Can we tell when a solar flare will lead to a potentially hazardous eruption of plasma from the Sun? A new look at hundreds of past solar flares may provide some clues.
Belches from the Sun
A large solar flare may or may not be accompanied by a violent ejection of matter in a CME. [NASA/SDO]Two of the most energetic phenomena in our solar system are solar flares and coronal mass ejections (CMEs). While both are explosions produced in active regions on the Sun, they are distinctly different: solar flares are intense bursts of radiation spanning the electromagnetic spectrum, whereas CMEs are violent, directed eruptions of hot, magnetized plasma — sometimes containing more than a billion tons of matter — into space. While the two phenomena sometimes arise hand in hand, this is not always the case.
The Earth’s magnetic field does a good job of protecting us from the greatest impact of these eruptions, but a CME directed at Earth still has the potential to be hazardous to our technology and communications systems, as well as to any unshielded life (such as astronauts on a lunar mission). Scientists are therefore interested in better understanding which solar flares are likely ...