A mass ejection of matter from the Sun is caught exploding outward. SOHO satellite image.
Coronal Mass Ejections (CMEs) are not uncommon, but they don't always hit the Earth when they do. On April 11th the SOHO satellite (Solar and Heliospheric Observatory) imaged an eruption of the year's strongest solar flare to date, which was soon accompanied by a CME. The CME is a gigantic mass of charged solar particles that can play havoc with our satellites, electrical grids, and people high in the atmosphere or in orbit. This CME is expected to hit the Earth sometime this weekend on the 13th. One benefit of these eruptions is that when the particles hit the Earth's magnetic field, they can result in magnificent Northern Lights displays. Of course here in Utah we have storms this weekend.
Today's solar disk. Sunspot group AR1719 is just above center to the right. Credit: SDO/HMI.
The flare and CME were sent out from sunspot AR1719. The Sun's activity has been a bit unusual of late, as it is approaching Solar Maximum in it's 11-year cycle, and the sunspot activity has been low. Some scientists believe we may experience a cycle with two peaks. You can read more about the irregularities of the current solar cycle at NASA Science News:
and keep updates on the CME alerts at SpaceWeather.com: