20 kilometres
20 kmLength · definition
The quantity is exact as entered. Comparisons use the clearly stated specimen, model or nominal measurement.
Length & distance
Just how long is 20 kilometres?
Our planet
20 km
20 kilometres
The quantity is exact as entered.
20 kmLength
0 - shared origin
Neutron star
A neutron star is the dense remnant core left after a massive star explodes as a supernova, composed mostly of neutrons.
20 kmDiameter
0 - shared origin
Both rulers start at the same zero and share one linear scale. Artwork keeps its original proportions. A ruler represents the selected distance or a measurement not visible in this view.
A little perspective
20 kilometres is approximately equal to the diameter of a neutron star.
Measurements, assumptions & sources +
20 kilometres
Length: 20 km; definition.
The quantity is exact as entered. Comparisons use the clearly stated specimen, model or nominal measurement.
Neutron star
Diameter: 20 km; representative.
A 20 km, 1.4 solar-mass teaching model. The precise radius depends on stellar mass and the uncertain behaviour of dense matter.
The marked diameter is calibrated. Unmeasured illustration details are representative.
Measurement details
Why these numbers?
Compare 20 kilometres with the diameter of a neutron star. The notes below explain how each value was chosen.
Neutron star
20 kmDiameter · representative
A 20 km, 1.4 solar-mass teaching model. The precise radius depends on stellar mass and the uncertain behaviour of dense matter.
- Comparing
- Length ↔ Diameter
- Relative size
- 20 kilometres is approximately equal to the diameter of a neutron star.
How to read the visual
The diagram uses the recorded measurements. Details outside the marked spans do not set the scale.
- The diameter of a neutron star: This is a representative comparison value; individual specimens or conditions can vary.
This comparison follows the selected length only; other dimensions may differ.
20,000 mmetres
65,617 ftfeet
12.427 mimiles
1.3369 × 10⁻⁷ AUastronomical units
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