☉Solar System Simulator

Help / simulator controls

Make the view your own.

Pause, choose a world, adjust the view, and start again. The same visible controls work with a mouse, keyboard, or touch.

Everyday controls

  • Pause / Resume: stop or continue the physical motion. Camera rotation is independent; turn it off in View options if needed.
  • Simulation speed: choose how much simulated time passes per real second. The calculation step stays fixed.
  • Restart: return to time zero with fresh trails. Your selection, speed, pause state, and view settings stay the same.
  • Find an object: search by name and filter by family. Your current selection remains available even if no objects match.
  • Show this system: fit a planet and its moons. For a selected moon, this includes its parent and siblings.
  • Center on this object: fit one body or its unknown-size marker. Show whole system selects the scene's first body (the Sun in the core) and restores the wide family view.
  • View options: zoom, stop camera rotation, switch scale, or reveal trails and vector directions. Real scale can make small bodies hard to see; switch back to Illustrative or center on the body.

Close a panel to return to the scene. Escape also closes it and returns keyboard focus to the button that opened it. Try the controls →

Learn and measure

Learn provides activities and lesson presets. Expand Advanced physics settings there to change the calculation method, timestep, or starting-speed multiplier, then press Load lesson. This starts a fresh physical state while keeping your pause setting; close Learn and press Resume if needed.

Advanced provides one-step playback while paused, physical CSV downloads, and prepared small-body experiments. Expand the measurement and diagnostic sections below the scene to inspect the numbers. Follow your first orbit →

Keyboard shortcuts and native controls

The separate comparison lab pairs run A/B settings at matched checkpoints and provides pause, resume, next-checkpoint, reset, CSV export and share/import controls. Main-runtime collision lessons use a smaller physical timestep and 1/5/10/25/50 simulated-seconds-per-second playback so contact remains observable. The Contact button or native M switches bounce/merge and restarts the contact lesson.

Guided lessons add preset, integrator, timestep and initial-speed controls plus SI snapshot export. Native L cycles lessons, I switches the teaching integrator, D changes the lesson timestep, and -/= adjust initial speed. These changes reset the lesson. T switches trail frame, X toggles vector directions and E exports CSV on both targets.

Space

Pause or resume physics. Paused wall time is not accumulated.

N

Advance one configured physics tick while paused (15 seconds for core/catalog); disabled during playback.

R

Reset physics, clock remainder, and trails to time zero. Selection, speed, pause state, view mode, and camera rotation setting are retained.

[ / ]

Select a requested orbital playback speed: 1 hour, 1 day, 5 days, 10 days, or 15 days per real second. The collision lesson uses 1/5/10/25/50 simulated seconds per real second. The configured physics step stays fixed. Achieved speed and retained pending time reveal when hardware cannot sustain the target.

Tab

Cycle camera focus in the native app; continue through page controls on the web.

C / 1–9 / 0

Cycle through bodies or select the first ten positions in the active scene; 0 selects Jupiter in the core demonstration. Lessons and catalog experiments have their own active order. The web dropdown lists names from the running C scene.

/

Native name/designation/group search: type a query, Down finds the next match, Enter selects, Escape closes. On the web, use Find a body and Body group; filters retain the current C selection.

B

Frame only the selected body or its unknown-size marker, independently of the much wider moon family.

V

Toggle illustrative scale and real-scale rendering.

F

Frame the selected system: planet and moons, a moon's parent and siblings, or all bodies when the Sun is selected.

A

Toggle camera auto-rotation independently of physics playback.

Mouse wheel

Zoom around the selected body or framed system root with clamp protection.

The web page provides buttons, speed/body selectors, and a rotation checkbox for touch and keyboard use. Shortcuts require canvas focus. Tab exits the canvas; ordinary form keys retain browser behavior.

Camera model and source

src/app/orbit_camera.c preserves viewing pitch. Direct body selection restores the default camera distance; framing uses the current family's rendered bounding sphere and viewport aspect ratio. The framed camera follows the family root while the inspector keeps the selected body.

Zoom changes distance only. Framing adjusts zoom limits and sensitivity for planetary or satellite scales; near/far clipping follows camera distance so real-scale systems stay visible. Reframe after motion or manual zoom to fit the family again. A viewport resize or scale toggle refits an already framed system.

Read the physical inspector

src/app/simulation_session.c computes distance from the parent's position and speed from the difference between body and parent velocities. Parent lookup uses stable catalog IDs, not array order or body names.

The page displays kilometres, kilometres per second, kilograms, and physical radius in kilometres. These values are derived from SI simulation state and remain identical when a paused scene switches render mode. The Sun has no parent, so relative distance and speed display N/A. Camera distance is explicitly labelled in visual render units.

Developer reference: core demonstration focus order

Sun → Mercury → Venus → Earth → Moon → Mars → Phobos → Deimos → Vesta → Jupiter → Io → Europa → Ganymede → Callisto → Amalthea → Thebe → Adrastea → Metis → Himalia → Elara → Pasiphae → Sinope → Lysithea → Carme → Ananke → Leda → Callirrhoe → Themisto → Megaclite → Taygete → Chaldene → Harpalyke → Kalyke → Iocaste → Erinome → Isonoe → Praxidike → Autonoe → Thyone → Hermippe → Aitne → Eurydome → Euanthe → Euporie → Orthosie → Sponde → Kale → Pasithee → Hegemone → Mneme → Aoede → Thelxinoe → Arche → Kallichore → Helike → Carpo → Eukelade → Cyllene → Kore → Herse → S/2010 J 1 → S/2010 J 2 → Dia → S/2016 J 1 → S/2003 J 18 → S/2011 J 2 → Eirene → Philophrosyne → S/2017 J 1 → Eupheme → S/2003 J 19 → Valetudo → S/2017 J 2 → S/2017 J 3 → Pandia → S/2017 J 5 → S/2017 J 6 → S/2017 J 7 → S/2017 J 8 → S/2017 J 9 → Ersa → S/2011 J 1 → S/2003 J 2 → S/2003 J 4 → S/2003 J 9 → S/2003 J 10 → S/2003 J 12 → S/2003 J 16 → S/2003 J 23 → S/2003 J 24 → S/2011 J 3 → S/2018 J 2 → S/2018 J 3 → S/2021 J 1 → S/2021 J 2 → S/2021 J 3 → S/2021 J 4 → S/2021 J 5 → S/2021 J 6 → S/2016 J 3 → S/2016 J 4 → S/2018 J 4 → S/2022 J 1 → S/2022 J 2 → S/2022 J 3 → S/2017 J 10 → S/2017 J 11 → S/2011 J 4 → S/2018 J 5 → S/2024 J 1 → S/2011 J 5 → S/2010 J 3 → S/2010 J 4 → S/2010 J 5 → S/2010 J 6 → S/2011 J 6 → S/2017 J 12 → S/2017 J 13 → S/2017 J 14 → S/2017 J 15 → S/2017 J 16 → S/2017 J 17 → S/2017 J 18 → S/2021 J 7 → S/2021 J 8 → Saturn → Uranus → Neptune