What exactly is a light year?
Contrary to what many think, a light year is actually a measurement of distance, not time. Specifically, a light year is the distance that light travels in one year. Considering light travels at 186,282 miles per second – and nothing travels faster than the speed of light – one light year equals 5.8 trillion miles. Similar units of astronomical measurement include a light minute and light second – the distance light travels in one minute or one second. Equivalents: 1 light year=5,865,696,000,000 miles 1 light minute=11,176,920 miles 1 light second=186,282 miles To keep numbers manageable, the measurement of a light year is necessary for astronomers in describing the enormous distances between the stars and galaxies of the universe. Proxima Centauri, the closest star to Earth other than the Sun, is 4.2 light years away. The most distant celestial body visible to the naked eye is the Triangulum Galaxy, almost 2.6 million light years away. Stars in the outer reaches of the cosmos are lite
