Last week, a swelling solar storm on the surface of the Sun sent a stream of charged particles hurtling toward Earth, making for beautiful northern lights in the planet's extreme latitudes. But late last night, at 10:59 p.m. EST, the now massive tempest unleashed an eruption that scientists expect will be responsible for Earth's largest solar radiation storm since 2005.
How powerful are we talking? The National Oceanic and Atmospheric Administration (NOAA) says that many plane flights scheduled for tomorrow can expect to be re-routed within the next few hours.
Cause for concern is due to the M9-class solar flare that was observed lashing out last night from a large sunspot — dubbed "1402" — on the Sun's northeastern hemisphere. The image you see up top reveals the extreme flash of ultraviolet radiation that was emitted by the sunspot, as captured by NASA's Solar Dynamics Observatory [Click here for a mesmerizing hi-res version].
The explosion's M9-ranking puts it just below the threshold of an X-flare, the most powerful classification of solar eruption there is. It's important to understand that while flares more violent than 1402's are often observed on the surface of the Sun, it's rare for one so powerful to eject subatomic particles in a wave aimed so directly at Earth; analysts at the Goddard Space Weather Lab have released an animated forecast track [click through to see], which shows the leading edge of the particle ejection reaching Earth tomorrow morning, shortly after 9 a.m. EST (1400 GMT).