Nombre de messages : 14079 Age : 39 Localisation : FRANCE Date d'inscription : 01/07/2004
Sujet: Solar storm set to impact planet Earth Mar 24 Jan - 16:22
Solar storm set to impact planet Earth http://www.adelaidenow.com.au/solar-storm-set-to-impact-planet-earth/story-e6frea6u-1226252841243
A SOLAR storm is lashing Earth with radiation that disrupts communication and satellite systems, while dazzling polar stargazers. Last night, plasma from Sunday's solar flare was expected to reach the Earth, causing problems for computers on satellites and prompting airlines to avoid northern polar routes.
US National Oceanic and Atmospheric Administration (NOAA) space weather centre physicist Doug Biesecker said the radiation was also a concern for astronauts in space, but the main problem was satellite systems.
"We don't expect major impacts," he said.
"It's the people who need GPS (global positioning system) accuracy of centimetres who have to worry, not people who want to know if you're going to turn the car 30m ahead." The NASA Solar Dynamics Observatory captured images of the flare, which show a brightening of the solar surface as gas became superheated and magnetically supercharged.
A solar eruption is followed by a "one-two-three punch", says Antti Pulkkinen, a physicist at NASA's Goddard Space Flight Centre in Maryland.
First comes electromagnetic radiation, then radiation in the form of protons and finally the coronal mass ejection - plasma from the sun - hits. That usually travels at about 1.6 or 3.2 million km/h but this storm is shooting out at 6.4 million km/h. The plasma causes much of the noticeable problems on Earth, such as electrical grid outages. In 1989, a solar storm caused a big blackout in Quebec.
Radiation from Sunday's flare (2.30pm SA time) arrived at Earth an hour later and has been reaching the surface for three days.
Levels are considered strong but other storms have been more severe. There are two higher levels of radiation on NOAA's storm scale - severe and extreme.
But this storm is the strongest for radiation since May 2005.
NASA's flight surgeons and solar experts examined the solar flare's expected effects and decided the six astronauts on the International Space Station did not have to do anything to protect themselves from the radiation, spokesman Rob Navias said.
But this coronal mass ejection seemed likely to be only moderate, with a chance for becoming strong, Biesecker said. Its worst was likely to go north of Earth.
Solar storm set to impact planet Earth
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