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12 December 2013 1:00 pm ,
Vol. 342 ,
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
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ScienceShot: Powering Up the Magnetosphere
26 September 2013 2:00 pm
Taking advantage of a rare chance alignment of eight Earth-orbiting spacecraft, space physicists have pinned down where and how the energy of the solar wind can surge Earthward to power the celestial light of the auroras and help fire up the Van Allen radiation belts. Researchers knew that the magnetosphere—Earth’s magnetic bubble of plasma—gets its energy from solar wind, which blows the plasma into its teardrop shape and stores energy by stretching and compressing the magnetosphere’s magnetic field lines (blue). These stressed magnetic field lines can merge, or reconnect, at a point about halfway between Earth and the orbit of the moon. But, contrary to expectations, the stored energy is not just released where reconnection occurs, researchers report online today in Science. Instead, energy is released at a magnetically intense “front” as reconnection slings the front toward Earth at almost 1.5 million kilometers per hour (and sends another front toward deep space). The passage of a front heats the plasma (yellow zone) and sends charged particles flying toward Earth (red arrow), where the onslaught powers both radiation belts and aurora.