1. Overview of Venus
- Position in Solar System: 2nd planet from the Sun
- Distance from Sun: ~108.2 million km (0.72 AU)
- Orbital Period: 225 Earth days (1 Venus year)
- Rotation Period: 243 Earth days (Retrograde rotation – spins opposite to most planets)
- Diameter: 12,104 km (95% of Earth’s size)
- Gravity: 8.87 m/s² (91% of Earth’s)
- Temperature:
- Surface: ~465°C (869°F) – Hottest planet in the solar system
- Moons: None
- Atmosphere: Thick and toxic (mainly carbon dioxide with clouds of sulfuric acid)
2. Key Characteristics
- Size: Slightly smaller than Earth (Earth’s “sister planet”).
- Surface: Volcanic plains, mountains, craters, and vast highland regions.
- Color: Yellowish due to thick clouds reflecting sunlight.
- Rotation:
- Slowest rotation of any planet.
- Retrograde spin: Sun rises in the west and sets in the east.
- No Magnetic Field: Minimal intrinsic magnetic field.
3. Orbital and Rotational Facts
- Orbital Speed: 35 km/s
- 1 Venus Day: Longer than its year (243 Earth days to rotate once).
- Axial Tilt: 177° (almost upside down).
- Eccentricity: Nearly circular orbit.
4. Atmosphere and Greenhouse Effect
- Composition:
- 96.5% Carbon Dioxide (CO₂)
- 3.5% Nitrogen
- Trace gases: Sulfur dioxide (SO₂), water vapor
- Pressure: 92 times Earth’s atmospheric pressure (equivalent to 900 m underwater).
- Greenhouse Effect:
- Thick atmosphere traps heat, creating extreme surface temperatures.
- Reflects 75% of sunlight, making Venus the brightest planet seen from Earth.
5. Surface and Geological Features
- Volcanoes:
- Maat Mons – Largest volcano (8 km high).
- Possible ongoing volcanic activity.
- Plains: Vast lava plains and domes.
- Craters: Few impact craters due to the thick atmosphere burning most meteors.
- Tesserae: Tectonic ridges unique to Venus.
6. Temperature and Climate
- Surface Temperature: 465°C (hotter than Mercury).
- No Significant Variation: Similar temperatures day or night, pole to equator.
- Wind Speed: 360 km/h in the upper atmosphere (super-rotation of clouds).
7. Exploration of Venus
- Mariner 2 (1962): First successful flyby (NASA).
- Venera Missions (USSR):
- Venera 7 (1970): First spacecraft to land on Venus.
- Venera 9 (1975): First images from the surface.
- Magellan (1990): Mapped 98% of Venus’ surface using radar.
- Future Missions:
- VERITAS (NASA): Launching 2031 to map surface.
- EnVision (ESA): Scheduled for the 2030s.
8. Interesting Facts
- Brightest Object in the Sky (after the Sun and Moon): Known as the “Evening Star” or “Morning Star.”
- Runaway Greenhouse Effect: Atmosphere traps so much heat that it surpasses Mercury’s temperature.
- Opposite Spin: Rotates clockwise unlike most planets (retrograde rotation).
- Closest to Earth: Venus is Earth’s nearest planetary neighbor.
9. Why is Venus Important?
- Study of Climate: Helps scientists understand the runaway greenhouse effect.
- Planetary Formation: Reveals insights about Earth-sized planets in other solar systems.
- Volcanism: Venus may still have active volcanoes, shaping its surface.
10. Key Measurements
| Property | Value |
|---|---|
| Diameter | 12,104 km |
| Distance from Sun | 108.2 million km (0.72 AU) |
| Orbital Period | 225 Earth days |
| Rotation Period | 243 Earth days |
| Gravity | 8.87 m/s² |
| Surface Temperature | 465°C |
| Atmospheric Pressure | 92 bar (900 m underwater) |
| Moons | 0 |
11. Venus in Mythology and Culture
- Named After: Venus, the Roman goddess of love and beauty (Greek: Aphrodite).
- Cultural Symbolism:
- Often associated with femininity and beauty.
- Astrological symbol: ♀️
12. Differences Between Venus and Earth
| Feature | Venus | Earth |
|---|---|---|
| Atmosphere | 96.5% CO₂, 3.5% N₂ | 78% N₂, 21% O₂ |
| Surface Temp. | 465°C | 15°C |
| Pressure | 92 times Earth’s | 1 bar |
| Rotation | Retrograde (243 days) | Prograde (24 hours) |
| Magnetic Field | Weak | Strong |
| Moons | 0 | 1 |
13. Can Venus Support Life?
- Surface: Hostile for life (extreme heat and pressure).
- Upper Atmosphere: Potential for microbial life in the cooler cloud layers (speculated by scientists).