Meteor Storm is an ability of the Advent Transcencia Star Base that is acquired after upgrading the starbase with Meteoroid Control. Bombards enemies within a radius of the target with telekinetically thrown meteoroids, causes immense damage.
This ability is the Advent's main AoE ability that wreaks havoc upon all enemy ships who get caught in the downpour. Defensively, this ability should be researched should your enemy heavily outnumber you and you need a way to lock down your position. A player caught off guard can have his fleet severely injured or even wiped out. Offensively, you will need to babysit your starbase until construction has been completed. Afterwards, research Meteoroid Control; once that is done your fleet will be practically untouchable, and the planet will be yours for the taking.