User:Spacepotato/Unsorted


 * 1E161348-5055
 * 2006 definition of planet
 * 2dF Galaxy Redshift Survey
 * 2MASS
 * 2MASS 0532+8246
 * 2MASS J07491255+5552336
 * 3C 191
 * 3C 212
 * 3C236
 * 3C 273
 * 3C 279
 * 3C 295
 * 3C 305
 * 3C 390.3
 * 3C 449
 * 3C 47
 * 3C 48
 * 3C58
 * 3C 75
 * 3C 83.1B
 * 3C 9
 * 3D/Biela
 * 4C 37.11
 * 4Frontiers Corporation
 * 4U 0142+61
 * 4U 0614+091
 * 4U 1700-37
 * 5D/Brorsen
 * 6Q0B44E
 * A1689-zD1
 * AB Doradus moving group
 * Abell 1689
 * Abell 1835
 * Abell 1835 IR1916
 * Abell 2029
 * Abell 2218
 * Abell 2667
 * Abell 3266
 * Abell 400
 * Abell 520
 * Abell 754
 * Abell catalogue
 * Abell S740
 * Abeona Mons
 * Accelerating universe
 * Accretion disc
 * Achernar
 * Achondrite
 * Acidalia Planitia
 * ACIGA
 * Active galactic nucleus
 * Adam Block
 * A. David Andrews
 * Adélie Land meteorite
 * Adeona family
 * Adhil
 * Adrastea (moon)
 * Adrián Galád
 * ADS 16402
 * AdS black hole
 * Advanced Composition Explorer
 * Advanced Technology Solar Telescope
 * Aegir (moon)
 * AEGIS (astronomy)
 * AFGL 2591
 * Age of the universe
 * AIGO
 * Air Force Maui Optical and Supercomputing observatory
 * Air Quality Index
 * Air quality modeling
 * Air shower (physics)
 * Airy-0
 * Airy (Martian crater)
 * Aitken Double Star Catalogue
 * Aitne (moon)
 * Åke Wallenquist
 * Akihiko Tago
 * Akimasa Nakamura
 * Akira Natori
 * Akna Montes
 * Aladin Sky Atlas
 * Alain Maury
 * Alamo bolide impact
 * Alan C. Gilmore
 * Alan Hale (astronomer)
 * Alan Magee
 * A. Laurent
 * Alba Patera
 * Albareto (meteorite)
 * Albert F. A. L. Jones
 * Albert George Wilson
 * Albert Marth
 * Albiorix (moon)
 * Albireo
 * Albor Tholus
 * Alcides Moreno
 * Aldebaran
 * Alderaan (astronomy)
 * Aldo Di Clemente
 * Alexander F. I. Forbes
 * Alexander Pravda
 * Alexandre Schaumasse
 * Alex Cruz
 * Alexis Brandeker
 * Alfred Bohrmann
 * Alfredo Caronia
 * Alfred Schmitt
 * Algol
 * Algol paradox
 * Algol variable
 * ALH84001
 * Alíz Derekas
 * Allan Sandage
 * Allende meteorite
 * All Sky Automated Survey
 * Al Niyat
 * Alpha² Canum Venaticorum variable
 * Alphabus
 * Alpha Centaurids
 * Alpha Cygni variable
 * Alpha Persei Cluster
 * Alphard
 * Alpher-Bethe-Gamow paper
 * Alphonse Louis Nicolas Borrelly
 * Altair
 * Altair (spacecraft)
 * Al Thalimain
 * Álvaro López-García
 * Alvin (crater)
 * AM 0644-741
 * AM-2
 * Amalthea (moon)
 * Amazonis Planitia
 * AMC-18 (satellite)
 * AMC 3
 * AM CVn star
 * American Association of Variable Star Observers
 * Ametlla de Mar Observatory
 * Amor asteroid records
 * Amphidromic point
 * Amphoterite
 * Am star
 * Amy B. Jordan (astronomer)
 * Anala Mons
 * Analemma
 * Ananke group
 * Ananke (moon)
 * Andrea Boattini
 * Andrea Di Paola
 * André Patry
 * Andrew Graham (astronomer)
 * Andrew Lowe
 * Andromeda Galaxy
 * Andromeda I
 * Andromeda II
 * Andromeda III
 * Andromeda IV
 * Andromeda IX
 * Andromeda-Milky Way collision
 * Andromeda's satellite galaxies
 * Andromeda V
 * Andromeda VIII
 * Andromeda X
 * Andromedids
 * Àngel López
 * Anglo-Australian Near-Earth Asteroid Survey
 * Angular size redshift relation
 * Anik (satellite)
 * Anlaug Amanda Djupvik
 * Annibale de Gasparis
 * Anomalous X-ray pulsar
 * ANSMET
 * Antares
 * Antennae Galaxies
 * Anthe (moon)
 * Anthropic principle
 * Anticenter shell
 * Anti-greenhouse effect
 * Antitaenite
 * Antlia Cluster
 * Antlia Dwarf
 * Antoniadi (Martian crater)
 * Antonín Mrkos
 * Antonio Vagnozzi
 * Anton Staus
 * Aoede (moon)
 * Apache Point Observatory Lunar Laser-ranging Operation
 * Ap and Bp star
 * APM 08279+5255
 * Apollo 1 Hills
 * Apollo Applications Program
 * Apollo asteroid records
 * Apollo Lunar Module
 * Apollo Lunar Surface Experiments Package
 * Apollo program
 * Apparent horizon
 * Apparent weight
 * Appearance of extrasolar planets
 * April 2005 lunar eclipse
 * Apse line
 * Apsis
 * Apstar VI
 * Aquariids
 * Aquarius Dwarf
 * Aram Chaos
 * Arcadia Planitia
 * Arche (moon)
 * Arches Cluster
 * Arctic Mars Analog Svalbard Expedition (AMASE) 2006
 * Arcturus
 * Arcturus stream
 * ArDM
 * Ardra (nakshatra)
 * Areocentric orbit
 * Areostationary orbit
 * Areosynchronous orbit
 * Ares Vallis
 * Argo (crater)
 * Argo Navis
 * Argument of periapsis
 * Argyre Planitia
 * Ariel (moon)
 * Arietids
 * Arjuna asteroid
 * Armstrong Limit
 * Arno Arthur Wachmann
 * Arnold Richard Klemola
 * Arp 104
 * Arp 107
 * Arp 220
 * Arp 299
 * Arp 87
 * Artemis Project
 * Arthur C. Clarke
 * Artificial gravity
 * Asalesha Nakshatram
 * Ascraeus Mons
 * Ashen light
 * Ashvini
 * Asiago-DLR Asteroid Survey
 * Aspects of Venus
 * Assyrian eclipse
 * Asterism (astronomy)
 * Asteroid belt
 * Asteroid deflection strategies
 * Asteroid family
 * Asteroid moon
 * Asteroid spectral types
 * Asteroseismology
 * Astos
 * Astra 1B
 * Astra 1C
 * Astra 1D
 * Astra 1KR
 * Astra 2A
 * Astra 2D
 * Astrobotic Technology
 * Astrology
 * Astrology and astronomy
 * Astrometric binary
 * Astronomer
 * Astronomical algorithm
 * Astronomical catalog
 * Astronomical constant
 * Astronomical naming conventions
 * Astronomical object
 * Astronomical seeing
 * Astronomical survey
 * Astronomical symbols
 * Astronomical transit
 * Astronomical unit
 * Astronomische Gesellschaft Katalog
 * Astronomy
 * Astronomy in Chile
 * Astronomy on Mars
 * Astrophysical maser
 * Asymptotic giant branch
 * Ataxite
 * Aten asteroid records
 * Athabasca Valles
 * ATHLETE (robot)
 * Atlantis basin
 * Atlas (moon)
 * Atlas of Peculiar Galaxies
 * Atmosphere
 * Atmosphere of Jupiter
 * Atmosphere of Mars
 * Atmosphere of Mercury
 * Atmosphere of the Moon
 * Atmosphere of Titan
 * Atmosphere of Triton
 * Atmosphere of Uranus
 * Atmosphere of Venus
 * Atmosphere (unit)
 * Atmospheric diffraction
 * Atmospheric Dispersion
 * Atmospheric duct
 * Atmospheric escape
 * Atmospheric models
 * Atmospheric pressure
 * Atmospheric waveguide
 * Atsuo Asami
 * Atsushi Sugie
 * Atsushi Takahashi
 * Atutahi
 * A-type asteroid
 * Aubrite
 * Audrey C. Delsanti
 * August 1989 lunar eclipse
 * August 2007 lunar eclipse
 * August 2008 lunar eclipse
 * August 2009 lunar eclipse
 * Augusta family
 * Auguste Charlois
 * August Kopff
 * Augusto Testa
 * Aurorae Sinus
 * Australia Mars Analog Research Station
 * Autonoe (moon)
 * Avernus Colles
 * A V star
 * Award star
 * Axino
 * Axion
 * AX J0851.9-4617
 * AXP 1E 1048-59
 * Azuara impact structure
 * Azure Dragon
 * Baade's Window
 * Babcock Model
 * Badlands Observatory
 * Baetylus
 * Baily's beads
 * Balanced flow
 * Baptistina family
 * Barium star
 * Barnacle Bill (Mars)
 * Barnard 147
 * Barnard (Martian crater)
 * Barnard's Loop
 * Barnard's Star
 * Barnes-Hut simulation
 * Barometric formula
 * Barred irregular galaxy
 * Barred lenticular galaxy
 * Barred spiral galaxy
 * Barringer Medal
 * Baryogenesis
 * Baryonic dark matter
 * Bastille Day event
 * BATTeRS
 * Battle of Halys (585 BC)
 * Bayer designation
 * Beagle (crater)
 * Beardsley meteorite
 * Bebhionn (moon)
 * Becquerel (Martian crater)
 * Bediasite
 * Beehive Cluster
 * Beer (Martian crater)
 * Behenian fixed star
 * Beijing Schmidt CCD Asteroid Program
 * Belinda (moon)
 * Bench Crater meteorite
 * Benjamin Jekhowsky
 * Bergelmir (moon)
 * Be star
 * Bestla (moon)
 * Beta Cephei variable
 * Beta Lyrae variable
 * Beta Pictoris Moving Group
 * Beta Taurids
 * Betelgeuse
 * Be X-ray binaries
 * Bharani
 * Bṛhaspati
 * Bianca (moon)
 * Bianchi classification
 * Biblis Patera
 * Bi-elliptic transfer
 * Big Bang
 * Big Bang nucleosynthesis
 * Big Bang Observer
 * Big Bounce
 * Big Crunch
 * Big Dipper
 * Big Rip
 * Binary pulsar
 * Binary star
 * Binary stars in fiction
 * Binary system (astronomy)
 * Bipolar nebula
 * Bipolar outflow
 * Birkat HaHammah
 * Bisei Spaceguard Center
 * BKL singularity
 * Black brane
 * Black drop effect
 * Black dwarf
 * Blackett effect
 * Black Eye Galaxy
 * Black hole
 * Black hole electron
 * Black hole information paradox
 * Black hole thermodynamics
 * Black moon
 * Black Stone
 * Black string
 * Black Tortoise
 * Blazar
 * BL Lac object
 * Blue blobs
 * Blue compact dwarf galaxy
 * Blue dwarf (red dwarf stage)
 * Blue giant
 * Blue moon
 * Blue shift
 * Blue straggler
 * Blue supergiant
 * Bohdan Paczyński
 * Bok globule
 * Boltzmann brain
 * Bond (Chinese constellation)
 * Bonneville (crater)
 * Bonnor-Ebert mass
 * Book of Fixed Stars
 * Boomerang Nebula
 * Boötes Dwarf Galaxy
 * Boötes void
 * Borasisi
 * Boss General Catalogue
 * Bouguer anomaly
 * Bouguer plate
 * Bounce Rock
 * Bow shock
 * Box orbit
 * Boyden Observatory
 * Boyer-Lindquist coordinates
 * BPM 37093
 * Brahin (meteorite)
 * Brane cosmology
 * Brasilsat B1
 * Brenham (meteorite)
 * Brian A. Skiff
 * Brian G. Marsden
 * Brian P. Roman
 * Brightest cluster galaxy
 * Bright giant
 * Bright Star Catalogue
 * Brocchi's Cluster
 * Bronze Star Medal
 * Brown dwarf
 * Brunswick star
 * B-type asteroid
 * Bubble Nebula (NGC 6822)
 * Budha
 * Bulge (astronomy)
 * Bullet Cluster
 * Burckle Crater
 * Burroughs (crater)
 * Butterfly Cluster
 * Butterfly Nebula (disambiguation)
 * B-V colour
 * B Velorum (supergiant)
 * B V star
 * BY Draconis variable
 * Calabash Nebula
 * Calar Alto Observatory
 * Calcium-aluminium-rich inclusion
 * Caldwell catalogue
 * Caliban (moon)
 * California and Carnegie Planet Search
 * California Nebula
 * Callirrhoe (moon)
 * Callisto (moon)
 * Caloris Montes
 * Calvera (neutron star)
 * Calypso (moon)
 * Campo Imperatore Near-Earth Objects Survey
 * Campo Imperatore Near Earth Object Survey
 * Cando event
 * Candor Chasma
 * Canes II Group
 * Canes Venatici Dwarf Galaxy
 * Canis Major Dwarf Galaxy
 * Canonical units
 * Canopus
 * Canso (crater)
 * Canyon Diablo (meteorite)
 * Cape Verde (Mars)
 * Cape York meteorite
 * Cappello romano
 * Captain Marvel (Marvel Comics)
 * Capture orbit
 * Carancas impact event
 * Carbonaceous chondrite
 * Carbonates on Mars
 * Carbon burning process
 * Carbon detonation
 * Carbon dioxide in the Earth's atmosphere
 * Carbon planet
 * Carbon respiration
 * Carbon star
 * Carina Dwarf
 * Carina Nebula
 * Carl A. Wirtanen
 * Carl Clarence Kiess
 * Carl Gustav Witt
 * Carlos Torres
 * Carlos Ulrrico Cesco
 * Carl Otto Lampland
 * Carl W. Hergenrother
 * Carme group
 * Carme (moon)
 * Carolyn S. Shoemaker
 * Carpo (moon)
 * Carrington rotation
 * Carte du Ciel
 * Cartwheel Galaxy
 * Casimir Marie Gaudibert
 * Cassini (Martian crater)
 * Cassiopeia A
 * Cassiopeia Dwarf
 * Castor Moving Group
 * Cataclysmic variable star
 * Catalina Sky Survey
 * Catalog of Components of Double and Multiple Stars
 * Catalogue of Galaxies and Clusters of Galaxies
 * Catalogues of Fundamental Stars
 * Cat's Eye Nebula
 * Causal dynamical triangulation
 * Cave Nebula
 * Caves of Mars Project
 * Caxias (crater)
 * Cayrel's Star
 * Celestial coordinate system
 * Celestial equator
 * Celestial mechanics
 * Celestial spheres
 * Centaur and TNO pronunciation
 * Centaur (planetoid)
 * Centaurus A
 * Centaurus A/M83 Group
 * Centaurus Cluster
 * Centaurus X-3
 * Central body
 * Central Fire
 * Centre de recherches en géodynamique et astrométrie
 * Cepheid variable
 * Cerberus Fossae
 * Cerberus Hemisphere
 * Cerberus (Martian albedo feature)
 * Ceres (dwarf planet)
 * Ceres in fiction
 * CERN Axion Solar Telescope
 * Cerro Tololo Inter-American Observatory
 * Cetus Dwarf
 * CfA Redshift Survey
 * Cha 110913-773444
 * Chad Trujillo
 * Chafe (crater)
 * ChaHα8
 * Chaldene (moon)
 * Chandrasekhar limit
 * ChaNGa
 * Chang-Refsdal lens
 * Chaotic Inflation theory
 * Characteristic energy
 * Charged black hole
 * Chariot (Chinese constellation)
 * Charles P. de Saint-Aignan
 * Charles T. Kowal
 * Charles W. Juels
 * Charon (moon)
 * Charon (mythology)
 * Chart datum
 * Chassigny (meteorite)
 * Cheonsang Yeolcha Bunyajido
 * Chereul 3
 * Chertan
 * Chiemgau impact crater
 * Chinese constellations
 * Chinese star maps
 * Chinguetti meteorite
 * Chiron (hypothetical moon)
 * Chondrite
 * Chondrule
 * Christian Heinrich Friedrich Peters
 * Christian Pollas
 * Christopher Aikman
 * Christopher McKay (planetary scientist)
 * Chromosphere
 * CH stars
 * Chthonian planet
 * Circinus Galaxy
 * Circular orbit
 * Circular polarization of starlight
 * Circumpolar constellation
 * Circumpolar star
 * Circumstellar disk
 * Cis-Neptunian object
 * Ciuacoatl Mons
 * CL0024+17
 * CL1358+62
 * Cl* 1806-20
 * Claes-Ingvar Lagerkvist
 * Claire Armstrong
 * Classical Kuiper belt object
 * Classical planets in Western alchemy
 * Clearing the neighbourhood
 * Climate of Mars
 * Climate of Uranus
 * Clovis comet
 * Clutter folding
 * Clutter (radar)
 * Clyde Tombaugh
 * CMBFAST
 * C. Michelle Olmstead
 * Coalsack Nebula
 * Code of the Lifemaker
 * CoKu Tau/4
 * Cold dark matter
 * Collinder catalog
 * Colonization of Ceres
 * Colonization of Europa
 * Colonization of Mars
 * Colonization of Mercury
 * Colonization of the Moon
 * Colonization of Titan
 * Colonization of Venus
 * Color-color diagram
 * Columbia Hills (Mars)
 * Coma Cluster
 * Coma (cometary)
 * Coma star cluster
 * Coma Supercluster
 * Comet
 * Comet Arend-Roland
 * Comet Bennett
 * Comet de Vico
 * Comet Donati
 * Comet dust
 * Comet Encke
 * Comet Galaxy
 * Comet Hale-Bopp
 * Comet Humason
 * Comet Hyakutake
 * Comet Ikeya-Seki
 * Comet IRAS-Araki-Alcock
 * Comet Kohoutek
 * Comet LINEAR
 * Comet Machholz
 * Comet McNaught
 * Comet McNaught-Russell
 * Comet Morehouse
 * Comet nucleus
 * Comet Pereyra
 * Comet Pojmański
 * Comet Rendezvous Asteroid Flyby
 * Comet Shoemaker-Levy 9
 * Comet Skjellerup-Maristany
 * Comet Skorichenko-George
 * Comet SWAN
 * Comet West
 * Comet White-Ortiz-Bolelli
 * Comet Zhu-Balam
 * Common envelope binary
 * Comoving distance
 * Compact star
 * Conamara Chaos
 * Cone Nebula
 * Conjunction (astronomy and astrology)
 * Constellation
 * Contact binary
 * Contributors to cosmology
 * Controlled atmosphere
 * Cooling flow
 * Co-orbital moon
 * Co-orbital satellite
 * Copenhagen University Observatory
 * Copernican period
 * Copernican principle
 * Cor Caroli
 * Cordelia (moon)
 * Cordell-Lorenz Observatory
 * Coriolis field
 * Cornelis Johannes van Houten
 * Corona
 * Coronal hole
 * Coronal loop
 * Coronal mass ejection
 * Coronal seismology
 * Cosmic Calendar
 * Cosmic censorship hypothesis
 * Cosmic distance ladder
 * Cosmic dust
 * Cosmic egg
 * Cosmic evolution
 * Cosmic gravitational wave background
 * Cosmic inflation
 * Cosmic infrared background
 * Cosmic latte
 * Cosmic microwave background experiments
 * Cosmic microwave background radiation
 * Cosmic neutrino background
 * Cosmic ray
 * Cosmic string
 * Cosmic variance
 * Cosmogenesis
 * Cosmogony
 * Cosmological constant
 * Cosmological decade
 * Cosmological horizon
 * Cosmological perturbation theory
 * Cosmological Principle
 * Cosmology
 * Cosmos
 * Counter-Earth
 * Coupling, Energetics and Dynamics of Atmospheric Regions
 * Crab Nebula
 * Crab Pulsar
 * Crater counting
 * Crescent
 * Crescent Nebula
 * Cressida (moon)
 * CRESST (Dark Matter Search)
 * Cretaceous–Tertiary extinction event
 * Crewe (crater)
 * Crew Exploration Vehicle
 * Crimean Astrophysical Observatory
 * Crivitz (crater)
 * Črni Vrh Observatory
 * Crucifixion eclipse
 * Cryogenic Dark Matter Search
 * C-type asteroid
 * Culmination
 * Cuno Hoffmeister
 * Cupid (moon)
 * Curved space
 * Cuspy halo problem
 * Custos Messium
 * CXO J164710.2-455216
 * CXOU J061705.3+222127
 * Cyanometer
 * Cyclic model
 * Cydonia Mensae
 * Cygnus A
 * Cygnus Arm
 * Cygnus OB2-12
 * Cygnus X-1
 * Cygnus X-3
 * Cyg OB2-12
 * Cyg OB2 -8A
 * Cyllene (moon)
 * Cyril V. Jackson
 * Cytherean
 * D/1892 T1
 * Dactyl (moon)
 * Dalton Minimum
 * DAMA/NaI
 * Dandelion Crater
 * DANEOPS
 * Daniel du Toit
 * Danjon scale
 * Dao Vallis
 * Daphnis (moon)
 * Darian calendar
 * Dark dune spot
 * Dark energy
 * Dark energy star
 * Dark fluid
 * Dark galaxy
 * Dark Horse (astronomy)
 * Dark matter
 * Dark matter behavior
 * Dark matter halo
 * Dark moon
 * Dark nebula
 * Dark star
 * Dark star (dark matter)
 * David C. Jewitt
 * David D. Balam
 * David Dunlap Observatory Catalogue
 * David H. Levy
 * David Hughes (astronomer)
 * David J. Asher
 * David J. Tholen
 * David L. Rabinowitz
 * Dawn (spacecraft)
 * Day length
 * DEAP
 * Debris disk
 * Decans
 * Deceleration parameter
 * December 1992 lunar eclipse
 * December 2001 lunar eclipse
 * December 2009 lunar eclipse
 * December 2010 lunar eclipse
 * December 2011 lunar eclipse
 * DEEP2 Redshift Survey
 * Deep Ecliptic Survey
 * Deep Impact (space mission)
 * Deep Lens Survey
 * Definition of planet
 * Degenerate matter
 * Deimos (moon)
 * Delaunay tessellation field estimator
 * Delaware Diamond
 * DeLisle Stewart
 * Delta Cancrids
 * Delta Scuti variable
 * Delta-v
 * Delta-v budget
 * DEN 0255-4700
 * DEN 1048-3956
 * Deneb
 * Deneb el Okab
 * Denebola
 * DENIS-P J020529.0-115925
 * Dennis di Cicco
 * Dennis K. Chesney
 * Density contrast
 * Desdemona (moon)
 * Desertec
 * Desert planet
 * De Sitter universe
 * Despina (moon)
 * Detached binary
 * Detached object (astronomy)
 * Deucalion
 * Deuteronilus Mensae
 * Diamond Cross
 * Diamond ring effect (solar eclipse)
 * Differential rotation
 * Diffuse interstellar band
 * Diffuse nebula
 * Diffuse sky radiation
 * Digitized Sky Survey
 * Dimensionless Hubble parameter
 * Dinorwic (crater)
 * Diogenite
 * Dione (moon)
 * Dipole anisotropy
 * Dipper (Chinese constellation)
 * Dirac large numbers hypothesis
 * Directional Recoil Identification From Tracks
 * DirecTV-10
 * DIRECTV-5
 * Disc galaxy
 * Disc (galaxy)
 * Discovery of cosmic microwave background radiation
 * Discovery of Neptune
 * Discovery of the Martian moons
 * Distance measures (cosmology)
 * Diurnal motion
 * Dog Days
 * Domain wall
 * Dong Fang Hong 02
 * Doppler imaging
 * Dorado Group
 * Dorsa Aldrovandi
 * Dorsa Andrusov
 * Dorsa Argand
 * Dorsa Barlow
 * Dorsa Burnet
 * Dorsa Cato
 * Dorsa Dana
 * Dorsa Ewing
 * Dorsa Geikie
 * Dorsa Harker
 * Dorsa Lister
 * Dorsa Mawson
 * Dorsa Rubey
 * Dorsa Smirnov
 * Dorsa Sorby
 * Dorsa Stille
 * Dorsa Tetyaev
 * Dorsa Whiston
 * Dorsum Arduino
 * Dorsum Azara
 * Dorsum Bucher
 * Dorsum Buckland
 * Dorsum Cayeux
 * Dorsum Cloos
 * Dorsum Cushman
 * Dorsum Gast
 * Dorsum Grabau
 * Dorsum Guettard
 * Dorsum Heim
 * Dorsum Higazy
 * Dorsum Nicol
 * Dorsum Niggli
 * Dorsum Oppel
 * Dorsum Owen
 * Dorsum Scilla
 * Dorsum Termier
 * Dorsum Thera
 * Dorsum Von Cotta
 * Dorsum Zirkel
 * Double Cluster
 * Double Helix Nebula
 * Double planet
 * Double quasar
 * Double star
 * Draco Dwarf
 * Dragon's Egg
 * Dragon Storm (astronomy)
 * Dream of Scipio
 * D region
 * D-type asteroid
 * Dumbbell Nebula
 * Dunhuang map
 * Durchmusterung
 * Dušan Kalmančok
 * Dust devil
 * Dwarf elliptical galaxy
 * Dwarf galaxy
 * Dwarf galaxy problem
 * Dwarf nova
 * Dwarf planet
 * Dwarf spheroidal galaxy
 * Dwarf spiral galaxy
 * Dwingeloo 1
 * Dwingeloo 2
 * Dynamical friction
 * Dynamical parallax
 * DY Persei variable
 * Dysnomia (moon)
 * Dyson's eternal intelligence
 * Dyson sphere
 * Eagle Nebula
 * Early bombardment phase
 * Early-type star
 * Earth
 * Earth and Moon
 * Earth Impact Database
 * Earthly Branches
 * Earth-Moon barycenter
 * Earth's atmosphere
 * Earth's gravity
 * Earth's orbit
 * Earth's rotation
 * Earth tide
 * Earth Trojan asteroid
 * East-Asian Planet Search Network
 * Eastern Mediterranean event
 * Eccentric anomaly
 * Eccentricity (mathematics)
 * Eccentricity vector
 * Eccentric Jupiter
 * Echus Chasma
 * Echus Montes
 * Eclipse
 * Eclipse Comet of 1882
 * Eclipse cycle
 * Eclipsing binary
 * Ecliptic
 * Edmund Neville Nevill
 * Édouard Jean-Marie Stephan
 * EDUSAT (Satellite)
 * Edward Emerson Barnard
 * Edward L. G. Bowell
 * Edwin Foster Coddington
 * Edwin Hubble
 * Effective temperature
 * Egg Nebula
 * Eighth Cambridge Survey
 * Einstein Cross
 * Einstein@Home
 * Einstein radius
 * Einstein ring
 * Ejecta
 * Ejnar Hertzsprung
 * Ekpyrotic
 * Elara (moon)
 * El Capitan (Mars)
 * Eleanor F. Helin
 * Electroweak epoch
 * Elephant's Trunk nebula
 * Elia Millosevich
 * Elizabeth Roemer
 * Ella Island
 * Elliptical galaxy
 * Elliptic orbit
 * Elongation (astronomy)
 * Elysium Mons
 * Elysium Planitia
 * Emil Ernst
 * Emission nebula
 * Emma Dean (crater)
 * Emptiness (Chinese constellation)
 * Empyrean
 * Encampment (Chinese constellation)
 * Enceladus (moon)
 * E Nebula
 * Energia Lunar Expedition
 * Eos Chasma
 * Ephemeris
 * Epimetheus (moon)
 * Episode list of The Universe (TV series)
 * Epoch (astronomy)
 * EPOXI
 * Equation of state (cosmology)
 * Equation of the center
 * Equation of time
 * Equations for a falling body
 * Equatorial bulge
 * Equatorial coordinate system
 * Equinox
 * Eratosthenian
 * Erebus (crater)
 * Ergosphere
 * Eric Walter Elst
 * Eridania Lake
 * Erinome (moon)
 * Eris (dwarf planet)
 * Eris (mythology)
 * Ernest Leonard Johnson
 * Ernst Wilhelm Leberecht Tempel
 * Erriapus (moon)
 * Escape orbit
 * Escape velocity
 * Eskimo Nebula
 * ESO 269-57
 * ESO 510-G13
 * Esperanto symbols
 * Esquel (meteorite)
 * Eta Aquariids
 * Eta Carinids
 * E-type asteroid
 * Euanthe (moon)
 * Eucrite
 * Eugène Joseph Delporte
 * Eugene Merle Shoemaker
 * Eukelade (moon)
 * Euler's three-body problem
 * Eunomia family
 * Euporie (moon)
 * Eurobird 1
 * Europa (moon)
 * Europa Orbiter
 * European Combined Geodetic Network
 * European Gravitational Observatory
 * European Mars Analog Research Station
 * European Space Information System
 * Eurydome (moon)
 * Evection
 * Evershed effect
 * Evolution of water on Mars and Earth
 * Exoplanetology
 * Exosphere
 * Exotic matter
 * Exotic star
 * Exploration of Jupiter
 * Exploration of Mars
 * Exploration of Neptune
 * Exploration of Saturn
 * Exploration of the Moon
 * Exploration of Uranus
 * Exploration Systems Architecture Study
 * Extended Groth Strip
 * Extended Net (Chinese constellation)
 * Extragalactic Distance Scale
 * Extrasolar moon
 * Extrasolar planet
 * Extraterrestrial atmospheres
 * Extraterrestrial cyclone
 * Extraterrestrial liquid water
 * Extraterrestrial materials
 * Extraterrestrial real estate
 * Extraterrestrial skies
 * Extremal black hole
 * Eyes Galaxies
 * EZ CMa
 * Faber-Jackson relation
 * Facula
 * Faint blue galaxy
 * Faint young sun paradox
 * Fallen Astronaut
 * Falling (physics)
 * False vacuum
 * Farbauti (moon)
 * Far side of the Moon
 * Fast Low-Ionization Emission Region
 * Features on Phobos and Deimos
 * February 1989 lunar eclipse
 * February 1990 lunar eclipse
 * February 2008 lunar eclipse
 * February 2009 lunar eclipse
 * Félix Aguilar Observatory
 * Fenrir (moon)
 * Ferdinand (moon)
 * Fermi glow
 * Fernand Courty
 * Fernand Rigaux
 * Fg (physics)
 * Fiasco (novel)
 * Field aligned irregularities
 * Field galaxy
 * Fifth Cambridge Survey of Radio Sources
 * Fifth planet (hypothetical)
 * Final anthropic principle
 * Fingers of God
 * First Cambridge Catalogue of Radio Sources
 * First contact (astronomy)
 * Five Chariots
 * Five-pointed star
 * Five star
 * Flag of Mars
 * Flame Nebula
 * Flamsteed designation
 * Flare star
 * Flashback (video game)
 * Flashline Mars Arctic Research Station
 * Flatness problem
 * Flattening
 * Flexiverse
 * Flight on Titan
 * Flora family
 * Flyby anomaly
 * Flying serpent (asterism)
 * Foe (unit of energy)
 * Follow the Drinkin' Gourd
 * Fomalhaut
 * Forbush decrease
 * Formation and evolution of the Solar System
 * Former constellations
 * Fornax Cluster
 * Fornax Dwarf
 * Fornjot (moon)
 * Fossil group
 * Four star
 * Four Symbols (Chinese constellation)
 * Fourth Cambridge Survey
 * Fox Fur Nebula
 * Fractal cosmology
 * Fra Mauro formation
 * Fram (crater)
 * Frame-dragging
 * Francesco Manca
 * Francesco Maria Grimaldi
 * Francisco (moon)
 * François Arago
 * François Gonnessiat
 * Frank B. Zoltowski
 * Frank Elmore Ross
 * Franz Kaiser
 * Frederici Honores
 * Frédéric Sy
 * Fred Lawrence Whipple
 * Free-air anomaly
 * Free drift
 * Free-fall
 * Free-fall time
 * Freimut Börngen
 * Friedrich Karl Arnold Schwassmann
 * Friedrich Tietjen
 * Frosty Leo Nebula
 * FSC15307+3253
 * F-type asteroid
 * Fukang (meteorite)
 * Full moon
 * Full moon cycle
 * Fundamental plane (elliptical galaxies)
 * Fusor (astronomy)
 * Future of an expanding universe
 * Fuzzball (string theory)
 * F V star
 * G117-B15A
 * G29-38
 * Gabriele Cattani
 * Gaea trilogy
 * Gal (acceleration)
 * Galactic anticenter
 * Galactic astronomy
 * Galactic Center
 * Galactic coordinate system
 * Galactic corona
 * Galactic cosmic ray
 * Galactic halo
 * Galactic tide
 * Galactic year
 * Galactocentric distance
 * Galactocentrism
 * Galatea (moon)
 * Galaxy
 * Galaxy 17
 * Galaxy 18
 * Galaxy 19
 * Galaxy 23
 * Galaxy 25
 * Galaxy 26
 * Galaxy 27
 * Galaxy 28
 * Galaxy 3C
 * Galaxy 4R
 * Galaxy AGN classification
 * Galaxy cloud
 * Galaxy color-magnitude diagram
 * Galaxy filament
 * Galaxy formation and evolution
 * Galaxy groups and clusters
 * Galaxy IV
 * Galaxy merger
 * Galaxy morphological classification
 * Gale (crater)
 * Galilean moons
 * Galileo (spacecraft)
 * Galle (Martian crater)
 * Gamma Cassiopeiae variable
 * Gamma Cephei Ab
 * Gamma Doradus variable
 * Gamma ray burst
 * Gamma ray burst emission mechanisms
 * Gamma ray burst progenitors
 * Ganesa Macula
 * Ganges Chasma
 * Ganymede (moon)
 * Gao-Guenie
 * Gary Hug
 * Gas giant
 * Gate orbit
 * Gauss' law for gravity
 * GCIRS 13E
 * GCRT J1745-3009
 * GD 358
 * GD 362
 * GD 66
 * Gefion family
 * Gegenschein
 * Geminga
 * Geminids
 * General Catalogue of Nebulae and Clusters
 * General Catalogue of Variable Stars
 * Genesis Rock
 * Genesis (spacecraft)
 * Geneva Extrasolar Planet Search
 * GEO 600
 * Geocentric model
 * Geocentric orbit
 * Geocorona
 * Geography of Mars
 * Geoid
 * Geological features of the solar system
 * Geologic Calendar
 * Geology of Mars
 * Geology of Mercury
 * Geology of the Moon
 * Geology of Venus
 * Geophysical MASINT
 * Geopotential
 * George Henry Peters
 * George Mary Searle
 * George Van Biesbroeck
 * Geostationary Operational Environmental Satellite
 * Geostationary orbit
 * Geostationary ring
 * Geostationary transfer orbit
 * Geosynchronous orbit
 * Gerard Kuiper
 * Germano D'Abramo
 * G-force
 * Ghost (Chinese constellation)
 * Giacobinids
 * Gianluca Masi
 * Giant diffuse galaxy
 * Giant impact hypothesis
 * Giant star
 * Gibeon (meteorite)
 * Gienah
 * Gilbert (Martian crater)
 * Giotto mission
 * Giovanni Battista Riccioli
 * Giovanni de Sanctis
 * Giovanni Domenico Cassini
 * Giovanni Schiaparelli
 * Girl (Chinese constellation)
 * Giuseppe Piazzi
 * Glass with embedded metal and sulfides
 * Glitch (astronomy)
 * Global Atmosphere Watch
 * Global Oscillations Network Group
 * Globular cluster
 * Globus Aerostaticus
 * Glowworm (astronomy)
 * Gnevyshev-Ohl rule
 * Goethe Link Observatory
 * Goldar
 * Gomez's Hamburger
 * Google Earth
 * Google Lunar X Prize
 * Google Moon
 * Gordon J. Garradd
 * Gorizont
 * Gould Belt
 * Gould Belt Survey
 * Graham E. Bell
 * Grand design spiral galaxy
 * Grand unification epoch
 * Grand unification theory
 * Granule (solar physics)
 * Graphical timeline from Big Bang to Heat Death
 * Graphical timeline of our universe
 * Graphical timeline of the Big Bang
 * Graphical timeline of the Stelliferous Era
 * Gravastar
 * Graveyard orbit
 * Gravimeter
 * Gravimetry
 * Gravitation
 * Gravitational acceleration
 * Gravitational binding energy
 * Gravitational biology
 * Gravitational collapse
 * Gravitational constant
 * Gravitational coupling constant
 * Gravitational field
 * Gravitational interaction of antimatter
 * Gravitational keyhole
 * Gravitational lens
 * Gravitational lensing formalism
 * Gravitational microlensing
 * Gravitational mirage
 * Gravitational redshift
 * Gravitational shielding
 * Gravitational time dilation
 * Gravitational two-body problem
 * Gravitational wave
 * Gravitational wave background
 * Gravitational wave detector
 * Gravitational well
 * Gravitation (astronomy)
 * Gravitation of the Moon
 * Gravitomagnetism
 * Gravitometer
 * Gravity anomaly
 * Gravity assist
 * Gravity darkening
 * Gravity drag
 * Gravity Field and Steady-State Ocean Circulation Explorer
 * Gravity Recovery and Climate Experiment
 * Gravity Research Foundation
 * Gravity turn
 * GRB 050509b
 * GRB 050904
 * GRB 060218
 * GRB 060614
 * GRB 070125
 * GRB 080319B
 * GRB 990123
 * Great Attractor
 * Great chain of being
 * Great Comet
 * Great Comet of 1577
 * Great Comet of 1729
 * Great Comet of 1843
 * Great Comet of 1882
 * Great Dark Spot
 * Great Diamond
 * Great January comet of 1910
 * Great Observatories Origins Deep Survey
 * Great Wall (astronomy)
 * Great White Spot
 * Greek astronomy
 * Greenhouse effect
 * Green Valley (Mars)
 * Gregory Benford
 * Gregory Scott Aldering
 * Greip (moon)
 * Grigory Abramovich Shajn
 * Grigory Neujmin
 * Grissom Hill
 * GRO J1655-40
 * Groombridge 1618
 * Groombridge 1830
 * Groombridge 34
 * Ground track
 * GRS 1124-683
 * GRS 1915+105
 * GSC 02652-01324
 * G. Thomson
 * G-type asteroid
 * Guabonito
 * Guest star (astronomy)
 * Guide Star Catalog
 * Guide Star Catalog II
 * Guillaume Bigourdan
 * Gullstrand-Painlevé coordinates
 * Gum Nebula
 * G V star
 * GW 123.4-1.5
 * György Kulin
 * Gyula M. Szabó
 * Gyula Szabó
 * HabCat
 * Hadley Rille meteorite
 * Hadron epoch
 * Haedi
 * Hairy Head (Chinese constellation)
 * Hale (Martian crater)
 * Halimede (moon)
 * Halley's Comet
 * Halo Occupation Distribution
 * Halo orbit
 * Hamburg/ESO Survey
 * Hans-Emil Schuster
 * Hansteen (crater)
 * Hapkeite
 * Hardwar
 * Harmonices Mundi
 * Harpalyke (moon)
 * Harry Edwin Wood
 * Hartle-Hawking state
 * Harvest moon
 * Hati (moon)
 * HATNet Project
 * HAT-P-5
 * HAT-P-6
 * Haughton-Mars Project
 * Haute-Provence Observatory
 * Hawking radiation
 * Hayabusa
 * Hayashi limit
 * Hayashi track
 * HCG 87
 * H chondrite
 * HCM-6A
 * HDE 268835
 * HE0107-5240
 * HE 0437-5439
 * HE0450-2958
 * HE1327-2326
 * HE 1523-0901
 * Head of tide
 * Heart (Chinese constellation)
 * Heart Nebula
 * Heat death of the universe
 * Heat Shield Rock
 * Heavenly Market enclosure
 * Heber Doust Curtis
 * Hebes Chasma
 * Hecates Tholus
 * HED meteorite
 * Hegemone (moon)
 * Heikki A. Alikoski
 * Heimdal (Martian crater)
 * Heinlein (crater)
 * Heinrich Louis d'Arrest
 * Heinrich Wilhelm Matthäus Olbers
 * Helene (moon)
 * Helike (moon)
 * Heliocentric orbit
 * Heliocentrism
 * Heliometer
 * Helion (meteoroid)
 * Helioseismography
 * Helioseismology
 * Heliosphere
 * Heliospheric current sheet
 * Helios probes
 * Heliosynchronous orbit
 * Helium flash
 * Helium Focusing Cone
 * Helix Nebula
 * Hellas-Sat
 * Hendrik van Gent
 * Henri Debehogne
 * Henri Joseph Anastase Perrotin
 * Henry Draper Catalogue
 * Henry E. Holt
 * Henry L. Giclas
 * Henyey track
 * Herbig Ae/Be stars
 * Herbig-Haro object
 * Hercules Cluster
 * Hercules X-1
 * Hermann Mayer Salomon Goldschmidt
 * Herman Potočnik
 * Hermippe (moon)
 * Herschel 400 Catalogue
 * Herschel (crater on Mimas)
 * Herschel (Martian crater)
 * Hertzsprung gap
 * Hertzsprung-Russell diagram
 * Hesperus
 * Hess diagram
 * Hexahedrite
 * HH 34
 * Hickson Compact Group
 * High Earth orbit
 * High-G training
 * Highly Elliptical Orbit
 * High-mass X-ray binary
 * High Possil meteorite
 * H II region
 * Hill sphere
 * Himalia group
 * Himalia (moon)
 * Hinode
 * HIP 14810
 * HIP 67593
 * HIPASS
 * Hipparcos Catalogue
 * Hirayama families
 * H I region
 * HiRISE
 * Hiroki Kosai
 * Hiroshi Abe (astronomer)
 * Hiroshi Araki
 * Hiroshi Kaneda
 * Hiroshi Mori (astronomer)
 * Hispasat
 * History of Solar System formation and evolution hypotheses
 * History of supernova observation
 * History of the Big Bang theory
 * History of the constellations
 * Hitoshi Shiozawa
 * HL Tau 76
 * Hoag's Object
 * Hoba meteorite
 * Hodge 301
 * Hodges meteorite
 * Hohmann transfer orbit
 * Holden (Martian crater)
 * Holger Thiele
 * Holmberg IX
 * Holocene Impact Working Group
 * Holographic principle
 * Homestead (meteorite)
 * Homunculus Nebula
 * Horace Parnell Tuttle
 * Horizon
 * Horizon problem
 * Horizontal branch
 * Horizontal coordinate system
 * Horizontal Falls
 * Horn Antenna
 * Horn (Chinese constellation)
 * Horologium Cluster
 * Horologium Supercluster
 * Horse and Rider
 * Horsehead Nebula
 * Horseshoe orbit
 * Host galaxy
 * Hot Bird
 * Hot dark matter
 * Hot Jupiter
 * Hourglass Nebula
 * Howardite
 * Hubble Deep Field
 * Hubble Guide Star Catalog - Astrographic Catalog/Tycho
 * Hubble sequence
 * Hubble's law
 * Hubble volume
 * Huchra's Lens
 * Huckitta
 * Hugh Percy Wilkins
 * Hungaria family
 * Hunter's moon
 * Husband Hill
 * Huya
 * Huygens (crater)
 * Huygens probe
 * HVC 127-41-330
 * Hyades (star cluster)
 * Hydra-Centaurus Supercluster
 * Hydra Cluster
 * Hydra (moon)
 * Hydrogen line
 * Hygiea family
 * Hypanis Vallis
 * Hyperbolic trajectory
 * Hypergiant
 * Hyperion (moon)
 * Hypernova
 * Hypervelocity star
 * Hypotheses non fingo
 * Hyrrokkin (moon)
 * Iani Chaos
 * Iapetus (moon)
 * Ice dwarf
 * Icy moon
 * IIE iron meteorite
 * Ijiraq (moon)
 * I.M.Chisov
 * Imilac
 * Immirzi parameter
 * Impact crater
 * Impact event
 * Impact gardening
 * Impactite
 * Impact structure
 * Impact winter
 * Imperial Earth
 * Improper motion
 * Inclination
 * Inclined orbit
 * Index Catalogue
 * Index Catalogue of Visual Double Stars
 * Indiana Asteroid Program
 * Inertial frame of reference
 * Inertial space
 * Inex
 * Inferior and superior planets
 * Inflationary epoch
 * Inflaton
 * Infrared cirrus
 * Infrared window
 * Ingrid van Houten-Groeneveld
 * Inhomogeneous cosmology
 * Initial mass function
 * Inner moon
 * Inner satellites of Jupiter
 * In-situ resource utilization
 * Instability strip
 * Intelsat 11
 * Intelsat 14
 * Intelsat 16
 * Intelsat 1R
 * Intelsat 2
 * Intelsat 3R
 * Intelsat 8
 * Intelsat 9
 * Intelsat I
 * Interacting binary star
 * Interacting galaxy
 * Interferometric gravitational wave detector
 * Intergalactic space
 * Intermediate circular orbit
 * Intermediate-mass black hole
 * Intermediate-mass X-ray binary
 * Intermediate polar
 * Intermediate spiral galaxy
 * Internal structure of the Moon
 * International Cometary Explorer
 * International Lunar Network
 * International Near-Earth Asteroid Survey
 * International Standard Atmosphere
 * Interplanetary dust cloud
 * Interplanetary medium
 * Interplanetary Transport Network
 * Interstellar cloud
 * Interstellar medium
 * Interstellar reddening
 * Intracluster medium
 * Intrinsic redshift
 * Introduction to general relativity
 * Introduction to M-theory
 * Invariable plane
 * Iocaste (moon)
 * IOK-1
 * Io (moon)
 * Ionization cone
 * Ionosphere
 * Ionospheric absorption
 * Ionospheric storm
 * IRAS
 * IRC +10216
 * Iridium
 * Iris nebula
 * Iron meteorite
 * Irregular galaxy
 * Irregular moon
 * Irregular variable
 * Isidis Planitia
 * Isonoe (moon)
 * Ixion
 * I Zwicky 18
 * J002E3
 * J0806
 * Jacchia Reference Atmosphere
 * Jack Sound
 * Jacobi integral
 * James Craig Watson
 * James Edward Keeler
 * James E. Faller
 * James Ferguson (astronomer)
 * James M. Roe
 * James Whitney Young
 * Jana Tichá
 * Jane Luu
 * January 2000 lunar eclipse
 * January 2001 lunar eclipse
 * Janus (moon)
 * Japan Spaceguard Association
 * Jarnsaxa (moon)
 * Jaume Nomen
 * JCSAT-9
 * Jean Chacornac
 * Jean-Claude Merlin
 * Jean Mueller
 * Jeff T. Alu
 * Jérôme Eugène Coggia
 * Jet Propulsion Laboratory Developmental Ephemeris
 * Jewel Box
 * Jezero (crater)
 * J. Lawrence Smith Medal
 * Joanny-Philippe Lagrula
 * Joel Hastings Metcalf
 * Johannes Hevelius
 * Johann Friedrich Julius Schmidt
 * Johann Gottfried Galle
 * Johann Heinrich von Mädler
 * Johann Hieronymus Schröter
 * Johann Holetschek
 * Johann Nepomuk Krieger
 * Johann Palisa
 * John Broughton
 * John Couch Adams
 * John Russell Hind
 * John Russell (painter)
 * John V. McClusky
 * Josep Comas Solà
 * Joseph Helffrich
 * Jovian Europa Orbiter
 * Joy's Law
 * JSC Moon Base
 * J-type asteroid
 * Juan Hartmann
 * Jules Alfred Pierrot Deseilligny
 * Julian day
 * Juliane Köpcke
 * Juliet (moon)
 * July 2000 lunar eclipse
 * July 2001 lunar eclipse
 * July 2009 lunar eclipse
 * Jun Chen
 * June 2002 lunar eclipse
 * June 2010 lunar eclipse
 * June 2011 lunar eclipse
 * June Bootids
 * Juno clump
 * Juno (spacecraft)
 * Jupiter
 * Jupiter-crosser asteroid
 * Jupiter mass
 * Jupiter (mythology)
 * Jupiter's moons in fiction
 * Juventae Chasma
 * Juxta Crucem
 * Kaidun meteorite
 * Kale (moon)
 * Kallichore (moon)
 * Kaluza–Klein theory
 * Kalyke (moon)
 * Kamacite
 * Kaoru Ikeya
 * Kapteyn's Star
 * Kara crater
 * Kari (moon)
 * Karin family
 * Karl Augustesen
 * Karl Ludwig Harding
 * Karl Ludwig Hencke
 * Karl Theodor Robert Luther
 * Karl Wilhelm Reinmuth
 * Kármán line
 * Karoonda meteorite
 * Kaspar Gottfried Schweizer
 * Katzman Automatic Imaging Telescope
 * KazSat
 * Kazuo Kubokawa
 * Kazuro Watanabe
 * Keeling Curve
 * Kemble's Cascade
 * Kenneth J. Lawrence
 * Kenzo Suzuki (astronomer)
 * Kepler (Martian crater)
 * Kepler orbit
 * Kepler's laws of planetary motion
 * Kerr metric
 * Ketu (mythology)
 * Keun Nan Mun
 * Kiichiro Hurukawa
 * Kin Endate
 * King tide
 * Kiviuq (moon)
 * Klemperer rosette
 * Kleť Observatory
 * Koga (crater)
 * Kōichirō Tomita
 * Korado Korlević
 * Kordylewski cloud
 * Kore (moon)
 * Koronis family
 * Koyo Kawanishi
 * Kozai mechanism
 * Krasnojarsk (meteorite)
 * KREEP
 * Kreutz Sungrazers
 * Krisztián Sárneczky
 * Kruger 60
 * Krzeminski's Star
 * K–T boundary
 * Kṛttikā
 * K-type asteroid
 * Kugelblitz (astrophysics)
 * Kuiper belt
 * K V star
 * KW Sagitarii
 * L1014
 * L1157
 * L 675-81
 * Labes
 * Lacaille 8760
 * Lacaille 9352
 * Lacus Doloris
 * Lacus Gaudii
 * Lacus Hiemalis
 * Lacus Lenitatis
 * Lacus Luxuriae
 * Lacus Oblivionis
 * Lacus Odii
 * Lacus Timoris
 * Lacus Veris
 * Ladislav Brožek
 * Lagoon Nebula
 * Lagrangian point
 * L'Aigle (meteorite)
 * Lalande 21185
 * Lalande 21185d
 * Lambda-CDM model
 * Laomedeia (moon)
 * Laplace limit
 * Laplace-Runge-Lenz vector
 * Large Magellanic Cloud
 * Large Synoptic Survey Telescope
 * Large Underground Xenon experiment
 * Larissa (moon)
 * Larry's Lookout
 * Laser accelerometer
 * Laser Interferometer Space Antenna
 * La Silla Observatory
 * Last Chance (Mars)
 * La Superba
 * Late Heavy Bombardment
 * Late-type star
 * LBQS 1429-008
 * LBV 1806-20
 * LCGT
 * L chondrite
 * Leda (moon)
 * Legs (Chinese constellation)
 * LEK Lunar Expeditionary Complex
 * Leland E. Cunningham
 * Lenka Kotková
 * Lenticular galaxy
 * Leo A
 * Leo Anton Karl de Ball
 * Leo Cluster
 * Leo I (dwarf galaxy)
 * Leo II (dwarf galaxy)
 * Leonard L. Amburgey
 * Leonard Medal
 * Leonids
 * Leo Triplet
 * Leptogenesis (physics)
 * Lepton epoch
 * Lernaean Hydra
 * Levitation
 * LGM-1
 * LH54-425
 * LH 95
 * LHA 120-N 157B
 * LHS 288
 * LHS 292
 * Libration
 * Life on Mars
 * Light curve
 * Light Dark Matter
 * Lighter than air
 * Lightest Supersymmetric Particle
 * LIGO
 * Liisi Oterma
 * Lilith (hypothetical moon)
 * Limb darkening
 * Lincoln Near-Earth Asteroid Research
 * Linus (moon)
 * Lipót Schulhof
 * Liquid air
 * Lissajous orbit
 * List of 16th century lunar eclipses
 * List of 17th century lunar eclipses
 * List of 18th century lunar eclipses
 * List of 19th century lunar eclipses
 * List of 20th century lunar eclipses
 * List of 21st century lunar eclipses
 * List of 22nd century lunar eclipses
 * List of 23rd century lunar eclipses
 * List of 24th century lunar eclipses
 * List of 25th century lunar eclipses
 * List of Abell clusters
 * List of Apollo missions
 * List of Arabic star names
 * List of artificial objects on the Moon
 * List of artificial objects on Venus
 * List of asteroid-discovering observatories
 * List of asteroid moons
 * List of asteroids
 * List of asteroids discovered by Carolyn Shoemaker
 * List of asteroids discovered by Nikolai Stepanovich Chernykh
 * List of asteroids named after people
 * List of asteroids named after places
 * List of astronomical catalogues
 * List of basic astronomy topics
 * List of brightest stars
 * List of brown dwarfs
 * List of comets
 * List of constellations
 * List of constellations by area
 * List of craters on 253 Mathilde
 * List of craters on Europa
 * List of craters on Proteus
 * List of craters on Puck
 * List of craters on Umbriel
 * List of cubewanos
 * List of current and future lunar missions
 * List of dark nebulae
 * List of diffuse nebulae
 * List of extrasolar planet extremes
 * List of extraterrestrial volcanoes
 * List of features on the Moon
 * List of galaxies
 * List of galaxy clusters
 * List of geological features on 243 Ida and Dactyl
 * List of geological features on 25143 Itokawa
 * List of geological features on 433 Eros
 * List of geological features on 951 Gaspra
 * List of geological features on Ariel
 * List of geological features on Europa
 * List of geological features on Miranda
 * List of geological features on Oberon
 * List of geological features on Titania
 * List of geological features on Triton
 * List of globular clusters
 * List of hypothetical planetary objects
 * List of impact craters on Earth
 * List of largest known stars
 * List of least massive stars
 * List of lineae on Europa
 * List of lists of small solar system bodies
 * List of lunar eclipses in saros series 121
 * List of lunar meteorites
 * List of Martian canals
 * List of Mercury-crossing asteroids
 * List of Messier objects
 * List of meteor showers
 * List of moons
 * List of moons by diameter
 * List of most luminous stars
 * List of most massive stars
 * List of named Amor asteroids
 * List of named asteroids (A-C)
 * List of named asteroids (D-E)
 * List of named asteroids (F-H)
 * List of named asteroids (I-K)
 * List of named asteroids (L-N)
 * List of named asteroids (O-R)
 * List of named asteroids (S-V)
 * List of named asteroids (W-Z)
 * List of named Solar System objects
 * List of names for the Milky Way
 * List of Near-Earth asteroids by distance from Sun
 * List of nearest bright stars
 * List of nearest galaxies
 * List of nearest stars
 * List of NGC objects
 * List of NGC objects (1000-1999)
 * List of NGC objects (1-999)
 * List of NGC objects (2000-2999)
 * List of NGC objects (3000-3999)
 * List of NGC objects (4000-4999)
 * List of NGC objects (5000-5999)
 * List of NGC objects (6000-6999)
 * List of NGC objects (7000-7840)
 * List of non-periodic comets
 * List of notable asteroids
 * List of numbered Aten asteroids
 * List of objects at Lagrangian points
 * List of orbits
 * List of periodic comets
 * List of planetary bodies
 * List of planetary nebulae
 * List of plutoid candidates
 * List of polar-ring galaxies
 * List of protoplanetary nebulae
 * List of quadrangles on Europa
 * List of quadrangles on the Moon
 * List of quasars
 * List of Saros series for lunar eclipses
 * List of semiregular variable stars
 * List of solar cycles
 * List of solar eclipses in antiquity
 * List of solar eclipses in the 20th century
 * List of solar eclipses in the 21st century
 * List of solar eclipses seen from China
 * List of solar eclipses visible from the United Kingdom 1000 - 2090 AD
 * List of Solar System objects
 * List of Solar System objects by mass
 * List of Solar System objects by radius
 * List of Solar System objects by surface gravity
 * List of spiral galaxies
 * List of star names
 * List of stars in the Hipparcos Catalogue
 * List of stars of Hyades
 * List of Stars of Hyades
 * List of stars with confirmed extrasolar planets
 * List of stars with proplyds
 * List of supernova remnants
 * List of symbolic stars
 * List of the brightest KBOs
 * List of traditional star names
 * List of trans-Neptunian objects
 * List of Trojan asteroids (Greek camp)
 * List of Trojan asteroids (Trojan camp)
 * List of unconfirmed exoplanets
 * List of variable stars
 * List of X-ray pulsars
 * Lists of astronomical objects
 * Lists of stars
 * Lists of stars by constellation
 * Little Dumbbell Nebula
 * Little Ghost Nebula
 * Living With a Star
 * LK Lander
 * Llanesco (crater)
 * LL chondrite
 * Local Bubble
 * Local Group
 * Local Interstellar Cloud
 * Lochium Funis
 * Lodestar
 * Loge (moon)
 * Lomonosov (Martian crater)
 * Longitude of the ascending node
 * Longitude of the periapsis
 * Long period variable
 * Lonsdaleite
 * Loop I Bubble
 * Loop II Bubble
 * Loop III Bubble
 * Loren C. Ball
 * Louis Boyer (astronomer)
 * Low Earth orbit
 * Lowell Observatory Near-Earth-Object Search
 * Low energy transfers
 * Lower Imbrian
 * Low-g condition
 * Low-ionization nuclear emission-line region
 * Low-mass X-ray binary
 * Low surface brightness galaxy
 * LP 944-020
 * LS 5039
 * LS I +61 303
 * L-type asteroid
 * Lubber fiend
 * Luboš Kohoutek
 * Luciano Tesi
 * Lucien LaCoste
 * Luigi Carnera
 * Luminosity function (astronomy)
 * Luminous blue variable
 * Luminous infrared galaxy
 * Luminous red nova
 * Lunar Architecture (NASA)
 * Lunar ark
 * Lunar Atmosphere and Dust Environment Explorer
 * Lunar conjunction
 * Lunar day
 * Lunar distance (astronomy)
 * Lunar distance (navigation)
 * Lunar dome
 * Lunar eclipse
 * Lunar Explorers Society
 * Lunar geologic timescale
 * Lunar government
 * Lunar ice
 * Lunar Laser Ranging Experiment
 * Lunar limb
 * Lunar magma ocean
 * Lunar mare
 * Lunar mass
 * Lunar meteorite
 * Lunar node
 * Lunar orbit
 * Lunar Orbit Insertion
 * Lunar outpost (NASA)
 * Lunar phase
 * Lunar precession
 * Lunar Precursor Robotic Program
 * Lunar Receiving Laboratory
 * Lunar Reconnaissance Orbiter
 * Lunar rover
 * Lunar soil
 * Lunar sortie
 * Lunar space elevator
 * Lunar standstill
 * Lunar surface
 * Lunar terminator
 * Lunar terrane
 * Lunar theory
 * Lunation Number
 * Lunex Project
 * Lunitidal interval
 * Lunokhod 1
 * Lunokhod 2
 * Lunokhod programme
 * Lute of Pythagoras
 * Lutz D. Schmadel
 * Luyten 726-8
 * Luyten's Star
 * Lyman-alpha blob
 * Lyman alpha emitter
 * Lyman-alpha forest
 * Lynds 1616
 * Lynx Arc
 * Lyons Groups of Galaxies
 * Lyrids
 * Lysithea (moon)
 * Lyudmila Chernykh
 * Lyudmila Karachkina
 * Lyudmila Zhuravlyova
 * M101 Group
 * M109 Group
 * M1-92
 * M51 Group
 * M74 Group
 * M81 Group
 * M82 X-1
 * M94 Group
 * M96 Group
 * Ma'adim Vallis
 * Maat Mons
 * Mab (moon)
 * Machina Electrica
 * MACHO-1997-BLG-41
 * MACHO-98-BLG-35
 * MACHO-LMC-5
 * Mach principle
 * Mach's principle
 * Mädler (Martian crater)
 * Maffei 1
 * Maffei 2
 * Magellanic Bridge
 * Magellanic Clouds
 * Magellanic Stream
 * Magha (nakshatra)
 * Magic star
 * Magnetar
 * Magnetic cloud
 * Magnetic field of celestial bodies
 * Magnetic field of the Moon
 * Magnetic reconnection
 * Magnetospheric eternally collapsing object
 * Magnitude of eclipse
 * Magumba
 * Main-belt comet
 * Main sequence
 * Main sequence star
 * Makemake (dwarf planet)
 * Makemake (mythology)
 * Makio Akiyama
 * Mamers Vallis
 * Mandora (crater)
 * Mangala
 * Mangala Valles
 * Mangere Lagoon
 * Manicouagan crater
 * Manned mission to Mars
 * March 1997 lunar eclipse
 * March 2006 lunar eclipse
 * March 2007 lunar eclipse
 * Marco Cavagna
 * Marc W. Buie
 * Mare Anguis
 * Mare Australe
 * Mare Cognitum
 * Mare Crisium
 * Mare Erythraeum
 * Mare Humorum
 * Mare Ingenii
 * Marek Wolf
 * Mare Moscoviense
 * Mare Spumans
 * Marfak
 * Margaret (moon)
 * Margaritifer Terra
 * Marian star
 * Mario Jurić
 * Mark Abraham
 * Markarian 421
 * Markarian's Chain
 * Mark Armstrong
 * Mars
 * Mars Analogue Research Station Programme
 * Mars-crosser asteroid
 * Mars Desert Research Station
 * MarsDrive
 * Mars for Less
 * Mars General Circulation Model
 * Mars hoax
 * Mars landing
 * Mars meteorite
 * Mars Piloted Orbital Station
 * Mars rover
 * Mars Simulation Project
 * Mars Society
 * Mars Society Australia
 * Martian
 * Martian canal
 * Martian spherules
 * Martian spiders
 * Mary Adela Blagg
 * Masahiro Koishikawa
 * Masakatsu Aoki
 * Masanori Hirasawa
 * Masanori Matsuyama
 * Masaru Arai
 * Masaru Inoue
 * Masaru Mukai
 * Masayuki Iwamoto
 * Masayuki Yanai
 * Massalia family
 * Mass concentration
 * Mass distribution
 * Massive compact halo object
 * Mass ratio
 * Mass to light ratio
 * Matsuo Sugano
 * Matter power spectrum
 * Maunder Minimum
 * Maura Tombelli
 * Mawrth Vallis
 * Maxwell Montes
 * Max Wolf
 * May 2002 lunar eclipse
 * May 2003 lunar eclipse
 * May 2004 lunar eclipse
 * Mayall II
 * Mayall's Object
 * McCool Hill
 * McDonald Observatory
 * MCELS (Magellanic Cloud Emission-line Survey)
 * McNeil's Nebula
 * Mean anomaly
 * Mean longitude
 * Mean motion
 * MEASAT
 * Medium Earth Orbit
 * Medusa Fossae
 * Medusa Nebula
 * Megaclite (moon)
 * Megamaser
 * Melas Chasma
 * Mellish (crater)
 * Membrane paradigm
 * Memnonia (Mars)
 * Mendel (Martian crater)
 * Mercury in fiction
 * Mercury-manganese star
 * Mercury (planet)
 * Mercury's moon
 * Mesopause
 * Mesoplanet
 * Mesosiderite
 * Mesosphere
 * Messier marathon
 * Messier object
 * Metallicity
 * Meteor burst communications
 * Meteor Crater
 * Meteorite
 * Meteorite classification
 * Meteorite fall
 * Meteorite fall statistics
 * Meteoritical Society
 * Meteoritical Society's Service Award
 * Meteoritics
 * Meteoritics & Planetary Science
 * Meteoroid
 * Meteor shower
 * Meteosat
 * Meteosat Second Generation
 * Methods of detecting extrasolar planets
 * Methone (moon)
 * Metis (moon)
 * Metric expansion of space
 * Mice Galaxies
 * Michael E. Brown
 * Michigan Mars Rover Team
 * Micro black hole
 * Microgravity environment
 * Microgravity University
 * Microlensing Observations in Astrophysics
 * Micrometeoroid
 * Microquasar
 * Microturbulence
 * Miguel Itzigsohn
 * Mihira
 * Milan Antal
 * Milky Way
 * Milky Way (mythology)
 * Milky Way's satellite galaxies
 * Millennium Run
 * Millisecond pulsar
 * Milorad B. Protić
 * Miloš Tichý
 * Mimas (moon)
 * Mineo (meteorite)
 * Mineral dust
 * MiniGrail
 * Minor planet
 * Minoru Kizawa
 * Mira
 * Mira B
 * Miranda (moon)
 * Mira variable
 * Mirror matter
 * M. Laugier
 * Mneme (moon)
 * Model spectrum
 * Modern Maximum
 * Moissanite
 * Moldavite
 * Molecular cloud
 * Molniya orbit
 * Monoceros Ring
 * Mons Agnes
 * Mons Ardeshir
 * Mons Argaeus
 * Mons Blanc
 * Mons Gruithuisen Gamma
 * Mons Hansteen
 * Mons Maenalus
 * Mons Maraldi
 * Mons Penck
 * Mons Rümker
 * Mons Vitruvius
 * Monte Agliale Supernovae and Asteroid Survey
 * Monte Milone (meteorite)
 * Montes Archimedes
 * Montes Secchi
 * Month
 * Moon
 * Moon illusion
 * Moon landing
 * Moonlet
 * Moonlight
 * Moonquake
 * Moon rock
 * Moonscape
 * Moon Society
 * Moons of Jupiter
 * Moons of Mars
 * Moons of Neptune
 * Moons of Pluto
 * Moons of Saturn
 * Moons of Uranus
 * Moreton wave
 * Moritz Ludwig George Wichmann
 * Moving group
 * MRC 1138-262
 * Mrigashīrsha
 * MS 0735.6+7421
 * MS 1512 +36-cB58
 * M-theory
 * M-type asteroid
 * Muggletonianism
 * Multiple histories
 * Multiple star
 * Multiverse
 * Mundilfari (moon)
 * Murchison meteorite
 * Mursili's eclipse
 * Musca Borealis
 * Muscida
 * Musica universalis
 * Myth of Er
 * My Very Exciting Magic Carpet Just Sailed Under Nine Palace Elephants
 * Mz 1
 * Mz 3
 * N 180B
 * N1 rocket
 * Naiad (moon)
 * Naked-eye planet
 * Naked singularity
 * Nakhla meteorite
 * Nakshatra
 * Name conflicts of Solar System objects
 * Naming of moons
 * Naoto Sato
 * Narvi (moon)
 * National Atmospheric Release Advisory Center
 * National Geographic Society - Palomar Observatory Sky Survey
 * Naturaliste (crater)
 * Natural satellite
 * Navarro-Frenk-White profile
 * Navigational stars
 * N-body problem
 * N-body simulation
 * Nearby Stars Database
 * Nearby Supernova Factory
 * Near Earth Asteroid Tracking
 * Near earth object
 * Near-Earth object
 * Near equatorial orbit
 * Near-extremal black hole
 * Near side of the Moon
 * Nebula
 * Nebulae in fiction
 * Nebular contraction
 * Nebular hypothesis
 * Neck (Chinese constellation)
 * Nectarian
 * Neith (hypothetical moon)
 * NEODyS
 * Neon burning process
 * Neptune
 * Neptune-crosser asteroid
 * Neptune in fiction
 * Neptune Trojan
 * Nereid (moon)
 * Nereidum Montes
 * Neso (moon)
 * Net (Chinese constellation)
 * Neumann line
 * Neutralino
 * Neutrino
 * Neutron star
 * Neutron-star oscillations
 * Neutron star spin-up
 * Neutron Star (story)
 * Neutron Tide
 * New General Catalogue
 * New moon
 * Newtonian gauge
 * Newton (Martian crater)
 * Newton's law of universal gravitation
 * New Worlds Mission
 * NGC 7331 Group
 * Nhill (crater)
 * Nicholson (Martian crater)
 * Nicolas Alkemade
 * Nier Prize
 * Niger Vallis
 * Nikolai Stepanovich Chernykh
 * Nilesat 101
 * Nilesat 102
 * Nili Fossae
 * Nilo Syrtis
 * Nine Views
 * Nininger Meteorite Award
 * Ninth Cambridge survey at 15GHz
 * Nix (moon)
 * Noachis Terra
 * Nobuhiro Kawasato
 * Noctis Labyrinthus
 * Noctua
 * No hair theorem
 * Non-Gaussianity
 * Non-inclined orbit
 * Nonsingular black hole models
 * Non-standard cosmology
 * Nordtvedt effect
 * Normaal Amsterdams Peil
 * Norma Cluster
 * Normalforcelessness
 * Normal star
 * Norman G. Thomas
 * Norman Robert Pogson
 * North America Nebula
 * Northern Local Supervoid
 * North Polar Basin (Mars)
 * North Star
 * Norton County (meteorite)
 * Norton's Star Atlas
 * Nova
 * Nova remnant
 * Novaya Zemlya effect
 * November 1993 lunar eclipse
 * November 2002 lunar eclipse
 * November 2003 lunar eclipse
 * NRAO VLA Sky Survey
 * NRLMSISE-00
 * NSS-6
 * NSS-7
 * Numerical model of solar system
 * Nyx
 * Oak Ridge Observatory
 * Oberon (moon)
 * Oberth effect
 * Observable universe
 * Observational cosmology
 * Observations and explorations of Venus
 * Observing the Moon
 * OB star
 * OCA-DLR Asteroid Survey
 * Ocean colonization
 * Ocean planet
 * Octahedrite
 * October 2004 lunar eclipse
 * October 2005 lunar eclipse
 * Odd number theorem
 * Odette Bancilhon
 * Odysseus (crater)
 * Odyssey Moon
 * Officina Typographica
 * OGLE-2003-BLG-235/MOA-2003-BLG-53
 * OH masers
 * OJ 287
 * Okuro Oikawa
 * Olbers' paradox
 * Old Woman meteorite
 * Olympia Undae
 * Olympus Mons
 * Omega Nebula
 * Omega Point
 * Omicron Centaurids
 * Omniverse
 * Onepoto (volcanic crater)
 * One star
 * Oort cloud
 * Oort Limit
 * Open cluster
 * Open cluster family
 * Open cluster remnant
 * Oph 162225-240515
 * Ophelia (moon)
 * Opposition effect
 * Optical black hole
 * Optical Gravitational Lensing Experiment
 * Optical pulsar
 * Optus fleet of satellites
 * Orbit
 * Orbital decay
 * Orbital eccentricity
 * Orbital elements
 * Orbital inclination change
 * Orbital maneuver
 * Orbital mechanics
 * Orbital motion
 * Orbital node
 * Orbital period
 * Orbital perturbation
 * Orbital plane (astronomy)
 * Orbital pole
 * Orbital resonance
 * Orbital speed
 * Orbital state vectors
 * Orbital station-keeping
 * Orbit determination
 * Orbit equation
 * Orbit@home
 * Orbiting body
 * Orbit of the Moon
 * Orbit phasing
 * Orcus (mythology)
 * Ordinary chondrite
 * Orgueil (meteorite)
 * Orion Arm
 * Orionids
 * Orion Molecular Cloud Complex
 * Orion Nebula
 * Orion (spacecraft)
 * Orion's Sword
 * Orion variable
 * Orlando A. Naranjo
 * Orrery
 * Orthosie (moon)
 * Osamu Muramatsu
 * Oscillatory universe
 * Osculating orbit
 * Oskar Lesser
 * Osservatorio San Vittore
 * OTELO
 * OTS 44
 * Otto Struve
 * O-type asteroid
 * Ourique (meteorite)
 * Outer space
 * Outflow channels
 * Overcontact binary
 * O V star
 * OVV quasar
 * Owl Nebula
 * Ox (Chinese constellation)
 * Oxygen burning process
 * Ozone layer
 * P/2007 R5
 * Paaliaq (moon)
 * Pablo Cottenot
 * Pair-instability supernova
 * Pallas family
 * Pallasite
 * Pallasovka (meteorite)
 * Pallene (moon)
 * Palomar 1
 * Palomar 12
 * Palomar 4
 * Palomar 5
 * Palomar Sky Survey
 * Palus Putredinis
 * Pamela M. Kilmartin
 * Pancake dome
 * Pandora (moon)
 * Pan (moon)
 * Pan-STARRS
 * Paolo Chiavenna
 * Parabolic trajectory
 * Paragould meteorite
 * Parker spiral
 * Park Forest (meteorite)
 * Parking orbit
 * Particle horizon
 * Particle physics in cosmology
 * PAS 1
 * Pascal Lee
 * Paschal Full Moon
 * Pasiphaë group
 * Pasiphaë (moon)
 * Pasithee (moon)
 * Patched Conics
 * Path-constrained rendezvous
 * Paul G. Comba
 * Paul Götz
 * Paul Henry and Prosper Henry
 * Paulo R. Holvorcem
 * Paul Pellas-Graham Ryder Award
 * Paul Wild (Swiss astronomer)
 * Pavlovka (meteorite)
 * Pavo-Indus Supercluster
 * Pavonis Mons
 * Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics
 * Payload fraction
 * Peak of Eternal Light
 * Peculiar galaxy
 * Peculiar star
 * Peekskill meteorite
 * Pegasus Dwarf Irregular Galaxy
 * Pegasus Dwarf Spheroidal Galaxy
 * Pelageya Shajn
 * Pelican Nebula
 * Pendulum rocket fallacy
 * Penrose process
 * Pentad (Greek philosophy)
 * Pentagram
 * Percival Lowell
 * Perdita (moon)
 * Perfect Cosmological Principle
 * Perifocal coordinate system
 * Perigalacticon
 * Perigean Spring Tides
 * Permian–Triassic extinction event
 * Perseids
 * Perseus Arm
 * Perseus Cluster
 * Perseus molecular cloud
 * Perseus-Pisces Supercluster
 * Perth Observatory
 * Perturbation (astronomy)
 * Petar Đurković
 * Peter Kušnirák
 * Petit-Prince (moon)
 * Petr Pravec
 * PG 1159 star
 * Phaeton (hypothetical planet)
 * Phantom energy
 * Phase angle (astronomy)
 * Phases of Venus
 * Philibert Jacques Melotte
 * Philip Herbert Cowell
 * Philipp Johann Heinrich Fauth
 * Phobos and Deimos in fiction
 * Phobos (moon)
 * Phobos program
 * Phoebe (moon)
 * Phoenicids
 * Phoenix Dwarf
 * Photodissociation region
 * Photoevaporation
 * Photometric standard stars
 * Photon diffusion damping
 * Photon epoch
 * Photon sphere
 * Photosphere
 * Physical cosmology
 * Physical geodesy
 * Picard horn
 * PICARD (spacecraft)
 * PICASSO (dark matter)
 * Pierangelo Ghezzi
 * Piero Sicoli
 * Pierre Antonini
 * Pingualuit crater
 * Pinwheel Galaxy
 * Pinwheel nebula
 * Pioneer 6, 7, 8 and 9
 * Pioneer anomaly
 * Pioneer Star
 * Pipe Nebula
 * Pi Puppids
 * Pisces Dwarf
 * PISMIS
 * Pismis 24-1
 * Pistol Nebula
 * Pistol Star
 * Plage (astronomy)
 * Planar deformation features
 * Planck epoch
 * Planck particle
 * Planck scale
 * Planemo
 * Plane of reference
 * Planet
 * Planetar (astronomy)
 * Planetary core
 * Planetary migration
 * Planetary nebula
 * Planetary nebula luminosity function
 * Planetary Nebula M2-9
 * Planetary nomenclature
 * Planetary Observer program
 * Planetary ring
 * Planetary-size comparison
 * Planetary system
 * Planet-Crossing Asteroid Survey
 * Planetesimal
 * PlanetQuest
 * Planet Quest
 * Planet-satellite system
 * Planets beyond Neptune
 * Planetshine
 * Planets in astrology
 * Planet V
 * Planisphere
 * Plaskett's star
 * Plasma cosmology
 * Plasmasphere
 * Pleiades
 * Plessite
 * Plinio Antolini
 * Plutino
 * Pluto
 * Plutoed
 * Plutoid
 * Pluto in fiction
 * Poeticon astronomicon
 * Polar (cataclysmic variable)
 * Polaris
 * Polar jet
 * Polar orbit
 * Polar-ring galaxy
 * Polar wind
 * Pole star
 * Polophylax
 * Polydeuces (moon)
 * Population III star
 * Population II star
 * Population I star
 * Porkchop plot
 * Pororoca
 * Portal:Astronomy
 * Portal:Mars
 * Portal:Solar System
 * Porter (Martian crater)
 * Porth (crater)
 * Portia (moon)
 * Potential energy
 * Potentially hazardous asteroid
 * Potentiometric surface
 * Pot of Gold (Mars)
 * POX 186
 * Poynting-Robertson effect
 * PPM Star Catalogue
 * Praxidike (moon)
 * Pre-main sequence star
 * Pre-Nectarian
 * Preon star
 * Presolar grains
 * Priestley (lunar crater)
 * Primordial black hole
 * Primordial fluctuations
 * Primordial isocurvature baryon model
 * Primum Mobile
 * Primum movens
 * Principal Galaxies Catalogue
 * Probing Lensing Anomalies Network
 * Procyon
 * Project Boreas
 * Project Constellation
 * Project Horizon
 * Promethei Terra
 * Prometheus (moon)
 * Promontorium Laplace
 * Pronunciation of asteroid names
 * Propellant mass fraction
 * Proper motion
 * Proper orbital elements
 * Prospero (moon)
 * Proteus (moon)
 * Protogalaxy
 * Protoplanet
 * Protoplanetary disk
 * Protoplanetary nebula
 * Protostar
 * Provisional designation in astronomy
 * Przybylski's star
 * Psalterium Georgii
 * Psamathe (moon)
 * PSR B0329+54
 * PSR B0329+54A
 * PSR B0329+54B
 * PSR B0950+08
 * PSR B1257+12
 * PSR B1257+12 A
 * PSR B1257+12 B
 * PSR B1257+12 C
 * PSR B1257+12 D
 * PSR B1259-63
 * PSR B1620-26
 * PSR B1828-10
 * PSR B1828-10A
 * PSR B1828-10B
 * PSR B1828-10C
 * PSR B1829-10
 * PSR B1829-10A
 * PSR B1913+16
 * PSR B1919+21
 * PSR J0537-6910
 * PSR J0737-3039
 * PSR J0855-4644
 * PSR J1748-2446ad
 * PSR J1903+0327
 * PSR J1951+1123
 * PSR J2144-3933
 * P-type asteroid
 * Puck (moon)
 * Puffy planet
 * Pulsar
 * Pulsar kicks
 * Pulsar planet
 * Pulsar wind nebula
 * Pulsating white dwarf
 * Pultusk (meteorite)
 * Punarvasu
 * Puppis A
 * Purple Forbidden enclosure
 * Purple Mountain Observatory
 * Pushya
 * PVLAS
 * Pwyll (crater)
 * Pyrrhotite
 * Q0906+6930
 * Qidong (meteorite)
 * QSO B0038+328
 * QSO B0040+517
 * QSO B0104+321
 * QSO B0109+492
 * QSO B0210+860
 * QSO B0220+427
 * QSO B0307+169
 * QSO B0316+413
 * QSO B0410+110
 * QSO B0605+480
 * QSO B0651+542
 * QSO B0702+749
 * QSO B0903+16
 * QSO B0917+458
 * QSO B0936+361
 * QSO B0958+290
 * QSO B1003+351
 * QSO B1030+585
 * QSO B1100+773
 * QSO B1203+645
 * QSO B1319+428
 * QSO B1336+391
 * QSO B1359+154
 * QSO B1409+524
 * QSO B1419+419
 * QSO B1441+5214
 * QSO B1522+546
 * QSO B1637+826
 * QSO B1939+605
 * QSO B2121+248
 * QSO B2153+377
 * QSO B2229+390
 * QSO B2243+394
 * QSO J0842+1835
 * Q star
 * Q-type asteroid
 * Quadrans Muralis
 * Quadrantids
 * Quadrupole
 * Quake (natural phenomenon)
 * Quantum cosmology
 * Quantum gravity epoch
 * Quaoar (mythology)
 * Quark epoch
 * Quark-nova
 * Quark star
 * Quasar
 * Quasar J1819+3845
 * Quasi-satellite
 * Quasistar
 * Quiescent prominence
 * Quintessence (physics)
 * Quintuplet cluster
 * Q Velorum (dwarf star)
 * R136
 * R136b
 * R 66 and R 126
 * Radiant (meteor shower)
 * Radiation-Dominated Era
 * Radiation pressure
 * Radiation zone
 * Radio galaxy
 * Radio halo
 * Radio-quiet neutron star
 * Radio relics
 * Radio star
 * Rafael Pacheco
 * Rahu
 * Rainbow-1
 * Rampart crater
 * Ramus Pomifer
 * Rance tidal power plant
 * Randall-Sundrum model
 * Raymond Smith Dugan
 * R Coronae Borealis variable
 * RCW103
 * RCW Catalogue
 * RD1
 * Red clump
 * Red dwarf
 * Red giant
 * Red Rectangle Nebula
 * Redshift
 * Redshift quantization
 * Redshift survey
 * Red Spider Nebula
 * Red Square Nebula
 * Red star
 * Red supergiant
 * Reflection nebula
 * Regulus
 * Reiki Kushida
 * Reiner Gamma
 * Reionization
 * Reissner-Nordström metric
 * Relative angular momentum
 * Relaxation time
 * Relic particles
 * Remus (moon)
 * Repulsive force (astronomy)
 * Resonant trans-Neptunian object
 * Retrograde and direct motion
 * Reull Vallis
 * Reuven Ramaty High Energy Solar Spectroscopic Imager
 * Reverberation mapping
 * Revised New General Catalogue
 * Rhadamanthus
 * Rhea (moon)
 * Richard D. Lines
 * Richard Martin West
 * Richard P. Binzel
 * Rigel
 * Rille
 * Rima Ariadaeus
 * Rimae Aristarchus
 * Rimae Fresnel
 * Rimae Sirsalis
 * Ring galaxy
 * Ring Nebula
 * Ring Nebula (NGC 6822)
 * Ring singularity
 * Rings of Jupiter
 * Rings of Neptune
 * Rings of Rhea
 * Rings of Saturn
 * Rings of Uranus
 * Rip current
 * Robert Burnham, Jr.
 * Robert Evans (astronomer)
 * Robert G. Harrington
 * Robert H. McNaught
 * Robert's Quartet
 * Robert Weber (astronomer)
 * Robert Zubrin
 * Robotic exploration of the Moon
 * Robur Carolinum
 * Robust Associations of Massive Baryonic Objects
 * Roche limit
 * Roche lobe
 * Roger Putnam
 * Rogue planet
 * Rohini (nakshatra)
 * Rome Observatory
 * Romulus (moon)
 * Rooftop (Chinese constellation)
 * Room (Chinese constellation)
 * Root (Chinese constellation)
 * Rosalind (moon)
 * Rosetta (orbit)
 * Rosetta (spacecraft)
 * Rosetta space probe timeline
 * Rosette Nebula
 * Ross 128
 * Ross 154
 * Ross 248
 * Ross 548
 * Ross 614
 * Rossiter-McLaughlin effect
 * Rotating black hole
 * Rotating ellipsoidal variable
 * Rotating radio transient
 * Rotating reference frame
 * Rotation around a fixed axis
 * Rotation period
 * Rotation-powered pulsar
 * Route-dependence
 * Royal Harwood Frost
 * Royal Observatory, Edinburgh
 * Royal stars
 * Roy A. Tucker
 * Rp-process
 * RR Lyrae variable
 * RS Canum Venaticorum variable
 * R. Scott Dunbar
 * R-type asteroid
 * Rucbah
 * Rudolphine Tables
 * Rudolph Minkowski
 * Rule of twelfths
 * Runaway star
 * Rupes Altai
 * Rupes Cauchy
 * Rupes Kelvin
 * Rupes Recta
 * RV Tauri variable
 * RX J0822-4300
 * RX J0852.0-4622
 * RXJ1242-11
 * RX J1416.5+2315
 * RX J1856.5-3754
 * S/2000 (1998 WW31) 1
 * S/2000 J 11
 * S/2003 J 10
 * S/2003 J 12
 * S/2003 J 15
 * S/2003 J 16
 * S/2003 J 17
 * S/2003 J 18
 * S/2003 J 19
 * S/2003 J 2
 * S/2003 J 23
 * S/2003 J 3
 * S/2003 J 4
 * S/2003 J 5
 * S/2003 J 9
 * S/2004 S 12
 * S/2004 S 13
 * S/2004 S 17
 * S/2004 S 3
 * S/2004 S 4
 * S/2004 S 6
 * S/2004 S 7
 * S/2006 S 1
 * S/2006 S 3
 * S/2007 S 2
 * S/2007 S 3
 * S4 Index
 * Sachs-Wolfe effect
 * Sadao Sei
 * Sagittarius A
 * Sagittarius A*
 * Sagittarius Arm
 * Sagittarius B2
 * Sagittarius Dwarf Elliptical Galaxy
 * Sagittarius Dwarf Irregular Galaxy
 * Sagittarius Star Cloud
 * Sagittarius Window Eclipsing Extrasolar Planet Search
 * Sakigake
 * Sakurai's Object
 * Samuel Oschin telescope
 * Sanduleak -69° 202a
 * Santa Lucia Stroncone Astronomical Observatory
 * Sao (moon)
 * Sapas Mons
 * Saros cycle
 * Satellite galaxy
 * Satoru Otomo
 * Saturn
 * Saturn-crosser asteroid
 * Saturn kilometric radiation
 * Saturn Nebula
 * Saturn's Gallic group of satellites
 * Saturn's Inuit group of satellites
 * Saturn's moons in fiction
 * Saturn's Norse group of satellites
 * Sawiskera (moon)
 * SAX J1808.4-3658
 * Sayh al Uhaymir 169
 * Scalar Field Dark Matter
 * Scalar-vector-tensor decomposition
 * Scale factor (Universe)
 * Scale height
 * Scalloped margin dome
 * Scattered disc
 * Sceptrum Brandenburgicum
 * Sceptrum et Manus Iustitiae
 * Schelte J. Bus
 * Schiaparelli (Martian crater)
 * Schreibersite
 * Schwarzschild metric
 * Schwarzschild radius
 * S. Cofre
 * Scorpius-Centaurus Association
 * Scorpius X-1
 * Scott J. Horowitz
 * SCR 1845-6357
 * SCUBA-2 All Sky Survey
 * Sculptor Dwarf Galaxy
 * Sculptor Dwarf Irregular Galaxy
 * Sculptor Galaxy
 * Sculptor Group
 * Scutum-Crux Arm
 * SDP4
 * SDSS J090745.0+024507
 * SDSSJ0946+1006
 * Seasonal lag
 * Second Cambridge Catalogue of Radio Sources
 * Secular resonance
 * Secular variations of the planetary orbits
 * Sedna (mythology)
 * Segin
 * Seidai Miyasaka
 * Seiji Ueda
 * Selenographia, sive Lunae descriptio
 * Selenographic coordinates
 * Selenography
 * Self-creation cosmology
 * Self-Indication Assumption
 * Self-interacting dark matter
 * Semidetached binary
 * Semi-major axis
 * Semi-minor axis
 * Semiregular variable star
 * Semi-synchronous orbit
 * Sentry (monitoring system)
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 * SN 1006
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 * Snake Nebula
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 * Sodium layer
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 * SOFA (Astronomy)
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 * Swift (Deimian crater)
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 * Swiss cheese features
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 * Table of lunar phases
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 * Tadpole Galaxy
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 * Tai Sui
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 * Tank Farm
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 * Terrestrial gamma-ray flash
 * Terrestrial planet
 * Terzan 7
 * Tests of general relativity
 * Tethys (moon)
 * Tetsuo Kagawa
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 * Thackeray's Globules
 * Thaicom 4
 * Thalassa (moon)
 * Thanos
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 * Tharsis Montes
 * Thebe (moon)
 * The Bitches
 * The British and Irish Meteorite Society
 * The Dust of Death
 * The Game-Players of Titan
 * The Great Daylight 1972 Fireball
 * The Hole Man
 * Theia (planet)
 * The Invisible Enemy
 * The Journeyman Project 3: Legacy of Time
 * Thelxinoe (moon)
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 * Themisto (moon)
 * Theodor Brorsen
 * The Puppet Masters
 * Thermal and Evolved Gas Analyzer
 * Thermodynamics of the universe
 * Thermopause
 * Thermosphere
 * The Sirens of Titan
 * The Spaceguard Foundation
 * The Sun in human culture
 * Theta¹ Orionis C
 * The Three Kings
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 * Thierry Pauwels
 * Thira (crater)
 * Third Cambridge Catalogue of Radio Sources
 * Thomas Gwyn Elger
 * Thorne-Hawking-Preskill bet
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 * Three enclosures
 * Three star
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 * Thrymr (moon)
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 * Thwing
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 * Tidal acceleration
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 * Tide
 * Tideline
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 * Timaeus (dialogue)
 * Timekeeping on Mars
 * Timeline of black hole physics
 * Timeline of cosmology
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 * Timeline of gravitational physics and relativity
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 * Timing noise
 * Timothy B. Spahr
 * Tip of the Red Giant Branch
 * Tirawa (crater)
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 * Tisserand's Criterion
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 * Titan (book)
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 * Titan in fiction
 * Titan (John Varley)
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 * Titan (moon)
 * Titius–Bode law
 * Tobias Mayer
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 * Tom Gehrels
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 * Total electron content
 * TRACE
 * Tracy's Rock
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 * Transit of Deimos from Mars
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 * Transit of Mercury
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 * Transit of Venus
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 * Transit of Venus from Jupiter
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 * Transit of Venus from Saturn
 * Transit of Venus from Uranus
 * Trans Lunar Injection
 * Trans-Neptunian object
 * Trans-Planckian problem
 * Transposition, docking, and extraction
 * Trapezium Cluster
 * Trapped null surface
 * TrES-1
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 * Triangulum Galaxy
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 * Trifid Nebula
 * Trinculo (moon)
 * Triton (moon)
 * Tritos
 * Trojan (astronomy)
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 * True anomaly
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 * Tsiolkovsky rocket equation
 * Tsuneo Niijima
 * Tsutomu Hioki
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 * T Tauri star
 * T Tauri wind
 * T-type asteroid
 * Tucana Dwarf
 * Tugaske (crater)
 * Tully-Fisher relation
 * Tundra orbit
 * Tunguska event
 * Turbopause
 * Turdus Solitarius
 * Turtle Beak (Chinese constellation)
 * Turtles all the way down
 * TVLM513-46546
 * Twenty-eight mansions
 * TW Hydrae association
 * Twin Quasar
 * Two-body problem
 * Two star
 * Tycho-2 Catalogue
 * Tycho Brahe (crater)
 * Tycho G
 * Tychonic system
 * Type Ia supernova
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 * Tyrrhena Terra
 * UAO-DLR Asteroid Survey
 * UESAC
 * UGC 11066
 * UGC 8091
 * UGCA 86
 * UK Dark Matter Collaboration
 * UKIRT Infrared Deep Sky Survey
 * Ulisse Munari
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 * Ultimate fate of the universe
 * Ultimi Scopuli
 * Ultraluminous X-ray source
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 * Ulysses (spacecraft)
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 * Unbarred lenticular galaxy
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 * Universe
 * University Rover Challenge
 * Upper Imbrian
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 * Uppsala General Catalogue
 * Upsilon Andromedae d
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 * Uranometria
 * Uranus
 * Uranus-crosser asteroid
 * Uranus in fiction
 * Urbain Le Verrier
 * Ursa Major Cluster
 * Ursa Major Dwarf
 * Ursa Major I Dwarf
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 * Ursa Major Moving Group
 * Ursa Minor (disambiguation)
 * Ursa Minor Dwarf
 * Ursids
 * UScoCTIO 108
 * User:Asimsky/European Combined Geodetic Network
 * User:Brian enke99/bio
 * User:Markpipe/DRIFT
 * User:Pfhreak/Solar Twin
 * User:Warwick-cfsa
 * U.S. Standard Atmosphere
 * Uttara Ashādhā
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 * Uzboi Vallis
 * V337 Car
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 * Van Biesbroeck 8
 * Van Biesbroeck 8b
 * Van Maanen's star
 * Variable nebula
 * Variable star
 * Variable star designation
 * Variation (astronomy)
 * Varuna
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 * Vega
 * Vega 1
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 * Vega program
 * Veil Nebula
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 * Vela Supernova Remnant
 * Vela X-1
 * Venetia Phair
 * Venus
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 * Venusians
 * Venus in fiction
 * Vermilion Bird
 * Verona Rupes
 * Vertical deflection
 * Vesna Vulović
 * Vesta family
 * Viktor Knorre
 * Vincenzo Cerulli
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 * Vincenzo Zappalà
 * Violeta G. Ivanova
 * Virginids
 * Virgle
 * Virgo-centric flow
 * Virgo Cluster
 * VIRGOHI21
 * Virgo interferometer
 * Virgo Stellar Stream
 * Virgo Supercluster
 * Virrat (crater)
 * Virtual black hole
 * Vishniac (crater)
 * Vision for Space Exploration
 * Višnjan Observatory
 * Visual binary
 * Vis-viva equation
 * Vitim event
 * VizieR
 * Vladimir Aleksandrovich Albitzky
 * Vladimir Shkodrov
 * Vogt-Russell theorem
 * Volcanism on Io
 * Von Zeipel theorem
 * Vostok (crater)
 * Voyager program
 * V-type asteroid
 * Vulcan (hypothetical planet)
 * Vulcanoid asteroid
 * W43A
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 * W50 (nebula)
 * Wall (Chinese constellation)
 * Walter Baade
 * Walter Goodacre
 * Walter R. Cooney, Jr.
 * Walther Augustin Villiger
 * Warm dark matter
 * Warren B. Offutt
 * Washington Double Star Catalog
 * WASP-1
 * WASP-12
 * WASP-2
 * WASP-4
 * WASP-8
 * Watari Kakei
 * WD 0137-349
 * WD 0346+246
 * WD B1620-26
 * Weak gravitational lensing
 * Weakly interacting massive particles
 * Weber bar
 * Weightlessness
 * Well (Chinese constellation)
 * Wen Yen Jen
 * Westerlund 1
 * Westerlund 2
 * Wet moon
 * Weyl curvature hypothesis
 * Weyl's postulate
 * Whirlpool Galaxy
 * White dwarf
 * White hole
 * White Tiger (Chinese constellation)
 * Wide-field Infrared Survey Explorer
 * Widmanstätten pattern
 * WikiProject Astronomical objects/Infoboxes
 * WikiProject Astronomical objects/Infoboxes galaxies
 * Wild Duck Cluster
 * Wilhelm Beer
 * Wilhelm Gotthelf Lohrmann
 * Wilhelm Julius Foerster
 * Wilkes Land crater
 * Willamette Meteorite
 * William A. Bradfield
 * William Herschel
 * William Kwong Yu Yeung
 * William Lassell
 * Willman 1
 * Willow (Chinese constellation)
 * Wilson effect
 * WIND
 * Wings (Chinese constellation)
 * Winnecke 4
 * Winnecke Catalogue of Double Stars
 * Winnowing Basket (Chinese constellation)
 * Winter Hexagon
 * Wise Observatory
 * WMAP cold spot
 * Wold Newton meteorite
 * Wolf 1061
 * Wolf 359
 * Wolf 424
 * Wolf 635
 * Wolf Bickel
 * Wolf-Lundmark-Melotte
 * Wolf moon
 * Wolf number
 * Wolf-Rayet nebula
 * Wolf-Rayet star
 * World
 * World (adjective)
 * Wormhole
 * WR 102ka
 * WR 104
 * WR 136
 * Wrinkle-ridge
 * Wunda (crater)
 * W Ursae Majoris variable
 * W Virginis variable
 * X/1106 C1
 * Xallarap
 * Xanthe Terra
 * XENON Dark Matter Search Experiment
 * Xifengite
 * Xinglong Station (NAOC)
 * XMMXCS 2215-1738
 * XO-1
 * XO-5
 * X-ray binary
 * X-ray burster
 * X-ray pulsar
 * XTE J1650-500
 * XTE J1739-285
 * X-type asteroid
 * Yamato 791197
 * Yarkovsky effect
 * Yarkovsky-O'Keefe-Radzievskii-Paddack effect
 * Yasukazu Ikari
 * Yellow hypergiant
 * Yellow supergiant
 * Ylem
 * Ymir (moon)
 * Yohkoh
 * Yoshiaki Banno
 * Yoshiaki Oshima
 * Yoshikane Mizuno
 * Yoshio Kushida
 * Yoshisada Shimizu
 * Younger Dryas impact event
 * Young stellar object
 * Yrjö Väisälä
 * Yuji Hyakutake
 * Yuty (crater)
 * Zdeněk Moravec
 * Zdeňka Vávrová
 * Zenithal Hourly Rate
 * Zenith Hourly Rate
 * Zero-velocity surface
 * Zhang Jiaxiang
 * Zhang Yuzhe
 * Zij-i-Sultani
 * Zodiac
 * Zodiacal constellation
 * Zodiacal light
 * Zond 1964A
 * Zond 1967A
 * Zond 1967B
 * Zone of Avoidance
 * Zubenhakrabi
 * ZW II 96