IT’S BILL NYE TIME!!!!!•https://www.youtube.com/watch?v=KUU7IyfR34o

Objective: I CAN- Explain how the positional relationships among the earth, moon, and sun control the length of the day, lunar cycle, and year

Think about it:Think about it:Why do we have Why do we have

Seasons?Seasons?

Earth’s rotation•The Earth rotates on its axis (imaginary vertical line around which Earth spins) every 23 hours & 56 minutes.

•One day on Earth is one rotation of the Earth.

•Day on Earth is when our side of the Earth faces the sun.

•Night on Earth is when the side of Earth we are on faces away from the sun.

Earth’s revolution

•It takes the Earth 365 & 1/4 days (or rotations) to travel or revolve around the Sun once.

•This is called a year.

Why do we have seasons?Seasons are the result

of the tilt of the Earth's axis to 23.5°.

This tilting is why we have SEASONS like fall, winter, spring, summer.

Winter in the Northern Hemisphere is caused by the tilt of the Northern Hemisphere away from the sun.

Summer in the Northern Hemisphere is caused by the tilt of the Northern Hemisphere toward the sun.

During Tennessee’s summer, the Earth’s tilt is positioned so that the Northern Hemisphere points towards the sun. Because of this tilt, the Northern Hemisphere receives more-direct solar energyand experiences higher temperatures and longer days than the Southern Hemisphere does.

During Tennessee’s winter, the Earth’s tilt is positioned so that the Northern Hemisphere points away from the sun. Because of this tilt, the Northern Hemisphere receives less-direct solar energyand experiences lower temperatures and shorter days than the Southern Hemisphere does.

Solstices

The time when the sun is furthest north or south of the equator is called the Solstice.

Winter solstice is the shortest day of the year in the Northern Hemisphere. It occurs on December 21 and marks the beginning of winter.

The Summer Solstice is the longest day of the year. It occurs on June 21 and marks the beginning of summer.

Equinoxes

Neither end of the Earth’s axis is tilted toward the sunBoth hemispheres receive the same amount of solar energyWhen the sun is directly above equator – called Equinox

SEASONAL CHANGESSome places on Earth do not have much seasonal change because their position in relation to the sun does not change.

http://www.nmm.ac.uk/uploads/gif/seasons-full.gif

Summary

Daylight and night are caused by the rotation of the Earth on its axis.

Seasons and the number of daylight hours are caused by the tiltof the Earth’s axis.

Equinoxes and Solstices are caused by the Earth’s tilt and by Earth’s revolution around the sun.

The amount of season change in an area is determined by the amount of change in the area’s position in relationship to the sun.

Putting it together

• In the space below, draw, label and color Figure 2 and 3 on page 291 and 292 in the space below.

• Finish for homework if necessary.

Space Story• Imagine you are an astronaut on a mission to travel through our solar system.

• Using information from Chapter 9.1-9.3, write a story that describes each planet in detail. Include diameter, relative distance, illustrations, and any other pertinent information.

• There should be at least 5 paragraph of information. (25 sentences)

• This counts like a test and is due Friday 3/13/2015.