Venus is only a little smaller than Earth, is made up of
rock, and has an atmosphere, but it is otherwise quite unlike our planet. Its
surface is covered with volcanoes, the atmosphere is crushing, and the
temperature is hotter than an oven. Venus completes its orbit in 225 Earth
days, but turns slowly, taking 243 Earth days to rotate once. This means that a
day on Venus is longer than its year.
Table 10. ESSENTIAL DATA
| Diameter at equator | 12,104 km (7,521 miles) |
| Average distance from Sun | 108.2 million km (67.2 million miles) |
| Orbital period | 224.7 days |
| Rotation period | 243 days |
| Mass (Earth=1) | 0.82 |
| Gravity (Earth=1) | 0.9 |
| Average surface temperature | 464°C (867°F) |
| Number of moons | 0 |
The atmosphere of Venus is much thicker than that of Earth and is
made up mostly of carbon dioxide. Its pressure is nearly 100 times
Earth’s atmospheric pressure. The dense clouds in the atmosphere are
made up of sulphuric acid droplets. The atmosphere traps heat like a
greenhouse, sending the temperature soaring to more than 475°C
(900°F).