Definitions for "Astronomical Unit"
The average distance between the Earth and the Sun, one astronomical unit is defined to be 150 million kilometers, or about 93 million miles.
a unit length equal to the distance from Earth to our sun--approximately 150 million kilometers (93 million miles).
A unit of measurement based on the average distance Earth is from the Sun in its orbit. One astronomical unit is equal to about 93 million miles.
Keywords:  encounter, read, number, you
a number you will encounter very often as you read about astronomy