Watch Dead Sunspot Send Huge Solar Flare Hurtling Towards Earth

Scientists have spotted a solar flare that erupted from a sunspot on Wednesday, causing a small radiation spike.

The flare came from a region of the sun known as AR3016 and at a strength of about M1. It was the first M-class flare in almost a week.

Solar flare
A screenshot of NASA Solar Dynamics Observatory (SDO) footage of Wednesday's solar flare, seen here at roughly 18:30 UT. Solar flares can interfere with communication systems on Earth. NASA/SDO/AIA

The flare was captured by NASA's Solar Dynamics Observatory (SDO) sun imaging spacecraft. SpaceWeather.com described the flare as coming from "a magnetic filament snaking through the corpse of decayed sunspot AR3016."

The video, seen above, shows how this region on the right-hand side of the sun suddenly flashes white. The flare can be seen towards the very end of the clip.

Solar flares are explosions of energy that come from the interactions of magnetic field lines near sunspots—dark regions on the sun's atmosphere associated with intense magnetic fields.

The scales involved are enormous compared to Earth. The average sunspot is about the size of our entire planet.

The electromagnetic energy released from flares travels at the speed of light towards Earth, causing increased levels of X-rays and extreme ultraviolet radiation. This radiation can sometimes disrupt communication systems on Earth by interfering with high-frequency radio signals.

Solar flares vary widely in strength and are measured in increasing strength from A, B, C, M, and X classifications. Flares don't tend to cause any problems on Earth until they reach the high M class and above, so yesterday's flare was quite weak and no cause for concern.

The U.S. National Oceanic and Atmospheric Administration Space Weather Prediction Center (SWPC) states that M1-class solar flares are minor and may be associated with "weak or minor degradation of high frequency radio communication".

An X20-class flare or above would, by comparison, cause complete high-frequency radio blackouts on the entire sunlit side of Earth. Low-frequency navigation signals would also be affected.

Solar flares are sometimes accompanied by coronal mass ejections (CMEs), which are clouds of plasma carrying an embedded magnetic field. These travel more slowly than flares and can take days to reach Earth if they're directed towards us. Once they do, though, they can cause geomagnetic storms which again can cause communication disruption and also power surges that can damage electrical grids. Like flares, CMEs vary in strength. Many of them are also not directed towards Earth.

On Twitter, solar observers wondered if Wednesday's flare would be accompanied by a CME. As of Thursday morning the SWPC's alerts page did not warn of any impending CMEs.

The sun is currently in the increasingly active phase of its roughly 11-year solar cycle, which is measured by the number of sunspots we can observe. SWPC data appears to show that solar activity recently is increasing faster than predicted. This solar cycle is forecast to peak some time between 2025 and 2026.