Astronomical Unit and Light Years

Light Years are a measure of:

• time
• speed
• distance
• light

A light year is...

• The speed light travels
• How long it takes light to get to you from the sun
• The distance light can travel in a year
• How many years it takes light to be emitted

Scientist use Light years to measure objects in space rather than units such as Miles or Kilometers because of how massive the Galaxy and Universe is.

• True
• False

Proxima Centauri is the closest star to Earth after the Sun and is located 4.3 light years away from Earth. How long does it take light from Proxima Centauri to reach Earth?

• 1 year
• 4.3 years
• 43 years
• 10 trillion years

A scale diagram of four galaxies is provided. Which galaxy has a diameter closest to 75,000 light years?

• Galaxy JK23
• Galaxy TO37
• Galaxy RB17
• Galaxy WD28

To express the distance between the Milky Way galaxy and the Andromeda galaxy, the most appropriate unit of measure is the -

• meter
• kilometer
• light year
• astronomical unit

It takes 8.9 years for light produced on Carinae V602 to reach the sun.  If Star X is 30 times as far from the sun as Carinae V602 is, how far is Star X from the sun, to the nearest light year?

• 267
• 5358
• 632
• 68