Why do astronomers use astronomical units (AU) instead of kilometers (km)? (1 point)

• Large distances are easier to express in AU than in km.
O There are no km in outer space, only AU.
O AU is used in astronomy, while km is used in physics.
• AU is used for spacing, while km is used for length

1 answer

It is because large distances in the solar system are easier to express in AU than in km.