Distance from Sun 0.718 AU 1 AU 5.20 AU Mass 4.8676 × 1024 kg 5.9726 × 1024 kg 1,898.3 × 1024 kg Planet Composition rocky mantle, iron core rocky mantle, iron core hydrogen, helium Gases in Atmosphere 96% carbon dioxide, 3% nitrogen, 1% other 78% nitrogen, 21% oxygen, 1% other mostly hydrogen and helium Atmospheric Pressure on Planet’s Surface 92 bars 1 bar > 1,000 bars Average Temperature 464°C 15°C -108°C Part A Which of these planets is Earth? Explain your answer.