A batch of new papers summarizes the lander's findings above and below the surface of the Red Planet.

A new understanding of Mars is beginning to emerge, thanksto the first year of NASA's InSight lander mission. Findings described in a setof six papers published today reveal a planet alive with quakes, dust devilsand strange magnetic pulses.

Five ofthe papers were published in Nature. An additional paper in Nature Geoscience details the InSight spacecraft's landing site, a shallow crater nicknamed"Homestead hollow" in a region called Elysium Planitia.

InSight is the first mission dedicated to looking deepbeneath the Martian surface. Among its science tools are a seismometer fordetecting quakes, sensors for gauging wind and air pressure, a magnetometer,and a heat flow probe designed to take the planet's temperature.

A cutaway view of Mars showing the InSight lander studying seismic activity. Credit: J.T. Keane/Nature Geoscience Larger view

While the team continues to work on getting the probeinto the Martian surface as intended, the ultra-sensitive seismometer, calledthe Seismic Experiment for Interior Structure (SEIS), hasenabled scientists to "hear" multiple trembling events from hundreds tothousands of miles away.

Seismic waves are affected by the materials they movethrough, giving scientists a way to study the composition of the planet's innerstructure. Mars can help the team better understand how all rocky planets,including Earth, first formed.

Underground

Mars trembles more often - butalso more mildly - than expected. SEIS has found more than 450 seismicsignals to date, the vast majority of which are probably quakes (as opposed todata noise created by environmental factors, like wind). The largest quake was aboutmagnitude 4.0 in size - not quite large enough to travel down below the crust intothe planet's lower mantle and core. Those are "the juiciest parts of theapple" when it comes to studying the planet's inner structure, said BruceBanerdt, InSight principal investigator at JPL.

Scientists are ready for more: It took months afterInSight's landing in November 2018 before they recorded the first seismicevent. By the end of 2019, SEIS was detecting about two seismic signals a day,suggesting that InSight just happened to touch down at a particularly quiettime. Scientists still have their fingers crossed for "the Big One."

Mars doesn't have tectonic plates like Earth, but it doeshave volcanically active regions that can cause rumbles. A pair of quakes wasstrongly linked to one such region, Cerberus Fossae, where scientists see bouldersthat may have been shaken down cliffsides. Ancient floods there carved channels nearly 800miles (1,300 kilometers) long. Lava flows then seeped into those channels withinthe past 10 million years - the blink of an eye ingeologic time.

Some of these young lava flows show signs of having been fracturedby quakes less than 2 million years ago. "It's just about the youngesttectonic feature on the planet," said planetary geologist Matt Golombek ofJPL. "The fact that we're seeing evidence of shaking in this region isn'ta surprise, but it's very cool."

At the Surface

Billions of years ago, Mars had a magnetic field. It is nolonger present, but it left ghosts behind, magnetizing ancient rocks that arenow between 200 feet (61 meters) to several miles below ground. InSight isequipped with a magnetometer - the first on the surface of Mars to detect magneticsignals.

The magnetometer has found that the signals at Homestead holloware 10 times stronger than what was predicted based on data from orbitingspacecraft that study the area. The measurements of these orbiters are averagedover a couple of hundred miles, whereas InSight's measurements are more local.

Because most surface rocks atInSight's location are too young to have been magnetized by the planet's formerfield, "this magnetism must be coming from ancient rocksunderground," said Catherine Johnson, a planetary scientist at theUniversity of British Columbia and the Planetary Science Institute. "We'recombining these data with what we know from seismology and geology tounderstand the magnetized layers below InSight. How strong or deep would theyhave to be for us to detect this field?"

In addition, scientists are intriguedby how these signals change over time. The measurements vary by day and night;they also tend to pulse around midnight. Theories are still being formed as towhat causes such changes, but one possibility is that they're related to thesolar wind interacting with the Martian atmosphere.

In the Wind

InSight measureswind speed, direction and air pressure nearly continuously, offering more datathan previous landed missions. The spacecraft's weathersensors have detected thousandsof passing whirlwinds, which are called dust devils when they pick up grit andbecome visible. "This site has more whirlwindsthan any other place we've landed on Mars while carrying weather sensors,"said Aymeric Spiga, an atmospheric scientist at Sorbonne University inParis.

Despite all that activity andfrequent imaging, InSight's cameras have yet to see dust devils. But SEIScan feel these whirlwinds pulling on the surface like a giant vacuum cleaner. "Whirlwindsare perfect for subsurface seismic exploration," said Philippe Lognonn ofInstitut de Physique du Globe de Paris (IPGP), principal investigator of SEIS.

Still to Come: TheCore

InSight has two radios: one for regularly sending andreceiving data, and a more powerful radio designed to measure the"wobble" of Mars as it spins. This X-band radio, also known as theRotation and Interior Structure Experiment (RISE), can eventually revealwhether the planet's core is solid or liquid. A solidcore would cause Mars to wobble less than a liquid one would.

This first year of data is just a start. Watching over afull Martian year (two Earth years) will give scientists a much better idea ofthe size and speed of the planet's wobble.

About InSight

A division of Caltech inPasadena, JPL manages InSight for NASA's Science Mission Directorate. InSightis part of NASA's Discovery Program, managed by the agency's Marshall SpaceFlight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built theInSight spacecraft, including its cruise stage and lander, and supportsspacecraft operations for the mission.

A number of European partners, including France's CentreNational d'tudes Spatiales (CNES), the German Aerospace Center (DLR) and theUnited Kingdom Space Agency (UKSA), are supporting the InSight mission. CNESprovided the Seismic Experiment for Interior Structure (SEIS) instrument toNASA, with the principal investigator at IPGP (Institut de Physique du Globe deParis). Significant contributions for SEIS came from IPGP; the Max PlanckInstitute for Solar System Research (MPS) in Germany; the Swiss FederalInstitute of Technology (ETH Zurich) in Switzerland; Imperial College Londonand Oxford University in the United Kingdom; and JPL. DLR provided the HeatFlow and Physical Properties Package (HP3)instrument, with significant contributions from the Space Research Center (CBK)of the Polish Academy of Sciences and Astronika in Poland. Spain's Centro deAstrobiologa (CAB) supplied the temperature and wind sensors.

News Media Contact

Andrew GoodJet Propulsion Laboratory, Pasadena, Calif.818-393-2433andrew.c.good@jpl.nasa.gov

Alana JohnsonNASA Headquarters, Washington202-358-1501alana.r.johnson@nasa.gov

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A Year of Surprising Science From NASA's InSight Mars Mission - Jet Propulsion Laboratory