Saturn, the sixth planet from the Sun, is probably best known for the beautiful system of seven rings that surround this giant planet. Known to many as the Ringed Planet’, Saturn is actually not the only planet in our Solar System to have a system of rings. Jupiter, Uranus, and Neptune all have rings orbiting round them; however they are darker in appearance and are thought to be made up of dustier and rockier material.
Saturn is one of the three gas giants’ in our Solar System. The planet is easily visible by the naked eye as a bright star; it was discovered in ancient times and was named after Saturnus the Roman God of agriculture.
The rings were a later discovery by the astronomer and scientist Galileo who was looking at Saturn through his telescope in 1610. The rings are visible with a small telescope or good binoculars and are made up of mainly ice with some tholin and amorphous carbon. The rings are made up of a variety of billions of small particles and larger rocks up to a few metres in diameter. The rings themselves are approximately 20 metres thick and are between 4120 miles to 76900 miles (6630km to 123700 km) above the planet’s equator.
The planet is about 885,904,700 miles (1,426,725,400 km) from the Sun. It is the second-largest planet in our solar system with an equatorial radius of 37,449 miles (60,268 km). It is so big that the Earth could fit inside it 755 times.
It takes 29.5 years for Saturn to orbit the sun and a day on Saturn is only 10 hours, 39 minutes meaning it spins on its axis much faster than the Earth. The planet itself has a very low density; the particles that make up Saturn are so far apart that if there was an ocean big enough, Saturn would float on it!
Saturn has 60 moons, the largest of which is called Titan. Titan is the second largest moon in the solar system and is larger than the planet Mercury with a diameter of approximately 3,200 miles (5,150 kilometres. Titan’s atmosphere is planet-like but denser than those of Mars, Mercury and Earth. Twenty five of Saturn’s moons are more than 6 miles (10 kilometres) in diameter.
Saturn has been visited by the following spacecraft; Pioneer 11, Voyager 1, Voyager 2 and Cassini-Huygens. The Cassini Spacecraft, a joint NASA and ESA robotic spacecraft, was the most recent craft to visit Saturn; it entered the planets orbit on the 30th June 2004 and began to send back images and data. On the 14th January 2005 Cassini sent the Huygens probe into Titan’s atmosphere, it landed on solid ground and sent back pictures of its descent and landing. Cassini has continued to orbit Saturn and its moons and continually sends images and data back to Earth. The Cassini probe has discovered many important things about Saturn and it’s moons, including radar images of liquid methane lakes on Titan and unique the polar vortex appearing to look similar to a huge hurricane approximately 5,000 miles across (8,000 kilometers).
The surface of temperature of Saturn is around -185C; however images from the Cassini probe showed that Saturn has unique property; a polar vortex at the Southern pole of the planet (a spot on its axis where the temperature is hottest), at this point the temperature reaches -122C. This is the first warm Pole ever to be discovered in the Solar System.
It would be impossible to live on the surface of Saturn; the wind blows at very high speeds, reaching velocities of around 1,100 miles an hour (500 meters a second). The atmosphere is 97% Hydrogen gas, about 3% helium gas and about 0.05% methane, with a little ammonia. The centre of Saturn is extremely hot, reaching temperatures of 11,700C, the planet itself radiates more heat than it receives from the Sun; it is thought to put out two and a half times more energy than it receives.
Despite exploratory missions by spacecraft and probes to Saturn there are many things we still do not know about this mysterious but beautiful ‘Ringed Planet’.