Brain Stinger Crossword

12345678910111213
Across
  1. 4. Shape of most planetary orbits
  2. 7. The first artificial satellite
  3. 8. Earth's only natural satellite
  4. 9. The curved path of an object around a star or planet
  5. 11. The line dividing day and night on a planet
  6. 13. Time taken for one full orbit
Down
  1. 1. Speed needed to escape gravity
  2. 2. The force that keeps satellites in orbit
  3. 3. Orbits that match Earth's rotation
  4. 5. The planet with the most moons
  5. 6. Closest orbital point to Earth
  6. 10. The lowest stable orbit around Earth
  7. 12. Region where satellites orbit Earth