ever? Life exists at edge, where equilibrium is off. Think of areas on Earth such as rmal vents at deep ocean ridges where chemistry provides energy for life rar than Sun. If it turns out re is liquid magma on Mars, and if we can pinpoint where planet is most geologically active, it might guide future missions searching for potential for life."

initial two Mars probes; Viking 1 and Viking 2 were designed for detecting signs of life. Each carried seismometers, but y were mounted directly on landers and provided useful data. Viking 1 instrument did t unlock properly, and Viking 2 only picked up ise from wind buffeting lander but convincing marsquake signals.

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About  InSight mission

However InSight mission is dedicated specifically to geophysical exploration, so engineers worked to solve previous ise problems. A robotic arm on lander placed SEIS seismometer directly on Martian ground some distance away to isolate it from lander. instrument is also housed in a vacuum chamber and covered by aptly named Wind and rmal Shield. SEIS seismometer is sensitive eugh to discern very faint ground vibrations, which on Mars are 500 times quieter than ground vibrations found in quietest locations on Earth. In addition, seismometer provided important information about Martian wear.

Low-pressure systems and swirling columns of wind and dust called dust devils lift ground eugh for seismometer to register a tilt in substrate. High winds flowing across surface of ground also create a distinct seismic signature. Combined with data from meteorological instruments, SEIS data help paint a picture of daily cycles of surface activity near InSight lander.

Researchers findings of  wind flow on Mars

researchers found that winds pick up from about midnight through early morning, as cooler air rolls down from highlands in Sourn Hemisphere onto Elysium Planitia plains in rrn Hemisphere where lander is located. During day, heating from sun causes convective winds to build.

Winds reach ir peak in late afteron when atmospheric pressure drops and dust devil activity occurs. By evening, winds die down, and conditions around lander become quiet. From late evening until about midnight, atmospheric conditions are so quiet, seismometer is able to detect rumblings from deeper inside planet. All of marsquakes have been detected during se quiet periods at night, but geologic activity likely persists throughout day.

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"What is so spectacular about this data is that it gives us this beautifully poetic picture of what a day is actually like on ar planet," Lekic said.

(With inputs from ANI)