Saturnis the sixth planet from the sun in the solar system. It is thesecond largest planet after Jupiter in the solar system, with aradius of 58232km and a surface area of 42.7 billion km2.It takes 29 earth years to orbit around the sun. Saturn containsrings made of chunks and small amounts of carbonaceous dust and itsonly 20 metres thick. Saturn has 150 moons and small moonlets so fardiscovered although only 53 of them have been named. They differ insize with some being as small as 10kms in diameter. The largest moonsare titans and Rhea. Enceladusis one of the unique moons of Saturnthan appears to have an ocean below the frozen surface (Anon, 2014).
Theuniqueness of Saturn has encouraged the exploration of the planet andits moon. So far four spacecraft have been sent to moon to enhancethe study of Saturn. So far one of space still orbits around Saturnand still sends more information about the moons, planet and therings. As more data is collected, more scholars venture in to thearea of Saturn’s study and each passing day a new thing isdiscovered. These also enhance exploration study and add up to theknowledge of the solar system.
Enceladusis the 8thmoon of planet Saturn and the 6thlargest after Titan, Rhea, Lapetus, Dione and Tethys. It wasdiscovered in 28thAugust 1789 by William Herschel. It’s approximately 500 km in adiameter, a tenth of the size of the largest moon of Saturn, thetitan. Enceladus was named after Greek mythology of the titan rebelwho rebelled against the godsbut was later defeated at war. Themoon details was learned comprehensively when the first voyagespacecraft passed close to the moon in early 1980s on its mission toSaturn exploration (spenser, 2011).
Themoon is about 238020 km from the Saturn and 180000 km from its cloudstops. It takes an orbital period of 1.37 days with a mean orbitalrevolution speed of12.6 km/second. The moon orbits around Saturnin the densest part of Ering. Its orbit is in between the orbits ofMimas and Tethys. The moon is kept in place by Saturn’sgravitational force and the surrounding satellites. It rotates in itsaxis when one of its sides is facing Saturn (Spencer, 2009).
Enceladusreflects almost 100% of the sun raise that reaches its surface due toit having the highest albedo in the solar system. The small water iceparticles on the surface are what facilitate the high reflexivity.The high reflection of sun light and the long distance of the moonfrom the sun results to low surface temperature. Its surface has atemperature of -201c0andthus the surface of the moon has solidified (Anon, 2014).
TheEnceladus surface contains many features. From the detailed imagescaptured by satellite, five distinct features have been identified.These are craters, linear cracks and ridges, fissures and crystaldeformation. The features were named by the internationalastronomical union based on the characters and places in the Burtonbook. The craters are named after the character while the rest of thefeatures were named after places. So far, 57 features have beennamed.
Thereare numerous craters on the surface of the earth but all of them aresmall as they are less than 35 km in diameter. There are presence ofridges, fissures and other unusual features that may indicate theinterior of the moon being in liquid form. Enceladus is heated by thetidal wave of Saturn that could explain the liquid state of theinterior of the moon. Enceladus has smooth plain surfaces. This couldbe an indication that the moon was not very old a hundred years oldand thus it is geologically young. The surface could have been formedthrough the action of water. It is considered as one of thegeologically active in the solar system. This could suggest that itcould have had internal melting in the recent past (Tobbie et al,2013).
Thereare features on the Enceladus that shows that there have beentectonic activities going on below the surface. This consists oftectonic terrains that cut across the crater terrains. The tectonicterrain consists of bands of fractures that are few hundred metresinto the crust. There is also the presence of linear grooves thatextends across the different types of terrains. The ridges presentalso extend widely. All this reveals the recent tectonic activitythat had been going on in Enceladus.
Enceladushas neither detectable atmosphere nor magnetic field thus, thesurrounding of the moon cannot be conclusively explained. Even so, itis suggested that it contains a significant atmosphere compared tothe others. It is proposed that it contains 91% water vapour, 4%nitrogen, 3.2 carbon IV oxide and 1.7 % methane. From Cassinispacecraft images, it is seen that in the southern polar region thereis water rich plume venting from the surface of Enceladus. Othercomponents that are contained in the geysers are sodium chloride andice particles. There were more than 60 geysers spotted by Cassini(spenser, 2011).
Mostinformation collected about Enceladus and its characteristics haveenhanced the analysis and research. This has attracted many scholarswho study the possibility of having terrestrial life in this moon.From some of the images obtained by the space craft, it is suggestedthat the moon contains carbon and water which forms the basis oflife. There have been studies of the images for analysis of sodiumthat could ascertain if there is really an underground ocean inEnceladus. These studies have shaded little light on the issue(Spencer, 2009).
Researchersalso have focused on the geology of the moon to ascertain the realsource of heat that leads to melting of the interior of the moonhence, can predict the age as well as the future of the moon. Inaddition the geo chemist researchers through modelling are trying tofind out if the ellipsoid shape of the moon is differentiated or not.The Enceladus is a unique body in the solar system with a possibilityof having water. This is due to its distance from the sun and itshigh reflection capacity that leads to it having low temperature anda freezing surface. A lot of studies and exploration of Enceladushave been done and more is being done to understand it as well as toexplain some of the questions asked and clear the doubts of many. Itis clearly evident that less is known about the Enceladus and morehas to be learnt.
Anon.(2014, 0ctober 31). Saturn. Retrieved fromhttp://solarsystem.nasa.gov/planets/profile.cfm?Display=Sats&Object=Saturn
Spencer,J. (2009). Enceladus with a Grain of Salt. PLANETARY SCIENCE.
Spenser,J. (2011). watery Enceladus. physics today, 38-44.
Tobbie,G., Teanby, N. A., Coustenis, A., Raulin, F., & Schimidt, J.(2013). Science goals and mission concept for the future explorationof Titan and Enceladus. In Planetary and Space Science, 233-323.