Largest solar flares in the current solar cycle

Description

NASA reports that the flare on 6 March 2012 is the second largest so far in the current 11-year solar cycle. This flare was categorised as an X5.4, making it the second largest flare after an X6.9 on 9 August 2011. Solar flares are categorised by their size – according to the peak flux recorded in watts per square metre (W/m2) as an A, B, C, M or X-class flare. A B-class solar flare releases 10 times more energy than an A-class flare, while a C-class eruption releases 10 times more than a B-class flare (and 100 times more than class A). Within each letter class, there is also a scale from 1–9.

The current solar cycle is expected to peak in the next 12 months, so we can expect more and possibly larger flares in the year ahead. However, not all solar storms are ejected towards the Earth.

Dr Alina Donea, an astrophysicist in the Monash Centre for Astrophysics in Australia, says the X5.4 solar flare was similar in size to one called the Bastille Day flare, which occurred on 14 February 2000.