Measuring Distances in Space

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 is a constellation?

• a pattern of stars visible in the night sky

• a region of the sky described by the celestial sphere

• both A and B

• neither A nor B

Approximately how many astronomical units are equivalent to one light-year?

• 63,000 AU

• 150,000 AU

• 300,000 AU

• 150,000 million AU

A light-year is a measure of

• time

• distance

• speed

• velocity

How do scientists define an astronomical unit?

• the distance between Earth and the moon

• the distance between Earth and the sun

• the distance from one end of the solar system to the other

• the distance from one end of the Milky Way galaxy to the other

Tags

NGSS.MS-ESS1-3

Which of the following best describes the difference between two different units of distance in space?

• An AU is useful for measuring distances within the solar system; a light-year is useful for measuring distances beyond the solar system.

• An AU is calculated by dividing kilometers by 150 million; a light-year is calculated by determining how long it takes an object to travel 150 million AUs.

• An AU is useful for measuring objects fewer than 300 light-years from Earth; a parsec is useful for measuring objects more than 300 light-years from Earth.

• An AU equals the distance between Earth and the Sun; a parsec equals the angle between an object’s apparent positions when viewed from two different locations.

Your friend argues that all the stars in a typical constellation are approximately the same distance from Earth. Is your friend correct?

• Yes. All the stars in a typical constellation are approximately the same distance from Earth.

• No. The stars in a constellation fall within the same patch of sky on the celestial sphere, but some stars are typically much closer to Earth than others.

• No. The stars in a constellation fall within the same patch of sky on the celestial sphere, but brighter stars are always much closer to Earth than dimmer stars.

• No. The stars in a constellation fall within the same patch of sky on the celestial sphere, but only equally bright stars are the same distance from Earth.

An astronomical unit is equivalent to

• 150,000 miles

• 150,000 kilometers

• 150 million miles

• 150 million kilometers

Tags

NGSS.MS-ESS1-3

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

• the parallax angle

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

• the distance between the two points of observation

• all of the above

How are objects located on the celestial sphere?

• longitude and latitude

• declination and parallax

• declination and right ascension

• left ascension and right ascension