Explicit physics instruction
A satellite in orbit is continuously falling under gravity while moving tangentially fast enough to miss Earth.
Remote sensing measures electromagnetic radiation reflected or emitted by a target; it does not require direct physical contact.
Orbit choice affects revisit time, coverage, resolution, and communication geometry.
Vocabulary: orbit; remote sensing; revisit time; resolution; electromagnetic signal.
Worked example
A satellite that revisits the same region frequently may trade broad coverage for temporal detail, depending on its orbit.
Guided question
Why is a satellite in orbit still accelerating even if its speed magnitude is nearly constant?
Independent work
- Sketch velocity and acceleration vectors for circular orbit.
- Compare two orbit choices qualitatively.
- Name two remote-sensing measurements that rely on EM radiation.
Misconception check
Orbiting does not mean gravity is absent; gravity supplies centripetal acceleration.
Formative check
What direction is orbital acceleration in a circular model?
Reveal response
Toward the center of Earth.
Mentor evidence conference
Ask Archaemenes to separate direct measurement from inference and audit model assumptions.
Teacher guidance
Foundation: Use vector diagrams.
Core: Connect orbit geometry with sensing tradeoffs.
Extended: Compare circular-orbit assumptions with real orbital limits.