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5 December 2013 11:26 am ,
Vol. 342 ,
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Earth's Friendly Fire
10 May 2002 (All day)
When a space storm whips up, Earth becomes enveloped by high-energy ions that can damage satellites and even interfere with electronics on the ground. Now, new satellite data show that most of those nefarious ions originate in our planet's own protective atmosphere.
A space storm starts with a gust of particles flowing from the sun. Earth's magnetic field deflects this solar wind, but not before it blows oxygen ions from the atmosphere into space. These ions and particles from the solar wind then collect in a long tail of magnetic fields stretching away from Earth. The tail occasionally snaps back, surrounding Earth in a vast doughnut-shaped cloud of particles called the ring current. Particles from the ring current then rain down, creating a hazard for satellites. But how much of the ring current originates in the solar wind, and how much comes from ions blown out of the atmosphere, has been an open question.
Now, NASA's Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) has given researchers their first bird's-eye view of entire space storms, and the new vantage makes clear that Earth's atmosphere plays an active role. IMAGE's orbit takes it high above the North Pole, far enough away to watch tons of oxygen ions flow out into space, collect in the magnetic tail, and boomerang back. As it turns out, these oxygen ions make up most of the ring current, IMAGE researchers reported on 9 May at a press conference at NASA headquarters in Washington, D.C.
IMAGE data could be a boon to researchers developing computer models to forecast space weather, says Terry Onsager of the National Oceanic and Atmospheric Administration's Space Environment Center in Boulder, Colorado: "This kind of result will help us to understand ... what kind of measurements we need to look at to feed our models more accurately."