fro science astronomical units are used.BUt we use light year as a unit of science for distance
metre
By unit of length and distance and conversion ,we can say that SI basic unit of length is meters.
By unit of length and distance and conversion ,we can say that basic SI unit of length is km .
The basic metric unit is the metre.
By unit of length and distance and conversion ,we can say that the basic unit for length is meter ( m).
The meter.
meters
distance
Metre
the metre
Distance is measured metrically in meters
The basic unit of distance within the solar system is the astronomical unit (AU), which is defined as the average distance between the Earth and the Sun, approximately 93 million miles (150 million kilometers).