PASADENA, Calif. - Scientists have found a new moon hidden in one of Saturn's dazzling outer rings.

The international Cassini spacecraft spotted the moon, which measures about a half-kilometre wide.

The discovery was announced Tuesday in a notice by the International Astronomical Union.

Researchers have long puzzled over the formation of Saturn's G ring, one of the planet's more mysterious arcs. They now think the G ring was likely formed from icy debris that scattered when meteorites crashed into the newfound moon.

Scientists confirmed the moon's existence last summer after analyzing images from Cassini. Saturn has over five dozen moons.