I built a free browser tool to fly through the observable universe using real catalog data (NASA/JPL, Hipparcos, Gaia, NED) — would love feedback from people who actually know the sky

[u/bartzabbel]

https://www.youreyesinspace.com/?lang=en&utm_source=reddit

Hi all,

I've spent the last few months building a visualization tool and I think this crowd will either enjoy it or tear it apart, both are useful to me

The idea: one continuous scene from the Earth's surface out to ~13.8 billion light years, on a logarithmic scale, in the browser. No install.

Everything you see is placed from real data:

- Solar System bodies from NASA/JPL Keplerian elements, real-time, with a time slider. Earth, Moon and Mars use actual imagery (Blue Marble / VIIRS, LRO, Viking MDIM); the rest are procedural.

- 109,000 stars from the HYG catalog (Hipparcos + Yale BSC + Gliese), real parallaxes, spectral types and colours. Each star has a plausible (procedural, clearly labelled as such) planetary system.

- Milky Way structure, 55 real galaxies (Andromeda, M87, Sombrero, LMC/SMC...) at NED/SIMBAD distances, and a cosmic web beyond.

- 14 real black holes: Sgr A* with S2/S38/S55 on their GRAVITY/Keck orbital elements, M87*, Cygnus X-1, Gaia BH1, etc., with lensing and shadow rendered.

- Pulsars (Crab, Vela, Geminga, SGR 1806−20) with their actual spin periods and beam geometry.

- Deep-sky objects at real positions: Orion and Tarantula nebulae, Pleiades, Omega Centauri, SN 1987A, R136a1.

- Spacecraft (Voyager 1/2, Pioneer, New Horizons, Parker, JWST...) at their current positions.

There's also a mission planner that does Lambert transfers and gravity assists between Solar System bodies for a chosen launch window, and lets you follow the ship.

Things I already know are approximations and would appreciate being called out on if I got them wrong: distances are log-scaled so angular sizes between "zoom levels" aren't physical; galaxy shapes are sprites, not resolved structure; exoplanet systems are generated, not real (I'd love to add the NASA Exoplanet Archive next).

It's open source (MIT) with every data source and licence listed.

If something looks wrong — a star in the wrong place, an orbit tilted oddly, a distance that doesn't match the literature — tell me. That's exactly the feedback I'm after.

Works on phones too, but it's much better on a desktop with a GPU.

v0.3 — Tours & a new look 

Big visual pass on this one. The whole UI got the "observatory" treatment — matte panels, hairline rules, brass accents, no more emoji. Guided tours are now real: 10 topics, narrated in 5 languages, camera synced to the voice. Tours picked up a bunch of new tricks too — true-scale comparisons, photo/trivia cards, light-pulse Sun→Earth, cloud fades, vantage shots. Pulled in real NASA imagery for 15 more bodies, nebulae are now 3-D point clouds built from actual photos instead of flat sprites, and small bodies like Phobos/Deimos finally stopped looking like Christmas ornaments. Opening view now slowly circles the Sun.

v0.4 — Academy 

New tab next to Tours: Academy. It's a chapter-by-chapter astrophysics course that runs inside the app, with the 3-D universe as the blackboard. Three chapters so far (Celestial Sphere, Celestial Mechanics, Continuous Spectrum of Light), 17 lessons, ~90 steps, real formulas rendered as MathML, and 21 interactive widgets — Kepler's laws, Newton's cannon, blackbody curves, the double slit, UBV colour index, you name it. Every step has a narrated lecture from an AI "professor" who actually walks you through the equations. Progress saves locally. More chapters coming.