Image: yoursolarsystem.space · The night side of Earth, its city lights and a thin sunlit crescent, with the Sun and the Milky Way beyond
A solar system simulator for any date, checked against JPL Horizons
A browser simulator of the solar system from 1000 to 3000, with Claude Code helping on rendering and UI while the maker did the physics.
Credits
Earliest dated source:
The full story
The simulator shows the solar system for any date between 1000 and 3000, opening at real scale. Planet positions come from VSOP87-based theories plus the maker's own fitted moon models, and were compared with JPL Horizons over 1800 to 2050: within 30 arcseconds for planets and 30 km for the Moon. Solar eclipses match NASA's Five Millennium Canon to about 5 km and 5 seconds.
The maker prototyped the physics in Python, ported it to JavaScript and chose the models and tolerances. Claude Code did much of the rendering and UI. Outside 1800 to 2050 it extrapolates and says so.
How it was done
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Sources
From a short post by the maker, so the details are as they tell them.
- Reddit: Solar system simulator for any date 1000–3000: real scale by default, checked against JPL Horizons (Reddit poster: SinnyJPosted
The maker's post on r/ClaudeCode.
If it disappears: archived copy of Reddit: Solar system simulator for any date 1000–3000: real scale by default, checked against JPL Horizons ( (opens in a new tab)
- The project: yoursolarsystem.space
The simulator.