What is the most common intermediate unit for measuring distances within our solar system?

Astronomical Unit (AU)

The Astronomical Unit, abbreviated as AU, serves as the preferred, standardized scale for measuring distances within the solar neighborhood. This unit is derived specifically to manage the immense stretches of space encountered when moving between planets. Its primary utility comes from its contextual anchoring; it is defined by the average distance between the Earth and the Sun. By using AU, astronomers can express relationships intuitively. For example, stating Jupiter's distance from the Sun as approximately $5.2$ AU immediately provides context relative to Earth's orbit, a clarity that cannot be achieved when dealing with kilometer counts that quickly balloon into hundreds of millions or billions for objects like Jupiter.