Page #136Feb. 5, 2013 Focus : Day & Night, Seasons, Rotation & Revolution

Page #136 Feb. 5, 2013Focus: Day & Night, Seasons, Rotation & RevolutionObjective: explain how the movement of the Earth affect different cyclesEQ: In what ways do planets move? What is affected by this movement? HW: lesson review questionsWarm Up: 1. What is gravitational pull and how does it affect our solar system? 2. How do we get day and night?

OH Last Class!

Why do the planets revolve around the sun?What would happen without gravity?What is gravitational pull and how does it affect our solar system?

http://www.youtube.com/watch?v=RIBNgx2hlyU

Day & Night

Thinking Ahead

• What is a day?

• What is a year?

• Are days and years the same on other planets? Why do you think so?

http://player.discoveryeducation.com/index.cfm?guidAssetId=D621326A-36AB-47BF-9CC7-77BE8EB7589A

• DIRECTIONS:

• 1. Color and label the sun

• 2. Color the day time half of the Earth green and blue

• 3. Color the night time half of the Earth black

The Earth spins on its axis

• The spinning is called ROTATION

• The direction of rotation is counterclockwise if you are looking at it as if you were floating over the North Pole

http://vortex.plymouth.edu/sun/sun.html

Each morning, the sun rises in the east and sets in the west.

Read more: http://www.universetoday.com/18117/why-does-the-sun-rise-in-the-east-and-set-in-the-west/#ixzz2JxtfwWlH

As the Earth spins, part of the Earth is facing toward the Sun,

and part is facing away from the Sun.

The part of the Earth facing the Sun has daytime

Day and Night

• The Earth rotates around once in 24 hours

• The time it takes the Earth to rotate completely around once is what we call a day.

• It's Earth's rotation that gives us night and day

• http://www.onr.navy.mil/focus/spacesciences/observingsky/motion1.htm

So the reason we have day and night is because the Earth rotates.

Rotate means

to turn.

The Earth rotating on its ______gives us day and night.

axis

Earth’s axis is

the imaginary line that goes through the center of the Earth.

Rotation

Rotation: Planets spin on an axisOne Rotation = DayFast Rotation = short daySlow Rotation = long day

Rotation is measured in hours.Earth’s Rotation: 24 hours (1 day)

But guess what! Rotating isn’t the only way the Earth moves in space!

The Earth also revolves.

Revolve – When one object moves around another object

It takes the Earth one year, or 365 ¼ days to orbit the sun.

Does anyone know what orbit means?

Orbit -

The path that an object follows as it revolves around another object.

How long does one revolution take?

RevolutionRevolution: Planets revolve around the

sunRevolution = YearFast Revolution = short year

You would be olderCloser to the sun

Slow Revolution = long yearYou would be youngerFarther from the sunRevolution is measured in _days___Earth’s Revolution 365 days (1 year)

Planet Callisto Ganymede Europa Dione

Rotation Period (hours)

36 hours 567 hours 909 hours 3,085 hours

Revolution Period (days)

6,396 days 350 days 2,349 days 54,938 days

Other planetsOther planetsWhich planet do you think rotates the Which planet do you think rotates the

fastest? Why? fastest? Why? Which planet do you think has the longest Which planet do you think has the longest

revolution? Why? revolution? Why?

Rotation DataRotation Data

Planet Length of Day

Mercury 58.6 Earth days

Venus 243.02 Earth days

Earth 24 hr

Mars 24 hr 37 min

Jupiter 9 hr 55 min

Saturn 10 hr 32 min

Uranus 17 hr 14 min

Neptune 16 hr 6 min

Rotational SpeedsRotational Speeds

Planet Length of Day Rotational Speed

(km/h)

Mercury 58.6 Earth days 10.9

Venus 243.02 Earth days 6.5

Earth 24 hr 1670

Mars 24 hr 37 min 867

Jupiter 9 hr 55 min 45600

Saturn 10 hr 32 min 37000

Uranus 17 hr 14 min 10900

Neptune 16 hr 6 min 8460

RevolutionsRevolutions

Why are the revolutions of each planet different than Earth’s Why are the revolutions of each planet different than Earth’s revolution? revolution?

•Smallest planet

•Closest to Sun, moves around fastest (88 days)

•no tilt of axis so poles are cold

Mercury

Venus • Nearly the same size as Earth

• Slowest rotation of any planet (243 days)

• Spins backwards

Can see it in the night sky without a telescope!

EarthLiquid water – lots! - at

surface

23 degree axis tilt (seasons!)

Earth’s Rotation:

24 hours (1 day)

Earth’s Revolution:

365 days (1 year)

Can see it without a telescope!

25 degree axis tilt (seasons!)

Rotates once every ~24 hours and orbits the Sun once every 687 days

Very cold

No liquid water at surface; ice in poles

Mars Can see it in the night sky without a telescope!

diameter – 11x Earth

largest planet completes one orbit in 4,333

Earth days, or almost

12 Earth years. Jupiter rotates faster than any other planet. It

takes 9 hours 56 minutes to spin around once on its axis, compared with 24 hours for Earth.

Which means it has the shortest day.

Jupiter

•9x the size of Earth

•11 hour rotation / 29 year orbit

Saturn

Seasons

What do think causes the seasons?

http://nix.ksc.nasa.gov/info

What Causes Earth’s Seasons?

• Earth’s axis is tilted 23.5 degrees – it always points in the same direction (Polaris, the North Star) as we orbit our Sun once a year

• This tilt causes the hemispheres to alternate in the amount of our Sun’s light and heat they receive through the year

http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

More daylight hours, more direct sunlight

Northern Hemisphere Summer

http://www.lpi.usra.edu/education/skytellers/seasons/about.shtml

But why do we have four seasons?

It’s because the Earth’s axis is tilted.

Take a good look at our globe. It‘s not tilted like that because it looks nice. No way. That’s the way the Earth is tilted in space.

That tilt gives us seasons!

Look at this diagram. Notice how the Earth is always tilted in the same direction. As the Earth __________ the part of Earth tilted toward the sun changes.

revolves

During part of the year, the North Pole points

away from the sun. This season is _.winter_____

During part of the year the North Pole tilts

towards the sun. This season is

________.summer

When the North Pole is tilted toward the Sun, the Sun travels higher overhead in the sky. The Sun’s rays shine straighter down on that part of the Earth. It is summer in that part of the Earth.

It’s like pointing a flashlight at a piece of paper. When you hold the flashlight straight above the paper, the rays from the flashlight shine down straighter.

When the North Pole is tilted away from the Sun, the Sun stays lower in the sky. It is then winter in that part of the Earth.

If you point your flashlight at a piece of paper at an angle, the rays from the flashlight spread out.

In the Spring and Fall

http://k12.ocs.ou.edu/teachers/reference/equinox.gif

EQUINOXEQUINOX

A day lasts 12 hours and a night lasts 12 hours at

all latitudes.

Sunlight strikes the earth most directly

at the equator.

In the Summer and Winter

http://k12.ocs.ou.edu/teachers/reference/solstice.gif

SOLSTICESOLSTICEDuring the winter the Northern Hemisphere day lasts fewer

than 12 hours and the Southern Hemisphere day lasts more than 12 hours.

During the winter solstice, the North Pole has a 24-hour night and the South Pole has a 24-

hour day.Sunlight strikes the earth most

directly at the Tropic of Capricorn.

In the Summer and Winter

http://k12.ocs.ou.edu/teachers/reference/solstice.gif

SOLSTICESOLSTICE During the summer solstice the Northern Hemisphere day lasts

more than 12 hours and the Southern Hemisphere day lasts

fewer than 12 hours.

During the summer, the North Pole has a 24-hour day and the South Pole has a 24-hour night.

Sunlight strikes the earth most directly at the Tropic of Cancer.

Because the Earth is tilted, different parts of the planet get different amounts of sunlight at

different times of the year.

Why does the earth experience seasons?

Independent Practice

A.

B.

1. Draw pictures A and B.

2.Label the picture that shows the red dot is in the season of summer. Label the picture that shows the red dot in the season of winter.

http://ithacasciencezone.com/earthzone/lessons/07meteor/daylight.jpg

Page # January 17, 2011

Title: Rotation and Revolution

Objective: analyze how Earth’s movement affects day and night

HW: all work is due by Wednesday, check calendars

Warm-Up:

Does the Earth move around the Sun?

How do we get day and night?

RIGHT PAGE 52December 2, 2008

Title: Lets Start a Revolution !Objective: Describe a planet and the effects of a planet’s movement.Words to Know:- orbit - path of an object in space as it moves around another object.year- amount of time a planet takes to revolve around the sun.day- how many hours does it take a planet to rotate on its axes.