Universe

1234567
Across
  1. 2. Made of rock, dust and ice
  2. 4. Everything combined into one
  3. 6. A group of mass with gravity and atmosphere
  4. 7. The only known planet with life
Down
  1. 1. orbits around a planet
  2. 3. One of the most important forces in space
  3. 5. Main source of light and heat