1 Lunar eclipse

When the moon

passes through the

Earth’s shadow.

They occur 2-3 times a year.

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Have you ever wondered why the moon is more orange or yellow in color when it first rises at

night?This effect is caused by the atmosphere of the earth. The reason for the orange color is due to the scattering of light by the atmosphere. When the moon is near the horizon, the moonlight must pass through much more atmosphere than when the moon is directly overhead. •The moon can have an orange color at any time of the year. Sometimes the moon appears orange even when it's directly overhead. This occurs when there's a lot of dust, smoke, or pollution in the atmosphere. The size of those particles will determine the type of color you will see.

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2 Solar eclipseWhen the

Earth passes through the

moon’s shadow. They occur about once every 2

years.The next total solar eclipse visible from the mainland U.S. will be on August 21,

2017.

Solar Eclipse 2

Solar Eclipse2

Why can’t I look at a solar eclipse?

Did you ever take a magnifying glass out into the sun and burn leaves? If so, you probably remember that the focused sunlight coming through the lens was concentrated to a small spot (refracted!) and got hot enough to start the fire. Well, you have a lens just like that in your eye. If you look at the sun, your eye-lens will concentrate the sun's light and focus it to a very small spot on the back of your retina. This can cause permanent eye damage or blindness! Additionally, there are no pain sensors back there so you won't even know it's happening! The damage may not be apparent for several hours.

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3 Tides• What are tides?

– The periodic rise and fall of the sea level under the gravitational pull of the moon.

• The Moon’s gravity exerts a strong pull on Earth.

• The water bulges outward as Earth and the Moon revolve around a common center of mass.

• The moon’s gravity pulls on the earth, and pulls the water towards it. The water moves up into a slight bulge on the side of the earth that faces the moon.

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Sand Bar

Have you ever been able to stand on a sand bar at low tide that was not there at high tide?

At the right, are pictures of Bar Island in Bar Harbor, Maine. The bridge is accessible for walkers during low tide but not at high. A land bridge is exposed at low tide.

High tide

Low Tide

4 Spring & Neap Tides

• Spring (strong) – High tides are higher than usual and low tides are lower than usual. This happens twice a month during the new and full moons.

• Neap (weak) – High tides are lower than usual and low tides are higher than usual. This happens twice a month during the first and third quarter moon phases.

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5 Moon’s Surface

Craters, Maria, Highlands, Mountains, Valleys,

Mariaa. Large, dark flat areasb. People thought they were the

“seas”c. Formed by huge lava flows

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6 Solstice6 Solstice

DEFINITION: an astronomical event that DEFINITION: an astronomical event that happens twice each year as the Sun reaches its happens twice each year as the Sun reaches its highest or lowest point in the skyhighest or lowest point in the sky

LATIN: sol (sun) and sistere (to stand still). LATIN: sol (sun) and sistere (to stand still).

The Sun appears to stand still as the Sun's The Sun appears to stand still as the Sun's path (as seen from Earth) comes to a stop path (as seen from Earth) comes to a stop before reversing direction.before reversing direction.

SolsticesSolsticesSolsticesSolstices• SolsticesSolstices occur twice a year, when the tilt of the Earth's axis is occur twice a year, when the tilt of the Earth's axis is

oriented directly towards or away from the Sun, causing the oriented directly towards or away from the Sun, causing the Sun to appear to reach its northernmost and southernmost Sun to appear to reach its northernmost and southernmost extremes. extremes.

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

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

Tyrrhenian Sea and Solstice Sky Credit & Copyright: Danilo Pivato

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SOLSTICESOLSTICE

• During the winter the During the winter the Northern Hemisphere day Northern Hemisphere day lasts fewer than 12 hours and lasts fewer than 12 hours and the Southern Hemisphere day the Southern Hemisphere day lasts more than 12 hours.lasts more than 12 hours.

• During the winter solstice, the During the winter solstice, the North Pole has a 24-hour North Pole has a 24-hour night and the South Pole has night and the South Pole has a 24-hour day.a 24-hour day.

• Sunlight strikes the earth Sunlight strikes the earth most directly at the Tropic of most directly at the Tropic of Capricorn.Capricorn. http://k12.ocs.ou.edu/teachers/ref

erence/solstice.gif

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For Discussion 6Observances of the winter solstice have had a unique history. For hundreds of years, many people believed that the changing seasons and fluctuating hours of

sunlight were controlled by a group of deities known as sun gods. The early pagans celebrated the Winter Solstice by honoring those gods with a variety of

festivals and rituals designed to curry the gods' favor and ensure the sun's speedy return. In the Roman

Empire, the Winter Solstice was further recognized by the celebration of the "Birthday of the Sun" on

December 25th.

Solstice are still celebrated around the world. Why do people find them so special?

7 Equinox7 Equinox

DEFINITION: When the tilt of the Earth's axis DEFINITION: When the tilt of the Earth's axis is inclined neither away from nor towards the is inclined neither away from nor towards the SunSun

LATIN: The name "equinox" is derived from LATIN: The name "equinox" is derived from the Latin aequus (equal) and nox (night).the Latin aequus (equal) and nox (night).

During the equinox, night and day have During the equinox, night and day have approximately equal length.approximately equal length.

EquinoxesEquinoxes

• A day lasts 12 hours and A day lasts 12 hours and a night lasts 12 hours at a night lasts 12 hours at all latitudes.all latitudes.

• Equinox literally means Equinox literally means "equal night"."equal night".

• Sunlight strikes the Sunlight strikes the earth most directly at earth most directly at the equator. the equator.

• This occurs twice a year. This occurs twice a year. http://k12.ocs.ou.edu/teachers/reference/equinox.gif

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EquinoxEquinox

• The vernal (spring) equinox occurs March 21.The vernal (spring) equinox occurs March 21.• The autumnal (fall) equinox occurs September 21.The autumnal (fall) equinox occurs September 21.

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