Parsec to Kilometer Converter

A parsec (pc) is a unit of length used in astronomy, equal to approximately 3.26 light-years or 206,265 astronomical units. It is defined as the distance at which one astronomical unit subtends an angle of one arcsecond.

The parsec was defined in 1913 by British astronomer Herbert Hall Turner. The name combines 'parallax' and 'arcsecond', referring to the trigonometric parallax method used to measure stellar distances. It became the preferred unit for professional astronomical distance measurements.

Parsecs are the standard unit for measuring stellar and galactic distances in professional astronomy. They're used in stellar catalogs, galactic structure studies, and cosmological research. Kiloparsecs and megaparsecs are used for larger cosmic distances.

A kilometer (km) is a unit of length in the metric system equal to 1,000 meters. It is one of the most commonly used units for measuring medium to long distances on Earth.

The kilometer was first introduced in 1795 during the French Revolution as part of the original metric system. The term comes from the Greek word 'khilioi' meaning 'thousand' and the French word 'mètre'. It became widely adopted throughout Europe in the 19th century and is now the standard unit for road distances in most countries worldwide.

Kilometers are extensively used for measuring road distances, city planning, geographical surveys, and athletic events like marathons. Most countries use kilometers for speed limits (km/h) and fuel efficiency measurements. It's the standard unit for mapping and GPS navigation systems globally.