0 NASA warns of geomagnetic storm after behemoth solar flare

NASA says geosynchronous satellites could therefore be directly exposed to solar wind plasma with latest blast

NASA today said a strong-to-severe geomagnetic storm is in progress following a massive solar flare and coronal mass ejection (CME).   CMEs are a solar phenomenon that can send solar particles into space and affect electronic systems in satellites and on Earth.  Simulations indicate that solar wind plasma has penetrated close to geosynchronous orbit starting at 9am today. Geosynchronous satellites could therefore be directly exposed to solar wind plasma and magnetic fields. High-latitude sky watchers should be alert for auroras after nightfall, NASA stated.

The National Oceanic and Atmospheric Administration's Space Weather forecast center went further saying: A CME that erupted from NOAA Active Region 1302 on Saturday September 24 in conjunction with an M7 strength solar flare, arrived this morning at 1237 UT (8:37am Eastern Time). It has kicked off moderate (G2) geomagnetic storms for low latitudes, but high latitudes are seeing severe (G4) levels of activity. Aurora watchers in Asia and Europe are most favorably positioned for this event, though it may persist long enough for viewers in North America. The bulk of the CME missed the Earth, meaning the storm intensity and duration are less than what they would have been in the case of a direct hit. Region 1302 remains capable of producing more activity and will be in a favorable position for that activity to have impacts on Earth for the next 3-5 days.

NASA's Solar Dynamics Observatory (SDO) recorded the extreme ultraviolet flash.

This particular sunspot, 1302 has already produced two X-flares (X1.4 on Sept. 22nd and X1.9 on Sept. 24th). The entire active region stretches more than 100,000 km from end to end. None of the blasts have been squarely Earth-directed, but this could change as the sunspot turns toward our planet in the days ahead. AR1302 is growing and shows no immediate signs of quieting down, NASA said.

The sunspot's magnetic field is currently crackling with sub-X-class flares that could grow into larger eruptions as the sunspot continues to turn toward Earth, NASA stated. The Goddard Space Weather Lab reported a strong compression of Earth's magnetosphere.

According to the space agency: "The biggest flares are known as "X-class flares" based on a classification system that divides solar flares according to their strength. The smallest ones are A-class (near background levels), followed by B, C, M and X. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. Within each letter class there is a finer scale from 1 to 9.  C-class and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts."

Earlier this year NASA noted that the Sun hadn't blasted out any X-flares for four years but produced two of the powerful blasts in less than one month: Feb. 15th and March 9th. This continues the recent trend of increasing solar activity associated with our sun's regular 11-year cycle, and confirms that Solar Cycle 24 is indeed heating up, as solar experts have expected. Solar activity will continue to increase as the solar cycle progresses toward solar maximum, expected in the 2013 time frame.

NASA and NOAA - as well as the US Air Force Weather Agency and others -- keep a constant watch on the sun to monitor for X-class flares and their associated magnetic storms. With advance warning many satellites and spacecraft can be protected from the worst effects, NASA stated.