Question

How is space measured?

Answer 1

Answer
The universe is measured in Astronomical Units, and Light Years.
Explanation:
A Astronomical Unit is the average distance between the Earth and the sun , and as of 2012, it is 149,597,870,700 meters. A light year is the distance light travels in a year, which is about nine trillion kilometers (9,000,000,000,000 kilometers = 1 ly).
Here is some more measurements (Taken from
1 Pc ( Parsec ) = $2.06\times 105AU=3.1\times 1018cm=$ one parsec, i.e. a distance to a star with a parallax equal to one second of arc. A parallax is an angle at which the radius of earth’s orbit around the sun is seen from a distance of the star. Notice : $2.06\times 105$
is the number of seconds of arc in 1 radian.
1 kpc = 103 pc = one kilo-parsec,
1 Mpc = 106 pc = one mega-parsec,
1 Gpc = 109 pc = one giga-parsec,
$dH=c/HO\approx 1.4\times 1028cm,\approx 4Gpc=$ Hubble distance , where $HO\approx 70kms-1$ Mpc- 1 is the Hubble
Constant ; $c=3\times 1010cms-1$ is the speed of light . The Hubble distance is approximately the
radius of the observable universable universe with us the ''centre ''.
$1R.\approx 7\times 1010cm=$ solar radius
Most stars have radii between 10−2R. (white dwarfs) and 103R. (red supergiants); neutron stars
have radii of about 106 cm = 10 km .