Convert Handbreadth (handbreadth) to Astronomical Unit (AU) instantly.
About these units
Handbreadth (handbreadth)
The handbreadth, roughly 0.1 meter, represents the width of a human hand with fingers extended. It served as a convenient, body-based subunit for cubits and larger measures. Handbreadths were integral to construction, tailoring, and craftwork, allowing precise division of larger units into manageable increments. In ancient Egyptian, Greek, and Hebrew measurement systems, the handbreadth facilitated scaling and proportioning for artisans and builders. Today, the handbreadth is mainly of historical interest, helping reconstruct ancient architectural plans and understand the human-centered logic of early measurement systems.
Astronomical Unit (AU)
The astronomical unit (AU) is one of the most important distance units in astronomy and planetary science. Defined as exactly 149,597,870,700 meters, it represents the average distance between Earth and the Sun. Early astronomers could estimate the AU only indirectly through geometric and observational methods; modern techniques such as radar ranging and spacecraft telemetry have vastly improved its precision. The AU serves as a natural and intuitive scale for describing distances within the solar system. Planetary orbits, asteroid trajectories, comet paths, and interplanetary mission distances are often expressed in astronomical units because they avoid cumbersome scientific notation. For instance, Jupiter orbits at about 5.2 AU from the Sun, while the asteroid belt lies roughly between 2 and 3.3 AU. Beyond practical measurement, the AU forms part of a conceptual framework for understanding solar system layout. It appears in discussions of habitable zones, solar radiation intensity, and celestial mechanics. The unit's significance extends from education to high-level astrophysics, making it one of astronomy's cornerstone measurements.