Two important skills in science are being able to identify and interpret patterns. And there’s a really worthwhile, enjoyable way to help our students develop these skills by collecting data and sharing it with others: making observations of the moon.
My interest in the moon and the patterns inherent in its movement and interactions with the Earth and the Sun were first kindled by my experiences teaching these interactions in my final practicum. My supervising teacher had designed a unit around the topic, and joined an international project that aimed to share cultural and scientific experiences and narratives about the moon between students around the world.
In this and the next post, I’m going to talk about making observations of the moon to identify patterns and make predictions (Part 1), including Indigenous Australian knowledge of the moon and its effects on Earth and addressing cultural and social portrayals of the moon (Part 2).
First, let’s locate ideas about the moon in the Australian Curriculum: Science
Earth and space sciences strand, Year 7: Predictable phenomena on Earth, including seasons and eclipses, are caused by the relative positions of the sun, Earth and the moon (ACSSU115).
- investigating natural phenomena such as lunar and solar eclipses,
seasonsand phases of the moon
- comparing times for the rotation of Earth, the sun and moon, and comparing the times for the orbits of Earth and the moon
- modelling the relative movements of the Earth, sun and moon and how natural phenomena such as solar and lunar eclipses and phases of the moon occur
Physical sciences strand, Year 7: Earth’s gravity pulls objects towards the centre of the Earth (ACSSU118).
- exploring how gravity affects objects on the surface of Earth (such as large bodies of water)
- considering how gravity keeps planets in orbit around the sun
Overarching idea: Patterns, order and organisation
- in the movements of the Earth, sun and moon
Cross-curricular priority: Aboriginal and Torres Strait Islander histories and cultures
- Indigenous astronomical knowledge of moon phases, eclipses, and the tides (discussed in part 2 of this series)
Teaching about the moon: Observing the moon’s phases
Central to our scientific study of the moon was the recording of regular observations of the moon’s position in the sky and the portion that was illuminated. Each day, students were asked to make at least one observation of the moon, noting the date, time, direction, angle above the horizon, and portion of the moon visible, which was achieved by shading a circle to match what could be seen of the moon in the sky. Some days this was easy, and we could see a sliver of a crescent in the late afternoon. Other days students set their alarms to awaken early and find the moon in a different part of the sky.
Not all students were engaged to begin with but as the weeks progressed, and we made astrolabes (simple technologies) to measure the angle of the moon more accurately, and we gained a better knowledge of compass directions and constellations in the sky, more and more students were taking observations to share first thing each morning. We used black paper with white chalk to illustrate one or two of the previous day’s observations and posted this in the next place on the classroom ceiling. Slowly, several patterns were detected:
- the moon was in a different place in the sky at the same time each night, and we could predict where it would at any time be from previous observations
- the moon was travelling in the same direction through the sky each day/night, east to west, just like the sun does (technically, we are moving beneath them as well)
- we were looking at the same face each night (some children used binoculars to view the face of the moon)
- the moon’s apparent shape was changing, and after a time we could predict the pattern
Patterns in the tides
In class, we graphed the height of the tides against the percentage of the moon that was “visible” to see if there was a relationship between the phase of the moon and the height of the tide. Low and behold, there was! We made physical models to demonstrate the movements between the Earth and moon that brought about the tides, and then extended these models to include the sun (which also has a small effect on the tides, enough to cause some tides to be rather lower (neap) or rather higher (king) than other low and high tides). We drew diagrams and wrote explanations drawing on evidence and reasoning to demonstrate our understandings of the phases of the moon and tides.
We also explored the question of why we do not experience eclipses twice a month (a solar eclipse at the full moon and a lunar eclipse at the new moon). The models we’d practised with lamps and balls indicated that we should. So, students reasoned, there must be something wrong with our models. Students explored alternative models, and hypothesised that if the angle of the plane of orbit of the moon around the Earth was tilted slightly, we would rarely experience an eclipse. We checked our hypothesis against what we could find in books and online, and discovered that our hypothesis was correct, according to astronomers.
In Part 2, I will detail some of the astronomical understandings of Indigenous Australian groups, and briefly discuss cultural phenomena that can be discussed alongside children’s scientific studies of the moon.
More websites and articles to help you learn about the moon
- NASA: Earth’s Moon
- Galaxy Zoo: Moonzoo
- The Nebraska Astronomy Applet Project – Online Labs for Introductory Level Astronomy
- CrashCourse: Astronomy