crescent Moon waxing full Moon first quarter Moon gibbous Moon last quarter Moon lunar cycle new Moon waning

Observations of the Moon What did you observe day to day with the moon? Describe in words and sketches both the pattern of the Moon’s phases and the general time of day when you saw the different phases of the Moon.

Read the introduction and look for key ideas

How can we predict changes in the Moon’s appearance? Full moon rising

Phase Phase describes the shape of the visible portion of the Moon. Suggest names for the different phases of the Moon you have observed so far.

Complete the procedure and record your data

Discuss the following terms: new Moon quarter Moon crescent Moon First Quarter Last Quarter Gibbous

The complete lunar cycle

Analysis question 1 Explain how you made your predictions for Procedure Steps 6 and 7.

Analysis question 2 In 2004, there was a full Moon on May 4. In 2005, there was a full Moon on May 23. Why doesn’t the full Moon fall on the same day every year?

Analysis question 3 Predict the date of the next first quarter Moon for the June calendar on Student Sheet 79.2. Explain how you made your prediction.

Analysis question 4 Summarize the complete cycle of the Moon’s phases in words and with a labeled diagram.

Analysis question 5 About how many days does a complete cycle of the Moon’s phases take?

How can we predict changes in the Moon’s appearance?

Key vocabulary definitions Crescent Moon - The phase of the Moon in which the lit portion of the Moon visible from Earth’s surface is less than a half-circle (crescent shaped). Crescent moons occur right after and right before the new Moon.

Key vocabulary definitions Full Moon - The phase of the Moon that occurs about fourteen days after the new Moon in which the complete lighted portion of the Moon is visible from Earth’s surface and appears as a full circle.

Key vocabulary definitions First quarter Moon - The phase of the Moon, occurring about seven days after the new Moon, in which the lighted portion of the moon that is visible from Earth’s surface is a half-circle. Gibbous Moon - A phase of the Moon before or after it is full, when more than half of its disk is illuminated.

Key vocabulary definitions Last quarter Moon - The phase of the Moon that occurs about seven days after the full Moon in which the lighted portion of the Moon that is visible from Earth’s surface is a half-circle.

Key vocabulary definitions Lunar cycle - The revolution of the Moon around Earth that produces the changing phases of the Moon. One complete lunar cycle takes about 29.5 days.

Key vocabulary definitions New Moon - The phase of the Moon, occurring about 14 days after the full Moon, in which none of the lighted portion of the Moon is visible from Earth’s surface. Waning - The phases of the Moon when the illuminated portion visible from Earth is decreasing (between the full and new Moon).

Key vocabulary definitions Waxing - The phases of the Moon when the illuminated portion visible from Earth is increasing (between the new and full Moon).