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There's a jet stream in our core
19 December 2016
We would normally associate jet streams with the weather but, thanks to ESA's magnetic field mission, scientists have discovered a jet stream deep below Earth's surface - and it's speeding up.
Launched in 2013, the trio of Swarm satellites are measuring and untangling the different magnetic fields that stem from Earth's core, mantle, crust, oceans, ionosphere and magnetosphere.
Together, these signals form the magnetic field that protects us from cosmic radiation and charged particles that stream towards Earth in solar winds.
Measuring the magnetic field is one of the few ways we can look deep inside our planet. As Chris Finlay from the Technical University of Denmark noted, "We know more about the Sun than Earth's core because the Sun is not hidden from us by 3000 km of rock."