Which statement best describes outer planets?

Which statement best describes outer planets?

• A. They are rocky and dense
• B. They are small and close to the Sun
• C. They are gas/ice giants with many moons and rings
• D. They have the highest densities

Answer: (C)

Outer planets are far from the Sun and dominated by light materials, not rocky surfaces. The description that they are gas/ice giants with many moons and rings fits what we observe: Jupiter and Saturn are gas giants with thick hydrogen–helium atmospheres, while Uranus and Neptune are ice giants with icy interiors and methane giving them their blue color. All four have numerous moons and ring systems, with rings most famous around Saturn but present around others too. In contrast, inner planets are rocky and dense, smaller, and lie closer to the Sun, so they don’t match the outer planets’ characteristics. That combination of composition, size, and the presence of many moons and rings makes this statement the best description of outer planets.

Outer planets are far from the Sun and dominated by light materials, not rocky surfaces. The description that they are gas/ice giants with many moons and rings fits what we observe: Jupiter and Saturn are gas giants with thick hydrogen–helium atmospheres, while Uranus and Neptune are ice giants with icy interiors and methane giving them their blue color. All four have numerous moons and ring systems, with rings most famous around Saturn but present around others too. In contrast, inner planets are rocky and dense, smaller, and lie closer to the Sun, so they don’t match the outer planets’ characteristics. That combination of composition, size, and the presence of many moons and rings makes this statement the best description of outer planets.