In November, the European Space Agency (ESA) launched three satellites, called the Swarm, to create a 3-D map of Earth’s magnetic field. Four months later, the Swarm has already gathered enough data to allow comparisons with a decade of information collected by a German satellite, reports the BBC.
Geophysics now use the new Swarm maps to cross-check the data collected from the earlier German satellite, called CHAMP. The scientists found that the maps largely agreed with each other.
The Swarm satellite mission marks the first attempt to use multiple satellites, flying at different heights, to create a 3-D map of the magnetic field, which protects the planet from the sun and aids in navigation.
Magnetic field maps could lead to improvements in GPS and smartphone navigation, and guide efforts to drill for natural resources, according to the ESA. Earthquake prediction also could benefit from the Swarm’s maps.
There are still mysteries about the field that have yet to be solved. Scientists know the field results mostly from iron in the Earth’s core, along with the movement of the oceans and other forces. However, the details of why the field’s strength varies between regions remains elusive. The field is currently weakening for unknown reasons, and the Swarm may help explain why.
Beyond regional variations, the field can completely flip its orientation every few hundred thousand years. When that happens, magnetic north shifts to the other side of the planet. After that flip, a compass would point south, as opposed to north.
The magnetic field shields the planet from a constant bombardment of charged particles streaming from the Sun at approximately 1 million miles per hour. This flow of particles, known as the solar wind, have the power to shred Earth’s atmosphere.
Thanks to the field’s protection, the solar wind creates the spectacular light shows of the aurora borealis, the Northern Lights, and the aurora australis, the Southern Lights. Instead of blowing the atmosphere away, the magnetically pacified particles glow when they strike oxygen and nitrogen particles floating 20 to 200 miles (32 to 320 kilometers) above the surface.
Photo: An artists conception shows the Swarm satellite group. Credit: ESA/AOES Mediala