Inner and Outer Planets Crossword Puzzle

QUESTIONS LIST:

• twice : uranus is _ as far from the sun as saturn, so it is much colder.
• volcanoes : some regions of mars have giant _ .
• probes : space _ have given scientists important information about mercury, venus, and mars.
• gas giants : because the four outer planets are so large, they are often called _ _ .
• ninety : uranus’s axis is tilted at an angle of about _ degrees from the vertical.
• sulfuric : the thick clouds on venus are made up mostly of _ acid droplets.
• mercury : all the inner planets have an atmosphere except _ .
• ring : a(n) _ is a thin disk of small particles of ice and rock.
• cassini : space probes such as _ have revealed many details of the outer planets.
• titan : a few scientists believe that saturn’s largest moon, _ , may support life.
• rocky : the inner planets are small and dense and have _ surfaces.
• blue : neptune’s _ color comes from methane in its atmosphere.
• greenhouse : the inner planets that experience a _ effect are venus and earth.
• venus : _ rotates so slowly that its day is longer than its year.
• carbon dioxide : mars’s atmosphere is composed mostly of _ _ .
• increase : temperatures _ tremendously from the outer to inner layers of the gas giants.
• moons : all the outer planets have many _ , which range in number from 13 to greater than 60.
• water : earth is unique in our solar system for having liquid _ on its surface.
• twenty : oxygen makes up about _ percent of earth’s atmosphere.
• hydrogen : all the gas giants’ atmospheres are made up primarily of helium and _ .