Phoebe, Moon Of Saturn

Learn more about Phoebe, a moon of Saturn.

Saturn is one of the largest planets in the solar system and is characterized by the rings around her body. Along with the rings around her body, Saturn is home to several moons. One of those moons is known as Phoebe.

Phoebe is a one of Saturn's moons, and was discovered by William Henry Pickering in 1899. He discovered Phoebe from photographic plates that had been taken in August of 1898 in Peru by DeLisle Stewart. This was the first moon to be discovered photographically.

The moon is named after Phoebe, a Titan in Greek mythology. Phoebe was also designated as Saturn IX. Phoebe was known as Saturn's outermost moon for more than 100 years until the discovery of smaller moons in 200 proved this was not the case.



Phoebe is roughly spherical and has a diameter of 220 kilometers, which is about 137 miles. This is equal to about one fifth of the diameter of the Earth's moon. Phoebe rotates on its axis every nine hours and she completes a full orbit about Saturn in about eighteen months. It has a very cold surface temperature of about -198 degrees Celsius.

Phoebe has a dark surface. And is heavily scarred with craters up to 80 kilometers across. Most of Saturn's inner moons are brighter than this, which makes Phoebe quite unique. Since Phoebe is so dark, scientists believed that she was simply a captured asteroid. However, images from a space probe have indicated that Phoebe's craters she is a considerable variation in brightness, which indicates the presence of large quantities of ice. Also, quantities of carbon dioxide have been detected on the surface of Phoebe. These findings have never been found on an asteroid, which leaves scientists to agree that Phoebe is in fact a moon of Saturn.

Phoebe is thought to be made up of about 50% rock, and the material that is displaced on Phoebe's surface has been caused by microscopic meteor impacts. The debris from these impacts may have been the building blocks for other moons that are in Phoebe's group, all of which are less than 10 kilometers in diameter.

There was very little known about Phoebe until Voyager 2 flew by her in 1981 from a distance of 2.2 million kilometers. At that distance it was hard to tell exactly what you were looking at. It was seen as a vague dark shape with some lighter patches and somewhat of a red color. On June 11, 2004 the real nature of Phoebe was uncovered during a flyby of the Cassini spacecraft. The spacecraft was at a distance of 2,068 kilometers, which was more than 1000 times closer than Voyager 2. The findings suggest that Phoebe may be a frozen artifact from over four billion years ago. Phoebe is likely a mixture of ice, rock, and carbon compounds similar to materials seen on Pluto and Neptune's moon, Triton. Scientists believe that bodies like Phoebe were plentiful in the outer solar system about four and a half billion years ago.

Saturn is home to many moons that orbit this large planet. Phoebe is one of those moons and is located in the outer orbits of Saturn. Though Phoebe was originally thought to be an asteroid, it has come into clear view that she is a moon of Saturn.

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