How do we measure the distance from the sun?
Ahh oks…. Astro-physicists use AU. AU stands for “Astronomical units”. Now to explain exactly why… Distances in the solar system are often, NOT ALWAYS measured in AU. From way back in history a polish physicist called Nicolaus Copernius basically came up with thereoy, and from then onwards astronomers were able to work out how far planets were from the sun, relative to earth using AU. But these were not the actual distances. One AU is defined as the mean distance between earth and the sun. The size of an AU was not known untill 1769 when it was carefully measured during a transit of Venus. Now… what you would think is that we measure the distance from the sun in light years. Light years are the distance that an electromagnetic wave travels in one year. BUT one light year is equal to about 63,000 Astronomical units (AU). So… in breif… we measure the distance from the sun in Astronomical units (AU) .
