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Dimorphos · equivalent diameter (2023): size, dimension and comparison

The adopted reference is about 151 m.

Volume-equivalent diameter before DART: 151 ± 5 m

151 m = 0.151 km. A meter contains 100 centimeters, or 1,000 millimeters.

The small moon of Didymos struck by DART in 2022.

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Dimorphos · equivalent diameter (2023), interpreted illustration
Interpreted illustration · dimension stated in the fact sheet.

What does this number measure?

The model published by the DART team in 2023 gives a pre-impact volume-equivalent diameter of 151 ± 5 m: the diameter of a sphere with the same volume as the body model. It is not its greatest length. A later revision of the model gives approximately 150 ± 2.5 m; the explicitly dated 2023 reference is retained here. The rocky silhouette is interpreted and does not establish a post-impact shape.

Compare the stated dimensions

The comparison uses the number in each fact sheet: altitude, height, diameter, length or distance, depending on the reference. Two values in metres do not necessarily describe the same property.

Compare with Bennu · radar mean diameter in the explorer →

Source and limitations

Pre-impact shape model published in 2023: ±5 m on the equivalent diameter. The dimension is neither a maximum axis nor a measurement of the current shape.

Uncertainty stated in the catalogue: about 5 m.

Interpreted rubble pile of Dimorphos before DART. Reference width illustrating the diameter of a sphere with the same volume; neither this silhouette nor its longest dimension is a measurement of 151 m.