Astronomers do not always use light-years as a unit distance. The chosen unit heavily depends on the context. It could be light years (ly), astronomical unit (AU), parsecs (pc), kilometres (km), or others.
AU is convenient as it represents the distance between the earth and the sun. Using it for the distance between planets gives you a better representation than if it was given in light minutes.
In the same way that it’s more convenient to represent contenance in litres than in meters cubed
Illustrious_Ear_5728 t1_j20lc8c wrote
Reply to ELI5: If astronomers use "light-years" for interstellar distances, why do we use AU for interplanetary distances instead of "light-minutes"? by concorde77
Astronomers do not always use light-years as a unit distance. The chosen unit heavily depends on the context. It could be light years (ly), astronomical unit (AU), parsecs (pc), kilometres (km), or others.
AU is convenient as it represents the distance between the earth and the sun. Using it for the distance between planets gives you a better representation than if it was given in light minutes.
In the same way that it’s more convenient to represent contenance in litres than in meters cubed