Ion storm

Ion storms were a space phenomena that could cause problems during space travel for the denizens of the galaxy.

Created by a release of magnetic energy within a star, ion storms were fast-moving bursts of plasma that radiated outward into the surrounding star system. They were considered dangerous, as they had the potential to wreak havoc on bodies unprotected by a magnetic field. Starships were particularly vulnerable and, as ion storms could knock out shielding and a ship's electrical systems (compare ion cannon), they were avoided wherever possible.

Text and facts from the “Ion storm/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.