**Symbol**: l.y. / **Base data**: Astronomical unit.

1 light year = 9.46050 x 1012 km

**A distance so long it will make your mind boggle!**

The distance traveled by light in one year. This unit is used to measure distances in space. Light travels 300,000 km, equivalent to seven and a half laps around the Earth, in one second. Therefore, the distance traveled by light in one year is approximately 9.4605 trillion km. The distance to the nearest star to the Earth is apparently about 4.2 light years, but even knowing that we are still none the wiser.

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