HOW BIG
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Cosmos

Local Group: size, dimension and comparison

The adopted reference is about 9.9992 million light-years.

approximate extent; diffuse boundary

A light-year is a distance: how far light travels in one year. Here, those distances are counted in millions.

Our neighbourhood of gravitationally bound galaxies.

Explore at this scale
Local Group, interpreted illustration
Interpreted illustration · dimension stated in the fact sheet.

What does this number measure?

Our neighbourhood of gravitationally bound galaxies. The Local Group includes the Milky Way, Andromeda, Triangulum and many smaller galaxies. Its extent is a reference with diffuse boundaries, not the diameter of a solid object.

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 Perseus Cluster in the explorer →

Source and limitations

Catalogue order of magnitude; a source is provided, but this measurement has not been individually audited.

Local Group: conceptual distribution diagram; galaxies enlarged, positions simplified and the diffuse boundary approximate.