NASA's
Solar Dynamics Observatory or SDO, captured this image on the sun of an
M9.4-class solar flare, which peaked at 8:30 pm EDT on Oct. 23, 2013.
The image displays light in the wavelength of 131 Angstroms, which is
good for viewing the intense heat of a solar flare and typically colored
teal. Image Credit: NASA/SDO. › View full disk image
The sun emitted a mid-level solar flare that peaked at 8:30 pm EDT on
Oct. 23, 2013. Solar flares are powerful bursts of radiation. Harmful
radiation from a flare cannot pass through Earth's atmosphere to
physically affect humans on the ground, however -- when intense enough
-- they can disturb the atmosphere in the layer where GPS and
communications signals travel. Such radiation can disrupt radio signals
for as long as the flare is ongoing, anywhere from minutes to hours.
To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.
This flare is classified as an M9.4 flare, on a scale from M1 to
M9.9. This rating puts it at the very top of the scale for M class
flares, which are the weakest flares that can cause some space weather
effects near Earth. In the past, they have caused brief radio blackouts
at the poles. The next highest level is X-class, which denotes the most
intense flares.
Increased numbers of flares are quite common at the moment, since the
sun is near solar maximum. Humans have tracked solar cycles
continuously since they were discovered in 1843, and it is normal for
there to be many flares a day during the sun's peak activity.
NASA's Goddard Space Flight Center, Greenbelt, Md.
