At DTU Space scientists have developed a magnetometer, known as the MSMO (Mars Surface Magnetetic Observatory) which is to be part of the first European Mars lander mission, ExoMars. The MSMO will be the first magnetometer on the surface of Mars.


The MSMO is part of the Humboldt Payload for ESAs next Mars lander mission ExoMars.

The overall purpose of ExoMars is to search for traces of life on our cold sister planet Mars. It will be the first mission in an exploration programme named Aurora which is first to formulate and then to implement a European long-term plan for the robotic and human exploration of solar system bodies holding promise for traces of life. ExoMars is planned to be launched in 2013 and to arrive at Mars in September 2014.

ExoMars is a unique mission as it will have both a lander module and a rover. ExoMars will land with the aid of airbags after which the solar panels on the lander module will unfold and the rover will drive off to explore the site. The lander module will remain stationary throughout the mission operations (presently expected to be 180 days).

The ExoMars lander instruments are referred to as the Humboldt payload and consists mainly of geophysical and environmental instruments, hereunder the MSMO. For more information on ExoMars and the Aurora programme, see



Science objectives


It is assumed that Mars must have had a substantial atmosphere earlier in its lifetime, however, today the atmosphere is roughly one hundredth of the atmosphere we have here on Earth. How, when and why this atmosphere disappeared is of yet unknown, however, seeing as Mars is also assumed to have had an internal magnetic dynamo and a global magnetic field which has since disappeared, it is tempting to assume that the two may be connected.

With a magnetometer on the surface of Mars, we hope to gain knowledge about the interaction between the solar wind and the Martian atmosphere, and perhaps also gain insight into why the atmosphere has been, and still is, disappearing from Mars.

We also hope to be able to determine whether there are any water reservoirs below the Martian surface. This will be achieved by making a conductivity profile through means of electromagnetic sounding. Normally in electromagnetic sounding a signal is sent down through a surface and the reflection is measured. On Mars we hope to use the currents induced in the thin atmosphere by the solar wind as our signal and measure the reflection of this. If successful, this will not only tell us whether a water reservoir is present, but also how thick it is and at what depth it is located.

Investigating the crustal fields themselves may be difficult to achieve as the landing site for ExoMars is unlikely to be close to any large crustal fields, even though it has not yet been determined. However, we do hope to investigate some of the effects the mini-magnetospheres have on the solar wind interaction, and perhaps plasma-sheet crossings observed from the surface of the planet during the local night time.





The magnetometer is a development of the magnetometer used on the Danish satellite Ørsted, the main difference being in its size and weight. For the ExoMars mission weight and volume are of the highest priority and the magnetometer has therefore been improved to be the approximate size and weight of a small matchbox.

The magnetometer consists of three fluxgate sensors placed perpendicularly to one another, each measuring the field in one direction, thereby creating a three dimensional measurement.

In order to determine which direction is which i.e. up/down, an accelerometer is included in the mission in order to measure the direction of the gravitational pull in relation to the magnetometer sensor.

The MSMO is, presently, the smallest and most precise magnetometer in the world.





The team behind the MSMO is lead by Senior Scientist Susanne Vennerstrøm at DTU Space, and the magnetometer itself is developed by a group lead by José Merayo, also at DTU Space.

Besides the Danish scientists the team also includes French, English and German collaborators.