Solar flare seen by ESA/NASA SOHO satellite
on 23 January,
shortly after a large solar flare
occurred at 03:59 GMT. Credits: ESA/NASA

25 January 2012 – A stronger-than-average solar flare at 03:59 GMT on Monday set off a coronal mass ejection travelling at 1400 km/s and reaching Earth yesterday afternoon. Its effects are likely to continue throughout today (Wednesday 25 Jan).

Solar flares are enormous explosions caused by the sudden release of energy from the magnetic fields of sunspots – temporary areas of intense magnetic activity in the Sun’s atmosphere (corona). Solar flares in turn can result in coronal mass ejections (CMEs) – huge clouds of high-energy particles blasted into space by a solar flare. These clouds of material can strike the Earth
causing geomagnetic storms and triggering a range of phenomena. Some of these are beautiful like the aurora, but others can be disastrous – disrupting satellites and communications systems.

Monday’s solar flare triggered the strongest stream of protons seen since 2005. However, scientists predict that the current CME will only cause a minor geomagnetic storm without any visible effects on the ground nor any serious effects on satellites, phone networks or power grids.

Get involved – You can help spot and track solar storms at Solar Stormwatch, a joint web project of the Royal Observatory Greenwich, Zooniverse and Rutherford Appleton Laboratory. If you get involved your work will help give astronauts an early warning if dangerous solar radiation is headed their way – and you could make a new scientific discovery.