Here's a mind-bending fact: the International Space Station is constantly FALLING towards Earth — but it keeps missing! It's moving so fast sideways (28,000 km/h) that by the time it falls, the curved Earth has dropped away beneath it. This is what an orbit really is: falling forever but never hitting the ground. Newton figured this out in the 1600s by imagining a cannon on a very high mountain...
This introduction covers Falling Around the Earth within Orbits for GCSE Physics. Revise Orbits in Space Physics for GCSE Physics with 14 exam-style questions and 10 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 1 of 8 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Orbits
What is a protostar?
Explain why a main sequence star remains stable (in equilibrium) for billions of years.
Quick recall flashcards
What is Low Earth Orbit (LEO)?
Orbit at 200-2000 km altitude with ~90 minute orbital period. Used for ISS, imaging, and Earth observation
What is a polar orbit used for?
Mapping - the satellite orbits at ~800 km altitude covering the whole Earth as the planet rotates beneath it