Cassie is writing an equation to show the effect of the gravitational pull of the sun and the moon on tidal range. Which equation would Cassie use to show the effect of the sun and the moon on spring tides? A. sun + moon = spring tides B. sun + Earth = spring tides C. moon – sun = spring tides D. Earth – moon = spring tides

Which gravitational pull has the greatest effect on tides? A. the sun’s gravitational pull on Earth B. the moon’s gravitational pull on Earth C. Earth’s gravitational pull on the moon D. the sun’s gravitational pull on the moon

Satellite Gravity Lunar phases Eclipse Umbra Penumbra

 Complete page 217 and read lesson 3

Essential Question: How do Earth, the moon, and the sun affect each other?

 Our moon is Earth’s natural satellite.  Mass of Earth is larger than the mass of the moon, thus Earth’s gravity has a stronger pull on the moon.  The mass of sun exerts a large gravitational pull on Earth.  The distance between Earth and the moon is roughly 383,000km (238,000 mi).

 The moon is only visible when it reflects the sunlight that reaches the moon.  The moon takes 28.5 days or about a month to orbit the Earth.  Only one side of the moon faces Earth, often called the near side of the moon.

 As the moon revolves around the Earth, the portion of the moon that reflects sunlight changes, causing the moon’s appearance to change.  The cycle begins with a new moon, then waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, then waning crescent.  During waxes the moon seems to grow, and waning the moon seems to shrink.  During gibbous phases the moon is almost fully visible, and during crescent only a sliver is visible.

 Just before a lunar eclipse, sunlight streaming past Earth produces a full moon.  On Earth, a lunar eclipse occurs when the moon moves through Earth’s shadow.  The entire moon can be in darkness because the moon is small enough to fit within Earth’s umbra.  The moon’s orbit around the Earth is tilted by about 5 ̊.  The tilt is enough to place the moon out of Earth’s shadow for most full moons and Earth out of the moon’s shadow for most new moons.

 During a total solar eclipse, the sun’s light is completely blocked by the moon.  When the moon is directly between the sun and Earth, the shadow of the moon falls on a part of Earth and causes a solar eclipse.  Outside the umbra, but within the penumbra, people see a partial solar eclipse.  The umbra of the moon is too small to make a large shadow on Earth’s surface.  A total solar eclipse usually lasts between 1 to 2 minutes at any one location.

Write a 2-3 sentence summary on what you learned in this set of notes.  A total eclipse of the sun covers only a small part of Earth and is seen only by people in particular parts of the Earth at a narrow path.

 Eclipses are predictable, solar system events. The answer choices below list relative positions of Earth, the sun, and the moon. Which list represents the position of Earth, the sun, and the moon during a lunar eclipse? A. sun, Earth, moon B. Earth, sun, moon C. sun, moon, Earth D. moon, sun, Earth

 Tide  Tidal range  Spring tide  Neap tide

Sara is recording water levels in the ocean near her home once an hour for one day. She observes the water level slowly rising and falling twice that day. What is Sara observing? A. currents B. gravity C. tides D. waves

Earth and the other planets of our solar system orbit the sun. Which of the following keeps planets in our solar system in orbit around the sun? A. electromagnetism B. friction C. gravity D. vacuum