# The Milky Way, to scale (Galactic Space)

> A free, interactive WebGPU web piece at https://galactic-space.com: one continuous zoom from low Earth orbit (300 km up) to the Andromeda galaxy (780 kpc, about 2.54 million light-years), with every star, planet, cluster and galaxy at its measured distance and real brightness. Nothing is enlarged or brightened to stay visible. Made by Galactic Space, an independent art and science project. English. Last updated 2026-10-19.

The main page is a real-time GPU canvas and needs a browser with WebGPU; its text content is on the pages below.

Key values used by the piece (from its code):

- Sun to Galactic Centre (Sagittarius A*): 8.178 kpc, about 26,700 light-years
- Sun above the Galactic mid-plane: 20.8 pc
- Milky Way disc: about 100,000 light-years across (scale-ladder figure); model spiral arms run 2.2-22 kpc from the centre; stellar halo to about 45 kpc
- Stars in the Milky Way: an estimated 100-400 billion
- Galactic model: thin disc (scale length 2.6 kpc, height 300 pc), thick disc (3.6 kpc, 900 pc), boxy bulge, bar of about 4.6 kpc half-length at 25 degrees, six spiral arms after Reid et al. 2019, pattern speed 25 km/s/kpc, dust extinction
- Sun's circular speed: 233 km/s; galactic year about 227 million years (model)
- Sagittarius A* mass: about 4.2 million solar masses, derived from the orbit of the star S2 (period 16.05 years)
- Andromeda (M31): 780 kpc; Triangulum (M33): 840 kpc; Large Magellanic Cloud: 49.97 kpc; Small Magellanic Cloud: 62 kpc
- Proxima Centauri: 1.301 pc (4.24 light-years); Sirius: 2.637 pc; Orion Nebula: 412 pc
- Oort cloud: 2,000-120,000 AU; heliopause: about 120 AU; Voyager 1: 171.8 AU on 2026-09-06
- Contents: the 88 constellations (Sky & Telescope figures, 721 stars, in 3D), every star within 5.2 pc, open and globular clusters, nebulae, supernova remnants, nearby galaxies, 306 exoplanet systems within 30 pc (510 planets), 25,000 main-belt asteroids, the planets and moons, Voyager 1 and 2, JWST, and live Earth layers (ISS, earthquakes, clouds, rain, tropical cyclones, aurora)

## Pages

- [The Milky Way, to scale](https://galactic-space.com/): the interactive zoom itself (WebGPU)
- [About: distances, data and method](https://galactic-space.com/about/): what "to scale" means, key distances with units, the galaxy model, FAQ
- [Data sources and credits](https://galactic-space.com/sources/): catalogues, papers, textures and live feeds, with licences

## Also in the piece

- [How a star dies](https://galactic-space.com/collapse/): a star's collapse simulated, from the main sequence to white dwarf, neutron star or black hole
- [Mining the Solar System](https://galactic-space.com/mining/): what it would cost to go and get an asteroid

## Optional

- [Sitemap](https://galactic-space.com/sitemap.xml)