April 22, 2013
Three Coronal Mass Ejections And A Solar Flare In Three Days On The Sun
Lawrence LeBlond for redOrbit.com - Your Universe Online
NASA´s Solar Dynamics Observatory (SDO) recorded a coronal mass ejection (CME) on Saturday April 20, 2013, at 2:54 a.m. EDT. That was only to be the first of three such events over the course of the weekend.
CME´s, solar phenomena that send billions of tons of solar particles and radiation speeding through space at over 500 miles per second, have the potential to affect communication systems and electronics here and in orbit when they occur on the Earth-facing side of the Sun.
However, Friday´s CME was not Earth-directed. Still, NASA data shows that it likely would pass by the space agency´s Messenger and STEREO-A satellites, and as such, their respective mission operators had been notified. The good news, data readings show there was no radiation associated with this event, which would be the main concern for operators of spacecraft since the particles can disrupt electrical systems on board.
When it is known that radiation has been released, NASA and mission operators have the ability to switch spacecraft into safe mode to protect them from damaging impact. Early Saturday´s CME was also facing Mercury.
The same region of the Sun erupted again with another CME on April 21, 2013, at 3:54 a.m. NASA research models showed that this CME left our solar neighbor at speeds of 550 miles per second, and was also expected to pass by Messenger and possibly STEREO-A. The space agency said there could be some radiation associated with this event.
Less than 10 hours later, a third CME was recorded at 12:39 p.m. EDT. This ejection was estimated to be traveling at 625 miles per second and would catch up to the earlier CME before the combined effects of both CME´s impact Messenger. NASA said this event also released radiation, which could produce an even greater danger to the on board electrical systems of Messenger.
NASA said further updates may be needed.
And to add to the mix, today (April 22) at 10:29 UT, the Sun´s active region 1726 erupted with an M1-class solar flare. The AR1726 region has grown to an extremely large size — about 90,000 miles wide (the equivalent of about 12 Earths placed end-to-end. The M1-class flare is the lowest in the Medium-sized category.
Not to be confused with a coronal mass ejection, a solar flare is a large brightening that suddenly appears over the Sun´s surface. A solar flare occurs when accelerated charged particles, mainly electrons, interact with plasma. These events, which are powerful phenomena in their own rights, often lead up to coronal mass ejections.