Gravimetric torpedo

Kim, Janeway, and Tuvok work on a gravimetric torpedo

A gravimetric torpedo was a type of torpedo weapon which could be created by outfitting a standard photon torpedo with a gravimetric charge. In theory, if a gravimetric torpedo were used to detonate a type-6 protostar, it could result in the formation of a wormhole.

In 2374, after having detected the presence of the Omega molecule in the Delta Quadrant, Kathryn Janeway, captain of the USS Voyager, ordered Lieutenant Commander Tuvok and Ensign Harry Kim to outfit a photon torpedo with a gravimetric charge with a yield of fifty-four isotons, to create a gravimetric torpedo with which to destroy the molecule, in accordance with the highly-classified Omega Directive. When further investigation revealed that there may have been hundreds of Omega molecules, however, Janeway ordered the yield increased to eighty isotons, which Harry Kim remarked to be enough to destroy a small planet. Eventually it was discovered that the amount of molecules was too great for even a torpedo to destroy, so Janeway had to resort to using a harmonic resonance chamber to destroy nearly fifty percent of the molecules, using the torpedo to destroy the rest. (VOY: "The Omega Directive")

According to the video game Star Trek: Starfleet Command III, gravimetric torpedoes were the standard heavy weapon used by the starships of the Borg Collective. The torpedoes utilize an advanced graviton inversion field to cause a gravimetric shear in its target, causing severe structural damage.

Gravimetric torpedoes are a special weapon available in the video game Star Trek Online, and have the special effect of creating miniature gravity wells when impacting their targets.