CHAPTER NEW CHAPTER Earth, Moon, and Sun the BIG idea Earth and the Moon move in predictable ways as they orbit the Sun. 2.1 Earth rotates on a tilted axis and orbits the Sun. 2.2 The Moon is Earth’s natural satellite. 2.3 Positions of the Sun and Moon affect Earth. CHAPTER OUTLINE

Earth rotates on a tilted axis and orbits the Sun. 2.1 Earth rotates on a tilted axis and orbits the Sun. Earth’s rotation in sunlight causes day and night. The changing angles of sunlight on Earth cause seasons. axis of rotation revolution season equinox solstice SECTION OUTLINE

2.1 Earth rotates on a tilted axis and orbits the Sun. axis of rotation axis of rotation revolution season An imaginary line about which a turning body, such as Earth rotates. equinox solstice KEY CONCEPT SUMMARY

2.1 revolution Earth rotates on a tilted axis and orbits the Sun. axis of rotation revolution revolution season The motion of one body around another, such as Earth in its orbit around the Sun; the time it takes an object to go around once. equinox solstice KEY CONCEPT SUMMARY

2.1 season Earth rotates on a tilted axis and orbits the Sun. axis of rotation season revolution season One part of a pattern of temperature changes and other weather trends over the course of a year. Astronomical seasons are defined and caused by the position of Earth’s axis relative to the direction of sunlight. equinox solstice KEY CONCEPT SUMMARY

2.1 equinox Earth rotates on a tilted axis and orbits the Sun. axis of rotation equinox revolution season In an orbit, a position and time in which sunlight shines equally on the Northern Hemisphere and the Southern Hemisphere; a time of year when daylight and darkness are nearly equal for most of Earth. equinox solstice KEY CONCEPT SUMMARY

2.1 solstice Earth rotates on a tilted axis and orbits the Sun. axis of rotation solstice revolution season In an orbit, a position and time during which one hemisphere gets its maximum area of sunlight, while the other hemisphere gets its minimum amount; the time of year when days are either longest or shortest, and the angle of sunlight reaches its maximum or minimum. equinox solstice KEY CONCEPT SUMMARY

The Moon is Earth’s natural satellite. 2.2 The Moon is Earth’s natural satellite. The Moon’s near side always faces Earth. mare Dark-colored maria formed from lava-filled craters. Light-colored highlands are old and cratered. SECTION OUTLINE

The Moon is Earth’s natural satellite. 2.2 The Moon is Earth’s natural satellite. The Moon’s near side always faces Earth. mare The Moon has layers. crust mantle core SECTION OUTLINE

2.2 mare The Moon is Earth’s natural satellite. A large, dark plain of solidified lava on the Moon. The plural form of mare is maria. KEY CONCEPT SUMMARY

Positions of the Sun and Moon affect Earth. 2.3 Positions of the Sun and Moon affect Earth. Lunar phases are different views of the Moon’s sunlit half. eclipse umbra penumbra Moon Earth SECTION OUTLINE

Positions of the Sun and Moon affect Earth. 2.3 Positions of the Sun and Moon affect Earth. Lunar phases are different views of the Moon’s sunlit half. eclipse Shadows cause eclipses. umbra penumbra umbra penumbra SECTION OUTLINE

Positions of the Sun and Moon affect Earth. 2.3 Positions of the Sun and Moon affect Earth. Lunar phases are different views of the Moon’s sunlit half. eclipse Shadows cause eclipses. umbra The Moon’s gravity causes tides as Earth turns. penumbra Moon low tide High tide rotation of Earth SECTION OUTLINE

2.3 eclipse Positions of the Sun and Moon affect Earth. umbra An event during which one object in space casts a shadow onto another. On Earth, a lunar eclipse occurs when the Moon moves through Earth’s shadow, and a solar eclipse occurs when the Moon’s shadow crosses Earth. penumbra KEY CONCEPT SUMMARY

2.3 umbra Positions of the Sun and Moon affect Earth. eclipse umbra umbra The dark, central region of a shadow, such as the cone of complete shadow cast by an object. penumbra KEY CONCEPT SUMMARY

2.3 penumbra Positions of the Sun and Moon affect Earth. eclipse penumbra umbra A region of lighter shadow that may surround an umbra; for example, the spreading cone of lighter shadow cast by a space object. penumbra KEY CONCEPT SUMMARY

2.1 Earth rotates on a tilted axis and orbits the Sun. I. Earth rotates on a tilted axis and orbits the Sun. axis of rotation A. Earth’s rotation causes day and night. revolution B. Earth’s tilted axis and orbit cause seasons. season equinox 1. Seasonal Patterns solstice 2. Angles of Sunlight 3. Lengths of Days KEY CONCEPT SUMMARY

The Moon is Earth’s natural satellite. 2.2 The Moon is Earth’s natural satellite. II. The Moon is Earth’s natural satellite. mare A. The Moon rotates as it orbits Earth. B. The Moon’s craters show its history. 1. Craters and Maria 2. Moon Rocks C. The Moon has layers. 1. Structure 2. Formation KEY CONCEPT SUMMARY

Positions of the Sun and Moon affect Earth. 2.3 Positions of the Sun and Moon affect Earth. III. Positions of the Sun and Moon affect Earth. eclipse A. Phases are different views of the Moon’s sunlit half. umbra 1. Waxing Moon penumbra 2. Waning Moon 3. Crescent and Gibbous Moons B. Shadows in space cause eclipses. 1. Lunar Eclipses 2. Solar Eclipses C. The Moon’s gravity causes tides on Earth. KEY CONCEPT SUMMARY