Chapter 1 Section 2 Phases, Eclipses, and Tides Objective: Students will define phase, eclipse, and tide. Star Log: #2 What does “phases of the moon” mean?

Phases of the Moon The positions of the moon, Earth, and the sun cause the phases of the moon, eclipses, and tides. The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.

Moon Phases

Moon Facts The moon does not have it’s own light, it reflects light from the sun. The amount of the sunlit side of the moon that you can see determines its phase. The moon goes through a whole set of phases about once a month.

Solar and Lunar Eclipses Solar Eclipse A solar eclipse occurs when the moon passes between the Earth and the sun, blocking the sunlight from reaching the Earth. Lunar Eclipse A lunar eclipse occurs at a full moon when Earth is directly between the moon and the sun.

Solar and Lunar Eclipses

What is a tide? A tide is the rise and fall of water every 12.5 hours. The water rises for about 6 hours and then falls for about 6 hours.

What causes the tides? The force of the gravity pulls the moon Earth (especially the water on Earth’s surface) toward each other. Tides occur mainly because of differences in how much the moon pulls on different parts of the Earth.

Spring and Neap Tides Spring Tides Neap Tides Once a month, at a new moon, the sun, Earth, and moon are nearly in a line. The gravity of the sun and moon pull in the same direction causing a tide with the greatest difference between low and high tide. Neap Tides Twice a month when the Earth and sun are at right angles to line between the Earth and moon. The sun and moon pulling in these directions causes a tide with the least difference between low and high tide.

Class Review Why does the moon change its phases as the month progresses? Why are a day and a year on the moon the same length?

Homework for Tonight Page 45 Key Terms for Chapter 1 Section 2 Read the Key ideas for Section 2