Orrery

added asteroid belt and a comet to the orrery. 200 rocks between mars and jupiter, each on its own orbit with real kepler speeds they all at different rates based on their distance from the sun. the comet has a tail that always points away from the sun and gets brighter as it swings closer. took a while to get the tail direction right. still a single file no frameworks

ok so after shipping i kept looking at the payout and the ratings and it was pretty obvious why the multiplier was low people said it looked cool but there was nothing to DO with it. fair. it was a screensaver. so i turned it into a sandbox.

biggest change: the sim now runs on REAL orbital data. each planet has its actual semi-major axis (AU), eccentricity, and period from nasa’s jpl, and the sun actually sits at the true focus of every orbit now (before, the ellipses were centered on the sun which is wrong kepler’s first law says the sun is at a focus). i also found out my local copy of main.js was some old backup from day 1, so the kepler code i thought was there had vanished from disk good reminder to commit more.

new stuff:

• click any planet and get a data panel with semi-major axis, eccentricity, period, live distance from the sun, mean anomaly and true anomaly
• pause/play + time speed slider (0-500x) + a real date picker, so you can jump to any date and see where the planets actually were. “where were the planets on my birthday” is now a use case instead of a screensaver
• solver view: the newton-raphson solve of kepler’s equation drawn on the canvas — auxiliary circle, M point, E point, and the iteration dots literally marching onto the answer. i think this is the coolest thing, you can watch the math converge
• orbit editor: eccentricity + orbit size sliders per planet, live reshape, reset to real values
• the moon orbiting earth at its real ~27 day period
• scroll to zoom

the solver viz took the longest to get right because i wanted the construction to be mathematically correct, not just decorative. the moon was easy lol.

readme + ship polish:
got feedback that my readme looked ai-generated so i rewrote the whole thing properly it has real info about how the kepler solver works, the feature list, how to run it, what’s next. also made the banner an actual frame of the app running instead of a logo. small stuff should be good to ship again 🤞

loader + terminal
gave the page an opening animation text that prints line by line ( orrery v0.3 , loading 300 stars …. ok , kepler solver …….. ok ) with a progress bar, then fades into the system. got a navy palette. small change, but the page feels like it has life now

kepler ellipses
finally got the planets off circular orbits. gave each one a real eccentricity and major axis (which i knew nothing about till now lol) , then a newton raphson solver for kepler’s equation so they speed up and slow down like actual planets. mercury goes fast through perihelion now while neptune barely moves the difference in speed is way more obvious than with the old circles. took longer than i expected to stop the planets from drifting off their ellipses, but it’s better now. (i hope you can see the developmental process through my pics)

long session about 3.5h
got a proper chunk of time today so I worked with it properly, I added saturn’s ringtook a while to get the tilt right, ended up rotating the area around the planet and drawing the ellipse there instead of trying to math itinline. then spent most of the time just looking at it turned the orbit speeds so mercury actually goes faster around while neptune is slower, fiddled with the starfield twinkle so it doesn’t look like static, and refreshed the page a hundred times checking the ring from different angles. also started reading up on real keplerian elements from NASA’s data that’s the next thing, getting planets off circular orbits and onto actual ellipses. no fancy UI yet, still plain black terminal vibes, but it feels alive now.

day 1, added saturns ring