Planet Earth and Beyond

Edit Answers
123456789101112131415161718192021
Across
  1. 1. The only planet that has abundant water and life.
  2. 3. Large planets of low density consisting predominantly of hydrogen and helium gas. There may be a molten rocky core.
  3. 5. The time taken by the Earth to make one revolution around the Sun.
  4. 6. Large, spherical objects that orbit the Sun. Have cleared their orbit of other objects of similar size.
  5. 9. The Sun and the objects that orbit it.
  6. 12. Large planets that contain more than just hydrogen and helium, with some "ices", such as water, methane, and ammonia.
  7. 13. Means "equal night". Usually happens on 21st March and 21st September.
  8. 14. The time it takes the moon to orbit the Earth once.
  9. 15. The time it takes the moon to change from "new moon" to "first quarter" or from "first quarter" to "full moon".
  10. 16. The object with 99.86% of all mass in the Solar system.
  11. 18. Caused by the Earth's tilted axis of rotation.
  12. 19. Our home galaxy.
  13. 20. The planet that rotates backward and has the highest mean atmospheric pressure and temperature.
Down
  1. 2. Means "Earth-like". This type of planet is primarily made up of rock and metal.
  2. 3. A collection of solar systems which are gravitationally bound.
  3. 4. The bluish planet(due to methane in the atmosphere)that takes 165 years to orbit the sun and 19 hours to rotate once. It has the strongest wind in the solar system up to 2100km/h.
  4. 7. The biggest planet in the solar system with 92 moons- one of the brightest objects in the sky- after the Moon and Venus. Composed of 90% Hydrogen and Helium
  5. 8. Everything that is. Contains about 200 billion galaxies
  6. 10. Has a large, beautiful ring structure with 83 moons. The second biggest planet in the solar system.
  7. 11. The fastest planet to orbit the Sun (88 days). It has a temperature of 465 ℃ on one side and -184 ℃ on the other side.
  8. 17. The time taken by the Earth to complete one rotation.
  9. 19. The neighbour of the Earth that has seasons. It has half of Earth's diameter and one-third gravity of Earth. Its day is close to an Earth's day - 24.5 hours.
  10. 21. The faint bluish planet that rotates on its side. Summer lasts 42 Earth years and after that comes 42 years of darkness.