Section 1: Sun, Earth and MoonPreview Key Ideas Bellringer The View from Earth A Family of Planets Earth’s Orbit The Planets in the Solar System The Moon Phases of the Moon Solar and Lunar Eclipses

Key Ideas

〉Why does the night sky look the way it does from Earth?

〉What objects make up the solar system?

〉How does the moon affect Earth?

BellringerBased on what you have learned, as well as previous

knowledge, answer the following questions.

1. Earth moves around the sun, and the moon moves around Earth. What force keeps these bodies in their paths?

2. Describe two situations in which the sun, moon, and Earth interact with each other.

3. The moon’s surface is covered with craters, which were created by meteorites striking the moon’s surface. Although similar meteorites landed on Earth’s surface at the same time, there are very few craters to be found on Earth. Apply knowledge of the moon and Earth to explain this difference.

The View from Earth〉 Why does the night sky look the way it does from

Earth?

〉 The positions of objects in the sky change over time because Earth, and everything else in the universe, is constantly moving.

planet: a celestial body that orbits the sun, is round because of its own gravity, and has cleared the neighborhood around its orbital path

• The sun is the closest star to Earth.

Visual Concept: Structure of the Sun

Visual Concept: Sunspots

The View from Earth, continued

Nature uses the sun to set daily cycles.

Planets and distant stars are visible in the night sky.

A Family of Planets〉What objects make up the solar

system?

〉The solar system is the sun and all of the objects that orbit it.

solar system: the sun and all the other planets and bodies that travel around it

Gravity holds the solar system together.

Earth’s Orbit

A Family of Planets, continued Eight planets orbit the sun.

The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Satellites orbit objects that have a greater mass.

satellite: a natural or artificial body that revolves around a celestial body that is greater in mass

The Planets in the Solar System

Visual Concept: Satellites

The Moon〉 How does the moon affect Earth?

〉 Like the sun, the moon affects life on Earth through its movements and gravitational influence.

The moon has phases because it revolves around the Earth.

phase: the change in the illuminated area of one celestial body as seen from another celestial body; phases of the moon are caused by the positions of Earth, the sun, and the moon

Phases of the Moon

Visual Concept: Lunar Phases

Visual Concept: Moons of Earth and Other Planets

The Moon, continued Eclipses are caused by bodies casting shadows.

eclipse: an event in which the shadow of one celestial body falls on another

The moon affects Earth’s tides. Coastal areas on Earth have two high tides and two

low tides each day. Tides are mainly a result of the gravitational

influence of the moon.

Solar and Lunar Eclipses

Visual Concept: Solar and Lunar Eclipses

Take a picture of the same spot in the sky every 10 minutes for 1 hour. Analyze the pictures and tell me what you see happening.