Across
- 4. The light-sensitive layer containing rods and cones at the back of the eye.
- 6. A lens shape that is thinner in the middle and spreads rays apart.
- 9. An instrument that collects light to make distant objects easier to observe.
- 11. A bowl-shaped hole formed when an object strikes the Moon’s surface.
- 12. The coloured part of the eye that controls the size of the pupil.
- 13. The force that attracts objects with mass towards one another.
- 15. A device that uses lenses to magnify very small objects.
- 18. An imaginary line through Earth from the North Pole to the South Pole.
- 19. The spinning of Earth on its axis, causing day and night.
- 20. A device that produces a narrow and precise beam of light.
Down
- 1. The opening through which light enters the eye.
- 2. Large, dark plains on the Moon formed by ancient lava flows.
- 3. A lens shape that is thicker in the middle and brings rays together.
- 5. An imaginary line drawn at a right angle to a surface.
- 7. The regular rise and fall of ocean levels caused mainly by the Moon’s gravity.
- 8. The bending of light as it changes speed between materials.
- 10. The clear front surface of the eye that protects it and begins refracting light.
- 14. Bright, mountainous, and heavily cratered regions of the Moon.
- 16. The path of one object around another object in space.
- 17. An uncrewed spacecraft sent to gather information about space.