Elysium Planitia is an ideal landing site for InSight due to its smooth surface.

The Mars InSight Mission was launched on 5^th May 2018 with the intentions of studying the interior of the red planet of our solar system. It is expected to land on the surface of Mars on the 26^th of this month. It is one of the most anticipated events in the astronomical world these days as this mission aims to discover the processes that led to the formation of rocky planets of the inner solar system. The landing site chosen for InSight is called Elysium Planitia and is a complete contrast of what we observe at Mars, most of the times. It is incredibly plain and this is an ideal result for the mission which intends to study the planet below its surface. Bruce Banerdt, the Principal Investigator of InSight Mission at the Jet Propulsion Laboratory of NASA referred to that and said,

“If Elysium Planitia were a salad, it would consist of romaine lettuce and kale – no dressing. If it were an ice cream, it would be vanilla. Previous missions to the Red Planet have investigated its surface by studying its canyons, volcanoes, rocks, and soil. Previous missions to the Red Planet have investigated its surface by studying its canyons, volcanoes, rocks, and soil. But the signatures of the planet’s formation processes can be found only by sensing and studying evidence buried far below the surface. It is InSight’s job to study the deep interior of Mars, taking the planet’s vital signs – its pulse, temperature and reflexes.”

The entire working mechanism of InSight is dependent on three instruments. Firstly, the Seismic Experiment for Interior Structure (SEIS) is assigned the task of recording seismic waves traveling through the interior of the planet. Other than that, we have Rotation and Interior Structure Experiment (RISE), which will make use of radios to measure the wobble of the rotation axis of Mars. Lastly, the Heat Flow and Physical Properties Package (Hp³) to assess the amount of heat that is flowing out of the planet. This will enable researchers to decide whether Earth and Mars are made up of the same material or not. This instrument will go deeper into the Martian surface than any other probe. Tom Hoffman, the Project Manager of InSight said,

“Picking a good landing site on Mars is a lot like picking a good home: It’s all about location, location, location and for the first time ever, the evaluation for a Mars landing site had to consider what lay below the surface of Mars. We needed not just a safe place to land, but also a workspace that’s penetrable by our 16-foot-long (5-meter) heat-flow probe.”

In order to meet the temperature and light constraints of the probe, the mission team relied on a band around the equator to find a suitable spot. Initially, a total of 22 sites were selected. However, only 3 (Elysium Planitia, Valles Marineris, and Isidis Planitia) of them were short-listed. The final decision was made after considering the weather records. Reconnaissance images taken by Mars orbiters of NASA provided that vital information. Eventually, Elysium Planitia was selected as both the other candidates were too rocky and windy for an ideal landing of a three-legged Mars lander. Hoffmann explained that by saying,

“The site has to be a low-enough elevation to have sufficient atmosphere above it for a safe landing because the spacecraft will rely first on atmospheric friction with its heat shield and then on a parachute digging into Mars’ tenuous atmosphere for a large portion of its deceleration. And after the chute has fallen away and the braking rockets have kicked in for final descent, there needs to be a flat expanse to land on – not too undulating and relatively free of rocks that could tip the tri-legged Mars lander.”

If all goes well, the Mars InSight Mission will land at a flat landing site in 2 weeks’ time. Having said that, you can enjoy a visit to the red planet with the Mars InSight Mission: