Why do astronomers use astronomical units (AU) instead of kilometers (km)?(1 point) Responses AU is used for spacing, while km is used for length. AU is used for spacing, while km is used for length. Large distances are easier to express in AU than in km. Large distances are easier to express in AU than in km. There are no km in outer space, only AU. There are no km in outer space, only AU. AU is used in astronomy, while km is used in physics.

Answer 1

The correct response is: Large distances are easier to express in AU than in km.

Astronomers use astronomical units (AU) because the distances in space between objects like planets and stars are immense, making them cumbersome to express in kilometers. One AU is the average distance from the Earth to the Sun, approximately 93 million miles or about 150 million kilometers, which makes it a more manageable unit for discussing distances within our solar system.