General Overview
Performance Expectation 5-ESS1-2: Represent data in graphical displays to reveal patterns of daily changes in length and direction of shadows, day and night, and the seasonal appearance of some stars in the night sky.
Clarification Statement: Examples of patterns could include the position and motion of Earth with respect to the sun and selected stars that are visible only in particular months. Assessment does not include causes of seasons.
Three of the most ancient and reliable patterns observable from Earth’s surface are captured in this single standard: the daily lengthening and shortening of shadows as the sun arcs across the sky, the regular alternation of day and night as Earth rotates, and the changing cast of constellations visible in the night sky as Earth orbits the sun across a year. These patterns are not coincidences. They are the direct observable signatures of Earth’s two primary motions: its daily rotation on its axis, which drives the first two patterns, and its annual orbit around the sun, which drives the third. But the standard does not ask students to explain these motions in Grade 5. It asks them to represent the patterns in data and let the representations speak for themselves.
The science and engineering practice is Analyzing and Interpreting Data: students represent data in graphical displays, including bar graphs, pictographs, and pie charts, to reveal patterns that indicate relationships. The disciplinary core idea is ESS1.B (Earth and the Solar System): Earth’s rotation on its axis and its orbit around the sun cause observable patterns including day and night, daily changes in shadow length and direction, and the seasonal visibility of different stars. The crosscutting concept is Patterns: similarities and differences in patterns can be used to sort, classify, communicate, and analyze simple rates of change in natural phenomena.
This standard completes and formalizes the sky observation work that began in kindergarten. Students have been observing shadow patterns since Grade 1. Now, in Grade 5, they bring those observations into formal graphical representations that make the underlying patterns explicit, quantitative, and communicable to others. This is what scientists do with observational data: they represent it in formats that make patterns visible and that allow comparisons across time, location, and conditions.
Scope and Sequence
The sky observation strand of the NGSS has been building toward this moment across five grade levels. In Grade 1, students observed the sun’s daily arc and made simple moon phase observations. In Grade 1 also, students tracked the changing amount of daylight across seasons. In Grade 4, students analyzed maps to find patterns in Earth’s geological features, deepening their data analysis skills. 5-ESS1-2 brings together all of the sky observation experience from lower grades with the formal graphical representation skills developed across the upper elementary grades and applies them to three interconnected sky phenomena: shadow patterns, day-night cycles, and seasonal constellation visibility.
The instruction at Grade 5 differs from earlier grades in its emphasis on formal data representation. Lower-grade students described patterns qualitatively: “shadows are shorter at noon than in the morning.” Fifth-grade students represent this pattern quantitatively: a bar graph of shadow length at six times throughout a school day shows clearly that length decreases from morning to noon and increases from noon to afternoon, and the bars encode specific numerical values rather than just relative comparisons. Similarly, a graphical display of day length across twelve months makes the seasonal pattern immediately visible and allows precise comparison of specific months, not just general seasonal descriptions.
In middle school, students use these same patterns to develop and use models of the Earth-sun-moon system. They explain why shadows change the way they do, invoking Earth’s rotation and the geometry of sunlight striking Earth’s surface at different angles at different times of day and year. They explain why different constellations are visible at different times of year, invoking Earth’s orbital motion around the sun. The patterns documented in Grade 5 become the evidence that drives the mechanistic explanations of middle school astronomy. Students who have personally gathered and graphed sky data are far better motivated and prepared to understand the explanations than students who have only read about the phenomena.
What Students Must Understand
Shadows change in length and direction throughout the day in a systematic, repeating pattern. In the early morning, shadows are long and point roughly westward because the sun is low in the eastern sky. At noon, shadows are shortest because the sun is at its highest point in the sky, shining most steeply downward. In the late afternoon, shadows lengthen again and point roughly eastward because the sun has descended toward the western horizon. This daily pattern repeats precisely every 24 hours and is directly caused by Earth’s rotation, which carries observers through positions relative to the sun that change continuously through the day. The noon shadow is also not the same length year-round: in winter the sun reaches a lower maximum height at noon than in summer, producing longer noon shadows in winter than in summer. When students graph shadow lengths at the same time of day across different months, this seasonal pattern in noon shadow length becomes visible in the data as a reflection of the changing height the sun reaches in the sky across the year.
Day and night alternate with extraordinary regularity because Earth rotates on its axis approximately once every 24 hours. The half of Earth facing the sun is in daylight; the half facing away is in night. As Earth rotates, any location moves from the sunlit side to the dark side and back again in a daily cycle. The length of daylight and darkness is not equal across the year. In the Northern Hemisphere, summer days are long and nights are short because Earth’s axial tilt causes the Northern Hemisphere to be angled toward the sun during the months around June. Winter days are short because the Northern Hemisphere is tilted away from the sun during the months around December. At the equinoxes, around March 21 and September 21, day and night are approximately equal in length everywhere. Students who graph the number of hours of daylight for each month of the year see a smooth sinusoidal pattern with a maximum in June and a minimum in December.
Different constellations are visible in the night sky at different times of year because Earth orbits the sun and its nighttime side faces different regions of space in different months. When Earth is on one side of the sun in January, the nighttime sky faces one direction in space, and the constellations visible in that direction, such as Orion, Taurus, and Gemini, fill the winter night sky. Six months later in July, Earth is on the opposite side of the sun, and the nighttime sky faces the opposite direction in space, showing different constellations such as Scorpius, Sagittarius, and Aquila. Constellations associated with a given season are simply those that happen to be in the direction Earth faces at night during that season. This pattern, the seasonal appearance and disappearance of specific constellations, is direct observational evidence of Earth’s orbital motion around the sun, even though that mechanism is not required to be stated at Grade 5.
Key vocabulary includes: shadow, rotation, orbit, axis, day, night, season, solstice, equinox, constellation, graphical display, bar graph, pattern, data, daily, seasonal, length, direction, and apparent motion.
Lesson Ideas and Activities
A year-long shadow data collection and graphing project is the richest way to develop the seasonal shadow pattern. Beginning in September, students measure and record the length of a fixed object’s shadow at noon on the first school day of each month. Plot the data as a bar graph with months on the horizontal axis and shadow length on the vertical axis. By the time December arrives, students see the shadow lengthening dramatically month by month. When the spring measurements are added, the shadow begins to shorten again, and by the end of the year the graph traces a clear annual arc from short summer shadows to long winter shadows and back. Students write a description of the pattern and make predictions based on it: “I predict next August’s noon shadow will be about the same length as this August’s because the pattern shows that August consistently has shorter shadows than December.”
A daily shadow tracking investigation on a single clear day generates the intraday shadow data needed to graph the daily pattern. Students measure the shadow of the same fixed object, ideally a vertical pole or stake, at hourly intervals throughout the school day. They record both the length and the direction of the shadow. From this data they create two graphs: a bar graph of shadow length by time of day showing the noon minimum, and a directional diagram showing how the shadow direction sweeps from west in the morning to north at noon to east in the afternoon. The directional diagram can be made by having students draw the shadow directly on a large sheet of paper placed under the pole, creating a time-lapse record on a single sheet. Students identify the shortest shadow and the current sun position at each observation time, reinforcing the direct connection between sun height in the sky and shadow length on the ground.
A day length graphing investigation uses published sunrise and sunset times to create a bar graph of day length across all twelve months. Sunrise and sunset times for any US city are freely available from the US Naval Observatory or timeanddate.com. Students calculate the hours of daylight for each month, record the values in a data table, and draw a bar graph. The seasonal pattern is unmistakable: daylight hours peak in June and trough in December, with a smooth increase across winter and spring and a smooth decrease across summer and fall. Students compare their graphs to those created by classmates using data from a city at a different latitude and discover that the seasonal variation in day length is larger for cities farther from the equator, a powerful preview of why latitude affects climate that will be formally explained in middle school.
A seasonal constellation investigation asks students to research which constellations are best visible in each of the four seasons and plot their positions on a star map. Students use sky charts, the free Stellarium software, or a published seasonal star chart to identify three or four constellations visible in each season and record which are visible, which are not visible, and when transitions occur. They create a seasonal constellation calendar showing which constellations can be observed in which months. Students write a description of the pattern: certain constellations are associated with specific seasons, appear for several months, and then disappear below the horizon as the year progresses, replaced by a different set of constellations. The pattern repeats precisely every year.
A data synthesis discussion asks students to connect the three patterns they have documented. Shadow length changes daily because the sun’s position in the sky changes as Earth rotates. Shadow length also changes across seasons because the sun’s maximum height in the sky changes as Earth orbits the sun. Day length changes across seasons for the same reason. Seasonal constellation visibility changes because Earth’s orbital position determines which region of space Earth’s nighttime side faces. Students draw a simple diagram showing Earth in different positions in its orbit and label which constellations would be visible at night from each position. This synthesis activity, even without formal explanation of axial tilt, builds a coherent model of Earth’s two motions and their separate effects on observable sky patterns.
A graphical display analysis activity gives students completed graphs made from real astronomical data and asks them to read, interpret, and compare them. Provide a bar graph of shadow length for a location at 40 degrees north latitude and one for a location at 25 degrees north latitude. Ask: which location has longer shadows in December? Which shows greater seasonal variation? What does this tell you about the difference in sky patterns between the two locations? This comparison across latitudes extends the standard’s pattern recognition to a geographic dimension without requiring students to understand the mechanism, following the same discovery-before-explanation approach used throughout the K-5 sequence.
Common Student Misconceptions
The most widespread misconception is that the sun moves around Earth, causing the daily change in shadow direction and length. This is the geocentric misconception that has appeared throughout the K-5 sky science sequence. In Grade 5, where the assessment boundary still does not require students to explain the cause of seasons, teachers should use language that attributes observable patterns to Earth’s motion rather than the sun’s: “As Earth rotates, the sun appears to move across the sky” rather than “the sun moves across the sky.” Students who have used this careful language across several years are better prepared for the Grade 5 expectation that they describe patterns caused by Earth’s rotation and orbital motion, and for the full mechanistic treatment of Earth’s motions in middle school.
A second misconception is that all shadows have the same length and direction at any given time of day, regardless of season. Students who have only observed shadows in one season may generalize their experience as the universal rule. The year-long shadow data collection activity directly challenges this by producing concrete evidence that the same time of day produces very different shadow lengths in December and in June. The seasonal variation in noon shadow length is one of the most striking and easily measurable sky patterns available to elementary students, and it is directly proportional to the same seasonal cycle of sun height that causes the variation in day length.
A third misconception is that constellations move or change their shapes across the year. Students sometimes interpret the fact that different constellations are visible in different seasons as meaning the constellations themselves are moving. In fact, the pattern of stars making up each constellation is essentially fixed on timescales of human observation: it would take tens of thousands of years for the individual stars in a constellation to move enough for a human observer to notice a change in the constellation’s shape. What changes is which part of the sky is visible in the night sky from Earth, which is determined by Earth’s orbital position. The constellations are always there; it is our line of sight that rotates through them as Earth orbits the sun.
A fourth misconception is that the sun is directly overhead at noon everywhere in the world. In the continental United States, the sun is never truly directly overhead because all of the contiguous 48 states are north of the Tropic of Cancer (23.5 degrees north latitude). At noon in the US, the sun is always in the southern sky, never directly above. The sun is directly overhead at noon only at latitudes between the Tropics of Cancer and Capricorn, and only on specific dates related to the solstices. This misconception matters because it can lead students to incorrectly model the relationship between sun height and shadow direction, predicting a north-south shadow alignment at noon rather than the correct northward shadow pointing in the Northern Hemisphere midday.
A fifth misconception is that stars are only visible at specific times because they turn on and off. Children who have absorbed cartoon or storybook imagery of stars “turning on” at night and “turning off” during the day may hold this misconception even after the Grade 1 investigation showing that stars are always present but invisible during daylight because of the sun’s overwhelming brightness. Returning to this concept in Grade 5, with the more sophisticated vocabulary and reasoning tools available to fifth graders, allows teachers to develop a more complete and durable correct model: stars are always producing light, they are always at the same distances from Earth, but our ability to observe them depends on our position relative to the sun at any given moment.
A sixth misconception is that seasons are caused by Earth’s distance from the sun rather than by its axial tilt. This misconception was flagged at Grade 1 and reappears frequently as students develop more sophisticated astronomical thinking. The assessment boundary for 5-ESS1-2 explicitly excludes assessment of the causes of seasons, meaning teachers are not required to teach axial tilt in Grade 5. However, if students propose the distance explanation, teachers should not affirm it. The appropriate response is to plant doubt without providing the full explanation: “That would make sense if it were true, but scientists have found that Earth is actually slightly closer to the sun in January than in July, when the Northern Hemisphere has summer. How can you explain that?” This question creates productive cognitive dissonance that motivates deeper investigation in middle school.
Assessment Questions
Here is a table of shadow lengths for a vertical meter stick measured at six different times during one school day. Create a bar graph of this data. What pattern does the graph reveal? What does the shortest shadow tell you about where the sun was at that time?
Look at the bar graph of monthly day lengths for our city. In which month is the day longest? In which is it shortest? How much longer is the longest day than the shortest day? Describe the overall pattern you see in the graph across the year.
We measured noon shadows on the first school day of every month for a year. Our data shows that December shadows were much longer than June shadows, even though we measured at the same time of day. What pattern does this reveal? What does it tell us about how the sun’s position in the sky changes across the year?
Orion is a constellation clearly visible in the night sky in January but cannot be seen in July. What pattern does this represent? Why does this pattern repeat every year? What does it tell us about Earth’s position and motion?
A student says: “The shadow data shows a pattern where shadows are shortest at noon and longest in morning and afternoon. I predict this same pattern will occur every day next year.” Is this a reasonable prediction? What evidence from the data supports making this prediction? What might cause the prediction to be slightly off for some days?
Compare a bar graph of day lengths for a city at 25 degrees north latitude with one for a city at 55 degrees north latitude. Which city shows a greater difference between its longest and shortest day? What pattern does this comparison reveal about how latitude affects seasonal variation in day length?
Draw two diagrams: one showing Earth early in the morning, and one showing Earth at noon of the same day. On each diagram, show where the sun appears to be in the sky from the perspective of an observer in the Northern Hemisphere, and draw the shadow the observer would cast. Explain how the two diagrams show the daily shadow pattern.