Saturn Planet Profile
- Diameter 120660 km
- Average Distance from Sun 9.539 AU
- Mass 5.69 x 10(26) kg
- Mean Density 690 kg/cubic meter
- Escape Velocity 35600 m/s
- Rotation period 10.2 hours
- Revolution Period 29.46 years
- Orbit Eccentricity 0.056
- Obliquity 26.7 degrees
- Orbit Inclination 2.49 degrees
- Visual Geometric Albedo 0.46
- Mean temperature 88 K (1 bar level)
- Atmospheric Components
- 97% hydrogen,
- 3% helium,
- .05% methane
- Rings Rings are 270,000 km in diameter, but only
a few hundred meters thick. Particles are centimeters to decameters in size and are
ice (some may be covered with ice); there are traces of silicate or carbon minerals.
There are four main ring groups and three more faint, narrow ring groups separated
by gaps called divisions.
Saturn Images
Clouds and Spokes
Two bright convective cloud patterns appear in the mid-northern hemisphere of Saturn, and several dark spoke-like features can be seen in the broad 8-ring (left of planet). The moons Rhea and Dione appear as blue dots to the south and southeast of Saturn, respectively. This photo was taken July 21, 1981, when the spacecraft was 33.9 million km (21 million mi) from the planet. Voyager 2 made its closest approach to Saturn on August 25, 1981.
Three Moons
The disk of Saturn casts a shadow across its rings away from the sun. The satellites Mimas, Enceladus, and Tethys seen in the lower right, all orbit Saturn in the plane defined by its rings and equator.
Saturn's Moons
Saturn and two of its moons, Tethys and Dione, were photographed by Voyager 1 at a distance of 13 million km (8 million mi). The shadows of Saturn's three bright rings and Tethys are cast onto the cloud tops. The limb of the planet can be seen easily through the 3500 km (2170 mi) wide Cassini Division, which separates the A- and B-rings. The view through the much narrower Encke Division, near the outer edge of the A-ring is less clear. Beyond the Encke Division (at left) is the faintest of Saturn's three bright rings, the C-ring or crepe ring, barely visible against the planet.
Rings in Shadow
This image of Saturn was taken while the spacecraft was departing the Saturnian system. The planet's disk casts a shadow across the ring system. The visible side of the rings are directly illuminated by the sun.
Red Oval Cloud
This unique red oval cloud feature is visible in Saturn's southern hemisphere. The difference in color between the red oval and surrounding bluish clouds indicates that material within the oval contains a substance that absorbs more blue and violet light than the bluish clouds. The oval feature has been observed by Voyager 1 since August 1980, and has not changed in appearance since then. This photo was taken November 6, 1980 at a distance of 8,500,000 km (6,300,000 mi).
Braided Rings
Saturn's outermost ring, the F-ring, is a complex structure made up of two narrow, braided, bright rings along which "knots" are visible. Scientists speculate that the knots may be clumps of ring material, or mini moons. The F-ring was photographed at a range of 750,000 km (470,000 mi).
Smooth Crust
In this image of Saturn's fourth moon, Dione, the trailing hemisphere is visible. This region was protected from billions of years of impact gardening, which obliterated old surface features in the leading hemisphere. Icy fluids escaped to the surface through breaks in the crust and formed giant crisscrossing, wispy, bright marks on the exterior.
Full Disk
Impact craters are visible records of the collision of cosmic debris. On Dione, the largest crater is less than 100 km (62 mi) in diameter and shows a well-developed central peak. The sinuous valleys may have formed when faults broke the moon's icy crust. Images in this mosaic were taken from a range of 162,000 km (100,600 mi) on November 12, 1980.
Global Mosaic
This global mosaic of Enceladus was assembled from images acquired by Voyager 2 during its close flyby of Saturn's second satellite. Although Enceladus shows an abundance of impact craters, lava flows particularly near the center of the disk show much lower occurrences of craters, some of which are cut in half. This confirms the multiple stages or episodes of volcanism that formed and reformed the icy body's surface.
Irregular Body
Scientists believe that this small irregular satellite may once have been a piece of a larger satellite. Hyperion measures approximately 370 x 280 x 225 km (229 x 174 x 140 mi).
Global Dichotomy
The leading hemisphere of Iapetus is covered by extremely dark material, whereas the trailing hemisphere is covered with bright material. This dichotomy puzzled the discoverer, astronomer Giovanni Cassini, who noted that the satellite was visible only from one side of its orbit. Two models have been proposed to explain this. The first proposes that dark material from Phoebe, a dark exterior moon, falls onto Iapetus from orbit. The second model says that the dark material erupted from the interior of Iapetus into an low area in the leading hemisphere.
Cataclysmic Impact
Mimas, the innermost moon of Saturn, was nearly shattered by a cataclysmic impact. From observing Mimas' crater Herschel, scientists speculate that the inner satellites of the outer planets have, in fact, been shattered and gravitationally reassembled many times in their geologic history. Herschel's walls are approximately 5 km (3.2 mi) high, parts of its floor measure 10 km (6.2 mi) deep, and its central peak rises 6 km (3.7 mi) above the crater floor. The diameter of this moon is 394 km (244 mi).
Water Ice
The density of this satellite suggests that it is largely made of water ice with a small proportion of rocky material. Note that the ancient impact scars that ripped through the ice early after the formation of the solar system are still preserved to this day.
Bright Satellite
The surface of Enceladus resembles that of Jupiter's satellite Ganymede. Some areas are smooth and uncratered while others contain impact craters up to 35 km (22 mi) in diameter. Linear sets of grooves tens of kilometers long traverse the surface and are probably faults resulting from deformation of the crust. The uncratered regions are geologically young and may indicate that Enceladus has experienced a period of relatively recent internal melting. The satellite is about 500 km (310 mi) in diameter and has the brightest surface of any of Saturn's satellites.
Impact Craters
Tethys is approximately 1100 km (684 mi) in diameter and is densely populated with impact craters. The youngest of these, Odysseus (above center), is surrounded by a hummocky ejecta blanket. Odysseus measures 400 km (249 mi) in diameter, or approximately 40% of the diameter of Tethys. Ithaca Chasma stretches from left center up toward Odysseus, covering three quarters of the circumference of Tethys.
Obscure Titan
This view of Saturn's largest satellite was taken from a position looking almost directly back toward the sun at the Mercury-sized satellite. Titan's hydrocarbon-rich nitrogen atmosphere scatters sunlight in a forward direction over the limb around the entire disk. The surface of Titan is obscured due to a deep cloud layer. The only visible markings are the dark north polar hood and a difference in the brightness and color in the north and south hemispheres. The diameter of Titan is 5150 km (3200 mi).
The disk of Saturn casts a shadow across its rings away from the sun. The satellites Mimas, Enceladus, and Tethys seen in the lower right, all orbit Saturn in the plane defined by its rings and equator.
Saturn and two of its moons, Tethys and Dione, were photographed by Voyager 1 at a distance of 13 million km (8 million mi). The shadows of Saturn's three bright rings and Tethys are cast onto the cloud tops. The limb of the planet can be seen easily through the 3500 km (2170 mi) wide Cassini Division, which separates the A- and B-rings. The view through the much narrower Encke Division, near the outer edge of the A-ring is less clear. Beyond the Encke Division (at left) is the faintest of Saturn's three bright rings, the C-ring or crepe ring, barely visible against the planet.
This image of Saturn was taken while the spacecraft was departing the Saturnian system. The planet's disk casts a shadow across the ring system. The visible side of the rings are directly illuminated by the sun.
This unique red oval cloud feature is visible in Saturn's southern hemisphere. The difference in color between the red oval and surrounding bluish clouds indicates that material within the oval contains a substance that absorbs more blue and violet light than the bluish clouds. The oval feature has been observed by Voyager 1 since August 1980, and has not changed in appearance since then. This photo was taken November 6, 1980 at a distance of 8,500,000 km (6,300,000 mi).
Saturn's outermost ring, the F-ring, is a complex structure made up of two narrow, braided, bright rings along which "knots" are visible. Scientists speculate that the knots may be clumps of ring material, or mini moons. The F-ring was photographed at a range of 750,000 km (470,000 mi).
In this image of Saturn's fourth moon, Dione, the trailing hemisphere is visible. This region was protected from billions of years of impact gardening, which obliterated old surface features in the leading hemisphere. Icy fluids escaped to the surface through breaks in the crust and formed giant crisscrossing, wispy, bright marks on the exterior.
Impact craters are visible records of the collision of cosmic debris. On Dione, the largest crater is less than 100 km (62 mi) in diameter and shows a well-developed central peak. The sinuous valleys may have formed when faults broke the moon's icy crust. Images in this mosaic were taken from a range of 162,000 km (100,600 mi) on November 12, 1980.
This global mosaic of Enceladus was assembled from images acquired by Voyager 2 during its close flyby of Saturn's second satellite. Although Enceladus shows an abundance of impact craters, lava flows particularly near the center of the disk show much lower occurrences of craters, some of which are cut in half. This confirms the multiple stages or episodes of volcanism that formed and reformed the icy body's surface.
Scientists believe that this small irregular satellite may once have been a piece of a larger satellite. Hyperion measures approximately 370 x 280 x 225 km (229 x 174 x 140 mi).
The leading hemisphere of Iapetus is covered by extremely dark material, whereas the trailing hemisphere is covered with bright material. This dichotomy puzzled the discoverer, astronomer Giovanni Cassini, who noted that the satellite was visible only from one side of its orbit. Two models have been proposed to explain this. The first proposes that dark material from Phoebe, a dark exterior moon, falls onto Iapetus from orbit. The second model says that the dark material erupted from the interior of Iapetus into an low area in the leading hemisphere.
Mimas, the innermost moon of Saturn, was nearly shattered by a cataclysmic impact. From observing Mimas' crater Herschel, scientists speculate that the inner satellites of the outer planets have, in fact, been shattered and gravitationally reassembled many times in their geologic history. Herschel's walls are approximately 5 km (3.2 mi) high, parts of its floor measure 10 km (6.2 mi) deep, and its central peak rises 6 km (3.7 mi) above the crater floor. The diameter of this moon is 394 km (244 mi).
The density of this satellite suggests that it is largely made of water ice with a small proportion of rocky material. Note that the ancient impact scars that ripped through the ice early after the formation of the solar system are still preserved to this day.
The surface of Enceladus resembles that of Jupiter's satellite Ganymede. Some areas are smooth and uncratered while others contain impact craters up to 35 km (22 mi) in diameter. Linear sets of grooves tens of kilometers long traverse the surface and are probably faults resulting from deformation of the crust. The uncratered regions are geologically young and may indicate that Enceladus has experienced a period of relatively recent internal melting. The satellite is about 500 km (310 mi) in diameter and has the brightest surface of any of Saturn's satellites.
Tethys is approximately 1100 km (684 mi) in diameter and is densely populated with impact craters. The youngest of these, Odysseus (above center), is surrounded by a hummocky ejecta blanket. Odysseus measures 400 km (249 mi) in diameter, or approximately 40% of the diameter of Tethys. Ithaca Chasma stretches from left center up toward Odysseus, covering three quarters of the circumference of Tethys.
This view of Saturn's largest satellite was taken from a position looking almost directly back toward the sun at the Mercury-sized satellite. Titan's hydrocarbon-rich nitrogen atmosphere scatters sunlight in a forward direction over the limb around the entire disk. The surface of Titan is obscured due to a deep cloud layer. The only visible markings are the dark north polar hood and a difference in the brightness and color in the north and south hemispheres. The diameter of Titan is 5150 km (3200 mi).