Description: For my science activity, sixth graders will use Stellarium to view seasonal constellations. Students will hypothesize whether or not the night sky changes during the course of a year. Students will look at the night sky as it appears from Utah during the four different seasons. Students will look at the constellations visible in April, July, October, and December and determine if the constellations visible are the same or different for each season. Students will also look at the night sky as it appears in the late evening and early morning on one day during each season to determine if different constellations are visible at different times of the night. Students will then use their observations to analyze why different constellations are visible during each season, and why constellations “rise” and “set” during the night.
Content: This science activity meets the sixth grade science core Standard 4: Students will understand the scale of size, distance between objects, movement, and apparent motion (due to Earth's rotation) of objects in the universe and how cultures have understood, related to and used these objects in the night sky; Objective 2 a & d: Locate and identify stars that are grouped in patterns in the night sky. Relate the seasonal change in the appearance of the night sky to Earth's position.
Students will learn that the constellations that are visible in the late evening are different from those visible in the early morning. This is because the Earth rotates on its axis. As Earth rotates through one full day, we see different parts of the sky throughout the day and night. In the evening, we see several constellations. However, as we rotate during the night, we see different constellations because our part of Earth is facing toward another part of the sky. Throughout a season, we will see the same group of constellations “rise” and “set” during the night. As earth makes its orbit, or revolves, around the sun, the position of Earth in the night sky changes. This means that we see a different part of Earth’s orbital path during each season. For instance, during winter, Earth is in the part of the night sky that contains the constellations Orion and Taurus. Because of Earth’s rotation (one full day), we will see Orion and Taurus during different times of the night, but we will see both throughout the winter because of Earth’s orbital position around the sun. Some constellations are circumpolar, meaning they are visible in all seasons because of their position in the sky. These include the Big and Little Dippers, and Cassiopeia. Circumpolar constellations, as well as the North Star, could be discussed in a separate lesson and activity.
Pedagogy: Students will be constructing hypotheses, observing and collecting data, and analyzing data. Students will develop a hypothesis to the question: “Does the night sky change during the year?” and test their prediction by looking at the constellations during each of the four seasons using Stellarium. After observing that the sky does change, students will analyze their observations on Stellarium to determine what might cause this change. From the Content Standard for Science as Inquiry handout, students will “develop descriptions, explanations, predictions and models using evidence,” and “think critically and logically to make the relationships between evidence and explanations.” Since constellations are visible, students can collect data that either supports or refutes their hypotheses, and use concepts of rotation and revolution to analyze and explain the results.
Technology: Using Stellarium to view changes in the night sky over the course of the year is a good fit with learning about the different constellations and relating the seasonal change in the appearance of the night sky to Earth's position. It would be very difficult to send students home with an assignment to watch how the constellation positions change over the course of a night and a year. The students would have a difficult time remembering such an extended assignment, and the teacher would find it a hassle to remind students over that many months. Stellarium allows students to observe the constellations as they appear from Utah, and to see how the constellations that are visible from the Northern Hemisphere change during the night and over the course of a year. Students can gather the observations in a matter of minutes, rather than months, and deduce that it is Earth, not the night sky, that is rotating (which means we see different constellations in the late evening than we do in the early morning) and revolving (which means we see a different part of the night sky, and hence different constellations, during each season, depending on where we are in our orbit around the sun).
