While the streams of particles cannot travel through the atmosphere and harm humans on the ground, the particles can affect electronic systems in satellites and on the ground, the space agency said.
Observations from NASA's Solar Terrestrial Relations Observatory show the CME departed the sun at speeds of around 570 miles per second, a fairly typical speed for CMEs, scientists said. The particle stream would reach the Earth Thursday or Friday.
Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm that can degrade communication signals and cause unexpected electrical surges in power grids.
They also can create atmospheric auroras seen at high latitudes.
Geomagnetic storms caused by CMEs of the strength of the current one have usually been mild, NASA said.