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Ice in the Shadows Exploring Ice I MAIN MENU IN THE SOLAR SYSTEM C E SCIENCE & LITERATURE 2 L CONCEPT OVERVIEW 3 I N PRE K–GRADE 2 CONCEPTS 3 GRADE 3–GRADE 5 CONCEPTS 3 T LESSON SUMMARY & OBJECTIVES 4 H E STANDARDS 5 E ESSENTIAL QUESTION 8 S ACTIVITY QUESTION 8 H BACKGROUND 9 A ACT OUT THE SCIENCE 16 D MATERIALS 20 O S DEMONSTRATION 20 W PRE K–GRADE 2 21 S GRADE 3–GRADE 5 21 MAIN ACTIVITY 22 PREPARATION 22 S TEACHING TIPS 22 WARM-UP AND PRE-ASSESSMENT 23 PROCEDURES 24 DISCUSSION AND REFLECTION 27 CURRICULUM CONNECTIONS 28 O ASSESSMENT CRITERIA 29 RESOURCES 30 PHOTO GALLERY N D I R E This lesson develops pre- C cursor understanding about how we detect the T presence of ice on the O permanently shadowed R craters of Mercury and Y the Moon. Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS SCIENCE & LITERATURE “…I had journeyed down To where the shades were covered wholly by ice…. Through a round aperture I saw appear Some of the beautiful things that Heaven bears Where we once more came forth, and once more saw the stars.” —Dante’s Inferno Robert Pinsky translation The discovery of ice in the forbidding shadows of impact craters on two airless inner planets is most surprising. That we have the knowledge and technology to detect—that through the round apertures of spectrometers and radar telescopes, we can even get a glimpse of places where sunbeams never strike is as amazing and as elegant as the evocative closing lines of Dante’s great 14th century poem. PRINT 2 Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS CONCEPT OVERVIEW This lesson develops precursor understanding GRADE 3–5 CONCEPTS about how we detect the presence of ice on I The more direct the angle of sunlight, the permanently shadowed craters of Mercury the stronger its effect. and the Moon. I The effect of sunlight shining on a spherical Concepts: surface, like a planet or a moon with low obliquity is strongest in the equatorial 1. Sunlight striking spherical surfaces. 2. Detecting gamma rays & neutrons. region and weakest at the poles. (Obliquity is the tilt of a body with This lesson provides concrete experiences of: respect to its plane of orbit around 1. The angle of sunlight striking a planetary the Sun). surface. I Cold traps exist where there is no sunlight 2. Temperature and pressure conditions in (extremely low temperature) and no a “cold trap.” atmosphere (no air pressure), in the 3. How science instruments detect ice on permanently shadowed craters near Mercury and the Moon. the poles of Mercury and the Moon. I We detect the likely presence of ice PRE K–2 CONCEPTS in the cold traps by using different I Direct sunlight is warmer than kinds of science instruments called indirect sunlight. spectrometers that measure gamma rays and energetic neutrons. I It is extremely cold where there is no sunlight and no atmosphere. I There are places on Mercury and the Moon where there is no sunlight and no atmosphere PRINT (no heat source, no air pressure)—in the permanently shadowed craters near the poles. I We can detect the presence of ice in shadowed craters near the poles of Mercury and the Moon. 3 Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS LESSON SUMMARY & OBJECTIVES When cosmic rays strike the surface of Objective 1: Notice that sunlight strikes an airless world they create a moving a planet at different angles. cascade of photons and particles, including A planetary object is spherical. As sunlight gamma rays and neutrons. By measuring radiates from the Sun it strikes the surface this cascade with a Gamma Ray and Neu- of a planetary object most directly at its tron Spectrometer, scientists learn a great equatorial region and least directly at its poles. deal about the composition of the world, This means it is possible that on some Solar including detecting the presence of ice System worlds there are places near the polar in otherwise hidden places: such as the region that NEVER get sunlight. permanently shadowed craters of Mercury Objective 2: Notice that ice can exist and the Moon. where there is no sunlight and no air. Infalling ice from the outer Solar System can strike places like Mercury and the Moon and stay intact for billions of years in a cold trap— where with no sunlight, the temperature is so low that there is virtually no molecular motion, and where with only a near-vacuum exosphere, there is no air pressure. Under these conditions, ice is stable. Objective 3: Notice that we detect evi- dence of ice on Mercury and the Moon. Water ice can be cold-trapped in permanently shadowed craters near the polar regions of PRINT Mercury and the Moon. In both cases, remote sensors have detected radar-bright patches that are likely indicators of ice. Looking for ice on the Moon has led to even more exciting ways to look for ice on Mercury. 4 Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS STANDARDS BENCHMARKS: NSES: 4E The Physical Setting: Energy Transfor- Content Standard D Earth and Space mations Science: Objects in the sky GRADES K–2, PAGE 83 GRADES K–4, PAGE 134 I The sun warms the land, air, and water. I The sun provides the light and the heat 4D The Physical Setting: the Earth necessary to maintain the temperature of the Earth. GRADES 9–12, PAGE 70 I Life is adapted to conditions on the Earth, Content Standard D Earth and Space including the force of gravity that enables Science: Earth in the Solar System the planet to retain an adequate atmos- GRADES 5– 8, PAGE 161 phere, and an intensity of radiation from I The sun is the major source of energy for the sun that allows water to cycle phenomena on the Earth’s surface, such as between liquid and vapor. growth of plants, winds, ocean currents, and the water cycle. Seasons result from I Weather (in the short run) and climate (in the long run) involve the transfer of variations in the amount of the sun’s energy in an out of the atmosphere. Solar energy hitting the surface due to the tilt radiation heats the landmasses, oceans, of the Earth’s rotation on its axis and the and air. Transfer of heat energy at the length of the day. boundaries between the atmosphere, the landmasses, and the oceans results in lay- NCTM MATH STANDARDS ers of different temperatures and densities Geometry Standard for Grades Pre-K–2 in both the ocean and atmosphere. The Expectations: prekindergarten through action of gravitational force on regions of grade 2 all students should: different densities causes them to rise or I Analyze characteristics and properties of PRINT fall—and such circulation, influenced by two- and three-dimensional geometric the rotation of the Earth, produces winds shapes and develop mathematical argu- and ocean circulation. ments about geometric relationships. – recognize, name, build, draw, compare, and sort two- and three-dimensional shapes – describe attributes and parts of two- and three-dimensional shapes – investigate and predict the results of putting together and taking apart two- and three-dimensional shapes 5 Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS I Specify locations and describe spatial rela- Geometry Standard for Grades 3–5 tionships using coordinate geometry and Expectations: In grades 3–5 all students other representational systems should: – describe, name, and interpret relative I Analyze characteristics and properties of positions in space and apply ideas two- and three-dimensional geometric about relative position shapes and develop mathematical argu- – describe, name, and interpret direction ments about geometric relationships and distance in navigating space and – identify, compare, and analyze attrib- apply ideas about direction and distance; utes of two- and three-dimensional – find and name locations with simple shapes and develop vocabulary to relationships such as “near to” and in describe the attributes coordinate systems such as maps – classify two- and three-dimensional shapes according to their properties I Apply transformations and use symmetry to analyze mathematical situations and develop definitions of classes of shapes such as triangles and pyramids – recognize and apply slides, flips, and turns – investigate, describe, and reason about the results of subdividing, combining, – recognize and create shapes that have and transforming shapes symmetry – explore congruence and similarity I Use visualization, spatial reasoning, and geometric modeling to solve problems – make and test conjectures about geometric properties and relationships – create mental images of geometric and develop logical arguments to justify shapes using spatial memory and PRINT conclusions spatial visualization – recognize and represent shapes from different perspectives – relate ideas in geometry to ideas in number and measurement – recognize geometric shapes and struc- tures in the environment and specify their location 6 Exploring Ice LESSON 12 DIRECTORY MAIN MENU IN THE SOLAR SYSTEM ICE IN THE SHADOWS I Specify locations and describe spatial I Use visualization, spatial reasoning, and relationships using coordinate geometry geometric modeling to solve problems and other representational systems – build and draw geometric objects – describe location and movement – create and describe mental images of using common language and objects, patterns, and paths geometric vocabulary – identify and build a three-dimensional – make and use coordinate systems to object from two-dimensional repre- specify locations and to describe paths sentations of that
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