"In some InSight is like a scientific time machine that will provide information about the earliest stages of Mars formation four and a half billion years ago," said InSight chief writer Bruce Banerdt of NASA's Jet Propulsion Laboratory. "It will help us to learn how rock bodies form, including the Earth, their moon, and even planets in other solar systems."
InSight, which will start in May, will use seismology (the study of quakes) to determine the make-up and structure of the core, cladding, and crust of the red planet. Currently, we know that the Martian crust is made up of lighter rocks and minerals, while heavier materials sink to their core and mantle. To learn more about its internal composition, the lander will use special instruments to observe seismic waves during "Marsquakes".
Seismic waves are generated when internal rocks break or shift. They travel through the planet until the waves hit the surface, their speed depending on the type of material they navigate through. InSight will use its highly sensitive seismometer, developed by the Center National d'Études Spatiales in France, to measure the speed, frequency and magnitude of these waves, providing insights into the geological material they cross. The research team believes that InSight will observe at least a few dozen quakes, but may see hundreds during its mission.
InSight's capabilities, however, go far beyond seismology. His Rotation and Interior Structure Experiment (RISE) uses a signal sent from Earth to track the lander's position on the Martian surface. Variations in the signal, known as the Doppler shift, show how much Mars wobbles as it circles the sun. Its orbital motion helps researchers determine if it has a liquid or solid core. The lander will also carry a heat probe developed by the German Aerospace Center, which can excavate up to 5 meters below the surface to measure the internal heat. Temperature, wind and pressure sensors are also on board to prevent vibrations due to weather conditions.
Despite InSight's forthcoming tools and experiments, researchers face a challenge ̵
Fortunately, this is not the first time that NASA has conducted seismic testing. The Apollo missions used seismometers to measure man-made vibrations on the moon, as well as observing naturally occurring meteor impacts and moonquakes. The Viking Landers also tried seismology on Mars in the 1970s, but with the seismometers on top of the lander, they blew in the wind and twisted the data.
"It was a disabled experiment," said Banerdt. "I joke that we did not do seismology on Mars – we did it three feet above Mars."
After the unsuccessful attempt of NASA and the high goals of InSight, the mission has started promisingly. The final test is currently underway at Vandenberg Air Force Base, California, where its center of gravity, which needs to be accurately positioned to ensure safe landing on Mars, was successfully tested on March 28. If everything goes according to plan, InSight will leave Mars with important information about the planet's internal composition, formation, and evolution. The data will not only help us better understand the red planet, but also planetary systems as a whole.