Saturn’s Rings and Many Moons

March 25, 2010
by findingDulcinea Staff
Saturn is one of the most recognizable planets in our solar system, yet much about the gaseous planet and its beautiful rings remains a mystery.

The Discovery of Saturn's Rings

Although ancient people had noticed Saturn in the sky, it wasn't until the early 1600s that Galileo caught a glimpse of Saturn through a telescope and saw objects on either side of the planet. At first, it was thought that Saturn was comprised of three separate spheres. Later a Dutch astronomer armed with a more powerful telescope correctly hypothesized that the planet was surrounded by a ring.

What Are Saturn's Rings Made Of?

Saturn has seven main rings and several fainter ones that are made up primarily of tiny ice particles.  Scientists do not know how old the rings of Saturn are, but they do know that the rings were formed in different ways. One ring seems to have been formed by blasts of ice from one of Saturn's moons; other rings may have been formed by the particles broken from Saturn's moons during collisions with space debris.

The Many Moons of Saturn

Saturn's many moons range in size from Titan, larger than the planet Mercury, to eight discovered “moonlets” that are only a few hundred meters across. Saturn has 52 named moons to date. NASA's page on the Cassini Equinox Mission offers information about each of Saturn's moons, explains how that Cassini probe looks for moons and discusses how the moons are named.
The exact number of Saturnian moons can’t be given because there is no objective boundary between the countless small anonymous objects that form Saturn's ring system and the larger objects that have been named as moons.  In 2004, the Cassini Spacecraft discovered two new moons orbiting Saturn. This was particularly groundbreaking because the moons were the smallest ever to be identified. In March 2009 Cassini discovered another new moonlet that is thought to shed light on the formation of the G ring.

The University Corporation for Atmospheric Research is a great resource for facts about Saturn’s moons (and rings). Easy-to-read data tables are paired with links to fun facts about the planet.

Penn State University has a slide show from an introductory college astronomy class that offers detailed images of many moons in the solar system. Look at the illustrations that compare the Earth’s moon with the moons of Saturn and Jupiter.

Sky and Telescope Magazine can help you identify Saturn's many moons with your own telescope. For any date and time up to December 2100, this interactive tool shows the positions of Titan and four other inner moons.

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