Wiktionary
n. (context astronomy English) The mean distance from the Earth to the Sun (the semi-major axis of Earth's orbit), approximately 149,600,000 kilometres (''symbol'' AU), used to measure distances in the solar system.
Wikipedia
The astronomical unit (symbol au, AU or ua) is a unit of length, roughly the distance from Earth to the Sun. However, that distance varies as Earth orbits the Sun, from a maximum ( aphelion) to a minimum ( perihelion) and back again once a year. Originally conceived as the average of Earth's aphelion and perihelion, it is now defined as exactly metres (about 150 million kilometres, or 93 million miles). The astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System or around other stars. However, it is also a fundamental component in the definition of another unit of astronomical length, the parsec.
Usage examples of "astronomical unit".
No human had gotten within an astronomical unit of those new lamps in space.
They had emerged, surprisingly, less than one astronomical unit from the Hague Limit.
It will not be captured, but the hyperbola of its orbit is narrow and it will come within an astronomical unit.
This is about forty astronomical units, where the astronomical unit, usually abbreviated to AU, is defined as the mean distance of the Earth from the Sun.
The basic unit of measure in the solar system is the Astronomical Unit, or AU, representing the distance from the Sun to the Earth.
No, he'd still be a hideous flat-eyed, non-intelligent monster plucked pretty much at random from the outer reaches of the universe, surrounded by creatures to whose minds his substantial knowledge of the many literatures of astronomical unit 649-301-3 would probably come across, allowing even for the miracle of translation, as so much schizophrenic word-salad.
Models of the Kuiper Belt showed that the icy chunks were on average an Astronomical Unit apart&mdash.
The regional Pilot's Manual and Ephemeris described a moderately eccentric orbit whose radius vector averaged about one astronomical unit.
Or maybe it was just that I'd been there, to the legendary home of the human race, and now, looking up, I could imagine, a single astronomical unit out from the glimmering star, a world in spin, a city by the sea dropping away into darkness as night came on, or rolling back up and into the light, a police cruiser parked somewhere and a certain police lieutenant drinking coffee not much better than mine and maybe thinking .
Any call to Saturn, under optimum conditions, requires a minimum of half an hour, because the orbit of that planet is more than four astronomical units from the orbit of Jupiter, and, of course, one astronomical unit is the archaic measure of Earth's distance from the sun, or about eight and a third light minutes.
Any call to Saturn, under optimum conditions, requires a minimum of half an hour, because the orbit of that planet is more than four astronomical units from the orbit of Jupiter, and, of course, one astronomical unit is the archaic measure of Earth’.
The enemy replied to a volley of Solarian missiles with a couple of volleys of its own, at a range of several tens of millions of klicks, a large fraction of an astronomical unit.