Sunrise to Sunset Two Friends Were Talking About Where the Sun Is in the Sky Between Sunrise and Sun- Set

The Sun-Earth System 7

Sunrise to Sunset Two friends were talking about where the Sun is in the sky between sunrise and sunset. They each drew a picture to explain their ideas. Here is what they drew and said:

Avi: “I think the Sun rises on one side and sets on the other.”

Jessica: “I think the Sun rises upward in the morning, then sets downward toward night. It looks like it goes up and down like this.”

Whom do you agree with the most? ______Explain why you agree. ______

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Purpose the Sun is moving across the sky in a left-to- The purpose of this assessment probe is to elicit right direction. At around noon (which is the students’ ideas about the apparent movement midpoint between sunrise and sunset) the Sun of the Sun. The probe is designed to reveal appears to be at its highest point in the sky. where students think the Sun rises and sets, However, the Sun only appears to move in an and how it moves during the day. arc across the sky. It is the Earth’s rotation that is responsible for this visual effect. Related Concepts Objects in the sky Administering the Probe Seasons: cause, length of day This probe is primarily designed for students Solar system objects: spin in the elementary and middle school grades. Sun: altitude at noon, path in the sky For the youngest children you may want to read the probe aloud and allow time for the Explanation children to ask questions. For middle school Avi has the best answer. The Sun’s apparent students you may want to add an additional motion across the sky during the course of a task—to draw how the Sun appears to move day is arclike as shown in Avi’s drawing. The through the sky during the day. [Safety note: Sun rises along the eastern horizon, appears If you follow this probe with Sun observa- to travel across the entire sky, and sets along tions throughout the day, make sure stu- the western horizon. Viewed from the North- dents do not look directly at the Sun.] ern Hemisphere, facing south, it seems like

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Related Ideas in Benchmarks the Sun was never overhead at noon at the for Science Literacy latitude where the children lived. Further- (AAAS 2009) more, there was no significant difference between third-grade students’ and eighth- grade students’ understanding of the Sun’s K–2 The Universe apparent motions. •  The Sun, oon,M and stars all appear to Plummer and Krajcik (2010) found that move slowly across the sky. children as young as first grade knew that the Sun gets higher in the sky during 3–5 The Earth the day and lower in the sky during the  The rotation of the Earth on its axis every evening, although most were not able to 24 hours produces the night-and-day accurately describe the Sun’s path. Some cycle. To people on Earth, this turning of the students envisioned the Sun going of the planet makes it seem as though the up and then down on the same side of Sun, Moon, planets, and stars are orbiting the sky. Other children thought the Sun the Earth once a day. stopped moving in the sky during the day. However, after a planetarium pro- Related Ideas in National gram about the Sun’s path, 86% of first- Science Education Standards and second-grade students were able to (NRC 1996) describe the Sun’s path as rising on one side of the sky, following a continuous arc, and setting on the other side of the sky. K–4 Objects in the Sky • • The Sun, Moon, stars, clouds, birds, and Mant and Summers (1993) interviewed airplanes all have properties, locations, primary school teachers in England. and movements that can be observed and Although most could explain the day-night described. cycle in scientific terms, few could relate their explanations to observations of how K–4 Changes in Earth and Sky the Sun appears in the sky. Some appeared  Objects in the sky have patterns of to work backward from their explanation movement. to describe what must be happening in the sky. That suggests it is important to have Related Research students first observe how the Sun changes its position during the daytime, before • Plummer (2008) interviewed 20 students explaining why that happens from the in each of grades 1, 3, and 8. Although she viewpoint of a spinning Earth. found a general trend toward higher levels of understanding among the older students, students at each grade level held miscon- Suggestions for Instruction and ceptions about how the Sun appeared to Assessment move through the sky during the day and • This probe can be combined with “Dark- how the Sun’s path across the sky changed ness at Night” in Uncovering Student Ideas with the seasons. Many of the children at in Science, Vol. 2: 25 More Formative Assess- all ages thought that the Sun was directly ment Probes (Keeley, Eberle, and Tugel overhead at noon every day, even though 2007).

 Indicates a strong match between the ideas elicited by the probe and a national standard’s learning goal.

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• For students who believe that the Sun rises to see the “sunrise” as they just start to see vertically above the horizon in the morn- the light, watch the Sun go from one side ing and then comes back down toward of their field of view as they slowly turn, evening, be aware that these students then see “sunset” as the Sun disappears on might be bound by the way we use the the other side of their view. words sunup and sundown or sunrise and • For older students, the University of Ore- sunset, which implies that the Sun literally gon’s Solar Radiation Monitoring Labora- goes up and down in the sky. It is particu- tory has a website where students can create larly important that these students have Sun path charts from their location: http:// an opportunity to observe the position of solardat.uoregon.edu/SunChartProgram. the Sun throughout the day. [Safety note: html Students should never look directly at the Sun.] The best way to do that is to References have them mark the position of a fixed American Association for the Advancement of Sci- object, like a flagpole. It is important to ence (AAAS). 2009. Benchmarks for science lit- explicitly point out that the shadow marks eracy online. www.project2061.org/publications/ the direction opposite the Sun. When the bsl/online Sun is highest in the sky, the shadow will Keeley, P., F. Eberle, and J. Tugel, 2007. Uncovering be the shortest. student ideas in science, vol. 2: 25 more formative • Although it is too early to teach kindergar- assessment probes. Arlington, VA: NSTA Press. teners or first graders the explanation for Mant, J., and M. Summers. 1993. Some primary- day and night and expect them to explain school teachers’ understanding of the Earth’s it clearly, they can learn that the Sun is out place in the universe. Research Papers in Educa- during the day but not at night and that tion 8 (1): 101–129. it is the Sun that in fact determines when National Research Council (NRC). 1996. National day starts and ends. Nighttime is simply science education standards. Washington, DC: the absence of sunlight. It is also impor- National Academies Press. tant for students in kindergarten or first or Plummer, J. 2008. Students’ development of second grade to observe that the position astronomy concepts across time. Astronomy of the Sun changes during the day, moving Education Review 7 (1): 139–148. http://aer.aas. in a smooth continuous arc from one side org/resource/1/aerscz/v7/i1/p139_s1 of the sky to the other. Plummer, J., and J. Krajcik. 2010. Building a learn- • In upper elementary school, when students ing progression for celestial motion: Elemen- study the Earth as a ball in space, you can tary levels from an Earth-based perspective. have the students simulate the spinning Journal of Research in Science Teaching 47 (7): Earth with their heads by slowly turning 768–787.

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