Shadow – results when one object blocks the light that another object emits or reflects Umbra – the central, darker part of a shadow where light is totally blocked Penumbra – the lighter part of a shadow where light is partially blocked Eclipses and Tides

Umbra Penumbra

Solar Eclipse - When the moon’s shadow appears on Earth’s surface, a solar eclipse is occurring

Review Questions: What is a solar eclipse? A solar eclipse is an event in which the Moon casts a shadow on Earth. Why does a solar eclipse occur only during a new moon? This is the only time when the Moon passes directly between the Sun and Earth.

http://www.brainpop.com/science/space/eclipse/preview.weml Brain Pop

A solar eclipse occurs only when the Moon moves directly between Earth and the Sun. Total solar eclipse – Moon appears to cover the Sun completely; lasts no longer than 7 minutes Partial solar eclipse – Can be seen from within the Moon’s penumbra Solar eclipse only occur during a new Moon, but do not occur every new Moon Important Facts

Lunar Eclipse - When the moon moves into the Earth’s surface, a solar eclipse is occurring

Review Questions: What is a lunar eclipse? A lunar eclipse is an event in which the Moon passes into Earth’s shadow. When can a lunar eclipse occur? Only during the Full Moon phase.

Tides What is a tide? daily rise and fall of sea level. What affects tides on Earth? Tides on Earth are affected by both the Sun and the Moon.

Spring Tide: During full moon and new moon phases; sun and moon gravitational effects produce higher high tides and lower low tides Neap Tide: a week after spring tide; sun earth, and moon form a right angle; causes high tides to be lower and low tides are higher; occurs at first-quarter moon and third-quarter moon

Where are tides the highest? On the side of Earth closest to the Moon and the side of Earth opposite it

Neap Tides Spring Tides Describe how the Moon is positioned relative to Earth and the Sun during spring and neap tides. During neap tides, the Moon, Earth and Sun are at right angles relative to one another. During spring tides, the Moon, Earth, and the Sun form a straight line in space Neap Tides Spring Tides

Vocabulary: Solar Eclipse: occurs when the moon casts a shadow on the earth Lunar eclipse: occurs when the Moon moves into Earth’s shadow Tide: the daily rise and fall of sea level

http://www.brainpop.com/science/earthsystem/ tides/preview.weml Brain Pop

Important Facts: It is primarily the Moon’s gravity that causes Earth’s oceans to rise and fall twice each day The Moon’s gravity is stronger on the side of Earth closer to the Moon and weaker on the side of Earth opposite the Moon. These differences cause tidal bulges High tides occur at tidal bulges and low tides occur between them

Have you ever eaten crab or lobster Have you ever eaten crab or lobster? If so, you know how delicious these shellfish can taste. However, did you know that these organisms and many others depend on the tides? Tides bring large volumes of nutrients from nearby mudflats and saltwater marshes, thus providing an abundance of food for crabs and lobsters, plus many of the birds, fish, and other organisms that also call the oceans home. Did you know?

Launch Lab You can see a shadow when an object blocks a light source. What happens to an object’s shadow when the object moves? Get into a group of 3 Select an object Shine a flashlight on the object, projecting its shadow on the wall. While holding the flashlight in the same position, move the object closer to the wall – away from the light. Then, move the object toward the light. Did the shadow have dark parts and light parts? Did these parts change?