The Milky Way: a 3D model of our Galaxy

Nobody has seen our Galaxy from outside: we live inside its disk, and dust hides most of it. This model puts together what astronomers have measured from here.

What is measured

• Spiral arms — fitted to the radio parallaxes of about 200 young, massive stars (Reid et al. 2019). Solid lines show the stretches of each arm that are mapped; dotted lines and the far side of the Galaxy, behind the center, are an extrapolation.
• The Sun — 26,600 light-years (8.15 kiloparsecs) from the center, about 70 light-years above the middle of the disk.
• The bar and the bulge — a bar of old stars about 33,000 light-years long, turned 27° from our line of sight to the center, with a boxy, peanut-shaped bulge (Bland-Hawthorn & Gerhard 2016).
• 157 globular clusters — at their distances from the catalogue of W. E. Harris. Most of them swarm in a round halo around the center, far above and below the disk.
• Famous star clusters and nebulae — at distances measured from the parallaxes of their stars by the Gaia satellite and by radio telescopes. Bright stars — from Hipparcos.

What is drawn

The glow of the disk, the arms, the bar and the dust is our own picture made from these numbers, not a photograph.

Estimates of how fast the spiral pattern turns differ from study to study; the clock uses 28.2 km/s per kiloparsec.

The arrows around the Sun show where each part of the Galaxy lies in our sky: toward Sagittarius we look at the center, toward Auriga and Taurus straight away from it. Click an arrow to open that constellation in the sky map.

Sources and credits

• Spiral arms, the distance to the center and the rotation curve: M. J. Reid et al., “Trigonometric Parallaxes of High-mass Star-forming Regions: Our View of the Milky Way”, ApJ 885, 131 (2019).
• Bar and bulge: J. Bland-Hawthorn & O. Gerhard, “The Galaxy in Context”, ARA&A 54, 529 (2016). Height of the Sun: Bennett & Bovy, MNRAS 482, 1417 (2019). Mass of Sagittarius A*: GRAVITY Collaboration (2022).
• Motion over time: pattern speed of the bar 39.0 km/s per kiloparsec, M. Portail et al., MNRAS 465, 1621 (2017); of the spiral arms 28.2 km/s per kiloparsec, W. S. Dias et al., MNRAS 486, 5726 (2019); the Sun’s up-and-down motion through the disk, once every 95 million years, R. Konietzka et al., “The Radcliffe Wave is oscillating”, Nature 628, 62 (2024).
• Globular clusters: W. E. Harris, Catalog of Parameters for Milky Way Globular Clusters, 2010 edition (Harris 1996, AJ 112, 1487).
• Distances to open clusters: E. L. Hunt & S. Reffert, A&A 673, A114 (2023), from Gaia DR3 (ESA/Gaia/DPAC), via the VizieR service of the CDS, Strasbourg. Orion Nebula: Kounkel et al. 2017; North America Nebula: Kuhn et al. 2020; Omega Nebula: Reid et al. 2019; Veil Nebula: Fesen et al. 2021; Crab Nebula: Trimble 1973; Magellanic Clouds: Pietrzyński et al. 2019, Graczyk et al. 2020.