Light-year Light-year The light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometres or 5.88 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Because it includes the word "year", the term light-year is sometimes misinterpreted as a unit of time. The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in nonspecialist and popular science publications. The unit most commonly used in professional astrometry is the parsec
Two miles Kenyan Daniel Komen in Hechtel, Belgium on 19 July 1997. The women's record is 8:58.58, set by Ethiopian Meseret Defar in Brussels, Belgium on 14 September 2007. Note: this list only covers boys because the history of 2 mile running largely occurred before Title IX, before high school girls were allowed to compete, which occurred about the same time as conversion to metric distances. Two miles The 2 mile (10,560 feet or exactly 3,218.688 metres) is a historic running distance. Like the mile run, it is still contested at some invitational meets, perhaps because it provides an easier record to