The sun shot out a torrent of charged particles on March 15 in an event called a coronal mass ejection (CME). The eruption, which occurred at 3:24 a.m. EDT, sent what might have amounted to billions of tons of electrons and protons streaming toward the Earth at 900 miles per second, NASA says.
(The ESA and NASA Solar Heliospheric Observatory (SOHO) captured these images of the sun spitting out the March 15 CME. This type of image is known as a coronagraph, since a disk is placed over the sun to better see the dimmer atmosphere around it, called the corona. Courtesy ESA&NASA/SOHO)
The space agency produced a space weather research model, below, to simulate the CME’s path. It repeats the ejection four times. On the left is a top-down view of the inner solar system. The right shows Earth from the side as the simulated CME passes it.
While CMEs bring the potential to disrupt ground-based electrical systems and satellite electronics, the agency expected this one to bring only mild to moderate impacts when the solar wind swept past the Earth.
It encountered the Earth’s protective magnetosphere on March 17, triggering a mild geomagnetic storm that charged up the aurora borealis when the energetic particles interacted with the upper atmosphere. The intensified Northern lights were reportedly seen as far south as Colorado in the Western Hemisphere.
Here was what residents of western Finland saw:
And this is what it sounded like, courtesy of a ham radio operator who recorded the electromagnetic disturbance on his device.
Top Image: Aurora taken on March 17, 2013, in Trondheim, Norway. Courtesy Alexandra Jarna/Spaceweather.com.