4.1 Planetary Phenomena

These are things associated with planets and solar systems. In the astronomical scheme of things, these are pretty small, but they are often of the most interest to our human space explorers. Unique items already seen are marked "Used."

comets dislodged from an Oort Cloud: Yet another form of gravitationally induced threat. Many solar systems apparently have a large belt of frozen comets orbiting far beyond the planets' orbit. It is possible for some passing object to gravitationally "knock" a large number of these comets out of their distant orbits, to fall toward the sun. If this happens, it is possible that a number of these might hit one or more of the planets in the solar system. Such an occurrence is one theory to the disappearance of Earth's dinosaurs.

Class M planet: In Star Trek astronomical parlance, this is a planet which approximates conditions of our own Earth, and is thus suitable for the support of humanoid life. Most Star Trek stories involve Class M planets, especially when our people have to beam down to the planets' surface.

destruction of a moon from tidal stresses: This might result in a new ring around the planet. Among planets with several moons, it is not uncommon for the gravity-induced tidal stresses between the moons and the planet to cause one or more of the moons to be torn apart, resulting in the creation of Saturn-like rings. This would certainly be a hazard to anyone living on that moon, or to a spacecraft in orbit near the moon. Additionally, it is possible that the moon's disintegration could cause an increase in meteor activity on the planet's surface.

gas giant planet: Several planets in our own solar system are Gas Giants, like Jupiter. Such planets tend to be characterized by poisonous atmospheres of methane and hydrogen, relatively high gravity, the absence of any stable surface, and very high magnetic fields and radiation belts. These latter two items are not a threat to Voyager under normal conditions because of its powerful (and normally very reliable) shielding systems. On the other hand, in the unlikely circumstance that those shields should fail....

ionized gas torus: A volcanic moon, (again, like Io orbiting Jupiter) can create a doughnut-shaped cloud of very tenuous gas along its orbital path around the mother planet. Such a gas torus can become ionized from the planet's magnetic field, and could interfere with the function of a starship's sensors.

near-collision of two planets: Another form of interaction between two planetary bodies might be a near-collision in which one or both planets is gravitationally slingshotted out of the solar system. This is a very unlikely occurrence in a stable system, but would certainly be unwelcome news to anyone living there.

panspermia: A theory suggesting that primitive microbes exist throughout the universe, and that life on Earth and other planets came from these microbes.

planetary nebula: A large, swirling, pizza-shaped cloud of dust and gas, which is a solar system in the making. The gases near the center may eventually compress enough to form a star, and the stuff around it may eventually coalesce to form planets. There is a planetary nebula in the main title sequence of our series.

planetary tidal stresses: When a planet is in an orbit near a star, another planet, or a moon, the gravitational stress can cause tides, much as we have in Earth's oceans. If the tides are sufficiently great, it is conceivable that the stresses could affect the planet's structure — possibly enough to eventually tear apart the planet.

protoplanet: An embryonic clump of gases and dust forming in a planetary nebula, a planet in the making.

ring system: Some planets, like our own Saturn, have beautiful rings orbiting them. Such rings seem to be composed of billions of small rock or ice fragments. It is possible that some rings are formed when a planet's moon is torn apart by gravitational or tidal stresses.

super-Jovian planet ignition: Imagine a gas giant planet, about 75 times the mass of Jupiter. If it should happen to collide with another Trans-Jovian planet (about ten times the mass of Jupiter), it would become heavy enough for gravity to cause the planet to suddenly begin fusion. In other words, the planet would become a small star (to the great annoyance of nearby property owners). Used.

volcanic plumes: Some small planets and asteroids have live volcanoes on their surface. In some cases, (like the moon Io, orbiting Jupiter) the volcanoes are powerful enough and the planet's gravity is weak enough that it can create a plume of ash and gasses rising hundreds of kilometers above the surface. Such a volcano could conceivable threaten a small spacecraft in a low orbit.