The ESA Just Discovered a Second Magnetic Field Surrounding Our Planet
A trio of satellites studying our planet's magnetic field has shown details of the steady swell of a magnetic field produced by the ocean's tides.
Four years of data collected by the European Space Agency's (ESA) Swarm missions have contributed to the mapping of this 'other' magnetic field, one that could help us build better models around global warming.
Physicist Nils Olsen from the Technical University of Denmark presented the surprising results at this year's European Geosciences Union meeting in Vienna, explaining how his team of researchers managed to detail such a faint signature.
"It's a really tiny magnetic field," Olsen told BBC correspondent Jonathan Amos.
"It's about 2 – 2.5 nanotesla at satellite altitude, which is about 20,000 times weaker than Earth's global magnetic field."
On a fundamental level, both fields are the result of a dynamo effec…
INTER-PLANETARY SHOCKWAVE HITS EARTH An interplanetary shock wave hit Earth's magnetic field on April 19th around 23:50 UT. When the shock arrived, the density of the solar wind flowing around our planet abruptly quadrupled. Moreover, magnetic fields in the solar wind near Earth have since intensified 10-fold. These developments set the stage for possible geomagnetic storms in the hours ahead.
Auroras are now being reported in northern Michigan. S. Evans sends this picture from Big Bay, MI:
"The auroras are brightening after midnight on April 20th with some rays and beams, and good color," says Evans.
What is an interplanetary shock wave? It is a supersonic disturbance in the gaseous material of the solar wind. These waves are frequently delivered by coronal mass ejections (CMEs). Indeed, this one might have been a minor CME that left the sun unrecognized earlier this week. Or it might be an unusually sharp co-rotating interaction region (CIR). CIRs are transition zones b…