1. Which planet is closest to Earth ?   Hint First letter clue   2. Which two planets rotate clockwise (east to west) on their axes ?   First letter clue   3. Which planet is known as "Earth's twin" or "Earth's sister" ?   First letter clue   4. Which of the following is not an 'Inner Planet' ?   First letter clue   5. Which planet is known as the "watery planet" or "blue planet" ?   First letter clue   6. Which planet was the destination of the Cassini-Huygens mission ?   First letter clue   7. Which is the 'King of the Planets' ?   First letter clue