CORONAL MASS EJECTIONCME

Coronal mass ejection toward Earth, September 30, 2026

Arrival forecast
Map: Coronal mass ejection toward Earth, September 30, 2026

A coronal mass ejection, a billion-ton cloud of magnetized gas, left the Sun on September 30, 2026 at 03:12 UTC, moving at about 488 km/s (1.1 million mph). NASA’s model forecast it to reach Earth around Saturday, October 3 at 12:34 UTC. In the model’s strongest scenario it pushes the K index to 4, below storm level. A geomagnetic storm followed.

Left the SunSep 30 03:12 UTC
Speed488 km/s
Arrival (model)Oct 3 12:34 UTC
Glancing blowNo
Kp forecastup to 4
Travel time81 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.

Did you know?

GPS and space weather. Strong space weather can disturb the upper atmosphere and reduce the accuracy of GPS signals.

Data: NASA DONKI (WSA-ENLIL model).

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