Convert League (lea) to Astronomical Unit (AU) instantly.
About these units
League (lea)
The league is an old unit of distance whose length varied widely across cultures, usually somewhere between 2.4 and 5.5 kilometers. Historically, it represented the distance a person could walk in an hour. Maritime and overland leagues existed, further complicating the unit's consistency across regions. In literature—particularly in adventure writing such as Jules Verne's Twenty Thousand Leagues Under the Seas—the league became a poetic and evocative measure of great distances. Even when not scientifically precise, its cultural and narrative resonance helped cement its place in storytelling. Though obsolete in modern measurement, the league remains an evocative relic of pre-industrial travel, when human endurance served as a baseline for measurement.
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.