Planetary · Stars
Neutron star
≈20 kmMore mass than the Sun can be compressed into a sphere roughly the width of a city.
Planetary ↔ Planetary
How small is a neutron star compared with Earth?
A neutron star can contain more mass than the Sun inside a diameter comparable with a city.
Linear ratio637.1×
Using the stated linear measurements, Earth is 637.1× Neutron star.
Planetary · Solar system
Earth
12,742 kmOur ocean world, measured by mean diameter — the anchor for familiar planetary comparisons.
The answer
A ratio, an analogy and the definitions behind both.
Using the stated linear measurements, Earth is 637.1× Neutron star.
About 637.1× Neutron star linear spans fit across the selected measurement of Earth.
representative stellar-remnant diameter versus mean diameter
The metre values can be divided as linear spans, but the two entries do not describe identical kinds of boundary.
Neutron star is representative; earth is measured.
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 |
|---|---|---|---|---|
| Neutron star | ≈20 km | representative stellar-remnant diameter | Representative | NASA Science ↗ |
| Earth | 12,742 km | mean diameter | Measured | NASA Science ↗ |