Hypothetical astronomical objects
36 entries in the Hypothetical Astronomical Objects compendium.
Hypothetical astronomical objectUnconfirmed celestial bodies proposed throughout history.Antimatter cometHypothetical comets of antimatter, never observed, proposed to explain phenomena.Chrysalis (hypothetical moon)Hypothetical moon whose breakup may have created Saturn's rings.Claimed moons of EarthHistorical claims of additional Earth moons remain unconfirmed.Coatlicue (star)Hypothetical massive star that may have birthed the Sun.Cosmic stringHypothetical 1D defects from early universe symmetry breaking.Dark galaxyHypothetical galaxies of dark matter, invisible to optical telescopes.Disrupted planetA planet destroyed by a star or black hole.Dyson–Harrop satelliteHypothetical satellite generating power from the solar wind.ExomoonExtrasolar moons remain unconfirmed but are theorized and sought.Fifth GiantHypothetical ice giant ejected from the early Solar System.Fifth planet (hypothetical)Hypothetical former fifth planet between Mars and Jupiter.Five-planet Nice modelA revised model of early Solar System evolution with five giant planets.Gaia SausageRemains of a dwarf galaxy that merged with the Milky Way.Galaxy X (galaxy)A hypothesized dark dwarf galaxy behind the Milky Way's disk.Hubble bubble (astronomy)A local void causing faster cosmic expansion near Earth.Hycean planetHypothetical planets with hydrogen atmospheres and liquid water oceans.Hyperbolic asteroidAsteroids with unbound solar orbits and no outgassing.Hypothetical moon of MercuryA suspected moon of Mercury was actually a star.Isotropic beaconHypothetical uniform EM beacon for interstellar communication.M32pHypothesized former galaxy merged into Andromeda 2 billion years ago.Messier 102A disputed Messier object with uncertain identity.MultiverseHypothetical set of all universes, debated in science and philosophy.Neith (hypothetical moon)Hypothetical moon of Venus, observed but never confirmed.Nemesis (hypothetical star)Hypothetical companion star proposed to explain periodic mass extinctions.Phaeton (hypothetical planet)Hypothetical destroyed planet proposed to explain the asteroid belt.Planet NineHypothetical planet proposed to explain distant Solar System orbits.Planet VHypothetical fifth terrestrial planet proposed to explain the Late Heavy Bombardment.Planets beyond NeptuneHypothetical worlds beyond Neptune, from Planet X to Planet Nine.Quark-novaHypothetical explosion from neutron star to quark star conversion.Rings of EarthHypothetical ring system that may have existed around Earth.Shell collapsarHypothetical compact object without a central singularity.SubsatelliteA hypothetical natural satellite orbiting a moon.SynestiaHypothesized doughnut-shaped mass of vaporized rock from planetary collisions.Theia (hypothetical planet)Hypothetical planet whose collision with Earth formed the Moon.Themis (hypothetical moon)Unconfirmed Saturnian moon announced by William H. Pickering in 1905.
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