← Back to course
Earth and Space 6-8 / Week 01 / Sky Night
6/6
Week 01 · Day and Night

Sky Night

Sky Night: Where does the Sun set?
// We ride a spinning Earth
⏱ about 20 min

Sky Night: Where Does the Sun Set?

Saturday evening, the crew gathers at the Sky Deck a few minutes before sunset.

Rocket has the ball and the sticker. Raven has the Sky Log open to Monday's horizon drawing.

"Nobody looks at the Sun," Raven reminds everyone. "We watch the glow and the shadows."

The shadows stretch long across the yard. The glow sinks toward the fence post Rocket named on Friday.

"What do you notice?" Raven asks. "It is setting in the same place as yesterday," Rocket says. "Almost."

Nova hovers low, her light off. "Almost," she repeats. "Keep this mark. In a few weeks, compare."

Rocket turns the ball so the sticker leaves the light. "Sunset," he says. "Right on time."

  1. Earth turns on its axis, an imaginary line through the North and South Poles, about once every 24 hours.
  2. East is the direction Earth turns toward, so the Sun appears to rise in the east and set in the west.
  3. The Sun does not move around us. We ride the turning Earth, and the ground feels still because everything near us turns too.
  4. A lamp and a ball with a sticker reproduce sunrise, noon, sunset and midnight.
  5. NASA lists a different length of day for every world, from 9.9 hours on Jupiter to 4222.6 hours on Mercury.
◇ FAMILY SUNSET MARK
Gather at the Sky Deck spot a few minutes before sunset. Everyone stands in the same marked place.
Without looking at the Sun, watch where the glow meets the horizon. Agree on the nearest landmark.
Each person draws the horizon and marks the sunset spot. Compare the drawings. Do they agree?
Write the date and the landmark in the Sky Log. The family will check this spot again in later weeks.
Cloudy night backup: indoors, use the lamp and ball. Take turns calling out sunrise, noon, sunset and midnight.
For a grown-up
The Sun is never looked at directly, even low on the horizon, with or without sunglasses, a camera or a phone.
Evening observing happens only with you, from the yard, a porch or a window. Use a known spot and a flashlight for the path.
The recap facts come from NASA at science.nasa.gov and nssdc.gsfc.nasa.gov, and OpenStax Astronomy at openstax.org.
Safety first
Never look at the Sun. Read its position from the glow on the horizon and from the shadows.
Stay in your known spot. Never cross a road or climb anything for a better view.
The flashlight is for the path only, never shone into anyone's eyes.
THINK IT THROUGH
  • Read the question.
  • Tap your answer.
The glow sinks below the western horizon. In the ball model, what is the sticker doing?
A friend east of you sees sunrise. Have you seen it yet?
Sky Night checkTrue or false?
The Sun sets in the west because Earth turns toward the east.?
It is safe to look at the Sun when it is low on the horizon.?
The lamp in the model stands for the Sun.?
WHY THIS EXERCISEMarking the sunset spot safely is the first entry in a Sky Log you will keep all course.
Draw tonight's horizon with the sunset glow marked. Add the date. Leave room beside it for a later drawing.
← Friday