This is the new updated edition of the first book in the bestselling Uncovering Student Ideas in Science series. Like the first edition of volume 1, this book helps pinpoint what your students know (or think they know) so you can monitor their learning and adjust your teaching accordingly. Loaded with classroom-friendly features you can use immediately, the book includes 25 “probes”—brief, easily administered formative assessments designed to understand your students’ thinking about 60 core science concepts.

Access this probe as a Google form: English | Español

Download this probe as an editable PDF: English | Español

The purpose of this assessment probe is to elicit students’ ideas about when objects can be seen in the sky. The probe is designed to reveal whether students consider light and distance in determining what they can see in the sky at different times.

Familiar phenomenon

Light, daytime sky, nighttime sky, stars, planets, Moon

The best response is: B for clouds, D for the Sun, B for the Moon (except during a new Moon or full Moon that is not at sunrise or sunset), N for stars (not including the Sun), B for the planet Venus, and N for the planet Saturn. Much to some people’s surprise (including adults), the Moon can be visible in the daytime blue sky when it is at a place in its orbit that puts it above Earth’s horizon during the daytime, although it is harder to see in the daytime because there is less contrast between the Moon and the day-lit sky. The Moon’s visibility during a bright day is due to its relative proximity to Earth and its reflection of sunlight. During the new Moon phase, the Moon is not observed during the day or night. The full Moon is visible only at night or just at sunrise or sunset. That is because the full Moon is always opposite the Sun in the sky, so it is just rising when the Sun is setting or just setting when the Sun is rising. Also, clouds can obscure the view of the Moon at night.

Stars, other than the Sun, can be seen only at night because they are so far away. The only star visible to us in the daytime sky is the Sun, and it is not visible at night because of its location facing the opposite side of Earth, where it is daytime. Venus has been called “the morning star” because of its visibility in the morning, but it is not a star. It is a nearby planet that reflects light from the Sun. The other planets, including Saturn, are seen at night. However, on a very rare occasion, Jupiter and Mars have been seen in the daytime by some astronomers using only the naked eye. Clouds can be seen in the daytime and sometimes at night, especially in the light from the full Moon.

Elementary Students

In the elementary years, students make regular observations of the sky, taking inventory of the familiar objects and their locations as seen during the day and night, including the Sun, Moon, and stars. They are encouraged to draw what they see. The emphasis at this level should be on observing and describing, including patterns of when and where the objects appear. In later elementary grades, students expand their observations and descriptions to include stars and planets. They also develop ideas about light reflection and light sources to explain how we see objects in the sky and why we cannot see stars in the daytime.

Middle School Students

Students at this level begin to add details to their model of objects in the solar system, extending out to the Milky Way galaxy and beyond.

High School Students

High school is when a more complete picture of the vast universe develops.

This probe can be used with students in grades 3–8. Be aware that students who live in cities may have never seen stars or planets in the nighttime sky. The probe can be extended for middle and high school students by adding other objects such as satellites, moons of other planets, comets, asteroids, the Milky Way galaxy, a nebula, meteors, and the International Space Station.

• A study of 20 first-grade students in a small Midwestern school revealed that 40% believed the Moon could be seen only at night. By third grade, 80% of the 20 students surveyed knew the Moon was visible during the daytime (Plummer and Krajcik 2010).
• Children’s early ideas about the Moon include the belief that the Moon is visible only at night or is in some way connected with the occurrence of night (Vosniadou and Brewer 1994).
• Researchers have identified several ideas that may help explain how students think about when sky objects can or cannot be seen: The Sun goes behind hills, clouds cover the Sun, the Moon covers the Sun, the Sun goes behind Earth once a day, Earth goes around the Sun once a day, and Earth spins on its axis once a day. It appears that at ages 15–16, many still hold covering and orbital theories of day and night (Driver et al. 1994).

Keeley, P. 2014. The daytime Moon. In What are they thinking? Promoting elementary learning through formative assessment, P. Keeley, 99–104. Arlington, VA: NSTA Press.

Keeley, P., and C. Sneider. 2012. Uncovering student ideas in astronomy: 45 new formative assessment probes. Arlington, VA: NSTA Press.

Morgan, E. 2014. Next time you see the Moon. Arlington, VA: NSTA Press.

Plummer, J. D. 2017. Core idea ESS1: Earth’s place in the Universe. In Disciplinary core ideas: Reshaping teaching and learning, ed. R. G. Duncan, J. Krajcik, and A. E. Rivet, 185–203. Arlington, VA: NSTA Press.

Wiebke, H., M. Rogers, and V. Nargund-Joshi. 2011. Sizing up the solar system. Science and Children 49 (1): 36–41.

• The probe “Seeing the Moon” in Uncovering Student Ideas in Astronomy can be used to elicit students’ ideas about when the Moon can be seen throughout the day and night (Keeley and Sneider 2012).
• Some ideas about light and sight need to be developed before children can understand astronomical phenomena. Develop the idea that a large light source seen at a great distance looks like a small light source that is much closer. This phenomenon should be observed directly outside at night or with photographs (AAAS 2009).
• It is not uncommon for children in the primary grades to be taught the idea, especially through picture books, that “the Sun is for the day, and the Moon is for the night,” even though that is not scientifically true. While the Sun does indeed define daytime as the hours between sunrise and sunset, the Moon can be seen during the daytime or nighttime. That is why it is important to take students outside when the Moon can be seen and have them observe it.
• Some books and nursery rhymes even depict the Moon as a character ready to go to sleep wearing a nightcap. Show children a picture book with one of those images and ask them if the Moon would ever come out during the day. Follow up by going outside to see the Moon when it is visible in the daytime sky (Allen 2010).
• Before students can discern planets in the night sky, it is necessary to help them distinguish between planets and stars in terms of both how they are seen in the sky and the difference between emitting light and reflecting it.
• Use concrete objects for models, such as a ball and light. Have students observe and record how the ball looks from various locations around the light to learn how reflected light allows us to see the Moon and other planets.
• Take photographs of the sky during the day and at night or use available photographs on the internet to look at differences in the sky depending on time and season.
• Introduce students to the various types of technologies, including space telescopes, that enable us to see farther into our universe than we could with our naked eyes or land-based telescopes.
• Today’s students are not as personally connected to the sky as were people in the past. The sheer wonder of the sky has “inspired the expressive powers of poets, musicians, and artists” (AAAS 1993, p. 61). Help students to realize that knowing the sky and what it holds is a tribute to human curiosity and our zest for understanding our place in the cosmos.