Agenda

Does the moon rotate? Eclipses Tides

Mid-term check inOn a notecard…

What is helping you learn the most in this class?

What is helping you learn the least? What one thing would you change

about this class?

The same side of the moon always faces us. Therefore

A. The moon does not rotate on its axis

B. The moon does rotate on its axis

If you lived here…How often would the Sun rise?How often would the Earth rise?How often would you see stars?

If you lived here…

How long would a day last?

How long would a night last?

Solar and lunar eclipses

Solar eclipse

Types of solar eclipses

Total solar eclipse

NASA

Types of solar eclipses

Annular eclipse

NASA

Total solar eclipse

Annular solar eclipse

Lunar eclipse

Lunar eclipse

Why don’t eclipses occur every month?

Size and distance to scale!

Actual tilt of the Moon’s orbit

Moon

Earth

line to the Sun

What causes tides?

To moon

The moon’s gravity distorts the oceans.Tides occur twice a day!

Low tide

High tide

What about the Sun?

Spring tideSun, moon in a line

Neap tideSun, moon atright angles

What is the phase of the moon on this day?

A. New or full

B. ¼ or ¾

C. Waxing

D. Waning

E. Can be any phase

Spring tideSun, moon in a line

Of course, the Earth is not all water

Land masses stop water flow Friction between oceans and floor Depth of ocean varies The Earth rotates

Not all surf is created equal

Summary

Lunar eclipses: Sun-Earth-Moon Solar eclipses: Sun-Moon-Earth Phases of the moon

From above the solar system, looking south

What is a haiku?

3 line poem: Line 1 – 5 syllables Line 2 – 7 syllables Line 3 – 5 syllables

Does not have to rhyme

On a note cardwrite 3 haikus

Eclipses

Tides

Gravity5

7

5

More on phases of the moon

Example: how does this look from above the solar system?

The moon is overhead at 3 am

It rose around 9 pm It will set around 9 am

It’s 3 a.m.

E

W

The moon is overhead

Rose at 9 pm

E

W

How does this look outside?

It rose around 9 pm

Example

What time is it?

How does the moon look?

How does this look outside?

It will set around 9 am

One month…

More on tides…

Largest tidal range: 50 ft (East coast of Canada)

Typical range: 5-10 ft Moon’s tidal strength is about 2 times

that of the Sun These forces actually cause the Earth

and Moon to change shape!