Kp index
The Kp index is a 0–9 scale of global geomagnetic activity over three-hour periods, and it is the number aurora watchers check to judge tonight's odds.
Low values (0–3) mean quiet conditions, while 5 or above marks a geomagnetic storm that pushes the aurora toward lower latitudes.
The higher the Kp, the farther from the poles the northern or southern lights can be seen.
See it live on Cosmik
Related terms
- Geomagnetic storm — A geomagnetic storm is a temporary disturbance of Earth's magnetic field driven by bursts of solar wind and coronal mass ejections from the Sun.
- Twilight — Twilight is the period before sunrise and after sunset when the sky is partly lit by the Sun below the horizon, split into civil, nautical and astronomical stages.
