Before We Go to Mars, Lander Will Check for ‘Marsquakes’

(Bloomberg) -- Forty-two years ago, the U.S. landed its first Mars probe on the red planet. Ever since Viking I touched down, NASA has sent a series of increasingly sophisticated rovers and orbiters to study our neighbor's features and atmosphere.

But that's all been skin deep. None of those craft has ever gotten very far beneath the surface.

On Saturday, NASA launched a machine designed to study Mars at a much more fundamental level, helping to fill large gaps in scientists' understanding of the planet's geologic structure, composition and seismic activity.

Mars InSight, scheduled to land later this year, is the first NASA mission to study the red planet's interior—or, as the agency's Jet Propulsion Laboratory (JPL) phrases it, “the vital signs of Mars.” (InSight stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport.)

The launch of InSight, aboard an Atlas V rocket, took place Saturday morning at Vandenberg Air Force Base in central California, and is NASA's first deep-space mission sent from the West Coast.

The 794-pound lander, built by Lockheed Martin Corp., is set to touch down on Nov. 26 after a six-month cruise and a six-minute re-entry and descent—the most perilous aspect of the journey.

For scientists, one principal question looms over the work InSight will perform: How did Earth and Mars become so radically different, given that each was formed of the same intergalactic “stuff” about 4.5 billion years ago?

Mars presents an interesting geologic specimen to study rocky planet formation because of its “Goldilocks” size: It's large enough that it experienced the same early processes as Earth and Venus during its formation, but it's small enough to have retained a record of those processes deep within.Unlike Mars, Earth has active tectonic plates and convection that carries heat from the core outward, moving around the mantle layer. One InSight instrument will dig 5 meters (16 feet) into the subsurface to measure heat from the interior.

“It's really a science of understanding the early solar system … how planets formed,” Bruce Banerdt, InSight's principal investigator from JPL, said on Thursday during a news briefing.

But even without plates, Mars on occasion rumbles—with Marsquakes, a geologic phenomenon that InSight investigators want to study.

While NASA's twin Viking landers from the summer of 1976 had seismometers to detect Marsquakes, those were atop the craft and produced “noisy data,” according to JPL. The InSight instrument will be on the ground and is expected to yield much more insight into the quakes, which are thought to be smaller than 6.0 on the Richter scale, given that Mars doesn't have the same plate structure as Earth. Seismic activity on Mars is thought to come from cracks forming in the crust, with the planet's interior energy expected to be less intense than Earth's.

The Atlas V also lifted two small CubeSats that will trail InSight to Mars to test deep-space communications technology. The launch marks the first time such small satellites, about the size of a briefcase, have flown in deep space.

Amid the heady science and bevy of “firsts” for this mission, it's worth noting that Mars missions have a spotty success rate of about only 40 percent, given the distance and the many perils associated with entry, descent and landing.

To contact the author of this story: Justin Bachman in Dallas at jbachman2@bloomberg.net.

To contact the editor responsible for this story: David Rovella at drovella@bloomberg.net.

©2018 Bloomberg L.P.