CORONAL MASS EJECTIONCME

Coronal mass ejection toward Earth, October 21, 2026

Arrival forecast
Map: Coronal mass ejection toward Earth, October 21, 2026

A coronal mass ejection, a billion-ton cloud of magnetized gas, left the Sun on October 21, 2026 at 08:53 UTC, moving at about 310 km/s (0.7 million mph). NASA’s model forecast it to reach Earth around Sunday, October 25 at 06:00 UTC, plus or minus several hours. In the model’s strongest scenario it pushes the K index to 4, below storm level.

Left the SunOct 21 08:53 UTC
Speed310 km/s
Arrival (model)Oct 25 06:00 UTC
Glancing blowNo
Kp forecastup to 4
Travel time93 hours
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What happens when it arrives

If the cloud’s magnetic field points south when it hits, it can couple with Earth’s and set off a geomagnetic storm: auroras far from the poles, and in strong storms trouble for power grids, satellites and GPS. Arrival times are model forecasts and are often off by six hours or more. Live outlook: aurora forecast.

Data: NASA DONKI (WSA-ENLIL model).

Did you know?

May 2024. In May 2024 a G5 storm, the first in over 20 years, brought auroras to skies across much of the US and Europe.

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