Earlier today, March 11th, the outskirts of a CME (Coronal mass ejections*) previously expected to miss Earth instead hit. The impact sparked a G2-class geomagnetic storm (now subsiding) and bright auroras around the Arctic Circle.
Tour guide Marketa S. Murray photographed the display just before sunrise near Fairbanks, Alaska.
“We didn’t expect to see much last night,” says Murray. “Instead, it was an amazing night–all the colors you can imagine! Our guests were very happy.”
This is a good time of year for auroras. For reasons that are only partially understood, geomagnetic storms favor the weeks around equinoxes; even a gentle gust of solar wind or, in this case, the sideswipe of an off-course CME can spark a good display. More lights are possible tonight as Earth moves deeper into the CME’s flank.
Monitor the aurora gallery for sightings. This page is continually updated with spectacular Aurora sightings (pictures).
*Coronal mass ejections (CMEs) are huge explosions of magnetic field and plasma from the Sun’s corona. When CMEs impact the Earth’s magnetosphere, they are responsible for geomagnetic storms and enhanced aurora. CMEs originate from highly twisted magnetic field structures, or “flux ropes”, on the Sun, often visualized by their associated “filaments” or “prominences”, which are relatively cool plasmas trapped in the flux ropes in the corona. When these flux ropes erupt from active regions on the Sun (regions associated with sunspots and very strong magnetic fields), they are often accompanied by large solar flares; eruptions from quiet regions of the Sun, such as the “polar crown” filament eruptions, sometimes do not have accompanying flares.
All pictures from SpaceWeather Gallery
By SpaceWeather, SouthFloridaReporter.com, Mar. 11, 2016
