In the fictional Star Trek universe, the Omega Particle is an extremely unstable molecule with enough internal energy to destroy a civilization by disrupting subspace and making warp travel impossible.

Omega can be synthesized from Boronite Ore, and can consist of one molecule or as a cluster. The more there are, the more danger it represents. In one instance, an Omega molecule was created by scientists on a base in the Lantaru Sector. Omega destabilized and exploded, destroying the base and disrupting subspace throughout the sector.

The Borg refer to it as Particle 010 and consider it a model of perfection as it consists of a a very complex pattern of energy making one stable whole. Seven of Nine's attitude towards it was almost religious; the Borg consider it to be a representation of perfection.

Because of its dangerous nature, all Starfleet admirals and captains have a standing order, the Omega Directive, to destroy all Omega particles. This can be done relatively safely with a special "gravimetric charge". Since it makes a tempting power source, its existence is a closely guarded secret, information about it limited to Starfleet captains and flag officers.

In particle physics, the omega minus particle is a type of hyperon, with the rest energy of 1672 MeV, the charge of -1, depending on the variety, spin of 3/2, and a strangeness of -3.

From http://en.wikipedia.org/wiki/Hyperon The omega minus baryon (Ω-) is composed of three strange quarks. Its discovery was a great triumph in the study of quark processes, since it was found only after its existence, mass, and decay products had already been predicted.