So far the only way to get any information about the interior of rocky planets was from the moment of inertia which is related to a planets mass distribution. This only allowed to estimate if a planet has a mantle and what the estimated thicknesses of the core and mantle are. Of course, other (remote sensing) methods like potential (gravity and magnetic) fields can also give more information about a planets interior. However, the only solid way to determine the layer interface and their depth and thicknesses is seismic imaging, a popular technique used to image Earth’s subsurface and interior.
Insight, short for Interior exploration using Seismic Investigations, Geodesy and Heat Transport, is a mission to explore the interior of the planet Mars using this (seismic) method. This is super exciting for geophysicists and planetary scientists as this is the first time that a mission explores the interior of a rocky planet. In particular, it is the first mission, other than one to the Moon, planned to take a seismometer (a device that measures seismic activity like earthquakes) along with a thermal gradient measuring device which will drill (for 2 months) to reach a depth of 4.5 meters (the deepest depth ever).
The seismometer device is named SEIS, short for Seismic Experiment for Interior Structure, which was developed and contributed by CNES, Centre National d’Etudes Spatiales in France.
The mission is planned to launch in May and to arrive to Mars in November26, 2018.
Below are a video explaining the mission and its goals followed by a Facebook live video feed streamed by NASA on January 23, 2018.
Finally, I end this post with this mesmerizing recap of 50 years worth of (the successful) Martian missions and exploration. How can one say anything other than science is beautiful (remember Richard P. Feynman)?
On a related note another geophysics-related mission is planned for 2020. The mission will involve a rover which is planned to use a Ground Pentrating Radar (GPR; think your beach metal detector, only more powerful). The GPR’s nickname is (RIMFAX), short for Radar Imager for Mars’ subsurFAce eXperiment. It is expected to help image Mars’ subsurface (a few meters to a few kilometers) in order to discern the crust layer. It comes close to the seismic imaging technique.