Moon and RingsMaureen M. GuarinBeed - IV

Saturn

Saturn has 12 rings and 2 divisions. It has the most extensive ring system of any planet in our solar system. These rings consist of countless small particles, ranging in size from micrometers to meters that form clumps orbiting the planet. The ring particles are made almost entirely of water ice that is contaminated with dust and chemicals. Saturn has several moons that are within the rings.

Titan

The GiantTitan is the fifteenth of Saturn's

moons and is the largest. It is also the second largest moon in the Solar System. Titan was names after the ancient race of giants in Greek Mythology. They were the children of Uranus and Gaia, who sought to rule the heavens but were overthrown by the family of Zeus.

Titan is the only known moon with a fully developed, planet-like atmosphere. Unfortunately, this thick atmosphere prevented us from learning much about its surface features during the Voyager missions. What we do know is that it appears to be composed of about half water ice and half rocky material. It is believed to be similar in composition to many of Saturn's other moons, but is much denser because of its large size and higher gravity. Titan's atmosphere is believed to have two cloud layers at about 125 miles (200 km) and 186 miles (300 km) above the surface.

Titan has no known magnetic field, and sometimes orbits outside Saturn's magnetosphere. This exposes it directly to the solar wind, which may ionize and remove particles from the atmosphere. In 2004, the Cassini probe arrived at Saturn and dropped a probe called Huygens into Titan's atmosphere. It landed and sent back images of the surface as well as measurements of Titan's atmosphere. Cassini was then able to map Titan's surface using radar, as was done on the Magellan mission to Venus. As amazing as these images were, they only posed more questions than answers. But thanks to Cassini, we have now witnessed some of the most detailed images yet of the ringed planet and her moons.

Liquid Lakes Because Titan has a thick atmosphere containing hydrocarbons, scientists had long

theorized that there could be lakes of liquid methane and ethane on its surface. When the Voyager spacecraft encountered Titan in 1980 and 1981, they were unable to see beneath the moon's thick layer of clouds. NASA's Cassini spacecraft arrived at Saturn in 2005 armed with radar. The radar instruments were able to see through the clouds and map the moon's surface. Radar images taken in 2006 proved the existence of liquid lakes on Titan. These are the first liquid lakes seen anywhere in the Solar System besides Earth. The largest of these newly discovered lakes is larger than the Great Lakes on Earth. In addition to the lakes, channels resembling rivers were observed. This provided strong evidence of liquid rain. Scientists believe that rain composed of liquid methane and ethane regularly falls across Titan's surface. In fact, the weather on Titan may be very similar to weather patterns on Earth.

Statistics for TitanDiscovered byYear of DiscoveryDiameterMean Distance from SaturnRotational PeriodOrbital PeriodOrbital EccentricityOrbital InclinationMean Surface TemperatureMain Atmospheric ComponentAtmospheric PressureApparent Magnitude

Christiaan Huygens16553,200.6 miles (5,151 km)759,067 miles (1,221,850 km)15.9 days15.9 days0.02920.33 degrees-289° F (-178° C)Nitrogen1.5 bars8.28

Neptune

The eight planet in distance from he sun, fourth largest planet in diameter and third largest mass in solar system.

Has 4 rings and 13 known moons. The planet named after the sea of god Neptune on Roman Mythology.

TritonSon of Poseidon

It was named after the Greek god Triton, who was the son of Poseidon (Neptune). He is usually portrayed as having the head and body of a man and the tail of a fish. This moon of Neptune was discovered by the British astronomer William Lassell in 1846. Since then it has been visited by only one spacecraft, Voyager 2, in 1989.

Triton orbits Neptune in what is known as a retrograde orbit. This means that it orbits Neptune a direction opposite the planet's rotation. It is the only large moon in the Solar System to do this. Astronomers are not quite sure of the reason for this retrograde orbit. Some believe that it condensed this way from the original material of the early solar system. Others think that Triton may have been formed elsewhere and then captured by Neptune's gravity. In fact, many astronomers have noticed that the surface features of Triton, as well as its size, are very similar to what they believe the planet Pluto to look like. Some even wonder if there is some connection between Triton's features and the fact that Pluto actually crosses Neptune's orbit from time to time. Just what that connection might be is anyone's guess at this point.

FEATURE OF TITAN  Triton is the coldest known object in the Solar System. Its surface

temperature averages only -391° F (-235° C). This is caused by the moon's high albedo. Very little sunlight is absorbed by the surface. Triton's axis of rotation is tilted 157 degrees with respect to Neptune's axis. This causes the moon's polar and equatorial regions to be alternately pointed towards the Sun. This causes extreme seasonal changes as Triton's orientation changes. This uneven heating and cooling could account for some of the moon's curious surface features. Triton has an extremely thin atmosphere composed mainly of nitrogen and methane. There are very few craters visible on the surface, indicating that the moon is very young and probably highly active. There are high ridges and deep valleys all over the moon's surface. Perhaps the most interesting discovery to be made by Voyager 2 was Triton's ice volcanoes. Voyager photographed a plume of frozen material being ejected from the moon's surface. Astronomers believe this material to be composed of liquid nitrogen or methane.

Statistics for Triton Discovered by Year of Discovery Diameter Mean Distance from Neptune Rotational Period Orbital Period Orbital Eccentricity Orbital Inclination Mean Surface Temperature Main Atmospheric

Component Apparent Magnitude

William Lassell 1846 1,677 miles (2,700 km) 220,405 miles (354,800

km) 5.87 days 5.87 days 0 157.4 degrees -391° F (-235° C)  Nitrogen 13.47

Luna This is Earth's moon, and it is the planet's only

natural satellite. Although we call it simply "the Moon", it is associated with the Roman goddess Luna, who was goddess of the hunt and of the Moon. It is the sixth largest moon in theSolar System, and has been Earth's partner for most of the planet's known history. Although it has been lighting our dark nights for so long, its origins are mostly unknown. Some believe it was formed when a gigantic asteroid smashed into the Earth. The resulting impact flung molten material far out into space where it cooled and formed the Moon we see today. Others believe it was a wandering planetoid captured by the Earth's gravitational pull. Wherever it came from, it has fascinated mankind for centuries. The Moon is the only planetary body whose surface can be seen from Earth with the naked eye.

Features of the Moon Perhaps the most prominent features of the Moon are its

numerous craters. Its surface has been bombarded continually throughout its history. Since the Moon has no measurable atmosphere and no liquid water, there is no erosion taking place. This has preserved the many thousands of craters on its surface.

Another prominent feature on the Moon are the smooth areas called maria. The maria are believed to have been formed by more recent lava flows which have covered over the older craters. There are also many mountain ranges and rift valleys on the Moon's surface. All of these features have combined to form a unique facial feature known as the "Man in the Moon" that can be seen if one knows what to look for. This feature is visible every night of the year because the Moon always keeps its same face towards the Earth. This is because its period of rotation and revolution are the same; 29 days, 12 hours and 44 minutes.

This cycle is known as the lunar month As the Moon orbits the Earth, it appears to change shape as more or less of its sunlit side is visible. When the Moon is on the opposite side of the Earth as the Sun, it appears as a full moon. When it is on the same side, it is invisible, also known as a new moon. Since it is so close to the Earth, the Moon's gravity pulls on our oceans and creates the tides.

Statistics of the Moon

Diameter Mean Distance from Earth Rotational Period Orbital Period Orbital Eccentricity Orbital Inclination Inclination of Axis Mean Surface Temperature Main Atmospheric

Component Atmospheric Depth Apparent Magnitude

2,160 miles (3,476 km) 238,800 miles (384,400

km) 27.32 days 27.32 days 0.05 5.14 degrees 1.53 degrees 0° F (-17° C) Hydrogen negligible -12.74

Surface and atmosphere The moon has a very heavily cratered surface, which tells the tale

of solar system. Earth would be the same way if it had no atmosphere nor plate tectonics. Without an atmosphere or water to erode the craters, the lunar landscape has remained relatively constant for billions of years.

It is through these craters that we can actually tell some of the solar system's history. Through dating the craters, planetary scientists have been able to determine that most of the craters were made in the early days of the solar system, approximately 3.8-4.5 billion years ago. This means that early in the solar system, there was a period of heavy asteroid bombardment. This is most likely due to all of the extra material left over from the solar system's formation. After approximately 1.2 billion years, most of the material had formed into the Asteroid Belt, been ejected from the solar system, or hit the planets and moons.

If you look at the moon closely, you can see dark patches. After the period of heavy asteroid bombardment, the moon's surface cracked in many places. The lowlands of the moon filled with volcanic material, which then cooled. This lasted for approximately 750 million years. They are called maria(singular is mare) due to their resemblance to dark oceans.

Video Clips

Ring of SATURN

The Moon

Thank you for LISTENING