Transcript Lesson 3: what is the solar system?

Chapter 10
Earth’s Place in the Solar System
LESSON 1: WHAT CAUSES EARTH’S
SEASONS?
LESSON 2: HOW DO EARTH AND THE MOON
INTERACT?
LESSON 3: WHAT IS THE SOLAR SYSTEM?
Lesson 1: What Causes Earth’s Seasons?
Vocabulary
 Axis: a line - that you cannot see – from the top of
the Earth, through the center of the Earth, to the
bottom of the Earth.
 Rotation: the spinning of Earth on its axis.
 Revolution: the movement of the Earth one time
around the Sun.
Lesson 1: What Causes Earth’s Seasons?
How Earth Moves
 Earth is always travelling and spinning.
 Earth’s axis is titled.
 Earth moves in two ways: rotation and revolution.
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The spinning of Earth on its axis is called rotation.
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One rotation takes one day - 24 hours.
Earth also revolves around the Sun.
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One revolution is one year - 365 days.
Lesson 1: What Causes Earth’s Seasons?
Seasons
 Some parts of Earth have four seasons.
 Because Earth is tilted on its axis, some parts are
titled toward the Sun while others are titled away.
 Places where the sun’s rays strike directly are
warmer than where the rays strike at a slant.
Lesson 1: What Causes Earth’s Seasons?
Day and Night
 As it rotates:
 Half of Earth faces the Sun and has daytime.
 Half of Earth faces away from the Sun and had nighttime.
 It can’t be the same time everywhere, so time zones
were created.
Lesson 2: How Do Earth and the Moon Interact?
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Vocabulary
Moon Phases: the different shapes that the Moon
seems to have in the sky when it is observed from
Earth.
Lunar Cycle: the pattern of phases of the Moon.
Lunar Eclipse: an event in which Earth blocks
sunlight from reaching the Moon.
Solar Eclipse: an event that occurs when the Moon
blocks the sunlight from reaching Earth and the
Moon’s shadow falls on Earth.
Lesson 2: How Do Earth and the Moon Interact?
Phases of the Moon
 Different shapes of the moon that we see are called
moon phases.
 The Moon does not really change, just how we see it.
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The amount of sunlight reflecting off of it cause the different
shapes.
 The Moon revolves around the Earth.
 Lunar Cycle lasts 29 days.
Lesson 2: How Do Earth and the Moon Interact?
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Eclipses of the Moon
Sometimes the Moon moves into Earth’s shadow.
This is called a lunar eclipse.
During a total lunar eclipse, the Moon can appear to
be red.
Lunar eclipses can only happen during the full moon
phase.
A partial lunar eclipse is when the Moon passes
through only part of Earth’s shadow.
Lesson 2: How Do Earth and the Moon Interact?
Eclipses of the Sun
 The Moon can block sunlight from Earth. This is
called a solar eclipse.
 When the Moon moves between the Sun and the
Earth, the sky gets dark for a few minutes.
 Since the Moon is small, a solar eclipse can be
viewed from only a few places on Earth each time.
Lesson 3: What Is the Solar System?
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Vocabulary
Planet: a large body of rock or gas in space.
Orbit: the path a planet takes as it revolves around
the Sun.
Solar System: the Sun, the planets and their moons,
and the small objects that orbit the Sun.
Star: a hot ball of glowing gases that gives off energy.
Constellation: a group of stars that appear to form
the shape of an animal, a person, or an object.
Lesson 3: What Is the Solar System?
The Solar System
 Our solar system includes:
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Sun
Objects orbiting the Sun:
Eight planets and their moons
 Dwarf planets
 Comets
 Asteroids
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Lesson 3: What Is the Solar System?
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The Sun
Center of our solar system
Biggest object in our solar system
One of many, many stars in the universe
Closest star to Earth
Light energy from the Sun is very important to Earth
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Helps plants grow
Keeps Earth warm
Lesson 3: What Is the Solar System?
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The Inner Planets
Mercury, Venus, Earth, and Mars
They look like stars, but their light is steady.
Rocky surfaces
Smaller than the outer planets
Warmer than the outer planets
Lesson 3: What Is the Solar System?
The Outer Planets… and Pluto
 Jupiter, Saturn, Uranus, Neptune
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Mostly made of gases
Very large
Have many moons
 …and Pluto
 Small
 Made of rock and ice
 2006: removed from the planet list
 “dwarf planet”
Lesson 3: What Is the Solar System?
Patterns of Stars
 Constellations are groups of stars that appear to
form patterns
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Animals
People
Objects
 Looking for constellations helps people find stars