Vol. Science · Astronomy · Milky Way
A beginner orientation to the Milky Way — barred spiral, major arms, and where Sol sits in the Orion Arm (Local Spur). The map opens in 3D. Face-on, edge-on, and a view from the Sun are in the toolbar; 2D keeps the classroom drawing. Schematic art only: not a Gaia catalog dump, not a precision kinematic map. A galaxy’s redshift is the redshift desk. The age and the cosmological distances at that redshift are the cosmology desk. The nearby cz/H0 toy is the distance ladder.
The same six lanes as the flat cartoon: Perseus, Orion/Local, Sagittarius–Carina, Scutum–Centaurus, Norma, and the Outer Arm. In 3D their ridges follow published log-spiral pitches. Real arms have gaps and kinks; distances here are a teaching scale, not a star catalog.
Interactive · 3D schematic
Artist-style schematic · drag to orbit · scroll to zoom · tap a lane
WebGL is unavailable in this browser, so the flat schematic is shown.
Sources · scale
Artist-style schematic. Star particles stand in for populations. Sol and Sgr A* markers are enlarged. Brighter arm stretches are where maser parallaxes anchor the fit; fainter stretches extend that same pitch. The 2D figure is the simpler classroom cartoon. Neither is a Gaia catalog.
Glossary · starter terms
Astronomy desk
Solar system
AU-scale neighborhood around Sol.
Luna
Phase dial for the night you look up at this disk.
Bay Area
Where the galactic band crosses Campbell’s sky.
Color
How disk stars live — types, colors, and death paths.
Neighborhood
The first few light-years out.
Other suns
Confirmed worlds still in a local patch of this disk.
The shift
How a spectrum moves. This map is the galaxy those spectra are taken from.
Nearby toy
Parallax, candles, and cz/H0. This page is inside the first rungs.
Past the disk
Age, lookback, and the cosmological distances once a redshift is no longer a nearby speed.
3D is the default. The 3D / 2D choice is remembered in this browser. If WebGL is unavailable, the flat schematic is shown on its own.
| 3D / 2D | 3D is a thin disc you can tilt. 2D is the classroom SVG. The choice stays in this browser. |
|---|---|
| Drag | Orbit. One finger orbits on a phone. |
| Right-drag | Pan. Two-finger drag pans as well. |
| Wheel or pinch | Zoom toward the pointer. Two fingers pinch. |
| Face-on | Look down on the spiral. |
| Edge-on | Look across the disc so its thinness shows. |
| From the Sun | A seat just outside Sol, looking in toward Sagittarius A*. |
| Reset view | The three-quarter view the map opens on. The motion eases. |
| Arrow keys | Orbit while the map is focused. Plus and minus zoom. 0 or Home resets. |
| Click or tap | Highlights that arm or feature and fills the panel. The named buttons under the panel do the same, and so do the labels on the map. |
| Click or tap | An arm, the bar, the bulge, Sol, Sgr A*, or the halo ring. Enter or Space does it from the keyboard. |
|---|---|
| Feature list | The same names, in a focusable row under the text. |