Discovering Venus: The Hottest Planet in the Solar System

Would you visit our closest planetary neighbour, Venus? I wouldn't!!

Venus is a fascinating planet, but it's also one of the most uninhabitable places in our solar system. Let's explore why, and hope it doesn't give you bad dreams.

Venus: Earth's Fiery Twin

Venus is similar in size to Earth, but it holds the title of the hottest planet in our solar system. Like Earth, Venus has a solid iron and nickel core, rocky mantle layers, and a silicate crust. However, its surface is very different, covered in volcanoes and craters. It is often described as Earth's evil or fiery twin.

Credit: Alberto Sava via Canva

Venus has three main highland regions, with Aphrodite Terra being the largest. The craters on Venus are named after notable women in history, like Spanish queens, physicists, the daughter of Galileo Galilei, and even Da Vinci's model, Mona Lisa. Do you recognise any of these names?

Cleopatra, Sappho, Curie, Kahlo, Dickinson, Nightingale, Meitner, Tereshkova, Franklin, Earhart

Credit: Zamonin, via Wikimedia Commons

One unique thing about Venus is that it spins in the opposite direction of most planets, from east to west. Scientists believe this unusual rotation may be due to a massive collision early in Venus's history, which reversed its spin.

Venus Data Dump

Size: 12,104 km (7,517 miles) in diameter, very close to Earth's size.

Temperature: 464°C (867°F), hot enough to cook a pizza in a few minutes.

Distance from the Sun: 108,000,000 km (67,000,000 miles).

Rotational Period: 243 Earth days, making a day on Venus longer than its year.

Orbital Period: 224.7 Earth days.

Axial Tilt: 177.4 degrees.

Why is Venus the Hottest Planet?

Even though Venus is not the closest planet to the Sun, it's the hottest because of its thick atmosphere made mostly of carbon dioxide. This atmosphere traps heat very well, creating a powerful greenhouse effect. Mercury, which is closer to the Sun, doesn't have much of an atmosphere to hold in heat.

Venus's thick atmosphere also creates extremely high pressure at the surface, about 93 times that of Earth's. This pressure would crush any human standing on it. Adding to its harsh conditions, Venus has thick clouds of sulfuric acid, making the environment even more dangerous with acid rain.

Credit: Rick Guidice Artist conception of surface of Venus via NASA

Fun Facts

Long Days and Short Years: A day on Venus (one full rotation) takes about 243 Earth days, which is longer than its year of 224.7 Earth days. This means that a day on Venus lasts longer than a year.

High Pressure: The surface pressure on Venus is so intense that it would feel like being 900 meters (about 3,000 feet) underwater on Earth. Just to put that into perspective, the average human can dive around 6 meters, and a very experienced diver with good equipment can dive around 18 meters deep.

Retrograde Rotation: Venus spins in the opposite direction to most other planets, a phenomenon known as retrograde rotation.

Why Does Venus Spin Backwards?

Scientists have a theory about why Venus spins in the opposite direction. They think that a long time ago, Venus might have been hit by a massive object, like a large asteroid or comet. This collision could have been powerful enough to change the direction Venus spins. Another idea is that the thick atmosphere on Venus might have interacted with the planet's rotation over millions of years, slowly reversing its direction. These theories help scientists understand the unusual backward spin of Venus, which makes it different from most other planets in our solar system.

Missions to Venus

Scientists have sent 46 missions to explore Venus. These missions include flybys, orbiters, and landers. It's challenging to land a probe on Venus because of its extreme conditions. From its thick, heat-trapping atmosphere to its acid rain and crushing surface pressure, Venus is one of the most challenging planets to explore.

Credit: NASA

Two notable missions, Magellan and Venus Express, orbited the planet and mapped its surface using radar and infrared technology. The Soviet space program's Venera 13 mission made history by landing on Venus and recording sounds from its surface. The Venera 13 probe lasted 127 minutes, during which it took surface samples and panoramic images.

The Soviet Union's Venera missions were pioneers in exploring Venus. Venera 13, in particular, was notable for transmitting images and data back to Earth before being destroyed by the planet's harsh environment.

True image taken from the Venera 13. Credit: The Planetary Society

The Magellan mission, launched by NASA, provided detailed maps of Venus's surface, revealing its volcanic landscape. The Venus Express mission by the European Space Agency studied Venus's atmosphere and climate, helping scientists understand why Venus has such extreme conditions.

Artist depiction of Magellan Spacecraft. Credit: NASA/JPL-Caltech

Thanks for exploring Venus with us today, and if you want to learn about some of these things in a little more detail, and to hear the real life recording from the Venara mission head over and watch the episode now.

Got the facts and think you can ace the quiz? Lets go!