Solar eruptions could spark 'northern lights' this week
Sky & Telescope contributing photographer Johnny Horne captured this view of the aurora borealis from Fayetteville, North Carolina, in April 2000
GREENBELT, Maryland (CNN) -- A spacecraft that monitors solar activity has detected two strong gas eruptions from the sun that scientists say could trigger unusually strong displays of the space phenomenon known as the aurora borealis, or "northern lights," between Wednesday night and Friday.
The solar eruptions -- called coronal mass ejections (CMEs) -- were observed by the Solar and Heliographic Observatory (SOHO), a satellite launched in 1995.
CMEs are expelled through space at speeds of 600 miles per second or more. The high-energy solar winds they produce have been known to temporarily alter Earth's magnetic field -- resulting in more frequent streaks of the eerily beautiful, usually greenish-colored northern lights seen in high latitude locations.
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While CMEs are also linked to occasional disruptions of some satellite communications, no such warnings have yet been issued for these eruptions.
The first highly charged bursts of solar winds could arrive as early as 11 p.m. EDT Wednesday, said experts at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Scientists from the U.S. National Oceanic and Atmospheric Administration estimated there is a 40 percent chance of "major" geomagnetic activity between Wednesday night and Friday.
That activity could bring brighter than normal northern lights displays in the regions of Canada, Scandinavia, and Russia where they are a fairly common nighttime sight.
But there is a chance, presuming clear weather, that the lights may be seen over a much wider area -- possibly reaching to the Mediterranean region and southern United States, as occurred following a CME in early May.
The sun is at the peak of an 11-year cycle of solar flare, CME, and sunspot activity.
The SOHO orbiting observatory is a joint effort of NASA and the European Space Agency.
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