A small spherical Xindi weapon that appeared over Earth in 2153 and cut a swathe from Florida to Venezuela, killing seven million people and sending the Enterprise NX-01 into the Delphic Expanse.
The Xindi probe is the prototype weapon whose attack on Earth opens the third-season story of Star Trek: Enterprise. In The Expanse it emerges from a vortex above the planet in 2153 and fires a beam that carves a trench from Florida to Venezuela. Seven million people die, among them Elizabeth Tucker, the sister of Trip Tucker.
The probe destroys itself after firing and its wreckage comes down in central Asia, where Starfleet recovers the body of its single pilot. Archer learns from a mysterious figure in the future that the Xindi built it as a test for a far larger weapon intended to destroy Earth outright.
The attack leads Starfleet to refit Enterprise and send her into the Delphic Expanse to find the Xindi. A second prototype is tested in Proving Ground, and the finished weapon is destroyed in Zero Hour.