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For teachers and students

Three lessons with the real sky

Everything here runs on live, public data: real orbits from CelesTrak, real recordings from the SatNOGS volunteer network, real space weather from NOAA. Nothing is staged, and every number can be checked at its source. No accounts, no cost, no special equipment beyond a screen and a clear evening. Suited to grades 7 to 12; simplify the questions for younger classes.

  1. Lesson 1 · 45 minutes

    Where is it right now?

    Students read real satellite positions and discover that what you can see depends on where you stand.

    Steps

    1. Open the tracking page on a projector. Explain the sky plot: the centre is straight overhead, the edge is the horizon, north is up.
    2. Point out the two kinds of dots. Gold ones (GEO) sit still; teal ones (Iridium, low orbit) move. Ask why.
    3. Switch the ground station from Brooklyn to Svalbard, then Singapore. Record how many satellites are in view at each.
    4. Pick one satellite in the list and read its azimuth, elevation and range. Have students point to where it is in the room.

    Discussion questions

    • Why do fewer GEO satellites show up from Svalbard (78 degrees north)?
    • A GEO satellite is about 36,000 km up. Why does it seem to stand still?
    • Round-trip delay is range times two, divided by the speed of light. Check one value on the page by hand.

    NGSS HS-ESS1-4: use mathematical or computational representations to predict the motion of orbiting objects.

  2. Lesson 2 · homework night + 20 minutes

    Go outside and see one

    Students predict a visible pass, observe it, and compare the prediction to what they saw.

    Steps

    1. In class, open the pass planner, choose your city (or Use my location) and pick a pass with a peak above 30 degrees.
    2. Students copy the time, the start direction, the end direction and the peak height onto the observing log below.
    3. That evening they step out a few minutes early, face the start direction, and look for a steady moving point of light.
    4. Next day, compare: was it on time? Did it fade before reaching the horizon? That fade is the satellite entering Earth's shadow.

    Discussion questions

    • Why can we only see satellites shortly after sunset or before sunrise?
    • Why did some passes fade out in the middle of the sky?
    • Your fist at arm's length is about 10 degrees. How many fists high was the peak?

    NGSS HS-ESS1-4 and science practice: planning and carrying out investigations.

  3. Lesson 3 · 45 minutes

    Hear a real satellite

    Students listen to a real recorded pass and connect the sound and the waterfall picture to radio waves and the Doppler effect.

    Steps

    1. Scroll to Listen to a real pass. Play one recording (headphones or speakers). Separate the hiss from the signal.
    2. Show its waterfall picture. Time runs down, frequency runs across. Trace the bright line with a finger.
    3. Ask why the line bends. Connect it to the sound of a passing siren: the satellite approaches, then moves away.
    4. Click the Record link to open the original on SatNOGS. Show that anyone can check where it came from.

    Discussion questions

    • Which way does the frequency shift as the satellite approaches you? As it leaves?
    • The recording came from a volunteer station on another continent. How could you set one up at school?
    • Why is a lower orbit easier to hear than a high one?

    NGSS HS-PS4-5 (how technology uses wave behaviour to carry information) and MS-PS4-2.

Observing log

Copy or print this for Lesson 2. One row per pass.

SatellitePredicted timeStart directionEnd directionPredicted peakWhat I saw

Safety: observe with an adult, from a safe open place, away from roads. Never look at or near the Sun.