Tachyon

In Solar Storms, tachyons are not particles, or at least, not particles in the conventional sense. Despite various efforts to come up with a better term, it has come to apply to a phenomenon that traverses space at a speed significantly faster than light. Instead of being detected directly, they cause telltale effects while passing across space in a line of effect, though it takes an extremely powerful signal to be picked up over the background noise of the Universe.

Regardless of what they actually are, tachyons do not travel backwards in time in any frame of reference. Using them, it is in theory possible to establish a common frame of reference between two objects, though currently this only applies to the three satmes in the Solar System.