Astronomical Distances

Astronomical Distances

Distances between objects in outer space can be so vast that to measure

them in terrestrial units would require huge numbers. For this reason,

astronomers have come up with alternate units for measuring distance in

the solar system, and beyond.

Light Distance

The distance light can travel in a unit of time

Light, travelling in a vacuum, can go 300,000 kilometers every second

(186,000 miles per second)

Light Distance The distance light can travel in a unit of time

•Light year- 9,460,730,472,581 kilometers•Light day- (calculate please)•Light hour- (calculate please)•Light minute- (calculate please)•Light second- (calculate please)

The Astronomical Unit (AU)

The average distance from the Earth to the Sun is one astronomical unit.

1 AU = 149,597,870.7 km(92,955,807.27 mi)

The ParsecThe parsec is a measure of the distance from the sun to any distant

celestial body.

•1 degree of arc is equal to 60 minutes of arc

•1 arc minute is equal to 60 seconds of arc

•1 arc second is equal to 1 parsec

A parsec is equal to 3.26 light years

The word “parsec” is an abbreviation of “distance corresponding to a parallax of one second of arc”.

The Parsec

Planet Light Distance Kilometers (millions) AU

Mercury 3.2 minutes

Venus 6.0 minutes

Earth 8.3 minutes

Mars 12.7 minutes

Jupiter 43.3 minutes

Saturn 1.3 hours

Uranus 2.7 hours

Neptune 4.2 hours

Pluto/Charon 5.4 hours