Fill in the gaps with the correct words

• comet,
• planet,
• solar system,
• satellite,
• moon,
• galaxy

1. Jupiter's largest
   [ ]
   is called Ganymede.
2. The first
   [ ]
   was launched into orbit around the Earth in 1957.
3. The outermost planet in the
   [ ]
   is Pluto.
4. The brightest
   [ ]
   in the night sky is Venus.
5. The name of a famous
   [ ]
   is Halley's.
6. The approximate diameter of the Milky Way
   [ ]
   is 100,000 light years.