నక్షత్రాలు, గెలాక్సీలు

Saturn (శని)

— 6th planet from Sun; 2nd largest planet (after Jupiter); most spectacular ring system; gas giant mostly hydrogen-helium. Distance from Sun: 1.43 billion km (9.5 AU); light from Sun takes 80 minutes. Year: 29.5 Earth years. Day: 10.7 hours. Diameter: 116,464 km (9x Earth). Mass: 5.7×10^26 kg (95 Earths). Surface gravity: similar Earth (1.07x); less dense than water — Saturn would float! Temperature: -178°C cloud tops; +11,700°C core. Composition: 96% hydrogen, 3% helium. No solid surface — all gas + liquid layers. Iconic Rings — observed since Galileo 1610 (Galileo thought "ears"); Christiaan Huygens 1655 identified rings. Ring composition: 90% water ice, 10% rock — fragments of moons + comets shattered by Saturn's gravity. 7 main rings: A, B, C, D, E, F, G; visible from Earth telescope; total mass equal to small moon; only 100 m to 1 km thick but 282,000 km wide! Ring formation: 100M-1B years ago; possibly disappear in 100M years (raining into Saturn). 83 confirmed moons (NASA 2024); (1) Titan — 2nd largest moon solar system after Ganymede; only moon with thick atmosphere (50% denser than Earth's); methane lakes-rivers-rain; possible alien life prebiotic. Cassini-Huygens mission 1997-2017 dropped Huygens probe on Titan 2005. (2) Enceladus — geysers spewing water from south pole; subsurface ocean = possible alien life. (3) Mimas — looks like Death Star Star Wars crater. (4) Iapetus — half-bright half-dark. NASA missions: Pioneer 11 (1979), Voyager 1+2 (1980-81), Cassini (1997-2017) — 13 years orbit, Dragonfly mission 2027 launch to Titan drone. Vedic astrology: Shani (శని) = 7th planet, karma planet; Saturday = Shanivar; serious teacher; slow-moving; brings discipline through hardship; Sade Sati 7.5-year period challenging; Tirupati Tirumala has Shani worship; Shani Shingnapur Maharashtra famous Shani temple. Telugu astrology: many fast on Saturday; visit Shani temple.