Astronomy: The Moon's Phases and Tides
Understanding moon phases and how the Moon affects ocean tides
Astronomy: The Moon's Phases and Tides
Understanding moon phases and how the Moon affects ocean tides
Astronomy - Grade 4-5
- 1
The Moon looks bright in the night sky. Explain where the Moon's light comes from.
Think about what object in space gives light to the Moon.
The Moon does not make its own light. It looks bright because sunlight reflects off the Moon's surface and travels to our eyes. - 2
Put these Moon phases in order, starting with the new moon: full moon, first quarter, new moon, third quarter.
The correct order is new moon, first quarter, full moon, and third quarter. This order shows the main phases as the visible lit part grows and then shrinks. - 3
A student sees a crescent Moon that gets a little larger each night. Name the type of phase change and explain what is happening.
Waxing means the visible lit part is increasing.
This is a waxing phase change. The lit part of the Moon that we can see from Earth is growing larger each night. - 4
A student sees the lit part of the Moon getting smaller each night after a full moon. Name the type of phase change and explain what is happening.
This is a waning phase change. The lit part of the Moon that we can see from Earth is shrinking each night. - 5
Explain why the Moon appears to have different shapes during the month.
The Moon is always half lit by the Sun, but we do not always see all of the lit half.
The Moon appears to have different shapes because the Moon moves around Earth. As the positions of the Sun, Earth, and Moon change, we see different amounts of the Moon's sunlit half. - 6
The whole face of the Moon that we see from Earth looks bright. Name this phase and describe the Moon's appearance.
This phase is the full moon. During a full moon, the side of the Moon facing Earth appears completely lit. - 7
Only a thin curved part of the Moon looks bright. Name the general type of phase and describe its appearance.
A crescent shape looks like a thin curved slice.
This is a crescent phase. A crescent Moon has only a small, curved part of the visible side lit. - 8
Explain what causes tides in Earth's oceans.
Tides are caused mostly by the Moon's gravity pulling on Earth's oceans. The Sun's gravity also affects tides, but the Moon has the strongest effect because it is much closer to Earth. - 9
Describe the difference between high tide and low tide.
Think about whether the water is farther up the beach or farther away from the beach.
High tide is when ocean water reaches a higher level along the shore. Low tide is when ocean water drops to a lower level and more shore or beach may be uncovered. - 10
Spring tides happen near the new moon and full moon. Explain what makes spring tides different from regular tides.
Spring tides are not about the season of spring.
Spring tides have a larger difference between high tide and low tide than regular tides. They happen when the Sun, Earth, and Moon are lined up so the Sun's gravity and the Moon's gravity work together more strongly. - 11
Neap tides happen near the first quarter and third quarter Moon phases. Explain what makes neap tides different from spring tides.
Neap tides have a smaller difference between high tide and low tide than spring tides. They happen when the Sun and Moon pull on Earth's oceans from different directions, so their effects do not add together as strongly. - 12
A classmate says Moon phases are caused by Earth's shadow covering the Moon every month. Correct this idea in a complete sentence.
Earth's shadow on the Moon is part of a lunar eclipse, not the usual monthly phases.
Moon phases are not caused by Earth's shadow. They are caused by the changing positions of the Sun, Earth, and Moon, which let us see different amounts of the Moon's sunlit half.