An M1.0 flare recorded late Monday was the strongest since September 5, according to the Solar Astronomy Laboratory of the Russian Academy of Sciences’ Space Research Institute.
The flare occurred at about 22:00 Moscow time and was the largest recorded since September 5, the laboratory said. Solar activity had remained subdued for nearly a month before a new series of flares began in October.
Researchers also observed two large sunspot groups where solar radiation is emerging. They linked the current increase in activity to energy accumulating in those regions.
The institute said the M1.0 event itself poses no threat, while cautioning that it could signal a longer-awaited change in solar activity. If the newer sunspot group continues to grow, flares could approach the more powerful X class in the coming days. The probability is difficult to estimate, the researchers said.
Solar flares are ranked A, B, C, M and X, from weakest to strongest. Each class is roughly ten times more powerful than the preceding one. Classes A through M use a numerical scale from 1 to 9, while the X class has no upper limit.
Strong flares can disrupt radio communications and affect satellites and spacecraft. The flare’s radiation does not pose a direct threat to people on Earth’s surface, which is shielded by the atmosphere and magnetic field.