Geomagnetisme, Copyright: ESA/AOES medialab

The Earth's magnetic field

Scientists at DTU Space are engaged in measuring, modelling and scientifically analysing the Earth’s magnetic field.

Scientists are studying the magnetic field to learn more about the Earth’s core, where the field is generated, and to determine how constant variations in the magnetic field affect life on Earth. At the moment, the Earth’s magnetic field is decreasing by approximately 5 percent per century, and scientists are unable to explain the reason for this or describe the consequences this will have.

DTU Space was heavily involved Danish Ørsted satellite project that ended in 2013. The satellite sends measurements of the Earth’s magnetic field to scientists, who use these data to devise advanced models of the Earth’s magnetic field. Developed by scientists at DTU Space in close cooperation with NASA, the models are used all over the world to search for oil and minerals.

Today ESA's Swarm-mission have taken over after Ørsted and provides even more precise Eeath magnetic field data. DTU Space participates in the mission. 

Swarm consists of three satellites that work in unison to measure the magnetic field. The constellation of three satellites provides measurements of the magnetic field that are almost ten times as accurate as previous measurements taken by lone satellites.

DTU Space has developed the magnetometers aboard the Swarm mission which record the measurements of the magnetic field. The magnetometers are further refinements of those used aboard the Ørsted, SAC-C and CHAMP satellites, and the positive experience from previous missions has played an important role in developing the magnetometers for Swarm. 

Facts on Earth's magnetic field:

The Earth's magnetic field is created from electric currents in the fluid part of the Earth's core.

Researchers still do not know much about the core of the Earth, and studies of the magnetic field may contribute to changing this fact.

The Earth's magnetic field changes on a continuous basis, and this is of practical significance for both air travelers and satellites. This is because the magnetic field protects the Earth from charged particles from space.

When the magnetic field in an area suddenly becomes weak, charged particles may penetrate the field and harm both satellites and passengers in high-flying aeroplanes.