Venus

Introduction

Venus, often called Earth’s twin, is the second planet from the Sun and one of the most fascinating worlds in our solar system. Despite its similar size and composition to Earth, Venus is a hellish landscape of scorching temperatures, crushing atmospheric pressure, and toxic clouds. This article explores Venus in detail—covering its physical characteristics, atmosphere, surface conditions, exploration history, and mysteries that still puzzle scientists.

Basic Facts About Venus

Distance from the Sun: 108 million km (67 million miles)

12,104 km (7,521 miles) in diameter, which is about the same as Earth's. Mass: 81.5% of Earth’s mass

Gravity: 90% of Earth’s gravity

Orbital Period (Year): 225 Earth days

Rotation Period (Day): 243 Earth days (longer than its year!)

Surface Temperature: ~465°C (869°F), the hottest planet in the solar system

Atmospheric Pressure: 92 times Earth’s (equivalent to being 900 meters underwater)

Why is Venus Called Earth’s Twin?

Venus and Earth share several key similarities:

Similar size and mass

Rocky composition (terrestrial planet)

Even though Venus' atmosphere is deadly, Volcanic activity and possible tectonic movements

However, Venus took a drastically different evolutionary path, becoming an uninhabitable inferno while Earth flourished with life.

The Deadly Atmosphere of Venus

Venus’s atmosphere is 96.5% carbon dioxide (CO₂), with traces of nitrogen and sulfuric acid clouds. This dense atmosphere creates

1. Extreme Greenhouse Effect

The thick CO₂ traps heat, making Venus hotter than Mercury despite being farther from the Sun.

Surface temperatures remain consistently above 450°C (842°F)—hot enough to melt lead.

2. Crushing Pressure

The atmospheric pressure is 92 times Earth’s, equivalent to the pressure nearly a kilometer underwater.

Any spacecraft landing on Venus must withstand immense forces—most have been crushed within hours.

3. Acidic Clouds

The upper atmosphere contains sulfuric acid clouds, which reflect sunlight, making Venus the brightest planet in the night sky (after the Moon).

These clouds also contribute to acid rain, though it evaporates before hitting the ground due to the extreme heat.

The Surface of Venus: A Volcanic Wasteland

Due to its thick clouds, Venus’s surface remained mysterious until radar mapping by spacecraft revealed its features:

1. Volcanic Plains

80% of Venus is covered in smooth volcanic plains, suggesting massive lava flows in the past.

Scientists believe Venus may still have active volcanoes, but no eruptions have been directly observed.

2. Ranges of mountains and highlands Maxwell Montes is the highest peak, rising 11 km (7 miles) above the average surface level.

Ishtar Terra & Aphrodite Terra are continent-sized highland regions.

3. Impact Craters (But Fewer Than Expected)

Venus has far fewer craters than Mercury or Mars, suggesting its surface is relatively young (300-600 million years old).

Possible causes include global resurfacing by volcanic activity.

Tectonic activity is erasing old craters.

The Strange Rotation of Venus

There are two bizarre rotational features on Venus: Retrograde Rotation: It spins backward (clockwise) compared to most planets.

A possible explanation: A giant impact early in its history flipped its rotation.

Slowest Rotation in the Solar System:

A day on Venus (243 Earth days) is longer than its year (225 Earth days).

The sun rises in the west and sets in the east due to its backward spin.

Missions to Venus: Past, Present, and Future

Despite its harsh conditions, Venus has been a key target for space exploration.

Past Missions

1960s-80s Soviet Venera Program: Venera 7 (1970)—First successful landing; survived 23 minutes before succumbing to heat and pressure.

Venera 9 (1975)—Sent back the first images of Venus’s surface.

NASA’s Magellan (1989-1994):

Mapped 98% of Venus’s surface using radar.

Current Missions

Japan’s Akatsuki (2010–present):

Studying Venus’s atmosphere and weather patterns.

Future Missions

NASA’s DAVINCI+ & VERITAS (Late 2020s):

DAVINCI+ will analyze atmospheric composition.

VERITAS will create high-resolution surface maps.

ESA’s EnVision (2030s):

Will study volcanic and tectonic activity.

The Big Mysteries of Venus

Despite decades of study, Venus still holds many secrets:

1. Was there once an ocean on Venus? Some scientists believe Venus may have had liquid water billions of years ago before a runaway greenhouse effect boiled it away.

2. Is There Active Volcanism Today?

Recent studies suggest possible lava flows, but no direct evidence yet.

3. Could Life Exist in Venus’s Clouds?

In 2020, astronomers detected phosphine gas in Venus’s atmosphere—a possible sign of microbial life.

However, this finding is still up for debate and requires additional investigation. Conclusion: Why Study Venus?

Understanding Venus helps scientists

✔ Learn about Earth’s climate future (as a warning against runaway greenhouse effects).

✔ Study extreme planetary environments for astrobiology.

✔ Prepare for future exploration, including possible floating habitats in its upper atmosphere.

Venus remains one of the most mysterious and hostile worlds in our solar system—a planet of extremes that continues to challenge our understanding of planetary science.