NASA's InSight Lander Confirms That Mars Is Seismically Active

On November 26, 2018, NASA's InSight Lander touched down on the surface of Mars. Now, scientists have released a set of papers based on data collected during the first 10 months of its mission—confirming that the Red Planet is seismically active, while providing a host of fascinating insights into its magnetic field, geology and atmosphere.

Using several instruments, the lander has been taking measurements from its location in a filled-up crater in Mars's Elysium Planitia region.

"We've been planning this mission and executing for the last 10 years so it's been a long road to get to these results—and the initial results are really exciting," Bruce Banerdt, principal investigator for the InSight mission, told reporters during a telephone conference.

The research finally establishes that Mars is seismically active today—a long-debated question among planetary scientists—and confirms the existence of "marsquakes," according to the InSight team. InSight has currently detected around 400 seismic events—24 of which measure between magnitude three and four. Most of these events originated at a depth of between 18 and 30 miles—much deeper than the average depth of earthquakes on our planet.

"The seismic activity is greater than that of the moon—which was measured back during the Apollo program—but less than the Earth," Banerdt said. "In fact, it's probably close to the kinds of seismic activity, you would expect to find away from the plate boundaries on the Earth and away from highly deformed areas."

According to Banerdt, the seismology results are "very promising" because scientists will now be able to look at how marsquake signals move through the planet's deep interior, providing a window into this hidden region.

While the exact cause of any individual marsquake remains a mystery, Banerdt suggests that, in general, long term cooling of the planet could play an important role.

"As a planet cools, it contracts, and then the brittle outer layers then have to fracture in order to maintain themselves on the surface. And that's kind of the long term source of stresses," he said.

The few events for which the researchers have been able to locate the origin—including two of the larger marsquakes—took place in a region known as Cerberus Fossae, a particularly "exciting" result, in the eyes of Suzanne Smrekar, deputy project scientist for the InSight mission. This region is the most recent geologically and volcanically active area in Mars, showing evidence of volcanism within the last 10 million years.

"This area has 1,500 kilometer-long faults, and evidence of large flows of both volcanic lava and water from melted ice," Smrekar told Newsweek.

"It's really intriguing in that if you just take a simple model of the thermal evolution of Mars, we wouldn't really expect such recent volcanism in that area. As we learn more about the specific type of geologic activity we're seeing in that region, it's going to tell us a lot more about potential variability around Mars," Smrekar told reporters.

NASA Mars InSight Lander
Artist's illustration shows NASA's InSight lander with its instruments deployed on the Martian surface. NASA/JPL-Caltech

In addition to the instruments which collect seismic data, InSight also features other pieces of equipment, including a magnetometer—a device that takes measurements of magnetic fields.

We know that today, Mars doesn't have a global magnetic field like that of the Earth's, however, the planet does display some limited magnetic activity. But while scientists know quite a bit about the Martian magnetic environment, most of this knowledge comes from satellite observations.

The magnetometer on InSight is the first on the surface of Mars, and it has revealed, unexpectedly, that there is a steady magnetic field in the area around the landing site which is around 10 times stronger than predicted by satellite observations. According to Catherine Johnson, a co-investigator on the mission from the University of British Columbia, Canada, this indicates that there are "magnetized blocks" beneath the landing site.