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

Answer 1

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

Astronomical units provide a more convenient scale for the vast distances in space, especially when dealing with distances between celestial bodies within our solar system. Using kilometers for such large distances would result in very large numbers, making them less intuitive and harder to work with.