In -925 the Abh project finished construction of its star probe. In -924 the second star probe, with improved shielding, was launched into Tarnis. The probe reached its operating depth of 300,000 km, and the meson communicator indicated an increasing instability in the sun, centered on the probe itself. Tarnis took a slight wobble and began throwing huge stellar flares.
These flares generated a huge electromagnetic pulse that blew all electronic components on Darrian. About three weeks later the physical wave front of expanding gas reached Darrian. When it hit, the last of superheated gases struck like a blowtorch, temporarily raising local temperatures to 250° and higher. The Maghiz destroyed whole areas of Darrian, scalding basins, evaporating shallow seas, burning forests and grasslands, and destroying populated areas. Fortunately, the flares lasted only three days. At the end of those three days, the surviving 20 percent of Darrian's population came out and began rebuilding.
The Abh Project station in the asteroid belt was never shielded for flares of the magnitude that were generated. The station itself was destroyed; most of its personnel were killed. The survivors spent four years repairing a single shuttle that would take them back to Darrian.
The electromagnetic pulse from Tarnis continued through interstellar space at the speed of light, hitting each of the Darrian colony worlds in turn. Even with forewarning, it was an impossible job to adequately shield every piece of electronic equipment from the pulse. As it arrived in each system (which scheduled a Pulse day for equipment to be powered down), some unshielded equipment was fried and some electronic systems failed.
https://wiki.travellerrpg.com/Maghiz