2.1.3 How far away is the Orion nebula?
How far away is the Orion Nebula? An ‘astronomical’ distance would be a good description!
It is estimated to be about 1600 light years away. It may sound a bit odd, to use time as a measurement of distance, but as Monica explains in the video, that is because the distances are so large. A light year is the distance light travels in one year. We can calculate what that is in kilometres or miles, as you can see in the following video.
So light travels about 9.5 million million kilometres, or 6 million million miles in a year.
If the Orion Nebula is 1600 light years away, that is 1600 x 9.5 million million kilometres – the best part of 15.2 thousand million million kilometres or about 9.6 thousand million million miles – which is quite far away. And also explains why astronomers use light years as a unit of distance.