BepiColombo (MERTIS)

MErcury Radiometer and Thermal Infrared Imaging Spectrometer

In October 2018, the thermal infrared imaging spectrometer MERTIS was launched on board the European-Japanese mission BepiColombo to Mercury – the least explored planet in the inner Solar System thus far. BepiColombo will arrive at its destination in 2025. The mission comprises a propulsion system and two orbiters: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). BepiColombo is a joint mission between the European Space Agency (ESA) and the Japanese space agency (JAXA).

Once in Mercury’s orbit, MERTIS will closely examine the surface and, indirectly, the innermost planet’s interior. Using a mid-infrared spectrometer, MERTIS will record the planet globally with a spatial resolution of 500 metres and identify rock-forming minerals on the surface. MERTIS uses the first space-qualified microbolometer produced in Europe. The resolution of the instrument can be flexibly adapted to the observation conditions. It can thus also be used to study the polar regions. These have not been investigated in detail so far and show a reflection of radar signals in deep craters into which sunlight never penetrates. Scientists suspect that water ice could be present due to the extremely low temperatures prevailing there. Knowledge of the mineralogical composition is crucial for researchers to understand the evolution of the Sun’s innermost planet. The MERTIS radiometer is designed to measure the surface temperature variations of the planet over the entire temperature range of 80 to 700 kelvin (about -190 to 430 degrees Celsius) and its thermal inertia. With the innovative instrument concept developed by DLR, it has been possible to reduce the weight of the instrument to three kilograms and the power consumption to 19 watts.

The MERTIS team is headed by the University of Münster and the DLR Institute of Planetary Research. The project is managed by the DLR Institute of Optical Sensor Systems.

German Aerospace Center (DLR)
Ulrich Köhler · E-Mail: ulrich.koehler@dlr.de · DLR.de/en