Scientists have many ways of studying the planet's surface and atmosphere from both ground and space, but looking into its interior is "much more difficult," says Roger Haagmans, a geophysicist at the European Space Agency's Earth Sciences Division.
"Looking inside the Earth, it's like you're blindfolded, just feeling with your hands," he
...Swarm's magnetic measurements will provide a new way of looking at Earth's interior at multiple depths, says Haagmans, principle scientist of ESA's Solid Earth Science and Applications Department.
To better sort out the different contributions to the overall magnetic signal , from the crust, mantle and core , the project will consist of three satellites: two flying side by side 150 kilometers (93 miles) apart, at about 450 kilometers (280 miles) above Earth's surface, and a third that will fly higher, more than 500 kilometers (310 miles) above the surface.Together, the three satellites will give simultaneous snapshots of the magnetic field over different regions of Earth, Haagmans
"If you look at gravity and seismic data, they give a kind of accumulated view of how density is distributed inside Earth," Haagmans
says.Now, with Swarm's three satellites, scientists can get a kind of three-dimensional picture of the mantle's conductivity and structure, adding another constraint to estimates of mantle temperatures provided by seismic and other data, he
Then there's the core, the ultimate source of the magnetic field.Scientists still do not fully understand how the fluid outer and solid inner core move and behave with respect to each other, and the possibility that the field may be waning is of great interest, Haagmans
says.By separating out all the other contributions to Earth's magnetic field, he
team hope that they will be able to learn much more about the current state of the dynamo.