Tooling
Make

Planetariums & Sky Maps

Stellarium, KStars, Cartes du Ciel, SkySafari — plan sessions, identify objects, drive scopes.

The "what's up tonight, where exactly is it, and is it above my horizon?" tool. Doubles as object database, observing planner, and (when wired to a mount) a slew GUI. The OSS desktop tier is genuinely excellent in 2026 — Stellarium and KStars cover most amateurs end-to-end and rival paid apps.

For pointing the scope at what you found see Mount & Session Control; for plate solving "where am I really pointing" see Plate Solving; for satellite passes see Satellite Tracking; for live forecast overlays see Astro Cloud & Weather.

Free / OSS desktop

  • ★ Stellarium — GPL, Win/macOS/Linux. The default planetarium. Photorealistic atmosphere, deep-sky catalogues (NGC/IC, Messier, Caldwell, Sharpless, Abell), Gaia DR3 stars, NORAD TLE satellites built-in, scriptable, plugin ecosystem (oculars, telescope control via INDI / Stellarium Telescope Server / RTS2). The reference; everyone has it installed.
  • ★ KStars — GPL, KDE project, Win/macOS/Linux. Planetarium that's also the front-end for Ekos (full astrophotography session manager). If you ever plan to plate-solve / autoguide / sequence, KStars is the better starting point — see Mount & Session Control.
  • Cartes du Ciel / SkyChart — freeware, Win/macOS/Linux. Old-school, dense, accurate, deep catalogues, ASCOM / INDI mount drive, telescope eyepiece overlays. Beloved by older observers; UI shows its age.
  • HNSKY (Hallo Northern Sky) — freeware Win; tiny, fast, runs on a potato; known for accurate ephemerides.
  • C2A (Computer Aided Astronomy) — freeware Win; specialty: comet / asteroid plotting from minor-planet center elements.
  • Where Is M13? — free, niche, 3D star-map visualizer. "What does the Milky Way look like from inside the cluster?" cool factor.

Mobile

  • ★ Stellarium Mobile — free Lite tier (full sky catalogue, no scope control); paid Plus (~$15) adds telescope control, Gaia DR3 / DSS sky-survey deep-zoom, and hi-res nebula imagery. The cleanest free mobile planetarium in 2026.
  • ★ SkySafari (Simulation Curriculum) — paid; tiers are Basic / Plus / Pro (~$5 / $20 / $50). Plus and Pro are the heavyweight mobile observing apps — full mount control over Wi-Fi/Bluetooth, professional catalogues, observing-list integration with Telrad / Nexus DSC. Pro is the field standard for visual observers.
  • Sky Tonight (Vito Technology) — freemium; pretty, beginner-friendly; subscription pushes hard.
  • Star Walk 2 (Vito) — paid one-time; AR sky pointing; same publisher.
  • ★ Sky Map (was Google Sky Map) — open-source, Android, free, no ads, no account. The "I just want to know what star that is" answer.
  • Night Sky (iOS) — freemium; AR; Apple-only.
  • TheSkyX Pro (Software Bisque) — perpetual, ~$400. Pro-grade planetarium + observatory automation; deep mount support; the choice for serious observatory operators on Windows / Mac.
  • Starry Night Pro Plus 8 (Simulation Curriculum) — perpetual, ~$250. Beautiful renderings; classroom favorite.
  • AstroPlanner (Quasar Observatory) — paid (~$45). Observing-list / session-planning specialist; talks to most mounts.
  • MaxIm DL — paid; primarily an acquisition app but ships planetarium views.

Honest take in 2026

Stellarium + KStars cover everything a hobbyist needs. Pay for SkySafari Plus/Pro on iOS or Stellarium Plus on iOS/Android only if you want a polished mobile planner with mount control in the field. TheSkyX Pro is for observatory operators with budget.

Catalogues / data sources to know

  • Gaia DR3 / DR4 — astrometry / photometry for ~1.8 billion stars; bundled in Stellarium / KStars; free.
  • NGC / IC, Messier, Caldwell, Sharpless, Abell, Hickson — bundled.
  • NORAD TLEs — for satellites; downloaded automatically by Stellarium / KStars / Gpredict.
  • Minor Planet Center elements — comets / asteroids; auto-fetched by most apps.
  • HiPS sky surveys (DSS2, SDSS, PanSTARRS, Aladin, Gaia DR3) — overlay survey imagery on the sky; supported by Stellarium and Aladin Lite.

Pick this if…

  • One free desktop planetarium: Stellarium.
  • Planning to autoguide / plate-solve / sequence: KStars (front-end for Ekos).
  • Old-school dense feature set: Cartes du Ciel.
  • Visual observer at the eyepiece, mobile: SkySafari Pro on a tablet.
  • Casual "what's that star": Sky Map (Android, free) or Stellarium Mobile Lite.
  • Observatory operator on Windows: TheSkyX Pro.

Previous

Streaming Music & Licensing

Next

Mount & Session Control

On this page