The following is a very small selection of the anomalies which Federation Starships have encountered during their travels through our galaxy.
A region located near to Cardassian and Bajoran space, the Badlands is a dangerous place with a very heavy concentration of plasma storms. The storms are extremely difficult to navigate, most especially for large ships. During the Cardassian occupation the Bajoran resistance took to hiding in the Badlands, since the large Cardassian warships were unable to follow the much smaller Bajoran craft into the region.1
After the end of the occupation the Maquis also took to hiding in the Badlands in order to hide from both the Cardassians and Starfleet. The Intrepid class was considered to be capable of safely navigating the plasma fields, although the Intrepid class USS Voyager was thought to have been lost when it attempted to pursue a Maquis Raider into the area in 2371. It later transpired that Voyager had been deliberately abducted from the Badlands by an advanced alien being, rather than having been lost to the storms.2
An area which surrounds the Ba'ku planet, the Briar patch is characterized by anomalies and pockets of metreon gas. Warp travel is impossible within the Briar patch, and Starships in the area need special modification in order to operate effectively. In 2375 the Enterprise-E was forced to enter the patch without modification. Whilst there the ship engaged in battle with two Son'a battleships. The Enterprise experienced significant difficulties, damaging its impulse manifolds. Nevertheless the Enterprise was able to use its Bussard collectors to scoop up some of the Metreon gas and detonate it in proximity to the Son'a ships, destroying one and damaging the other.3
A type of matter which is difficult to detect with normal sensor or scanner systems. Dark matter tends to be concentrated in nebulas4, although by some cosmological models the amount of dark matter in the universe as a whole is greater than the amount of normal matter.5
High concentrations of dark matter can create small gaps in the fabric of normal space. Normal matter passing through these areas can become momentarily phased in unpredictable ways, creating transient electrical currents similar to those created by a subspace distortion but without any trace of a subspace field.4
Dark matter can also act to degrade the performance of sensors against normal matter, making dark matter nebulas a good choice for hiding oneself. In 2374 Captain Sisko piloted his damaged Jem'Hadar vessel into a dark matter nebula in order to hide it from detection. Within he found an entire class M world which was undetectable from outside the nebula.6
Dark matter is also found outside nebulas. It has been speculated that a tertiary product of stellar consolidation could be a comet-like assemblage of dark matter. This would be strongly attracted to antimatter, which it would neutralize upon contact. Such a contact can lead to displaced protons in the materials involved and can induce forces sufficient to badly damage a Starship hull. In 2376 one of Voyagers shuttles encountered a phenomena which behaved initially in a manner similar to the proposed dark matter proto comet. On further investigation the crew discovered a new form of life composed of dark matter, although no significant degree of contact was established.7
In 2368 the USS Enterprise investigated FGC-47, a nebula which had formed around a neutron star. The nebula was composed of hydrogen, helium and trionium. On entering the nebula the ship experienced a strange drag effect which gradually reduced their speed. The effect was minor and the ship pressed on with its investigation of the area. On collecting samples of the nebula gas, the crew discovered that the nebula was permeated with filaments composed of a highly cohesive form of plasma. These filaments, which became visible when exposed to a high frequency warp field, created a resonant effect when they hit the ships shields, thus increasing the drag coefficient and reducing the ships speed for a given power output.
The Enterprise was able to chart the filaments within the nebula by running the warp field generators through the ships deflector grid to make them all visible, allowing it to make its way out of the nebula.8
A phenomenon which travels through subspace, occasionally moving into normal space for a time before returning. While in normal space subspace ellipses tend to sweep up various objects which are then carried along inside them. The ellipses can be billions of years old, and extremely ancient artefacts are sometimes discovered within them. The anomalies have only been encountered a handful of times; on October 19th, 2032, a subspace ellipse passing by Mars collided with and absorbed the Aries 4, one of the first manned spacecraft Mankind sent to the planet. This marked mankind's first encounter with a spatial anomaly, and almost derailed the Mars program entirely.
In 2376 USS Voyager encountered the same ellipse. The emergence of the phenomenon caused level 9 gravimetric distortions to emenate from subspace, and Voyager measured its total energy at 30 million Terajoules. The ellipse was strongly attracted towards Voyager, approaching at sufficient speed to prevent the starship from outrunning it at impulse and produced interference which disrupted the ships warp drive, making escape extremely difficult. The gravimetric stresses created are sufficient to rip the hull plating off a Starship, and no vessel which has passed close to a graviton ellipse has survived the encounter.9
Fortunately, Seven of Nine recognized the ellipse as Borg spatial anomaly 521 and recalled that it was attracted to objects which emit electromagnetic energy. She advised cutting power and reversing shield polarity, measures which prevented further pursuit and allowed Voyager to escape the anomaly.
Upon scanning the ellipses interior, Voyager detected a stable region within which gravimetric disturbances were negligible. The scans located some 2.8 billion compounds inside, including the hull materials of the Aries 4. Voyagers crew modified the shields of the Delta Flyer to allow it to penetrate the ellipse and discovered the space craft nearly intact within. Whilst the Flyer was within the ellipse the anomaly collided with a dark matter asteroid, badly damaging the shuttlecraft. Although this made retrieving the Aries impossible, they were able to recover the body of Lieutenant John Kelley from the capsule and give it a proper burial.9
A relatively common phenomena, ion storms can present a significant hazard to ships which encounter them. The storms can cause damage to various systems, depending on their strength.10 Level 5 ion storms are not regarded as much of a threat to ships, while level 7 storms are sufficient to badly damage shuttlecraft. A level 8 storm is sufficient to present a danger to starships such as the Intrepid class.11
The NCC-1701 Enterprise carried a pod which had to be ejected during ion storms. In 2267 the ship ejected its pod apparently with engineer Ben Finney still within it, causing Captain Kirk to be court martialled. Kirk was cleared when it was revealed that in fact Finney had faked his own death to gain revenge on Kirk for reporting a mishap he had made some time previously.10 When the Enterprise visited the Halkan planet later in the same year, an ion storm disrupted the ship's transporter system and caused several of its officers to be swapped with crew members of an Enterprise from an alternate universe.12
In 2375 the Delta Flyer was badly damaged by an ion storm and crash landed on an M class planetoid. Voyager managed to weather a level 5 storm and rescue the Flyer, shortly before a level 8 storm arrived.11
A neutronic wavefront is a phenomenon which is produced when two neutron stars collide. The collision forms a ring structure which expands outwards at a significant fraction of the speed of light, presenting a danger to spacecraft which encounter it.13
Prior to 2052 the Vulcan science vessel T'Plana was destroyed when it was caught in a Class 5 neutronic wavefront. In 2151 the NX-01 encountered a neutronic storm; unable to outrun it even at maximum warp speed, the crew were forced to shelter in a heavily shielded catwalk in one of the ship's nacelles to shield themselves from the radiolytic isotopes in the storm. The ship was almost captured by members of the Takret militia, who are naturally immune to the radiation carried by these storms.14
In 2376 Dala told two Telsian miners that she had to leave orbit because of an approaching neutronic storm; the deception was part of her plot to swindle the miners out of a cargo of Bolomite#6141}
In 2376 USS Voyager encountered a Class 9 neutronic wavefront which was expanding at 200,000 kilometres per second, approximately 66% of light speed. The phenomena extended for 3.6 light years, indicating that the collision had taken place several years previously. Voyager was unable to escape the wavefront at warp speeds as the neutron radiation it was emitting was disrupting plasma flow within the ships systems. Lacking sufficient impulse speed to escape the wavefront, Voyager generated an inverse warp field in order to lock itself within position, inoculated the crew against the expected radiation increase, and attempted to ride the storm out.13
While the ship was able to weather the majority of the wavefront successfully, the neutronic gradient increased towards the trailing edge. The ship experienced energies of well over 90 million terajoules. The inverse warp field destabilized and Voyager was dragged along with the wavefront, inflicting significant damage on the ship. Fortunately Voyager was able to use its main deflector dish to cut a path through the front and escape.13
Encountered by the Enterprise in 2267, Murasaki 312 is a quasar like phenomenon of great size and power. Following their standing orders, the Enterprise investigated the anomaly and discovered that it had a negative ionic concentration at 1.64x109 metres and was emitting radiation at a wavelength of 370 Angstroms, with harmonics upward along the entire upper spectrum. The effect had ionized an entire sector, covering at least four solar systems in the vicinity of the ship. The effects of Murasaki badly compromised the performance of both communications and sensor systems across this region.
The Enterprise launched a shuttlecraft to investigate the phenomenon, but the craft was disabled and dragged into the centre of Murasaki 312 where it crash-landed on Tarsus II. The shuttles crew were able to repair it sufficiently to launch again and make a brief orbital flight. Fortunately the Enterprise was still in the area and was able to recover those crew members who had survived the planet.
Although Murasaki 312 began to dissipate somewhat as the Enterprise left, the anomaly continued to exist for at least the next century. In 2367 the Enterprise-D conducted some sensor scans of Murasaki 312 whilst passing by.15
Encountered by Voyager in 2371, the region of twisted space initially caused various minor systems failures on board the ship, most notably in the communications system. When the captain attempted to send officers to the strategic portions of the ship it quickly became clear that something much stranger was happening. The vessels layout had changed radically. Worse, the layout was continuing to change on a second by second basis, without the crew being at all aware of the changes.
Captain Janeway and Ensign Kim attempted to access the bridge via the Jefferies tube system, but instead encountered some form of field which appeared to be distorting space itself. Janeways arm became enveloped in the field and although Kim was able to free her, the after-effects resulted in severe delirium.
All of the crews attempts to free the ship from the effect or to counter or even slow it failed, and eventually they resigned themselves to allowing the effect to take its course. The distortion enveloped the entire ship then vanished of its own accord, leaving Voyager and her crew completely undamaged. After the distortion had ended, Voyagers crew discovered that 20 million gigaquads of new information had been downloaded into the ships computer systems.
Even now it is unclear exactly what the nature of the distortion effect was. It may have been caused by a vessel occupying multidimensional space, or indeed may have been a vessel of some form in itself. It is even possible that the field was a life form in its own right. It seems that an answer may well lie in the information Voyager collected, and this will likely be the subject of much intensive study when and if the ship is able to return home.16
A region of space which extended over approximately 2,000 light years, encompassing many solar systems. The edge of the expanse came within 50 light years of Earth as of 2153. It was surrounded by thermobaric clouds which made it dangerous to enter17, and impossible to leave.18 The age of the Expanse is uncertain, though the Triannon believed that it was a supernatural phenomena which had been created in approximately 1153.19 Both Vulcans and Klingons were extremely reluctant to enter the expanse; in 2133 a Klingon ship emerged from the Expanse with the entire crew 'anatomically inverted', their bodies splayed open - and still alive despite their horrific injuries.17 The Vulcan ship Seleya entered the Expanse in 2152; all contact was lost with the ship, and when the Vaankara was sent to investigate the crew rapidly went insane and murdered one another.20
In 2152 the NX-01 Enterprise received information that the recent attack on Earth had been carried out by the Xindi, a species native to the Delphic Expanse.17 The ship spent almost ten months searching the area, and eventually managed to prevent a further attack.21 During the mission, Captain Archer learned that the Expanse was being maintained by a network of huge artificial spheres22 - at least 78 in all.23 The spheres were created deliberately in order to reconfigure the nature of space in the Milky Way galaxy to pave the way for an invasion by an alien species from another dimension.24 The various anomalies of the Expanse occurred where the intense gravimetric waves generated by different spheres interacted.25 These anomalies varied in type and effect; some merely interfered with artificial gravity fields in unusual ways22, others could be massvely damaging to any ship passing through them.26
In 2154 the NX-01 was able to destroy Sphere 41, a key element in the network. This action instigated a chain reaction which destroyed all the spheres. Freed of their influence, the region began to rapidly return to normal space.21
An energy wave which passes through our galaxy every 39.1 years, the Nexus was encountered by the Enterprise-B in 2293 when the ship moved to assist some El Aurian refugee ships which had become caught in it. The ships were destroyed, although the Enterprise managed to rescue several dozen survivors first. The Starship was badly damaged in the mission, leading to the apparent death of Admiral Kirk.27
In 2371 the Nexus returned. Captain Picard of the Enterprise-D discovered a plot by Dr. Soren, one of the original El Aurian survivors of the Nexus, to return to the anomaly by altering its course to take it near to a habitable planet. Soran was destroying stars using a trilithium torpedo in order to change gravitational fields and so alter the course of the Nexus. He successfully destroyed the Amagosa system, but was ultimately prevented from destroying the Veridian system by Picard's intervention.27
Picard was able to enter the Nexus himself during the mission. He discovered that it was some form of inter-dimensional vortex whose physical characteristics were shaped by the thoughts of the inhabitant into a perfect universe - one in which every fantasy could be fulfilled, forever. Soran had been determined to return in order to live out his own perfect life, and even Picard himself found it difficult to leave once he had entered.27
A type of anomaly which is considered high dangerous by the Federation after a dozen Starships were lost whilst investigating one in the Alpha Quadrant. Voyager encountered a Particle Fountain in the Delta Quadrant when the artificial intelligence system aboard the shuttle Alice attempted to force Tom Paris to pilot her into it. Alice claimed that the Fountain was a way for her to reach home, indicating that they may be gateways to another dimension of wormhole-like phenomena.28
A type of anomaly which was believed to be purely theoretical until 2368. Null space pockets form during the creation of a star system when clouds of interstellar dust and gas coalesce. Turbulent regions of magnetic and gravitational fields can develop, and if certain conditions occur these fields can form null space. The J'naii lost a shuttle into a pocket of null space in 2368, though the crew was subsequently recovered with the help of the Enterprise-D.29
A phemonenon which Voyager encountered in the Delta Quadrant. A plasma drift could occupy half of an entire sector. Interference from them could cause problems with at least some sensor systems. Federation ships could safely enter a plasma drift, though turbulence was possible.30 When Neelix was a child a huge plasma drift passed through the Talaxian system, blocking out the stars and moons for months.31
Phenomenon encountered by Voyager in 2377. The rift emits high levels of neutrinos and chronotons and a gravimetric surge which is capable of overloading a Starship's inertial dampers. Should a chrono-kinetic surge interact with the ship's warp core it can cause it to destabilise, resulting in different sections of a nearby object to become dislocated in time - so for instance a person hit with a burst may have organs which are radically different ages or a ship may have different parts located in different "time zones". Voyager was fractured into thirty seven different zones when it encountered a spatial rift.32
Located at the edge of our galaxy, the galactic barrier is a vast energy field which was first encountered by Humans in the year 2065 by the SS Valiant. The ship was lost during the encounter; the loss remained a mystery until two centuries later when the USS Enterprise recovered a distress beacon from the Valiant with some fragmentary records of the encounter.33
The Enterprise proceeded to its own encounter with the barrier, where it was badly damaged. In the aftermath two members of the crew, Gary Mitchell and Elizabeth Dehner, experienced strange side effects; silvered eyes and geometrically increasing ESP powers. Both had scored rather highly on ESP tests in the past, and apparently the encounter with the barrier had some effect on them which led their powers to increase hour by hour afterwards, although Mitchell's the effects on Dehner were rather delayed compared to Mitchell.33
Captain Kirk, faced with an officer who was coming to regard his shipmates as little more than entertaining pets, decided to maroon Mitchell on a nearby planet. Mitchell used his powers to escape, and Kirk was forced to kill him with some help from Dehner.33
The Enterprise encountered the galactic barrier again in 2268 whilst carrying the Medusan Ambassador Kollos. A passenger, driven mad when he saw Kollos, took the ship through the barrier to the energy void beyond. The ship was able to return with Kollos's help.34
A massive energy field located at the center of the Milky Way galaxy, the Great Barrier was for many years a complete mystery. It was clearly visible to the naked eye, yet sensors reported nothing there at all. Yet no probe sent into the barrier had ever returned from it, indicating that something dangerous lay inside.35
In 2285 the Starship Enterprise finally penetrated the Great Barrier after the ship was hijacked by Sybock and his followers. A Klingon Bird of Prey was able to follow the Enterprise through. Within, they discovered the fabled planet of Sha'ka'ree, which was the home to a malevolent energy being - although perhaps prison would be a better term. The barrier thus apparently served to isolate this being and prevent it from injuring others; prison walls, in effect.35
A cosmic string is an extremely narrow filament, no wider than a single proton but capable of generating gravitational fields as strong as a black hole. They are normally invisible to sensors directly, though they can be detected by the hyper-acceleration effect they have on interstellar gas nearby. They also emit a characteristic range of subspace frequencies due to the decay of particles on their event horizon.36
A species of two dimensional creatures live within cosmic strings; in 2367 the Enterprise-D was immobilised within a swarm of such creatures as they returned to their home, a 107 km long cosmic string. The ship was able to confuse the creatures enough to escape.36
A cosmic string is notably different to a quantum filament.37