Neutrino
Neutrinos are elementary particles, that have very small masses, and hence travel at close to the speed of light.
Although they interact very rarely, a starship's sensor array contains instruments capable of detecting them.
The presence of elevated neutrinos may indicate the presence of a ship – possibly cloaked.
The Bajoran wormhole also emits neutrinos before opening, which gives Deep Space 9 a moment to prepare before any ship comes through.
References
- Duras accused Mogh, Worf's father, of sending coded neutrino pulses to signal the Romulans, leading to the Khitomer Massacre.
- A neutrino field was used to isolate the Enterprise-D's cargo bay when aliens posessed three of its crew members.
- Deep Space 9 recognized that neutrino emissions were an indicator that the Bajoran wormhole was opening.
- Major Kira Nerys identified a Maquis ship by its neutrino signature in the Badlands.
- Data detected neutrino emissions coming from a lake on the Ba'ku planet and discovered a cloaked Federation holo-ship.
