Centimeter to Astronomical Unit Converter

A centimeter (cm) is a unit of length in the metric system equal to one-hundredth of a meter (0.01 m). It is widely used for measuring small to medium-sized objects and dimensions.

The centimeter was derived from the meter as part of the metric system's decimal structure, established in 1795. The prefix 'centi-' comes from the Latin word 'centum' meaning 'hundred'. It became popular due to its practical size for everyday measurements.

Centimeters are extensively used worldwide for measuring body dimensions (height, waist size), clothing sizes, small objects, and in medical applications. They're standard in tailoring, carpentry for precise measurements, and in many consumer products specifications.

An astronomical unit (AU) is a unit of length approximately equal to the average distance from Earth to the Sun, defined as exactly 149,597,870.7 kilometers or about 93 million miles.

The astronomical unit was originally defined as the semi-major axis of Earth's orbit around the Sun. It was first estimated by Giovanni Cassini in 1672 and has been refined over centuries. In 2012, the International Astronomical Union redefined it as an exact value rather than a measured quantity.

Astronomical units are primarily used for measuring distances within the solar system, including distances between planets, asteroids, and comets. They're standard in planetary science, space mission planning, and solar system astronomy.