Look for: The Earth’s axis points toward the North Star

2.A Use a graphical display (a virtual fisheye projection of the sun, moon, and stars in the sky and compass points across the horizon) to identify temporal and spatial relationships (patterns in location of sunrise/moonrise and sunset/moonset, the paths of motion of the sun and moon, and and how most stars move and which one doesn’t in the sky at night) in a large data set (across 6 months from a specific location on Earth’s surface).

Student models should incorporate data (temporal and spatial relationships) from the Observing the Sky video to determine that the patterns of movement of objects in the sky is due to Earth’s spin on its axis. One object, the North Star, does not appear to move in the sky because Earth’s axis is pointed toward it. Look for the following:

• The Earth’s axis points toward the North Star.
• A person standing on the surface of the Earth in the Northern Hemisphere.
• Other stars above the Northern Hemisphere of the Earth.
• The Earth spins on its axis counterclockwise.
• The Sun and Moon move across the sky from east to west.
• The North Star does not appear to move because Earth’s axis is pointed toward it.

Use your review of student initial models to make sure they use data as evidence to support that Earth’s axis is pointed toward the North Star. This understanding is the key one for them to have at this point in the unit, before moving on to the next year. If students are missing this understanding, ask them, What would explain why the North Star doesn’t appear to move in the sky, but all other stars, including our Sun, do appear to move? Have students revisit the patterns and non-patterns they identified earlier in the lesson to provide evidence for their thinking.