Britannica Sources used in this answer

How does a coronal mass ejection differ from a solar flare?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Space weather Earth's full North Polar auroral oval, in an image taken in ultraviolet light by the U.S. Polar spacecraft over northern Canada, April 6, 1996. In the colour-coded image, which simultaneously shows dayside and nightside auroral activity, the most intense levels of activity are red, and the lowest levels are blue. Polar, launched in February 1996, was designed to further scientists' understanding of how plasma energy contained in the solar wind interacts with Earth's magnetosphere.

While solar flares and coronal mass ejections (CMEs) are both manifestations of the Sun's magnetic activity and are often associated with one another, they are distinct phenomena.1

Solar Flare: A solar flare is a sudden, intense brightening in the solar corona. It is primarily an electromagnetic event characterized by a rapid release of energy that produces high-energy particles, X-rays, and radio bursts. Flares occur in the solar atmosphere and can be observed across the electromagnetic spectrum.23
Coronal Mass Ejection (CME): A CME is a massive eruption of magnetized plasma from the Sun's outer atmosphere that propagates outward into interplanetary space. Unlike the flash of light associated with a flare, a CME involves the actual physical ejection of solar material—often billions of tons of plasma—into the solar wind.13

Both events are thought to be driven by the explosive reconfiguration of solar magnetic fields through magnetic reconnection. While they frequently occur together, they can also happen independently. CMEs are the primary drivers of major geomagnetic storms on Earth, which can impact technological systems.1