Life & fun · alternatives · 2026
24 alternatives to Gravity – Interactive solar-system simulator, from Newton to Einstein
Just for fun and self education, I've built this over a weekend to teach myself why orbits exist, not just show planets going around. Something that was never clearly explain to me in school. It opens with a guided tour that builds the idea up step by step: two bodies and the equal/opposite force, inertia (the Sun is removed and Earth just drifts straight), then "an orbit is falling and continuously missing," cosmic velocities with a little rocket, Voyager 1 & 2's real gravity assists (the clock runs the actual 1977–1989 dates so the planets orbit into their grand-tour alignment and the…
Gravity is an interactive solar-system simulator that explains orbital mechanics through hands-on exploration. It opens with a guided tour building understanding from basic physics—Newton's laws, inertia, and… Below are 24 products that do a similar job, ranked by how close each is in meaning and then by launch-day votes. Prices are shown for the 3 we have checked on their own sites, 3 of them free or with a free tier.
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Atlas of Spacefree▲770Hello HN! Sharing a recent side project of mine, the Atlas of Space, that I built out to explore the Solar System. As a long-time space nerd, I realized recently that I didn't have a good intuition on the scale, speed, and relative orientation of the celestial bodies around us. So over the break I built out a kind of spatial Wikipedia to click around and learn about planets, moons, asteroids, and other bodies orbiting the Sun. The physics is all simulated in the browser using simple Newtonian mechanics. There's a lot left to do from here, including modeling objects in non-Keplerian orbits…
2025 · atlasof.space · its alternatives →
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I (17y/o) have been developing a rocket launch simulation that allows the user to explore what it's like launching a rocket from earth and putting it into orbit. This idea originally started as an educational simulation but as i've gone more down the rabbit hole the more i've wanted to make it realistic. The problem is that I've never had a formal orbital mechanics class or anything like that so I don't know what I'm missing, what I currently have implemented is: Variable gravity Variable Atmospheric drag (US Standard Atmosphere 1976) Multi-stage rockets Closed-loop guidance /…
Jan 2026 · donutthejedi.com · its alternatives →
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Gravity WebGL experiment in the Solar System
2016 · github.com · its alternatives →
- 4IB
2022 · multiplanetary.website · its alternatives →
- 5HO
3D gravity and space Simulator. Explore and play around with the force of gravity in the context of an array of scenarios from our solar system and beyond. You can add planets, delete the Sun, change the value of the gravitational constant or simply lean back and enjoy the dazzling beauty of the pen
2018 · thehappykoala.github.io · its alternatives →
- 6IB
Mar 2026 · structuredlabs.github.io · its alternatives →
- 7WI
Special relativity simulator in which light crawls along at a human speed, so Lorentz contraction, aberration and Doppler shift happen at walking pace.
Sep 2026 · rivendell.dmitrybrant.com · its alternatives →
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23d ago · space.bl2.net · its alternatives →
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- 11AS
I really like the look of the famous album art for Unknown Pleasures [1]. It was originally created by Harold Craft at the Arecibo Observatory from the signals of the first discovered radio pulsar [2]. I made a spectrogram that produces a similar look. It runs FFT in Rust and visualizes it with WebGL. [1]: https://en.wikipedia.org/wiki/File:UnknownPleasuresVinyl.jpg [2]: https://en.wikipedia.org/wiki/PSR_B1919%2B21
2024 · aestuans.github.io · its alternatives →
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Features include: - Several preset periodic orbits: the classic Figure-8, plus newly discovered 3D solutions from Li and Liao's recent database of 10,000+ orbits (https://arxiv.org/html/2508.08568v1) - Full 3D camera controls (rotate/pan/zoom) with body-following mode - Force and velocity vector visualization - Timeline scrubbing to explore the full orbital period The 3D presets are particularly interesting. Try "O₂(1.2)" or "Piano O₆(0.6)" from the Load Presets menu to see configurations where bodies weave in and out of the orbital plane. Most browser…
Nov 2025 · trisolarchaos.com · its alternatives →
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Interactive notes for algebra based physics with explorable explanations
2020 · landgreen.github.io · its alternatives →
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SpaceSim▲7Explore a free 3D space simulator in your browser. Travel across the Solar System, change time, inspect source-backed worlds, and collect postcards.
Jul 2026 · spacesim.co · its alternatives →
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Gravity by Orbit▲262A free magazine about building & scaling communities
2022 · orbit.love · its alternatives →
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AstraPixelsfree tier, from $5/mo▲267A pixel-art solar system at its real current positions.
Aug 2026 · astrapixels.com · its alternatives →
- 18IB
I built this because measuring my age in years felt boring—I wanted to see the kilometers. The first version only used Earth's orbital speed (~30km/s), but the number moved too slowly. To get the "existential dread" feeling, I switched to using the Milky Way's velocity relative to the CMB (~600km/s). The math takes some liberties (using scalar sum instead of vector) to make the speed feel "fast," but it gets the point across. Under the hood, it's a single HTML file with zero dependencies. No React, no build step. The main challenge was the canvas starfield—I had to pre-allocate the…
Jan 2026 · cosmic-odometer.vercel.app · its alternatives →
- 19SP
2014 · stefanom.org · its alternatives →
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Hey HN! We are the co-founders of Elodin (https://elodin.systems/), a code-first physics simulation framework. We just open-sourced our core libraries on Github: https://github.com/elodin-sys/elodin Have you ever wondered what happens when a satellite is first placed into orbit? It turns out that often, they tumble out of control, end over end, in a miraculous fight against stability. Check out our demo here of a control system attempting to rectify this: https://app.elodin.systems/sandbox/hn/cube-sat The spacecraft does not…
2024 · github.com · its alternatives →
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Second only to working at Space X
2015 · kerbalspaceprogram.com · its alternatives →
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Interactive Space Physics Sandbox In Your Browser
May 2026 · stellarillusion.com · its alternatives →
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A gravity simulator, with updated movement controls
2016 · valentinvichnal.github.io · its alternatives →
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AstroGrid▲113Explore the entire universe in your browser, in real 3D
Apr 2026 · velonspace.com · its alternatives →
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Ranked by how close each launch is in meaning, then by votes. Prices were read from each product’s own site when checked and can change. Refine with your own description →