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DiscoverDistances

Distances

One light-year: size, dimension and comparison

The adopted reference is about 1 light-years.

distance travelled in one Julian year

A light-year is a distance: how far light travels in one year. It is used for distances between stars.

A distance, despite a name that suggests time.

Explore at this scale
One light-year, interpreted illustration
Interpreted illustration · dimension stated in the fact sheet.

What does this number measure?

A distance, despite its name suggesting time. A light-year is the distance light travels in a vacuum during a Julian year of 365.25 days. It therefore does not measure the age of a star or galaxy.

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 Hills cloud — inner model in the explorer →

Source and limitations

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

Light-year: distance travelled in one Julian year, depicted as an axis between reference points; the wave and source are symbolic, not a visible object.