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Putting sizes in perspective

Neptune and Earth: comparing diameters

This comparison concerns the planets’ sizes. It does not represent the Earth–Neptune distance, which varies during their orbits.

Neptune: a dimension about 3.865 times that of Earth using the adopted values.

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How many Earth diameters make up Neptune’s diameter?

Dimensions adopted for the calculation
ReferenceDimension
Neptune49,244 km
Mean diameter ≈ 49 240 km
Earth12,742 km
Mean diameter ≈ 12 740 km

Calculation: 49,244 km ÷ 12,742 km, after conversion into the same unit. The ratio calculated from the catalogue data is about 3.865.

Both illustrations use a common factor for the stated dimension. Positions aid reading and do not represent physical separation.

Check the conventions

Neptune

Mean diameter calculated from the volume-equivalent radius in the NASA/JPL table. Rings and the outer atmosphere are excluded.

Approximate catalogue reference; a source is provided, but the measurement has not been individually audited.

Earth

Mean diameter calculated from the volume-equivalent radius in the NASA/JPL table. Rings and the outer atmosphere are excluded.

Approximate catalogue reference; a source is provided, but the measurement has not been individually audited.

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