Why don't satellites fall to Earth?
Show answer & explanation
Answer: Orbital velocity balances gravity
Engines keep them floating — Wrong. Most satellites don't fire engines continuously. They orbit because their sideways velocity balances gravitational pull—continuous free fall around Earth.
Orbital velocity balances gravity ✓ — Correct! Satellites are in free fall, constantly being pulled by gravity. But they move sideways fast enough (~8 km/s for low orbit) that as they fall, Earth's surface curves away at the same rate. They're perpetually falling around Earth—an orbit! Velocity too slow = crash; too fast = escape. Perfect balance = stable orbit!
Atmosphere holds them up — Wrong. Satellites orbit above most atmosphere (~200+ km). Thin remaining air creates drag, gradually lowering orbits without periodic boosts.
More Astronomy & Space questions
- The Sun is cooler than the proton barrier suggests. Why does fusion still start?
- Earth's atmosphere slowly leaks to space. Which gas escapes fastest?
- Why is Earth's day getting slightly longer every century?
- Why was Earth's day stuck at 19.5 hours for 1.5 billion years?
- Why might several small units beat one giant Moon reactor?
- Why is fission likelier than fusion for first Moon bases?
