Saturn, the second-largest planet in our solar system, is widely known for the rings that orbit the planet. These rings were first discovered in 1610 by Galileo Galilei. As space probes such as Cassini orbit the planet in 2010, more discoveries about Saturn are likely to be made.
Jupiter is the only planet in our solar system that is bigger than Saturn. However, Saturn is still a huge planet -- 700 Earths could fit inside it. At nearly 75,000 miles around, the diameter of Saturn is 9.4 times that of the Earth. Saturn is also 95 times more massive than our planet.
Saturn is the least-dense planet in our solar system. Saturn has a density rating of 0.687 grams per cubic centimetre, which is much lower than the Earth's 5.52 grams per cubic centimetre. Saturn is actually lighter than the other planets; its density is so low that it would actually float in water (if you could find a pool big enough to hold it).
The rate at which Saturn turns on its axis gives it the appearance of a flattened ball. The planet's poles are closer to the centre of Saturn than any point along the equator. The approximate difference between the equator's distance and the pole's distance from the centre of Saturn is over 3,700 miles.
Similiaries to Jupiter
Saturn is very similar to Jupiter. Both planets have large storm areas that are consistently active on the surface. While Saturn's are much more distinctive, they both have a series of rings that are visible around the planets.
Galileo originally thought the rings were moons; Christian Huygens was the first to see that they were rings. There are still questions about the composition of the rings in 2010, but scientists have determined that they are made up of billions of ice and rock particles.
Scientists have discovered a total of 60 moons that are orbiting Saturn as of September 2010. Titan is the second-largest moon in our solar system, but Saturn has a lot of moons that are very small as well.
As of September 2010, Saturn has been visited by four space probes. Pioneer 11 was the first in 1979, followed by Voyager 1 in 1980. Voyager 2 reached Saturn in 1981, and Cassini orbits the planet in 2010.
Scientists are not exactly sure how long a day is on Saturn. To understand the rotation speed of the planet, scientists have to study the planet's magnetic field. Estimates have placed an average day on Saturn as being 10 hours, 32 minutes and 35 seconds long.
Sometimes, Saturn's rings are directly in line with our view from Earth. When this occurs (and because the rings are so thin), they appear to have vanished when viewed through a small telescope.
While Saturn's surface is too hostile to support life as we know it, its moon Enceladus has ice geysers at its south pole. If there is liquid water on Enceladus, scientists think it may be able to support life.