Transcript Unit 3 The Earth-Moon-Sun System

Unit 3 The Earth-Moon-Sun System
The Big Idea:
Earth & the moon move in
predictable ways & have
predictable effects on each
other as they orbit the sun.
Unit 3 Lesson 1 Earth’s Days, Years, and Seasons
Spinning in Circles
• Rotation- the spinning of
a body, such as a planet,
on its axis (called a day)
– Earth rotates
counterclockwise
– Earth rotates west to east
– Only ½ of Earth faces the
sun
Unit 3 Lesson 1 Earth’s Days, Years, and Seasons
• Revolution- the motion of a body that
travels around another body in space
– Earth revolves the sun in 365 ¼ days
Unit 3 Lesson 1 Earth’s Days, Years, and Seasons
Tilt-a-Whirl
• Earth is titled at 23.5˚
Unit 3 Lesson 1 Earth’s Days, Years, and Seasons
Seasons change…
• Seasons – a specific time of the year that is
characterized by recurring weather
conditions
• Equinox- sun shines equally on both
hemispheres
• Solstice- area of sunlight is maximum in one
hemisphere & minimum in the other
Unit 3 Lesson 1 Earth’s Days, Years, and Seasons
Unit 3 Lesson 2 Moon Phases and Eclipses
Round and Round They Go!
• Moon – natural satellite that travels
around planets (revolution 28.5 days)
– Gravity – force that pulls all bodies that
have mass toward other objects.
http://www.nasa.gov/audience/forstudents/brainbites/nonflash/bb_home_moonrotation.html
Unit 3 Lesson 2 Moon Phases and Eclipses
It’s Just a Phase!
http://www.freewebs.com/rachelkalin/apps/photos/photo?photoid=6917256
Unit 3 Lesson 2 Moon Phases and Eclipses
Exploring Eclipses
• Eclipse – an event during which one object
in space casts a shadow on another object
– Umbra – darkest part of a shadow
– Penumbra – around the umbra a spreading cone
of lighter shadow
Unit 3 Lesson 2 Moon Phases and Eclipses
Lunar Eclipse
• Lunar eclipse occurs when the moon moves
through Earth’s shadow
Unit 3 Lesson 2 Moon Phases and Eclipses
Solar Eclipse
• When the moon is
directly between the
sun and Earth, the
shadow of the moon
falls on “part” of Earth
http://www.total-eclipse-2008.com/eclipse/geometry.php
Unit 3 Lesson 3 Earth’s Tides
A Rising Tide of Interest
• Tides – daily changes in the level of ocean
water due to the difference in the
gravitational force of the sun and mostly
moon across Earth
Unit 3 Lesson 3 Earth’s Tides
Tide Me Over
• Spring Tides – have the largest daily tidal
range, happens when the sun, moon, &
Earth form a straight line.
Unit 3 Lesson 3 Earth’s Tides
• Neap Tides – smallest daily tidal range,
happen when the sun, moon, & Earth form
a 90˚ angle.