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Auroras Visible in Continental U.S.
May 20, 2013

UPDATE: Over the weekend, a pair of CMEs reached Earth. The impacts rattled Earth's magnetic field and sparked Northern Lights visible in the continental United States as far south as Colorado.

Aurora as seen in Marquette, Michigan on May 18, 2013. › View larger
This aurora appeared over Marquette, Mich., on May 18, 2013, after coronal mass ejections from the sun made contact with Earth's magnetic fields, funneling energy and particles into near-Earth space. Image Courtesy of Amy Cherrette

Activity Continues On the Sun

SDO's view of X1.2 class solar flare on May 15, 2013. › View larger image
NASA's Solar Dynamics Observatory captured this image of the X1.2 class solar flare on May 14, 2013. The image show light with a wavelength of 304 angstroms. Credit: NASA/SDO

Solar activity continued on May 14, 2013, as the sun emitted a fourth X-class flare from its upper left limb, peaking at 9:48 p.m. EDT. This flare is classified as an X1.2 flare and it is the 18th X-class flare of the current solar cycle. The flare caused a radio blackout – categorized as an R3, or strong, on NOAA's space weather scales from R1 to R5 - which has since subsided.

The flare was also associated with a non-Earth-directed CME. CMEs and flares are separate but related solar phenomena: solar flares are powerful bursts that send light and radiation into space; CMEs erupt with billions of tons of solar material. They often, but do not always, occur together. Any time we can see a solar flare from Earth's view, than at least some of its light and radiation must be directed at Earth. CMEs on the other hand may or may not be Earth directed. NASA observes CMEs, however, even when they are not traveling toward Earth, because they may impact spacecraft.

Experimental NASA research models show that this CME left the sun at around 745 miles per second, beginning at 10:18 p.m. EDT. It is not Earth-directed, however it may pass the Spitzer and Epoxi orbits, and their mission operators have been notified. If warranted, operators can put spacecraft into safe mode to protect the instruments from solar material.

Updates will be posted as necessary.

NOAA's Space Weather Prediction Center (http://swpc.noaa.gov) is the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

Combination of blended images of all four X-class solar flare from AR1748, occurring May 13-25, 2013, as seen by SDO. › View larger
These images from NASA's Solar Dynamics Observatory show four X-class flares emitted on May 12-14, 2013 – the first four X-class flares of 2013. Each panel is a blend of two images one showing light in the 171 Angstrom wavelength and the other in 131 Angstroms. Credit: NASA/SDO/GSFC

Related Links

› Earlier X-Class Flares from this Active Solar Region
› About Strong Flare Impacts
› Frequently Asked Questions Regarding Space Weather
› View Other Past Solar Activity

Karen C. Fox
NASA's Goddard Space Flight Center, Greenbelt, Md.

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Page Last Updated: April 1st, 2014
Page Editor: Holly Zell