Unit 1: Earth and Sun

Disciplinary Core Ideas, Science & Engineering Practices, Crosscutting Concepts, Supporting Standards:

• 5-ESS1-1

• 5-ESS1-2

• 5-ESS2-1

• 5-ESS2-2

• 5-ESS3-1

• 5-PS2-1

• 3-5-ETS1-2

• 3-5-ETS1-3

Concepts & Skills:

1. The Sun: Students trace their shadows in the morning and afternoon. They use this information to monitor the position of the Sun as it moves across the sky. After using a compass to orient a Sun tracker, students make hourly records of the position of the shadow cast by a golf tee. Back in the classroom, students use flashlights to reproduce the shadow movements. Students imagine an observer on Earth (their head) and position themselves around a lamp to observe day and night. They discover that rotation of Earth produces day and night.

Students will know:

• Shadows are the dark areas that result when light is blocked.

• Shadows change during the day because the position of the Sun changes in the sky.

• The length and direction of a shadow depends on the Sun’s position in the sky.

• Day is the half of Earth’s surface being illuminated by sunlight; night is the half of Earth’s surface in its own shadow.

• The cyclical change between day and night is the result of Earth’s rotating around the stationary Sun.

2. Planetary Systems: The class starts a Moon calendar, on which they record the Moon’s appearance every day for a month and analyze their observations to discover the sequence of changes. Students grapple with the size and distance relationships among the Moon, Earth, and the Sun, and build a model of the Earth/Moon/Sun system.

Based on previous knowledge, information on solar system cards, and information provided by the teacher, students organize a model of the solar system. Gravity is introduced as the force that pulls on planets, changing their direction of travel to produce circular orbits. Students are introduced to constellations as patterns of stars. They simulate Earth’s rotation to observe the appearance of stars rising in the east and setting in the west. Students observe a demonstration of why different stars are visible in different seasons.

Students will know:

• The solar system includes the Sun and the objects that orbit it, including Earth, the Moon, seven other planets, their satellites, and smaller objects.

• The Moon is much smaller than Earth and orbits at a distance equal to about 30 Earth diameters.

• The Sun is 12,000 Earth diameters away from Earth and is more than 100 times larger than Earth.

• The pulling force of gravity keeps the planets and other objects in orbit by continuously changing their direction of travel.

• A great deal of light travels through space to Earth from the Sun and from distant stars.

• Stars are at different distances from Earth.

• Stars are different sizes and have different brightness.

3. Earth's Atmosphere: Students explore air by working with syringes and tubes to discover that air takes up space and is compressible. They are introduced to the atmosphere as a mixture of gases with properties that change with altitude above Earth’s surface. They review local weather reports and determine the variables that combine to produce the weather. They use a weather station to monitor the weather and look for patterns.

Students will know:

• Air is a mixture of gases held by gravity near Earth’s surface.

• Air has mass, takes up space, and is compressible.

• Most of Earth’s air resides in the troposphere, the layer of the atmosphere closest to Earth’s surface.

• Weather happens in the troposphere.

• Weather is the condition of Earth’s atmosphere at a given time in a given place.

• Meteorology is the science of weather, and meteorologists are the scientists who study Earth’s weather.

• Weather is described in terms of several variables.

Heating Earth: Students investigate energy transfer on Earth. They investigate uneven heating by recording and graphing temperature changes when two earth materials absorb solar energy. They observe examples of energy transfer by radiation and conduction and discuss mechanisms of energy transfer to and from the air. Students observe convection currents in water as a model of what happens in air. They test different designs for solar water heaters. Students consider how the atmosphere, hydrosphere, and geosphere interact.

Students will know:

• The Sun is the major source of energy that heats Earth.

• The different energy-transferring properties of earth materials (soil and water) can lead to uneven heating of Earth’s surface.

• The atmosphere is heated by conduction between Earth’s surfaces and air particles as a result of contact, and by absorption of energy radiated directly from the Sun and re-radiated from Earth’s surfaces.

• Convection is the circulation of fluid (liquid or gas) that results in energy transfer. Convection currents are driven by uneven heating of Earth’s surface.

• A solar water heater is a system that uses solar energy to heat water.

5. Water Planet: Students consider why Earth is called the water planet. They investigate systems to observe condensation on cold surfaces and determine the components of the water cycle. Students explore the conditions that promote evaporation. They simulate the travels of a drop of water through the water cycle to explore the complexities of the process. Students are introduced to world climate regions and global climate change.

Students will know:

• Evaporation and condensation contribute to the movement of water through the water cycle, redistributing water over Earth’s surface.

• As temperature increases, the rate of evaporation increases.

• Most of Earth’s water (97%) is salt water in the ocean; Earth’s fresh water is found in the atmosphere, lakes and rivers, soil, ground ice, groundwater, and glaciers.

• The Sun’s energy drives weather.

• Climate is the average or typical weather that can be expected to occur in a region of Earth’s surface.