The current solar storm is the most powerful of the present cycle. People living at high altitudes should check tonight, March 17, in their calendars. The chances of spotting breathtaking auroras are very high.
Initially set off by the collision of a coronal mass ejection (CME) striking Earth’s magnetosphere (its global magnetic field), a “relatively mild geomagnetic storm” broke out at about 04:30 UT (12:30 a.m. EDT). It soon became a G4-class geomagnetic storm which will surely create some amazing auroras visible for those living at high altitudes.
Auroras could be spotted early morning in Alaska. Photographer Marketa Murray was there. She described the whole event:
“The auroras were insane. I have never seen anything like this.”
A large CME was sent from the Sun in the direction of our planet on Sunday. It reached its target faster than initially thought. Solar activity has increased in the last days. The peak was reached last week with the first X-class flare of 2015. But the strength of this solar storm has taken scientists by surprise. It was assessed as “geoeffective”.
A coronal mass ejection is made out of energized gas molecules coming from the Sun’s intensely heated corona which is the star’s atmosphere. The gas is wrapped in a strong magnetic field. The impact a CME can have when interacting with Earth’s magnetic field depends on the speed with which it travels between the Sun and Earth and “the alignment of its magnetic field”. A CME can have a powerful influence on out planet’s magnetic field.
If the CME hits the Earth’s magnetosphere at a proper alignment, the CME’s magnetic field can connect with that of Earth’s which leads to strong magnetic interference due to the large amounts of solar plasma introduced in the planet’s magnetosphere. This is a situation when a CME is described as “geoeffective”. The magnetic storm that is generated through this interaction can be extraordinarily powerful.
The storm that occurred today was the strongest one recorded since the beginning of the current solar cycle.
Every 11 years, the solar magnetic activity develops variations in intensity. The peak is the solar maximum when the Sun’s magnetic field is so powerful that is generates frequent flares and CMEs. During the current solar cycle, it was predicted the Sun would reach its maximum in 2013 but today’s storm proved otherwise.
Image Source: Discovery