A beginner orientation to the Milky Way — barred spiral, major arms, and where Sol sits (roughly) in the Orion Arm (Local Spur). Schematic art only: not a Gaia catalog dump, not a precision kinematic map.
Arm names and geometry follow common educational cartoons (Perseus, Orion/Local, Sagittarius–Carina, Scutum–Centaurus, Norma / Outer). Real structure is messier; distances ~kpc are order-of-magnitude.
Interactive · Face-on schematic
Tap an arm · Sol marked on Orion Arm
Order-of-magnitude scale
Solar system
~0.001 ly
Nearest stars
~4–12 ly
Orion Arm width
~10³ ly
Sol → center
~26,000 ly
Disk diameter
~100,000 ly
Bars are logarithmic-ish for readability, not a strict log plot. 1 kpc ≈ 3,260 light-years.
Glossary · starter terms
Spiral arm
Denser lane of stars, gas, and dust where star formation is more active — a traffic jam in the disk’s density wave, not a rigid spoke.
Orion Arm / Local Spur
Our minor arm segment. “Local Spur” emphasizes it is not a grand-design major arm like Perseus or Scutum–Centaurus.
Galactic center
~8 kpc toward Sagittarius. Hosts the radio source Sagittarius A*, a supermassive black hole.
Bar
Elongated stellar structure through the inner galaxy; the Milky Way is a barred spiral (SBc-ish).
Halo
Sparse spherical population of old stars and dark matter surrounding the disk — globular clusters live here.
kpc / ly
Kiloparsec and light-year. Astronomers mix both; educational pages often translate to ly for intuition.
Plane / latitude
The Milky Way band in the night sky is the disk edge-on. Galactic latitude b = 0° hugs that plane.
Gaia
ESA space observatory mapping stellar positions and motions — the modern backbone for arm maps. This page is a cartoon, not Gaia data.