| Feature | Earth | Venus | Mars |
|---|---|---|---|
| Composition | 78% Nitrogen (N₂), 21% Oxygen (O₂), 1% other gases (CO₂, Argon, Water Vapor) | 96.5% Carbon Dioxide (CO₂), 3.5% Nitrogen (N₂), clouds of Sulfuric Acid | 95% Carbon Dioxide (CO₂), 2.7% Nitrogen (N₂), 1.6% Argon (Ar) |
| Atmospheric Density | Moderate (supports life) | Very Thick (92 times Earth’s pressure) | Very Thin (0.6% of Earth’s pressure) |
| Surface Pressure | 1 bar (100 kPa) | 92 bars (9,200 kPa) | 0.006 bar (0.6 kPa) |
| Average Temperature | 15°C (59°F) | 465°C (869°F) | -63°C (-81°F) |
