Scientists are trying to choose a landing spot for their next mission to Mars, but they are prioritizing what is below the surface rather than interesting geological features.
The stationary Interior Exploration Using Seismic Investigations, Geodesy and Heat Transport (InSight) will land on the red planet in the late summer of 2016. NASA has narrowed their landing site options down to four out of a pool of 22, a NASA jet propulsion laboratory press release reported.
"We picked four sites that look safest," geologist Matt Golombek of NASA's Jet Propulsion Laboratory, said. "They have mostly smooth terrain, few rocks and very little slope."
All four of the sites are located on "an equatorial plain in an area of Mars called Elysium Planitia," the press release reported. The scientists were looking for a landing spot along Mars' equator.
Over the next few months, scientists will analyze data from the Mars Reconnaissance Orbiter cameras and choose a winner.
For the first time the mission will not focus on Mars' surface, but aims to look inside the rocky planet.
"This mission's science goals are not related to any specific location on Mars because we're studying the planet as a whole, down to its core," Bruce Banerdt, InSight principal investigator at JPL, said. "Mission safety and survival are what drive our criteria for a landing site."
The mission will try to get to the bottom of how Mars was formed, and get a better idea of the properties of our solar system's rockier planets.
"Previous missions to Mars have investigated the surface history of the Red Planet by examining features like canyons, volcanoes, rocks and soil, but no one has attempted to investigate the planet's earliest evolution - its building blocks - which can only be found by looking far below the surface," InSight stated.
Each potential landing site measures 81 miles from east to west and 17 miles north to south. The remaining spots on the equator were too "rocky and windy" and didn't have enough flat surface for a safe landing, the press release reported.
Another priority for the landing spot is penetrable ground. Scientists are searching for "probe-blocking rocks" beneath the surface of their desired areas.
"For this mission, we needed to look below the surface to evaluate candidate landing sites," Golombek said.
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