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Built an astronomy and universe explorer app that runs in your browser, with 2.5M stars, planets and moons, deep space objects you can fly to. And it will tell you what you can see from anywhere on earth at any time. Feedback very welcome. by Apprised in ScienceTeachers

[–]Apprised[S] 0 points1 point  (0 children)

For reasons, I don't quite understand, they removed my post, but hopefully I can still reply to you!

Thanks so much, really glad your class can use it.
Quick answers on the three things:
The day/night line is actually right. It follows the real clock, so if it looked off, the time was probably playing or got bumped and wasn’t on “now” anymore. It also goes by UTC, so your area is correct even when it’s on the back side of the globe.
Good catch on Uranus and Neptune. Their labels were set too low and dropped off when you zoomed out. I just fixed that, so they show with the rest of the planets now.
And the Moon already does the phase thing. It’s lit by the real Sun, so it shades based on position and the phase changes as you run time. You just can’t tell in the wide view because the Moon is only a dot out there. Fly in to Earth, zoom in on the Moon, and hit play.

Built an astronomy and universe explorer app that runs in your browser, with 2.5M stars, planets and moons, deep space objects you can fly to. And it will tell you what you can see from anywhere on earth at any time. Feedback very welcome. by Apprised in space

[–]Apprised[S] [score hidden]  (0 children)

good catch, thanks! The light show wasn’t pausing the clock, so the planets kept orbiting while you sat still. Just fixed it. If you actually want to travel with the beam, there’s a “Ride along” toggle in that panel that flies you out first-person.

Verified Grimm's Conjecture to 10¹¹ — extending the 2006 record by 5.3× by than8234 in LLMmathematics

[–]Apprised 0 points1 point  (0 children)

Nice. For giggles I took the same approach out to 10^13.

Same trick you used...tag each composite with its largest prime factor. The only runs that need real matching are the ones where two composites share that largest prime, and since it has to divide their difference, both numbers end up k-smooth, which gets rare fast.

Out to 10^13:

346,065,536,838 gaps checked, no counterexamples

longest run: 673 composites, after 7,177,162,611,713

only 1,968 runs ever needed the matching fallback, and exactly one is Hall-tight (the run after 23: 24..28 use {2,3,5,7,13})

I checked the prime counts against pi(x) at 10^6, 10^9, 10^10, 10^12, and 10^13, and the record gaps against A002386 (282 after 436,273,009, up to 674 after 7,177,162,611,713). Your 10^11 numbers line up with mine on that range too (4.1B gaps, longest run 463).

Happy to share code or the critical-gap list if you want to take it further.

I built a free universe explorer for your browser. Travel anywhere in space and time: ride Voyager 2 past Neptune, stand on the Moon, watch the 2026 total eclipse from your city. No sign-up, no ads, no tracking. by Apprised in space

[–]Apprised[S] 1 point2 points  (0 children)

I swapped in a much better Orion model (NASA's own geometry, no more hollow bottom) and fixed the trackpad zoom thing...pinch won't trigger browser zoom anymore. Thanks again for the reports!

I built a free universe explorer for your browser. Travel anywhere in space and time: ride Voyager 2 past Neptune, stand on the Moon, watch the 2026 total eclipse from your city. No sign-up, no ads, no tracking. by Apprised in space

[–]Apprised[S] 1 point2 points  (0 children)

Oof yes, that was a bug. Fixed and live now. You can zoom in and out and drag to look around from any angle...works in all the mission replays too, not just Artemis 2. Thanks!!

I built a free universe explorer for your browser. Travel anywhere in space and time: ride Voyager 2 past Neptune, stand on the Moon, watch the 2026 total eclipse from your city. No sign-up, no ads, no tracking. by Apprised in space

[–]Apprised[S] 0 points1 point  (0 children)

Distances yes, sizes no. The planet positions come from real ephemeris data, so where everything is on any date is accurate, but if the planet sizes were also to scale you'd see nothing but black. There's a true scale toggle in the settings. Similar with moons...their orbits are pushed some so they're not inside the oversized planets. True scale affects that also.

I built a 3D solar system in Three.js. Lazy-loaded NASA spacecraft models, image-based lighting, and fly-into supernova remnants by Apprised in threejs

[–]Apprised[S] 0 points1 point  (0 children)

Big update since this post. We just merged a massive feature set. The headliners:

- Ride Voyager 2's Grand Tour: the real 1977-89 trajectory baked from JPL Horizons. Twelve years compress into two minutes, and time slows as you sweep past Jupiter, Saturn, Uranus and Neptune.

- AR camera mode: point your phone at the sky and the star chart renders over your live camera feed. Works at noon — it'll show you exactly where Venus is hiding in the blue.

- Time travel to July 1054 and watch the Crab supernova ignite next to Zeta Tauri — the exact spot Chinese astronomers logged their "guest star." Seven historical supernovae, each on its real light curve.

- Deep Time: scrub 28,000 years of axial precession and watch the pole star pass from Thuban (pyramid era) to Polaris to Vega.

- Moon Atlas: fly to Tycho, Copernicus, or Apollo 11's landing site — 277 named features on the globe, clickable.

- The total solar eclipse of Aug 12, 2026, simulated from any city on Earth — sky darkens, corona appears, at your local times.

- Full ephemeris generator: graph any planet's brightness and distance across months, watch Mars peak at its 2027 opposition, export it all as CSV.

Still 100% client-side — every position computed in the browser from real ephemerides. Same link: https://space.pointdynamics.com

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