1 Venus
Venus is the second planet from the Sun and the third brightest natural object in Earth’s sky after the Sun and Moon. Often referred to as Earth’s twin due to its similar size and composition, Venus differs drastically in surface conditions, featuring extreme temperatures, crushing atmospheric pressure, and a dense carbon dioxide-rich atmosphere. It is a terrestrial planet and one of the most studied objects in the Solar System.
1.1 General Properties
| Property | Value |
|---|---|
| Average Diameter | ~12,104 km |
| Distance from the Sun | ~108.2 million km (0.72 AU) |
| Orbital Period | ~225 Earth days |
| Rotation Period | ~243 Earth days (retrograde) |
| Moons | None |
| Surface Gravity | ~8.87 m/s² (about 90% of Earth’s) |
| Atmosphere | Very dense, CO₂-dominated |
| Surface Temperature | ~465 °C (hottest planet in the Solar System) |
1.2 Physical Characteristics
Venus has a rocky surface covered with volcanic plains, impact craters, and large highland regions. Its landscape features include:
- Maxwell Montes – the tallest mountain on Venus, ~11 km high
- Ishtar Terra and Aphrodite Terra – major highland plateaus
- Pancake domes – unique, flattened volcanic structures
- Tesserae – heavily deformed regions indicating ancient crustal activity
Venus has no liquid water on its surface and shows evidence of massive volcanic resurfacing events in its past.
1.3 Atmosphere and Climate
The atmosphere of Venus is incredibly thick and toxic, composed mostly of:
- CO₂ (~96.5%)
- Nitrogen (~3.5%)
- Traces of sulfur dioxide, water vapor, and other gases
Cloud layers, composed primarily of sulfuric acid droplets, permanently obscure the surface from visible observation. The atmosphere causes a runaway greenhouse effect, trapping heat and making Venus hotter than Mercury despite being farther from the Sun.
Surface pressure is about 92 times greater than Earth’s, equivalent to the pressure found 900 meters underwater.