Astronomical units are used for

• Distances within a solar system

• Distances between solar systems

• Distances within galaxies

• Distances between galaxies

The distance that light can travel in a year is called....

• A light second

• A light minute

• A light month

• A light year

An object at the other end of the universe is billions of ___________ away.

• AUs

• Light seconds

• Light minutes

• Light years

Why do we use light years and astronomical units to measure distances in space?

• Scientists want to sound smart.

• Hubble discovered these units and wanted to use them.

• Space is too small to use km, it wouldn't make sense.

• Space is too big, vast, enormous to use traditional units, like miles.

What is necessary to calculate a star's distance from Earth?

• the parallax angle

• the position of the star observed twice, six months apart

• the distance between the two points of observation

• all of the above

What is parallax?

• the average distance between a celestial object and Earth

• the angle formed by Earth and two celestial bodies located in different directions from Earth

• the apparent difference in the position of an object when viewed at the same time each year

• the apparent difference in the position of an object when viewed from different lines of sight

What galaxy do we live in?

• Andromeda

• Milky Way

• Solar System

• Parallax

A light year is approximately.....

• 59,987,812 kilometers

• 8,522,846,507 kilometers

• 9,460,730,472,581 kilometres

• 377,160,825,209,412,592 kilometers

A star with a large parallax:

• is at a short distance from Earth.

• is moving at a great speed with respect to Earth.

• is at a great distance from Earth.

• is not moving with respect to Earth.

Which of the following best explains why parallax has limitations in finding the distances to the stars?

• the brightness of the stars can effect parallax

• if the star is too cool, the star will have a parallax that is too small to measure

• the time of day of measurement can effect parallax

• if a star is too far, the star will have a parallax that is too small to measure