A space storm has been observed exploding from a central point in Earth鈥檚 upper atmosphere for the first time. The result could one day lead to better predictions of the storms, which can harm satellites and power grids on the ground.
The energy that powers space storms comes from clouds of plasma hurled at Earth by the sun. These clouds stretch our planet鈥檚 magnetic field like a rubber band, storing energy in a long magnetic tail behind our planet.
The energy released when the field snaps back into place creates the ethereal glow of auroras (see a gallery of the light shows). It also floods the space around our planet with radiation that can incapacitate satellites and sicken astronauts, and can trigger electric currents on Earth capable of knocking out power grids.
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Now, scientists have obtained the clearest view yet of the energy that was released in the magnetic tail arriving and initiating a disturbance in Earth鈥檚 upper atmosphere, or ionosphere.
鈥楻ock in a pond鈥�
Jonathan Rae of the University of Alberta in Edmonton led a team that made the observations of the onset of a space storm in March 2007, using a network of cameras and magnetic instruments at ground stations scattered across Canada.
The observations show magnetic ripples in the ionosphere spreading at speeds exceeding 100,000 kilometres per hour from an initial point above Canada. A strong auroral display, characteristic of a space storm, followed less than three minutes later.
鈥淭he magnetic oscillations come down and hit the upper atmosphere in a particular location and then spread out from that location,鈥� says Rae. 鈥淚t almost looks like a rock in a pond.鈥�
Power down
杏吧原创s hope the new insight into how space storms begin and unfold will help pave the way for better predictions.
鈥淚f we can predict these events with some certainty, hopefully more than minutes, maybe hours before they occur, we collectively can take remedial action,鈥� says David Kendall of the Canadian Space Agency, which is funding the ground-based observation network. That would allow astronauts to take cover inside their spacecraft and satellites to power down to prevent damage, he says.
Rae reported the results on Monday at a in Toronto.
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