ARCturus

Earth, our home planet, is the only celestial body with life. Moon, as a celestial body orbiting the Earth, has intrigued people’s imagination and inspired them to explore the activities in the sky. Previously, the Moon has been viewed as a mystical globe reflecting romantic love that shows its cyclically altering face to the Earth. In the picture, an artificial Earth presenting the continents and seas by colour (picture and painting VH, Finland).

 

The aim: Getting to know the essence of the Moon as the closest celestial body to the Earth and its only satellite by observing with naked eye.

Explorations: The Moon is the only celestial body orbiting the Earth, which surface can be observed by human eye. The Moon is visible from Earth in different places and illuminating different kind of light according to the time of the month. Therefore, many kinds of everyday explorations can be made about the movements of the Moon.

1) Explore the location of the Moon at the same time during consecutive days. The location can be examined in relation to the landmarks in viewing direction. Notes of the Moon’s location should be made everyday in writing or by marking the location in a drawing of the landscape attached to the window. The distances between the daily marks should then be measured and their significance pondered.

2) Explore the face of the Moon. Comparisons can be made according to the relations of the darker areas during a longer period of time. Discuss earthshine with the students. The picture taken through a telescope shows a trace of earthshine (IH, Finland).

 

From Earth, we see always the same side of the Moon. It means that the Moon revolves around its axis once while orbiting the Earth. As the Moon’s orbit around the Earth takes a month, the day on the Moon is a month long. Astronauts orbiting the Moon have seen the side of it facing the opposite direction.

3)  * Explore the location of the Moon in relation to the horizon during one month and different months on the Northern Hemisphere. On the Southern Hemisphere the viewing direction is opposite.

The Moon’s orbital plane differs slightly from that of the Earth. For this reason, the location of the Moon is sometimes on the southern sky, making a slight arch from east to west. Occasionally, the Moon rises high, making a bigger arch falling almost to Northwest.

While orbiting the Earth, the Moon is visible on different sides of the sky so we see different parts of it illuminated. These are called lunar phases that are repeated monthly almost similarly with few exceptions. When the Moon is aligned between the Earth and the Sun, there is a solar eclipse and lunar eclipse on the opposite side of the Earth.

4)  * Learn to recognise the different lunar phases according to the illuminated part of the Moon and its extent. Explorations can be conducted in a darkened room using a sunlamp and small ball representing the Moon, while the investigators own head is the Earth. By rotating the ball on different directions, it is easy to observe the lunar phases and their progress by the increase and decrease of the illuminated area. Understanding of the situation can be tested in two ways: the lunar phase is told and the pupils place their Moons to the right location around their head or the location of the Moon in relation to the head and solar lamp is told and they have to determine the lunar phase. After this, based on what has been learned, the pupils can identify the lunar phases outside. The benefit of the classroom activity is that all the lunar phases can be studied at once. In reality, only one phase can be observed at a time and the next one may have to wait for several days.

5)  * Photographing the Moon is easy to implement in schools. The needed equipment, camera and tripod, can be found from most schools. The Moon can be photographed even during the day or at dusk during the end of the school day. The pupils can also be asked to take photos during their spare time at home. Photographing the full moon is more difficult due to the brightness of the Moon but other lunar phases can be photographed in several ways. It’s nice to use own photographs for decorative or educational purposes in different astronomy assignments. The class can gather an information board to the school wall of the different faces of the Moon. Photo of the half moon was taken in Lapland in February at sunset (photo: IH, Finland).

 

Methods: Exploring the lunar phases with lamp and small ball in a dark space. Observations outside in clear weather when the Moon is visible. Register and statistics of orbits of the Moon.

Materials: Small balls, lamp, camera

 

Discussion: Discuss with the students about the different situations, for example, can the Moon be visible at noon in the north and when can the Moon’s left side be illuminated in the east?

Examining the results: When gathering the gallery of Moon images, make sure that each picture is placed the right way up. For example, in the picture the crescent moon can point to south even during the evening when the Sun is below the horizon in the north. Discuss these kinds of impossibilities and misunderstandings with the students and guide them to take a critical view on the pictures.

Tips: Misunderstandings can be brought up by modelling impossible situations. The students can be asked to explain the reason why a certain situation is impossible and how it should be in reality.

Keywords: Moon, lunar phase, lunar eclipse, solar eclipse, half moon, month, earthshine

 

 

 

 

 

 

 

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