MOSCOW, September 3. /TASS/. Scientists detected four powerful M-class explosions on the Sun on September 3, Russia’s Fedorov Institute of Applied Geophysics told TASS.

The most powerful of them occurred at 7:02 p.m. Moscow time (4:02 p.m. GMT).

"On September 3, an M3.4 flare that lasted 27 minutes was recorded in the X-ray spectrum," the scientists said.

Two more flares, of the M1.6 and M1.8 classes were registered in the early hours of Tuesday. An M1.5-class flare occurred on Tuesday morning.

Solar flares are divided into five classes according to their strength: the smallest ones are A-class, followed by B, C, M and X. A0.0 class is equal to the radiation energy found in the Earth’s orbit, 10 nanowatts per square meter. Each letter stands for a 10-fold increase in energy output. As a rule, the flares, known as giant explosions on the sun, send solar plasma into space, and the clouds of these charged particles can bring about geomagnetic storms when reaching the Earth.