Galactic · Galaxies
Milky Way
≈100,000 light-yearsOur barred spiral galaxy, containing the Sun and hundreds of billions of stars.
Galactic ↔ Galactic
Is Andromeda larger than the Milky Way?
Visible galaxy diameters are diffuse estimates, but the comparison gives useful context for the Local Group’s two dominant spirals.
Linear ratio2.199×
Using the stated linear measurements, Andromeda Galaxy is 2.199× Milky Way.
Galactic · Galaxies
Andromeda Galaxy
≈220,000 light-yearsThe nearest large spiral galaxy, approaching the Milky Way within the Local Group.
The answer
A ratio, an analogy and the definitions behind both.
Using the stated linear measurements, Andromeda Galaxy is 2.199× Milky Way.
About 2.199× Milky Way linear spans fit across the selected measurement of Andromeda Galaxy.
representative stellar-disc diameter versus representative extended-disc diameter
The metre values can be divided as linear spans, but the two entries do not describe identical kinds of boundary.
Milky Way is model-dependent; andromeda Galaxy is model-dependent.
Representative, variable and model-dependent values are useful for perspective only when their status remains visible.
Measurement ledger
What exactly was divided?
| Landmark | Value | Measurement | Certainty | Source |
|---|---|---|---|---|
| Milky Way | ≈100,000 light-years | representative stellar-disc diameter | Model-dependent | NASA Science ↗ |
| Andromeda Galaxy | ≈220,000 light-years | representative extended-disc diameter | Model-dependent | NASA Science ↗ |