9/12/16 Warm up In your own words describe why you think we have different seasons?

Reminder: No Hats/Hoodies allowed in the classroom! No Cell phones should be out during instruction! No FOOD ALLOWED!!

Dates to remember Friday, Sept. 16th – Astronomy Project Due Tuesday, Sept. 20 – Unit Test

The Seasons Objective 1.1.2 4

What causes the seasons? Essential Question What causes the seasons?

DAY NIGHT The Earth rotates on its axis 1 full rotation = one day Looking at the picture below, why is the left hemisphere experiencing a warm day and the right hemisphere experiencing a cooler night? DAY warmer NIGHT cooler Comparing Rotations: Earth=24 hrs Mercury=59 days Pluto=6 days

The Earth orbits (revolves around) the Sun How long is one full revolution? 365.25 days = 1 year Comparing Revolutions: Earth=365.25 days Mercury=88 days Pluto=248 years

The planets…What do we know? All the planets in our solar system revolve around the sun. Johannes Kepler discovered that they had elliptical orbits. A B C

So as the Earth revolves around the Sun it looks like this, right? axis

And it revolves around the Sun like this right? This shows orbit

This shows orbit WRONG!

Earth’s axis is not straight Earth’s axis is tilted 23.5° from vertical !! 23.5° tilt

The Earth actually looks like this as it orbits the Sun This shows orbit http://www.classzone.com/books/earth_science/terc/content/visualizations/es0408/es0408page01.cfm?chapter_no=visualization

The Earth’s tilted axis allows us to have seasons Why does that matter? The Earth’s tilted axis allows us to have seasons 4 seasons based on Earth’s position to the sun Spring Summer Fall Winter

The equator divides the Earth into top and bottom halves (Northern and Southern hemisphere) Because of the tilt of the earth, the hemispheres have opposite seasons. WHY?

Please draw the Seasons in your notebook! http://www.exploratorium.edu/ancientobs/chaco/HTML/TG-shadows.html Please draw the Seasons in your notebook!

Looking at your diagrams answer the following questions What causes summer in the northern and southern hemispheres? when it is tilted toward the Sun during Earth’s orbit What causes winter in the northern and southern hemispheres? when it is tilted away from the Sun during Earth’s orbit

Quick Recap The seasons in the northern and southern hemispheres are opposite each other because When one hemisphere is tilted towards the Sun, the other is tilted away from the Sun

Top tilted away from Sun= winter When the Earth is tilted away from the Sun. Coldest temperatures Top tilted away from Sun= winter

Beginning to be tilted toward the Sun= spring Moderate (medium) temperatures Starts cold and gets warmer as that part of Earth is tilted toward the Sun Beginning to be tilted toward the Sun= spring

Top titled toward the Sun= summer When the Earth is tilted toward the Sun. Warmest temperatures Top titled toward the Sun= summer

Beginning to be tilted away from the Sun= fall Autumn (fall) Moderate (medium) temperatures Starts warm and gets cooler as that part of Earth is tilted away from the Sun Beginning to be tilted away from the Sun= fall

Classwork After completing the classwork, work on your projects. (REMEMBER they are due on FRIDAY) Also if you haven’t finished the Kepler Laws foldable, finish it to turn in!

Homework Review your notes from 1.1.1 and 1.1.2, (there will be an exit ticket quiz tomorrow on 1.1.2) Work on your projects (Due Friday, September 16)

Warm up 9/13/2016 (Silently respond to the prompt) In your notebooks, respond to the following writing prompt: (You have ten minutes to respond – 12:50) How am I following the rules and improving the classroom culture? Are you portraying the characteristics of a classroom leader? If so how? If not how can you improve? (ONCE THE MUSIC STOPS BE PREPARED TO START THE NOTES)

Changes in The Seasons – Precession and Nutation Objective 1.1.2 EQ - What is the difference between precession and nutation? 26

Precession Precession is… the wobble in Earth’s rotational axis. One full cycle of precession takes 26,000 years!

Nutation Nutation is … a change in the angle of tilt of Earth’s axis a. Present tilt of Earth’s axis is 23.5°. b. The tilt can vary from 22.1° to 24.5 °.

http://www. cgrer. uiowa http://www.cgrer.uiowa.edu/people/carmichael/atmos_course/ATMOS_PROJ_99/bilskemp/natural_variability.html Nutation If the angle of tilt decreased there would be less of a temperature difference between seasons. If the angle of the tilt of Earth’s axis increased there would be more of a temperature difference between seasons.

You have four minutes to draw the diagram in your notebook!

Vocabulary RECAP: Precession: Change in direction of the axis with out a change in tilt. Impacts position of the stars but not the seasons. Nutation: rocking, swaying, or wobbling around the processional axis. Due to the moon.

Barycenter: Point between 2 objects that balance each other

(a.) Two bodies of similar mass orbiting around a common center of mass, or barycenter. (b.) Two bodies with a difference in mass orbiting around a common barycenter, like the Charon-Pluto system (c.) Two bodies with a major difference in mass orbiting around a common barycenter (similar to the Earth-Moon system) (d.) Two bodies with an extreme difference in mass orbiting around a common barycenter (similar to the Sun-Earth system)

Tides 36

What causes us to have tides? Essential Question… What causes us to have tides?

Study Jams Video

Tides Tides are the periodic rise and fall of sea level. Tides are caused by the gravitational attraction among Earth, the Moon, and the Sun. High tide Highest level to which the water rises Low tide lowest level of the water

Tides: Bay of Fundy… Low Tide High Tide

Moon’s Gravity and Tides The Moon’s gravity has the greatest effects the water on Earth’s surface. Since the Moon is close to the Earth, it has a strong gravitational pull on it (closer objects have stronger gravitational pull).

Moon’s Gravity – Tidal Bulges The Moon pulls on the water on the side nearest to it more strongly than it pulls on the center of the Earth. This pull creates a bulge of water, called a tidal bulge, on the side of Earth facing the the Moon.

Types of Tides

Spring Tides Spring tides occur 2 times a month, during a full and new moon when the Earth, Sun, and Moon are lined up. Spring tides are higher and lower than normal tides. “strong tides”

Neap Tides Neap tides occur in between spring tides, at the first and third quarters of the Moon when the Sun and Moon pull at right angles to each other. “weak tides”

Re-loop/Review Q: What are tides? Tide = the periodic rise and fall of the water level in the oceans and other large bodies of water. Q: What is the dominant force that moves ocean water? The gravitational forces from both the Sun and the Moon.

Re-loop/Review Q: Where is the Moon’s pull is strongest on the Earth? The Moon’s pull is strongest on the part of the Earth directly facing the Moon.

Re-loop/Review Q: Which one (the sun or the moon) has a bigger effect on tides? The Moon

Re-loop/Review Q: How are the Sun, Earth, and Moon situated in space so that we experience a spring tide? Sun, Earth, and the Moon are aligned

Re-loop/Review Q: How are the Sun, Earth, and Moon situated in space so that we experience a neap tide? The Sun, Earth, and Moon form a 90 degree angle

Clear your desk for your Exit Ticket ON SECTION 1.1.2 Make sure your name, block, and date are on the top of the page. You will have eight minutes to complete the quiz.

EXIT TICKET When the northern hemisphere is experiencing fall, which season is the southern hemisphere experiencing? Summer b. Fall c. Winter d. Spring The rotation of the earth on its axis is responsible for what time frame? An hour b. a day c. a season d. a year Who was credited with discovering the elliptical planetary orbit? a. Galileo b. Einstein c. Kepler d. Wegner What is the measure of the tilt of Earth’s axis? a. 5o b. 23.5o c. 75.3o d. 90.5o 5. What does Earth’s revolution refer to? Movement around its axis c. Movement around sun b. It’s formation of day d. Rotation around other planets

Independent Work When I say go, you will get your chrome book and go to google classroom to complete the web quest on Astronomy (Or Work on your project) You may write the answers on your own paper or download it and type the answers in. The only websites you should be on are the ones to help you answer the questions.