distance in space?

Question

does anybody know anything about distances in space?!?! it can be like an...inventer/discoverer/or a person who used it, or methods of making the units(Au, light yesr, parsec), when it was first used- ANYTHING WILL HELP!!! PLEASE INUCLUDE YOUR SORSE!!!!!!!!THNX FER UR HELP
-luv, pixie ^.^

Answer 1

The astronomical unit (AU) is the mean distance of of Earth's orbit. Th first measurements were attempted in classical Greece by Aristarchus and Eratosthenes, though they came up well short of the actual value.

The AU as a unit in its own right dates back to Kepler, who discovered the relationship between orbital distance and orbital period. Measuring the AU then took on added significance, as this one measurement could reveal the distances of all the planets. Cassini (namesake of NASA's Saturn mission) made an estimate in 1672 based on his measurements of the parallax of Mars that came within 7% of the correct value, but with a huge uncertainty. Gregory and Halley proposed a method using transits of Venus to get a more accurate measurement. These transits occur in pairs somewhat more than a century apart. The transits of 1761 and 1769 yielded a large number of measurements and a value of the AU reliable to within about 10%. By the time the next transits of Venus came around in 1874 and 1882, improvements in astronomical instruments had made it possible to make more refined measurements using parallax measurements of Mars and some of the asteroids.

Answer 2

i have heard of most, i know that one AU, astronomical unit, is the distance of the sun to the earth.

1 Astronomical Unit = 149 598 000 kilometers

a light year is the distance light in a vacuum will travel in the time of one year.

1 lightyear = 9.4605284 × 10^15 meters
1 lightyear = 63 239.6717 Astronomical Units

parsecs are harder to explain. it has to do with angle in the sky during the movement of the earth over a period of 6 months.

1 Parsec = 3.08568025 × 10^16 meters
1 parsec = 206 264.806 AU

Answer 3

The main distance measurement used in astronomy is the light year - the distance light travels in one Earth year.
That works out to 9,460,730,472,580.8 km or 5,878,625,373,183.61 miles.
The reason for using a light year is that stars and deep space objects are so far away that using miles or kilometers just makes for huge numbers that are hard to picture and can become really cumbersome.
They use megalightyears (one million light years) for distances between galactic clusters and huge cosmic distances

Another measurement is the parsec, which is equal to about 3.26 light years. Its based on the concept of "parallax of one second of arc", meaning how far is an object if it appears to be one second of arc in size in our sky (you need to read up on arc seconds to learn more about this concept).
Sometimes they use kiloparsecs (1000 parsecs) when dealing with distances between parts of a galaxy or within a cluster of galaxies.

The AU (astronomical unit) is smaller than these 2, and is defined as the average distance from the Earth to the sun (about 93 million miles or 150 million kilometers).
This measurement is used when scientists talk about the distances of planets from our sun, or the distances of exoplanets from their stars).

As for who invented these, that is probably lost to history.
All astronomers use these 3 measurements.