Tides, the Moon and Eclipses

Essential Questions How does the moon affect the tides and what causes lunar and solar eclipses?

1. Tides: the changing levels of the water in the Earth’s oceans and seas caused by the gravity of the moon and sun. Copyright © 2010 Ryan P. Murphy

Gravity: The force of attraction between all masses in the universe. 2. Tides: The rising of Earth's ocean surface caused by the gravitational forces of the Moon and the Sun acting on the oceans. Gravity: The force of attraction between all masses in the universe. Copyright © 2010 Ryan P. Murphy

3. During a tide the moon’s gravity is pulling on Earth 3. During a tide the moon’s gravity is pulling on Earth. The moon pulls on this side causing the water to rise (high tide).  On the side labeled low tide the effect of gravity is the weakest.

High Tide Low Tide

4. Why are tides important? 1. Fishermen and shipping companies need to know when they occur so they have easy access to docks and ports. 2. Countries use the tides to create hydroplants that make a renewable energy source (electricity) http://www.learn360.com/ShowVideo.aspx?ID=139912&IPK=98211979 Click to View video about Tides

The Moon’s Surface

The moon is full of craters from billions of years of impacts.

The earth has also been around for billions of years. Why aren’t craters everywhere on earth? Copyright © 2010 Ryan P. Murphy

Craters can be found on earth, but most craters are eroded away by wind and water. Most meteorites also burn up in our atmosphere. Copyright © 2010 Ryan P. Murphy

Some large craters can be seen on earth today but are being eroded as we speak. Copyright © 2010 Ryan P. Murphy

The moon does not have wind, water, or an atmosphere. Every little meteorite will make a mark.

Buzz Aldrin’s footprint on the moon. July 20, 1969. Buzz Aldrin’s footprint today…

What is a “blue” moon? A blue moon is an extra full moon that appears a second time in a solar calendar month. This only occurs every 2 to 3 years. It is an occasional 13th full moon that comes too early for its season. The moon does not really appear “blue.”

Harvest Moon Rises earlier than other full moons and at the beginning of autumn, when the “sunlit” part of our days get shorter. Looks bigger because we see it near the horizon. In the days before tractor lights, the lamp of the Harvest Moon helped farmers to gather their crops, despite the diminishing daylight hours. As the sun’s light faded in the west, the moon would soon rise in the east to illuminate the fields throughout the night.

5. What is an eclipse? An eclipse occurs any time something passes in front of the Sun, blocking its light. This can be the Earth or the Moon.

6. Is there more than 1 kind of eclipse? Yes!! There are lunar and solar eclipses. Lunar Eclipse- When the Earth casts a shadow on the moon, causing the moon to go dark. Earth comes between the Sun and the Moon and casts a shadow on the Moon (Full Moon) Solar Eclipse- When the Moon casts a shadow on the Earth, causing the sun to go dark. The Moon comes between the Sun and Earth and casts a shadow on part of Earth (New Moon)

Solar and Lunar Eclipses

7. Types of Lunar Eclipses Total Lunar Eclipse – when the Moon passes completely into the total shadow of the Earth. Partial Lunar Eclipse – Occur when the Moon does not fully move into the shadow.

Total Lunar Eclipse – when the Moon passes completely into the total shadow of the Earth.

Partial Lunar Eclipse – Occur when the Moon does not fully move into the Earth’s Shadow.

Lunar Eclipses Lunar Eclipse Video: What Causes a Lunar Eclipse: http://www.neok12.com/php/watch.php?v=zX027e52507b754877644063&t=Eclipse What Causes a Lunar Eclipse: http://www.neok12.com/php/watch.php?v=zX45704e56606151726a0377&t=Eclipse View a Lunar Eclipse: http://www.neok12.com/php/watch.php?v=zX005c5d181a5e68775c0706&t=Eclipse

Solar Eclipse Solar Eclipse

Total Solar Eclipse – can only occur if you are at the exact spot within the moon’s shadow (which isn’t very big).

How often do Eclipses Happen? That depends!! Lunar Eclipses happen more often than Solar Eclipses. Why? Well everyone who is experiencing nighttime during a lunar eclipse can see it. But you have to be at an exact spot on Earth to see a Solar Eclipse. The spot on Earth is so small, that the same place only sees a Solar Eclipse every 350 years!!

Solar Eclipses Why are solar eclipses only visible in some places?: http://www.neok12.com/php/watch.php?v=zX037f4505056b6978565c77&t=Eclipse Solar Eclipse in Turkey: http://www.neok12.com/php/watch.php?v=zX6a754f44674a7e5e006d45&t=Eclipse

Our Next Eclipses http://www.timeanddate.com/eclipse/in/usa/salt-lake-city http://www.space.com/15689-lunar-eclipses.html Scroll down on webpage to see a list of upcoming eclipses.

Earth’s Moon Big Idea: The moon affects life on Earth in many ways.  If the moon did not exist the night would be darker, more stars would be visible, we would never have eclipses and we would not have tides.