Jovian Moons: A Scientific Insight - Research Paper Example

11 September Jovian Moons Callisto is a moon found in planet Jupiter. It is termed as Jupiter’s dead moon. Callisto is oldest landscape as well as the most greatly cratered body in the whole of the solar system and also has the. It is called Jupiter’s dead moon because it is thought to be long dead with no geologic movement on its entire surface (Zimmermann). Above is the image of Callisto taken by Voyager 1 taken from 350,000 kilometers. At the top is a large bulls-eye believed to be a control basin formed in Callisto’s early history. At about 600 kilometers across lies a bright midpoint of the basin and on the outside ring is roughly 2,600 kilometers across. The age of Callisto is around 4.5 billion years, the same as that of the planet where it is located which is Jupiter. Callisto is the furthest of the Galilean moons since it orbits from Jupiter at around 1,168,000 miles. Due to this distance from Jupiter, it takes seven days of earth to make a single complete orbit around the planet. Its orbit outside Jupiter’s main radiation strap makes the moon experience less tidal influences as compared to other Jovian moons. The size Callisto is about 3,000 miles in diameter, which is 4,800 kilometers. It is approximately the same size as planet mercury making it the third largest moon of the solar system. Callisto has the lowest density. Callisto’s mean surface temperature is 218.47 Fahrenheit (Zimmermann). Callisto was discovered by Galileo Galilei on January, 7 1610. Of all the Jupiter’s moons, it was the fourth to be discovered. It was discovered along with other three Jovian moons and it was the first for a moon to be found circling a planet which is not Earth. Galileo’s discovery finally led to the knowledge that planets orbit the sun (Zimmermann). Jupiter and its moons have been visited by several spacecraft. In 1973, Pioneer 10 arrived and by 1974, pioneer 11 had followed. During their flybys, Voyager 1 as well as Voyager 2 brought back outstanding photos. Detailed images were later to be formed by the Galileo spacecraft that travelled as near to the ground as 162 miles which is 261 kilometers over the exterior of the Galilean moons. Craters are the most noticeable feature of Callisto. This is because of the entire solar system Callisto has the most craters. According to scientist’s approximation, of the entire solar system, Callisto has the eldest surface. This moon has glimmered keen scientific interest since in 4 billion years, there is no sign of change on its geologic landscape. With no impact change on the planet from plate tectonics and lack of volcanoes, scientists believe that the cause of any changes is the result of being knocked by objects. Multi-ring structures, lines of craters referred to as catenae, icy peaks and impact craters of variable shapes are some of the unique features found on Callisto’s surface. Although craters are the moon’s signature characteristic, it has the darkest coloring on the surface of all Galilean moons. The composition on Callisto is half rocky material and half water ice. The rocky material is made up of magnesium combined with iron-bearing hydrated silicates, sulfur dioxide, carbon dioxide and possibly ammonia and organic compounds (Zimmermann). Callisto has a likely presence of having an ocean. Due to this, there is open possibility that the moon cold sustain life. Callisto has been considered suitable among the Galilean moons for future exploration. This is because of the low radiation levels experienced by Callisto. Callisto has a thin atmosphere and is made of carbon dioxide and some molecular oxygen. Jupiter was surrounded by slow acceleration from disk of gas after its formation. This is thought to have resulted to the formation of Callisto. Ganymede is Jupiter’s largest moon. Ganymede is the largest satellite in the entire solar system. Ganymede is slightly smaller than Mars but larger than both Mercury and Pluto. If it were orbiting around the sun instead of the moon, Ganymede would have easily been classified as a planet (Zimmermann). This image was taken by NASA’s Voyager 2 on July 7, 1979 from a distance of 1.2 million kilometers which is 745,000 miles. The age of Ganymede is about the age of Jupiter which is 4.5 billon years old. It is the third Galilean satellite and seventh moon outward of Jupiter. It takes 168 hours to orbit the Jupiter and Ganymede orbits at 665,000 miles which is 1.07 million kilometers (Zimmermann). Jupiter’s largest moon Ganymede, has a mean radius of 1,635 miles which is 2,631.2 kilometers. Due to its large size, it can be seen with the naked eye. Ganymede’s first observation which shows its discovery is captured in Early Chinese astronomical records. Ganymede has half the mass of Mercury though it is larger than Mercury. This classifies Ganymede as low density. The average daytime temperature of Ganymede is -171Ferenheit to -297 Fahrenheit while night temperature drop to as low as -193. Living organisms are therefore unlikely to inhabit Ganymede. The discovery of Ganymede was on Jan 7, 1610 be Galileo Galilei. Galileo named this moon Jupiter III before the abandonment of the numerical naming scheme was in mid 1800s (Zimmermann). Ganymede is characterized by a core of metallic iron. The metallic iron is covered by a coating of rock. The layer of rock is carpeted by a crust of very thick ice. A number of bumps, considered to be rock formations are also found on Ganymede’s surface. Two types of terrain make up Ganymede’s surface. About forty percent of its surface is dark with many craters and sixty percent is of light color and has grooves that form complicated patterns to give its distinctive appearance. Grooves at a height of 2,000 feet, which stretch thousands of miles were likely formed by tectonic activity or water being released from beneath the surface (Zimmermann). Scientists believe Ganymede has a salt ocean located 124 miles below its surface as compared to Europa whose ocean is much closer to the surface. NASA’s Voyager 1, Voyager 2 as well as the Galileo spacecraft created observations about Ganymede. These observations were analyzed by NASA and the United States Geological Survey and unveiled the first comprehensive map of Ganymede in video animations and images. Ganymede’s atmosphere is characterized by oxygen that is too thin to support life. Ganymede has magnetosphere which makes it only satellite in the solar system to have a magnetosphere. Magnetosphere is used to describe a comet-shaped region which attracts or deflects charged particles and is typically found in planets such as earth and Jupiter. Mission Jonu, launched on August 5, 2011 will explore Jupiter, the largest planet on the entire solar system. This mission seeks to unlock secrets about the origin of Jupiter as well as that of the entire solar system (Mission Juno). Likewise, Cassini Solstice Mission, which will go all the way to September 2017 seeks to explore the Saturn System. Cassini has twelve instruments which have returned lots of data from planet Saturn since their arrival in Saturn in 2004. The mission’s important targets include moons Titan and Enceladus. This mission also targets Saturn especially the icy moons and will make closer studies of the Saturn and its rings as the mission approaches its end. (Munsell). This two will provide further insight into the solar system. Works cited Mission Juno. Home | Mission Juno. N. p., 2014. Web. 8 May. 2014. Munsell, Kirk. Introduction. Cassini Solstice Mission. N. p., 2014. Web. 8 May. 2014. Zimmermann, Kim Ann. Callisto: Facts About Jupiter’s Dead Moon. Space.com. N. p., 2014. Web. 8 May. 2014. Zimmermann, Kim Ann. Ganymede: Facts About Jupiters Largest Moon. Space.com. N. p. 2014. Web. 8 May. 2014. Read More