Satellite Swarm Spots North Pole Drift 80
An anonymous reader writes "A report from the European Space Agency shows the first collection of high-resolution results from the agency's three-satellite Swarm. The report illustrates the latest changes in the Earth's magnetic field and shows the movement of the magnetic North Pole. "Launched in November 2013, ESA's Swarm mission consists of three 9-meter satellites orbiting the planet at altitudes of 300-530 km (186-330 miles). Their goal is to monitor Earth's dynamic magnetic field, observing its changes over a period of four years. The data gathered by the Swarm satellites will help scientists better understand how our magnetic field works, how it's influenced by solar activity, and why large parts of it are found to be weakening.""
Important work - gives handle on earth's dynamo (Score:5, Insightful)
This is important work, which compliments terrestial geomagnetic measurements and space based observations.
The earth's magnetic field results from a planetary dynamo. Magnetic field lines get frozen into the electrically conductive fluid core. Then, differential motions in the fluid causes the magnetic field to get twisted up -- it's no longer is the simple dipole (like those bar magnets that you played with as a kid). Instead, the earth's magnetic field develops high order moments (sorta like bumps and dips). These shapes evolve as the conductive core moves. Eventually, the magnetic field gets so tangled up, that it unravels. At that time, the earth's field reverses. These magnetic field reversals show up in the geologic record ... every 10,000 to 100,000 years, there's a flipover.
Measurements like the ESA Swarm satellite give us a handle on the evoloution of the Earth's magnetic field, as well as showing how that field interacts with the magnetic and particle environment of the solar wind.
(disclaimer - most of what I just posted is from a terrific graduate class that I took at the Lunar & Planetary Labs way back in 1979, and when I worked with Charles Sonett, who studied the solar wind. Likely, much of this is way out of date!)
Re:Important work - gives handle on earth's dynamo (Score:4, Insightful)
That's not a dumb question.
Some of the biggest breakthroughs have come about from people asking "Why can't we do _X_?"