Mars InSight will help study the red planet at a much more foundational level, helping to fill large gaps in scientists’ understanding of the planet’s geologic structure, composition and seismic activity.
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 neighbour’s features and atmosphere.
But that’s all been skin-deep. None of those craft have ever gotten too deep into the place.
This weekend, NASA is launching a machine designed to study Mars at a much more foundational 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 phrases it, “the vital signs of Mars.” (InSight stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport.)
The launch is set for 4:05 a.m. PDT Saturday from Vandenberg Air Force Base in central California aboard an Atlas V rocket, with a two-hour daily launch window. It will become the first NASA deep-space mission sent from the West Coast.
The 794-pound lander, built by Lockheed Martin Corp., is set to touch down 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 sizable 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 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 Thursday during a news briefing.
But even without plates, Mars on occasion rumbles—with marsquakes—another geologic phenomenon that InSight investigators want to study.
NASA’s twin Viking landers from the summer of 1976 had seismometers to detect marsquakes but 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 such phenomenon, 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 be from cracks forming in the crust, with the planet’s interior energy expected to be lower than Earth’s.
The Atlas V will also launch two small CubeSats that will trail InSight to Mars to test deep-space communications technology. The launch is the first time such small sats, 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 only about 40 per cent, given the distance and many perils associated with entry, descent and landing.