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Earth and Space 6-8 / Week 02 / Sky Night
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Week 02 · Moon Phases

Sky Night

Sky Night: Start the Moon log
// The lit half seen from changing angles
⏱ about 20 min

Sky Night: Start the Moon Log

Saturday night, the crew steps into the yard. A flashlight points at the path, and the Sky Log is tucked under Raven's arm.

"There," Rocket says, pointing up. The Moon hangs above the roofline, more than half lit.

"What do you notice about the lit edge?" Raven asks. "It bulges," Rocket says. "Not a half, not full. Gibbous."

"Waxing or waning?" Raven asks. Rocket thinks. "It was a half Moon on Monday. It is growing. Waxing gibbous."

Nova hovers low with her light off so their eyes stay used to the dark. "Sketch it," she says. "Tonight and every clear night."

Raven draws a circle and shades the dark sliver. "Moon log, night one."

  1. The Moon makes no light of its own. It glows with reflected sunlight, and the Sun always lights half of it.
  2. The Moon orbits Earth about once a month, so we see the lit half from a changing angle. That is the cause of the phases.
  3. The eight phases, in order: new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, third quarter, waning crescent.
  4. Each phase rises later than the one before, about 50 minutes later each day. Full Moon rises around sunset.
  5. The Moon spins once per orbit, so we always see the same face. The far side is not dark.
◇ FAMILY MOON LOG, NIGHT ONE
Go out together after dark to the Sky Deck spot. Find the Moon. If it is not up yet, check the Thursday table for when it rises.
Each person sketches the Moon's shape in a circle. Shade the dark part. Compare and agree on the phase name.
Write the date, the phase name and roughly where the Moon was: low or high, and which direction.
Agree on a plan: a quick sketch each clear night at about the same time, all course long.
Cloudy night backup: indoors, redo the head-and-lamp model and sketch the phase the Moon should be tonight.
For a grown-up
Night observation happens only with you, from the yard, a porch or a window, in a known spot, with warm clothes.
A flashlight lights the path only. It is never shone into anyone's eyes. Never cross a road or climb for a better view.
The recap facts come from NASA at science.nasa.gov and spaceplace.nasa.gov, and from OpenStax Astronomy at openstax.org.
Safety first
Go outside at night only with a grown-up, to a spot you know well.
Keep the flashlight pointed at the ground. Never shine it at anyone's eyes.
Stay in the yard, on the porch or at the window. Never climb anything for a better view.
THINK IT THROUGH
  • Read the question.
  • Tap your answer.
The Moon is more than half lit and was a half Moon five nights ago. Which phase is it?
You cannot find the Moon at bedtime. What is one reason from this week?
Sky Night checkTrue or false?
The Moon log is a sketch of the Moon's shape each clear night.?
The far side of the Moon never gets sunlight.?
The Sun always lights half of the Moon.?
WHY THIS EXERCISEA log kept over weeks turns one night's shape into a pattern you can predict.
Draw tonight's Moon in a circle, shading the dark part. Add the date and the phase name. This is Moon log entry one.
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