The Cassini spacecraft has found a new moon in the outer edge of Saturn's bright main rings, confirming previous suspicions by scientists, NASA reported Tuesday.

The new moon, 7 km in diameter, is a tiny object in the center of the Keeler gap which is located about 250 km inside the outer edge of the A ring. A ring is also the outer edge of Saturn's bright main rings.

Cassini took images of the new moon and the wavy patterns its gravitational influence generates in the gap edges. A NASA news release said the spacecraft first caught the new moon's picture onMay 1 as it began climb to higher inclinations in orbit. A closer view the next day allowed it to measure the moon's size and brightness.

The new moon, provisionally named S/2005 S1, is the second known moon to exist within Saturn's rings. The other is Pan, whichorbits in the Encke gap.

Saturn's other known moons are all outside the main ring system.

Scientists predicted the new moon's presence and its orbital distance from Saturn after the discovery last July of peculiar spiky and wispy features in the Keeler gap's outer edge. The features are similar to those noted in Saturn's F ring and the Encke gap, where small-sized moons exist.

"It's too early to make out the shape of the orbit, but what we've seen so far of its motion suggests that it is very near the exact center of the gap, just as we had surmised," said Dr. JosephSpitale, imaging team associate and planetary scientist at the Space Science Institute in Boulder, Colorado, in a statement.

The new moon orbits approximately 136,505 km from the center ofSaturn, said scientists. More Cassini observations will be needed to determine if its orbit is circular or eccentric.

Cassini began an intensive survey on Saturn's rings last month.

Source: Xinhua