Earth & Space

What is a galaxy made up of?

• Gas, dust, and many stars

• Only stars

• Only planets

• Only moons

Answer explanation

A galaxy is composed of gas, dust, and many stars. While stars are a significant component, galaxies also contain interstellar gas and dust, which are essential for star formation and the overall structure of the galaxy.

Marla is observing stars in the night sky. Why do some stars appear larger than others?

• Some are smaller

• Some are larger

• Their size and distance from Earth

• Some are hotter

Answer explanation

Stars appear larger or smaller based on their actual size and their distance from Earth. Larger stars that are closer can look bigger than smaller stars that are farther away, making distance and size key factors in their appearance.

What makes stars look like points of light?

• They are very close

• They are very far away

• They are very small

• They are very dim

Answer explanation

Stars appear as points of light because they are extremely far away from us. Their vast distance means that even though they are massive, they are too small in our sky to be seen as anything other than points.

Which of the following is NOT an object of the Solar System?

• Sun

• Planets

• Galaxies

• Moons

Answer explanation

Galaxies are vast systems containing billions of stars, gas, and dust, and are not part of the Solar System. The Solar System consists of the Sun, planets, moons, and other objects orbiting the Sun.

Tags

NGSS.MS-ESS1-3

What is Earth's position in the Solar System?

• First planet from the Sun

• Second planet from the Sun

• Third planet from the Sun

• Fourth planet from the Sun

Answer explanation

Earth is the third planet from the Sun, positioned between Venus (the second planet) and Mars (the fourth planet). This unique position allows Earth to have the right conditions for life.

Tags

NGSS.MS-ESS1-3

Comets are made of...

• Gas and metal

• Metal and ice

• Ice, rock, and dust

• Metal and rock

Answer explanation

Comets are primarily composed of ice, rock, and dust. This mixture allows them to form a glowing coma and tail when they approach the Sun, distinguishing them from other celestial bodies.

Tags

NGSS.MS-PS1-1

What is NOT a component of a galaxy?

• Water

• Stars

• Gas

• Dust

Answer explanation

Water is not a fundamental component of a galaxy. Galaxies primarily consist of stars, gas, and dust, while water exists in various forms and is not a structural element of galaxies.

Why do stars that are much larger than the Sun still appear as tiny dots in the night sky?

• These stars emit less light than the Sun.

• These stars are much cooler than the Sun.

• These stars are much farther from Earth than the Sun.

• These stars are much closer to Earth than the Sun.

Answer explanation

Stars much larger than the Sun appear as tiny dots because they are located much farther from Earth. Their immense distance diminishes their brightness, making them look small in the night sky.

Planets in our Solar System have similarities and differences. Which of the following best describes how the inner planets are similar to each other?

• They are all the same size.

• They all have solid surfaces.

• They all have at least one moon.

• They all have a thick atmosphere.

Answer explanation

The inner planets—Mercury, Venus, Earth, and Mars—are similar because they all have solid surfaces, unlike the gas giants. They vary in size and atmosphere, and not all have moons.

Which characteristic should Sophie enter for common characteristics of planets?

-Round

-Rotate on an axis

-?

• made mostly of gas

• is a satellite of another planet

• have rings

• have a rocky surface

• revolve around a star

Answer explanation

Planets are defined by their ability to revolve around a star, which distinguishes them from other celestial bodies. Therefore, 'revolve around a star' is a common characteristic of planets that Sophie should enter.