Unit 4: Our Universe Retake

The image shows the Hertzsprung-Russell Diagram. Type in the classification for a star that has a luminosity of 10^6 L_sun and temperature of 20,000 K.

(a)  

Stars are composed primarily of —

• silicon and carbon.

• oxygen and nitrogen.

• helium and hydrogen.

• hydrogen and oxygen.

Astronomers must measure very large distances in space. The astronomical unit (AU) was defined to make some space measurements. Which of the following distances is equivalent to 1 AU?

• The distance that light travels in one second

• The distance between Earth and the Moon

• The distance that light travels in one year

• The distance between Earth and the Sun

What is used to measure a light year?

• The speed of light in the vacuum of space

• The speed of light from the Sun to Earth

• The speed of light as it refracts in water

• The speed of light in a uniform medium

Which of the following is the same for all stars?

• They all have the same size.

• They all have the same brightness.

• They are all made of the same basic materials.

• They are all the same distance from Earth.

An astronomer would use light years to express the size of —

• Earth.

• the solar system.

• the universe.

• the Sun.

Galaxies, which can contain up to a trillion stars, come in three types: spiral, elliptical, and irregular. Earth's galaxy is spiral, with a central disc and bright arms that rotate around the center. Which picture shows Earth's spiral galaxy?

• A

• B

Tags

NGSS.MS-ESS1-2

The table describes the properties of several objects in the universe. Which of the following correctly identifies each object from the table?

• X: solar system; Y: galaxy; Z: star

• X: galaxy; Y: star; Z: solar system

• X: solar system; Y: star; Z: galaxy

• X: star; Y: solar system; Z: galaxy

Tags

NGSS.MS-ESS1-3

In which galaxy is the Sun located? Type the correct word(s) into the box. The Sun is located in a spiral arm of the (a)   galaxy.

Tags

NGSS.MS-ESS1-2

Which star would take the shortest amount of time to reach by a satellite leaving Earth?

• Sirius

• Polaris

• The Sun

• Betelgeuse