Solar System

123456
Across
  1. 5. the branch of biology concerned with the study of life on earth and in space.
  2. 6. an attraction the earth exerts on an object or the object exerts on the earth
Down
  1. 1. The distance Earth orbits the Sun is just right for water to remain a liquid
  2. 2. the action of rotating around an axis or center.
  3. 3. the envelope of gases surrounding the earth or another planet.
  4. 4. an instance of revolving