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Eclipses and Tides. The Moon. Why is it so bright?. Although the Moon appears brightly in the night sky, it does not in fact shine but simply reflects the light from the Sun. Solar Eclipse. 2009. Solar eclipse.
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Eclipses and Tides The Moon
Why is it so bright? • Although the Moon appears brightly in the night sky, it does not in fact shine but simply reflects the light from the Sun.
Solar Eclipse • 2009
Solar eclipse • A solar eclipse occurs when the Moon, during its monthly trip around the Earth, happens to line up exactly between the Earth and the Sun, so that it casts a shadow on the Earth. • Next Solar Eclipse • http://www.timeanddate.com/eclipse/solar/2013-november-3
Lunar eclipse • A lunar eclipse occurs when the Moon, during its monthly trip around the Earth, is blocked from the Sun’s rays by the Earth and is in earth’s shadow. • Lunar Eclipse • http://www.moongiant.com/Lunar_Eclipse_Calendar.php
Parts of an eclipse • The innermost cone of total darkness is called the umbra • The outer shadow is partially illuminated by the Sun, and is called the penumbra.
Why eclipses happen • Sometimes the Moon gets between the Earth and the Sun, causing solar eclipses, and sometimes the Moon goes into the Earth's shadow, causing lunar eclipses.
When can they occur? • Solar Eclipses – can occur only during the new moon phase • Lunar eclipses – can occur only during the full moon phase
Why not every month? • As the Moon orbits the Earth, its orbit is tilted slightly (about 5 degrees) from earth’s orbital plane (ecliptic) • The moon crosses earth’s plane twice during its orbit. If this crossing happens at the new moon phase, the Moon will be lined up with the Sun and pass in front of it. • This alignment has to be perfect in order for the Moon to completely cover the Sun for a total solar eclipse.
Why we have tides • The gravitational pull of the moon and Sun • Affected by nearness of the moon more than the size of the Sun • As earth rotates, the tides move around the Earth alternating between high and low tides approximately every 6 hours.
When do tides happen • Spring Tides: new and full moon phase – greatest range • Neap Tides: 1st and 3rd Quarter phases – smallest range
Tides song • http://www.youtube.com/watch?v=KFYf_it461s • Mr. Parr Spring and Neap Tides
Moon phases and eclipses • http://www.youtube.com/watch?v=HkvlrWpsnuQ • Mr. Parr Moon phases
Bill nye is awesome • http://www.youtube.com/watch?v=r7G72DYAXUY • Bill Nye - moon