Phases of the Moon · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.
En anglais

The Moon's Changing Faces

Science · Space Systems & Earth's History · ages 11-12
Name ______________________   Date ____________

  1. Which event is a lunar eclipse?

    • Earth's shadow falls on the Moon during a full Moon.
    • The Moon's shadow falls on Earth during a new Moon.
    • The Moon's own light switches off for an entire month.

  2. What causes the Moon's ordinary phases?

    • Earth's shadow covering a different part of the Moon each night
    • Our changing view of the Moon's sunlit half as it orbits Earth
    • Changes in the Moon's actual size as it moves through space

  3. A solar eclipse happens at every new Moon.

    Circle one:   True   False

  4. Which phase follows first quarter as the sunlit part visible from Earth increases toward full Moon?

    New MoonWaxing CrescentFirst QuarterWaxing GibbousFull MoonWaning GibbousLast QuarterWaning Crescent
    • Waxing Gibbous
    • Waning Crescent
    • New Moon

  5. About how many days pass, on average, from one new Moon to the next? Give the value taught in the lesson, to the nearest tenth of a day.

    Answer: ______________

  6. Maria watches an animation showing the Moon pass in front of the Sun. Its shadow reaches part of Earth. What event does the animation show?

    • A solar eclipse, with the Moon between the Sun and Earth
    • A lunar eclipse, with Earth between the Sun and the Moon
    • An ordinary new Moon, with no shadow reaching Earth's surface

  7. Tonight is full Moon. About 22 days pass, roughly three quarters of a phase cycle. Which phase should you expect near that time?

    Full MoonWaning GibbousLast QuarterWaning CrescentNew MoonWaxing CrescentFirst QuarterWaxing Gibbous
    • Full Moon again
    • New Moon again
    • First Quarter

  8. Diego says, 'First quarter means one quarter of the Moon's visible disk is lit.' Which correction should he make?

    • Three quarters of the visible disk is lit at first quarter.
    • Half the visible disk is lit at first quarter.
    • All of the visible disk is lit throughout first quarter.
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Answer key

For grown-ups. Fold this page away before handing over the rest.

The Moon's Changing Faces W1-mt_4V-vYhFUcm-s1

  1. Earth's shadow falls on the Moon during a full Moon. · In a lunar eclipse, Earth is between the Sun and Moon and Earth's shadow reaches the Moon.
  2. Our changing view of the Moon's sunlit half as it orbits Earth · The Moon reflects sunlight. Its orbit changes how much of its sunlit half we see from Earth.
  3. False · The Moon's orbit is tilted. At most new Moons, its shadow misses Earth, so there is no solar eclipse.
  4. Waxing Gibbous · Waxing gibbous follows first quarter. More than half the visible disk is lit, and the lit portion is increasing.
  5. 29.5 · The average phase cycle is about 29.5 days. Individual cycles vary, so this is an average rather than an exact date prediction.
  6. A solar eclipse, with the Moon between the Sun and Earth · The Moon is between the Sun and Earth, and its shadow reaches Earth. Those conditions describe a solar eclipse.
  7. First Quarter · After full Moon, last quarter is about 7 days later, new Moon about 15 days later, and first quarter about 22 days later.
  8. Half the visible disk is lit at first quarter. · At first quarter, half the visible disk is lit. The phase name does not give the fraction of the disk that is lit.
Worksheet · LightMySky