# What is the astronomical unit defined as?

An astronomical unit is defined as 149.6-million kilometers. An astronomical unit is the mean distance from the center of the earth to the center of the sun.

### What is an astronomical unit?

An "astronomical unit" is a unit of distance/length that is the mean distance between the center of the Sun and the center of the Earth. It is an ISO standard with the value defined as 149,597,870,700 metres (92,955,807.273 mi) exactly. It is given the symbol "AU", while the astronomical constant (whose value is one astronomical unit) is given the symbol "A".

### Which planet is one astonomical unit from the sun?

Earth. An Astronomical Unit is a unit of distance measure defined as the mean (average) distance between the Earth and the Sun; thus, the earth orbits the sun at a distance of 1 Astronomical Unit. The Astronomical Unit was invented to make it easier to think of astronomical distances within the Solar System ... it is easier to get a feel for how close the planets and other bodies in the solar system are close…

### How long is an astronomical unit?

An Astronomical unit is the standard distance between the earth and the sun. It is about 149,597,870.691 kilometers (92,955,807.267 miles). It is defined as the distance that an object would have a perfectly circular orbit of exactly 365.2568983 days (31,558,196.01312 seconds). One light-year is ~63,241 AU, and one parsec is ~206,265 AU.

### How and when is an astronomical unit used?

An Astronomical Unit (AU) is defined as the average distance between the Earth and the Sun. This is about 93 million miles. This unit is used to express very long distances that would otherwise require scientific notation to express in miles. For example, Jupiter is about 5.2 AU from the Sun. This is much simpler than saying 483,600,000 miles from the sun(This is the equivalent in miles).