Convert Nautical League (UK) (nl (UK)) to Astronomical Unit (AU) instantly.
About these units
Nautical League (UK) (nl (UK))
This older British unit corresponds to 3 UK nautical miles, or 18,240 feet (about 5,563.6 meters), slightly longer than the international version. Before international standardization, distances in British naval operations were often recorded using UK nautical leagues, especially in long-range maritime planning. Like other historical British units, the UK nautical league reflects the era when each naval power maintained its own measurement standards. While no longer used for navigation, it appears in historic ship logs, naval battles, and exploration records—especially for events predating the 20th century. For historians, the distinction between the UK league and the international one is critical to accurate interpretation of maritime distances.
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.