Stellarium: Software which renders realistic skies in real time

Original Article ↗ Hacker News Discussion ↗

An open‑source planetarium program, Stellarium, is earning praise for bringing realistic, real‑time night skies to desktops, phones, web browsers, VR headsets, and even physical planetariums. Commenters highlight its use for stargazing, education, telescope control, scripting, and even game asset generation, while also comparing it with tools like Celestia, SkySafari, and KStars. The conversation touches on funding models and UX choices (such as mobile upsells and missing screenshots on GitHub), but overall presents Stellarium as a high‑quality, versatile tool that can make astronomy accessible even in light‑polluted environments.

Mobile, Web, and VR Versions

  • Many use the mobile app regularly; satellite identification (including ISS) is a highlight.
  • Web versions are noted: stellarium.org and stellarium-web.org; performance and browser graphics quality are praised.
  • Several people are excited about Stellarium VR, especially on Oculus/Quest, with reports that it finally matches expectations for immersive sky exploration.

Licensing, Open Source, and Mobile Apps

  • Desktop Stellarium is GPL/open source; Android/iOS versions are explicitly noted as not open source and not GPL.
  • Some are annoyed by “naggy” upgrade prompts in the mobile app, feeling this clashes with expectations of GPL/free software.
  • Others respond that GPL is about source freedom, not price; users unhappy with store builds could in theory compile their own (but not for the closed mobile apps).

Screenshots, README, and Project Presentation

  • Multiple comments criticize the GitHub README for lacking example images despite being a visual app.
  • Others argue the main website already has screenshots and that repositories are primarily for developers.
  • There’s a subthread on whether users should simply send PRs adding screenshots, and whether such PRs would even be merged.

Scripting, Automation, and Integration

  • Stellarium’s scripting is highlighted: automated wallpaper generation, study scripts for planetary orbits, and cron-driven renders.
  • It can drive telescope mounts and astrophotography rigs; other tools like KStars/EKOS and Astroberry are mentioned as alternatives or complements.

Code Quality and Developer Experience

  • One commenter reports independently implementing a feature only to find an almost identical patch just merged, taking this as evidence of very clear, well-structured code.
  • This sparks discussion on what “code quality” should mean in practice: ease of making changes vs. stylistic metrics, technical debt, and maintainable architecture.

Educational and Inspirational Uses

  • Stellarium is used to teach children about rising/setting of celestial objects and to prep for ISS passes and satellite viewing.
  • Some recount using it for school astronomy homework, planetarium shows, and even as a skybox source for games and room/ceiling projections.

Related Tools and Questions

  • Celestia, KStars, SkySafari, Space Engine, XEphem, and DarkSkys projectors are frequently referenced.
  • Text-only/CLI ephemeris tools (e.g., Swiss Ephemeris, NASA JPL Horizons) are suggested for users wanting numerical positions.
  • Questions about WebGL vs older 2D APIs surface; opinions differ on how feasible a full web implementation would have been 10–15 years ago.