A Bit of History 

The exact date for Venus’s discovery is unknown as it was discovered thousands of years ago and has been a part of many cultures here on Earth. It is the only planet in our solar system to be named after a female(Roman goddess of Love and Beauty).

The majority of study of the planet started in the 1960s with the Soviet Venera program shortly joined by United States’ Mariner 2 mission on 14 December 1962. On October 18, 1967, the Russian probe Venera 4 entered venus’s atmosphere, and in 1975, Venera 9 and 10 lander missions captured black and white images of the surface. Seven years later, the first colored images were obtained from Venera 13, and Venera 14 landers. 

Place in the Solar System

The second planet in our solar system orbits the Sun at an average distance of about 108 million km and completes one orbit in 225 days. It takes Sunlight 6 minutes to reach the planet at this distance.

Venus and Uranus are the only two planets in the solar system that rotate backward on their axis(Clockwise). It is also the slowest rotating planet(Speed at the Equator: 6.5 km/hr), with one complete rotation in 243 Earth days which makes it a nearly perfect spherical shaped planet. This results in, one Venusian year being 1.72 times one Venusian solar day. 

Venus’s Atmosphere

The Yellow planet is actually a runaway greenhouse effect with over 96% of its atmosphere consisting of Carbon dioxide and only 3.5% Nitrogen. This huge amount of CO2 in the climate absorbs and traps the heat from the Sun and as a result, Surface temperatures reach up to 470 degrees celsius(Hotter than the closest planet to the Sun: Mercury). This temperature remains the same at the equator and the poles of the planet.  

The atmosphere is very dense with 93 times the mass and 92 times the pressure we experience here on Earth. Above the thick layer of CO2, are clouds made of sulphuric acid which blocks the sunlight from reaching the surface of the planet, scattering or reflecting 90% of the light. The wind speeds at these cloud tops can be as high as 360 km/hr.

Venus’s Surface

Much like Earth, Venus has mountains and valleys with a dusty landscape. It has thousands of volcanoes and some of them are active as observed by ‘Venus Express’(Venus exploration mission by ESA) in the form of transient infrared hot spots. The surface is also covered by thousands of evenly distributed impact craters. But the size of the craters is no smaller than 2 km across. Because of the dense atmosphere, the projectiles lesser than 50 m in diameter and without certain kinetic energy simply burn up into the atmosphere unable to create craters on the surface. 

A bit of History 

The planet is named after a Roman god of agriculture. Galileo Galilei first observed Saturn with his telescope in 1610 and assumed this planet had 2 large moons close to it(These were the Rings). His second observation confused him even more as the moons disappeared(He was looking parallel to the plane of the rings this time). He finally interpreted his third observation after 2 years to be some form of arms around the Planet. 

Later in the Year 1959, Christiaan Huygens settled the mystery with the help of improved optics in his telescope correcting Galileo that the moons he observed were actually a ‘system of rings’ around the planet. 

Saturn’s Place in Solar System

It is the second-largest planet in our solar system after Jupiter. It revolves around the Sun every 29.4 Earth years. (10756 days on earth) and its average orbit distance from Sun is 1.4 billion km. At this distance, light from our star takes about 80 minutes to reach the planet. A day on Saturn is very short as it completes one rotation every 10.7 hours. This rotation speed is the reason for its Oblate spherical shape with a 10% difference in equatorial and polar radius. Saturn is tilted on its axis of rotation by about 27 degrees and approximately every 15 years, Saturns rings and Earth are in the same plane making them invisible to observers here on Earth. 

What is it made of?

The atmosphere of Saturn is mostly composed of Hydrogen(96%) and Helium(3.2%) with trace amounts of hydrocarbons such as acetylene, ethane, propane, methane providing it a yellowish-brown colour. 

As we move deeper into Saturn’s atmosphere, the density, and pressure rise, and the core of the planet is believed to have hydrogen in the metal form under such extreme conditions. The scientist also estimate the core to be denser than Earth and 9 - 22 times the mass of our planet. The core is so hot that it radiates 2.5 times the energy into space than it receives from the Sun. 

The Beautiful Rings

There are a total of 10 distinguished rings around Saturn. Made of mostly of solid water ice and some amount of dust particles. The particle sizes in the rings vary from micrometers to meters. A shepherd moon is also observed in the rings of Saturn. 1

Following are the Rings of Saturn from Innermost to outermost:

• D ring: With a width of 7,500 km, it is a very faint and the innermost ring of Saturn.

• C Ring: Discovered in 1850, it is 17,500 km wide.

• B Ring: The brightest and widest of inner main rings with a width of 25,500 km. It blocks over 99% of the light passing through it. 

• A Ring: It is the outermost bright ring of Saturn with a width of 14,600 km.

• F Ring: Discovered in 1979, it is the most active ring of the planet with shepherd moon ‘Prometheus’ creating spiral knots at the edge of the ring as it collides and attracts the particles with its own gravity. 

• Janus/Epimetheus Ring: 5000 km of width and is occupied by the inner satellites Janus and Epimetheus.

• G Ring: A thin and faint ring with a width of 9000 km between F ring and beginning of E ring. 

• Pallene Ring: Faint, dust ring sharing the orbit of Saturn’s natural satellite(Pallene). About the width of 2500 km.

• E RIng: Extremely wide, and thick(2000km) ring unlike other thin rings of Saturn. The Ring is distributed between the orbits of Mimas and Titan.

• Phoebe Ring: Virtually Invisible ring discovered by Spitzer Space Telescope in October 2009. 

Fun Facts

• About 2 tons of Saturn’s mass comes from Earth. Cassini spacecraft was intentionally vaporized into Saturn’s atmosphere. 

• Saturn has a total of 82 moons, 53 Known, and 29 awaiting confirmation. 

• Nine Earth-sized planets can fit into Saturn’s diameter side by side (excluding its Rings).