Astronomy
Articles about stars, planets, space and the universe.
Sagitta
Sagittarius (astrology)
Sagittarius (constellation)
Sagittarius (constellation) — the Archer and the Galactic Center
Sagittarius A
Sagittarius A — the Milky Way's central radio complex
Sagittarius A*
Sakigake
Sao (moon)
Sao — an irregular outer moon of Neptune
Saros cycle
Satellite (artificial)
Artificial satellite
Satellite flare
Saturn
Saturn Nebula
Saturn's Gallic group of satellites
Saturn's Norse group of satellites
Scattered disc
Scattered disc (Scattered disk) – distant trans‑Neptunian region
Sceptrum Brandenburgicum
Sceptrum Brandenburgicum — an obsolete constellation
Scholz's Star
Scholz's Star (WISE J072003.20−084651.2): a nearby binary that passed through the Oort cloud
Scorpio (astrology)
Scorpius
Scorpius–Centaurus Association
Scorpius–Centaurus Association (Sco–Cen): nearest OB association
Sculptor (constellation)
Sculptor galaxy
Sculptor Galaxy (NGC 253) — the Silver Coin Galaxy
Scutum
Scutum (constellation)
Search for Extra-Terrestrial Intelligence
Serpens
Serpens: the Serpent Constellation
Setebos (moon)
Sextans
Sextans (constellation)
Seyfert galaxy
Seyfert galaxy — nearby active galactic nuclei
SGR 1806-20
SGR 1806-20: a magnetar in Sagittarius and the 2004 giant flare
Shangri-La (Titan)
Shani
Shani (Saturn): Hindu Deity, Astrological Influence, and Cultural Role
Shape of the universe
Shapley 1
Shapley Supercluster
Shinsei
Shinsei — early Japanese scientific satellite (launched 1971)
Shukrayaan-1
Siarnaq (moon)
Siarnaq: Saturn's prograde irregular moon and largest member of the Inuit group
Sidereal time
Siding Spring Observatory
Sinope (moon)
Sinope (moon of Jupiter)
Sirius
Sirius (Dog Star): Brightest star in the night sky
Skathi (moon)
Skathi (Saturn XXVII): an irregular, retrograde moon of Saturn
Skoll (moon)
Skoll (Saturn XLVII) — irregular moon of Saturn
Sky
Sky: appearance, causes of color, visible features, and planetary differences
Skylab
Skylab: America's First Space Station
Small Dark Spot
Small solar system body
SN 1987A
SN 1987A — Nearby core‑collapse supernova in the Large Magellanic Cloud