



An active sunspot-filled region on the sun, AR 1504, rotated into our view on June 10, 2012. So far, the sunspot region fired off two M-class flares, and two coronal mass ejections (CMEs) on June 13th and 14th. The final flare lasted a long time for a CME, nearly 3 hours. It peaked around June 13, 2012 at 9:17 AM EDT. That CME traveled approximately 375 miles per second directly towards the Earth, but because of its relatively slow speed wasn’t expected to cause many problems.





The second flare was also a long-duration flare, it peaked on June 14, 2012 at 10:08 AM EDT. This CME was traveling much faster, nearly 800 miles per second, and was expected to impact the Earth, Mars, and the Spitzer spacecraft.



Both CMEs were forecasted to hit the Earth on June 16th.

Solar flares are intense bursts of radiation coming from the release of the magnetic energy associated with sunspots. “Flares are our solar system’s largest explosive events. They are seen as bright areas on the sun and they can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, at most every wavelength of the spectrum. The primary ways we monitor flares are in x-rays and optical light. Flares are also sites where particles (electrons, protons, and heavier particles) are accelerated.”

A Coronal Mass Ejection (CME) is an explosive eruption of magnetic fields containing matter. “The outer solar atmosphere, the corona, is structured by strong magnetic fields. Where these fields are closed, often above sunspot groups, the confined solar atmosphere can suddenly and violently release bubbles of gas and magnetic fields called coronal mass ejections. A large CME can contain a billion tons of matter that can be accelerated to several million miles per hour in a spectacular explosion. Solar material streams out through the interplanetary medium, impacting any planet or spacecraft in its path. CMEs are sometimes associated with flares but can occur independently.”

Source: NASA