The solar system consists of a number of objects and elements. Among them are the sun, comets, asteroids, planets, stars and interplanetary dust. The solar system is said to have been formed about 4.6 billion years ago. Among the object that are said to form the solar system, asteroids and comets are the most significant in the study of terrestrial planets (Christiansen & Hamblin 2007). It is the impact of these objects that has constantly been involved in reshaping the planet’s surface and redistribution of surface materials. They have also changed their chemistry and mineralogy. It is worth noting that the impacts of these objects leave scars. These scars are important in that they assist scientist in assessing the age of the solar system. Current study and knowledge of the solar system are based on laboratory study of the meteorites as well as the interplanetary dust particles which help in determining the age of the system. In addition, they help in determining the timescales of planetary differentiation, the solar nebula life, how primordial organic matters are distributed as well as the non volatile elements which make up the solar system (Carr 1983).
Asteroids are rocky articles, which are the remains of the solar system formation. They are not very big rocks. They orbit the sun in an asteroid belt. On the other hand, comets are dirty ice remains of the formation of the solar system. They are smaller in size as compared to the asteroids. They are important to the scientist study of the past since they have changed a little. They orbit the sun in elliptical orbits. Comets are brighter as compared to the asteroids since they are capable of getting closer to the sun (Christiansen & Hamblin 2007).
Generally, comets and asteroids are remains of the formation of the solar system. They can be used in understanding the formation of the solar system. This essay focuses on what the asteroids and comets can tell us about the formation of the solar system.
Origin of the solar system
The origin of the solar system is an issue that has for a long time posed a big problem to scientists. No clear evidence has ever been available to explain the formation of the universe. The early stages of the planets formation remain ambiguous to human beings and the understanding that we have is only modest. We do not know exactly to what extent the orbits of the planets changed during their formation and after their formation. In fact, even to the present day, it is not easy to say if terrestrial planets, which are similar to the Earth, are a common place or they are highly unusual. In addition, no one knows where the water, that makes the Earth an appropriate to live, originated. The much uncertainty on this issue makes us wonder if it is possible to know how the solar system was formed. However, in the recent past, there have been numerous studies on the origin of the universe (McFadden, Weissman & Johnson 2007).
Asteroids and Comets
Asteroids are irregular rocks, which were leftovers during the formation of the solar system. They are not so large. The largest of them is the Ceres which is known to cover a distance of about 1000km in diameter. Their movement in relation to stars makes it recognisable. There are two classifications of asteroids. The first classification can be done based on their orbits. This is important especially to those scientists who want to estimate the rate of impact that the asteroids have on the various planets. For instance, the Amor asteroid is present on Mars and not present on the Earth. Further, the Apollo asteroid is present in both Mars and the Earth. The other classification of asteroids is based on their albedo and spectral reflectivity. This helps scientists understand the composition of asteroids and also give an indication of the tentative correlation that are made between the various forms of meteorites and asteroid groupings (Seeds & Backman 2012).
Comets, on the other hand, have also been significant in the solar system formation. They are said to have impacted the planets throughout history. However, they affect the geology of the planets in the same manner the asteroids do. Comets are formed by ice and dust which have all gathered together to form a mass body. Comets are said to reside far away from the planets’ orbits in the Oort cloud (Carr 1983). “The cloud is believed to have formed early in the history of the solar system by ejection of material from the region of the planets, outward, almost to the edge of the Sun’s influence” (Carr 1983, p. 34). While the distances between the clouds and the sun are too great, the comets move slowly in the clouds. Stars cause the comets to move off their primary orbit and cause them to plunge into the inner side of the solar system on a near parabolic orbit around the sun. The comet is warmed by the sun and the ice melts making it visible with a specific shape (Carr 1983). Comets can be classified into two. One is the periodic comets, and the other one is the non periodic orbit. The later moves in a parabolic orbits and they pass through the center of the solar system only once. Periodic comets, on the other hand, lose their life once they pass the sun making an indication that some asteroids may be burned out comet remnants (Carr 1983).
Asteroids, Comets and solar system formation
Comets and asteroids are studied to understand how the solar system was formed and how it has evolved to become the way we know it today. Comets and asteroids are a part of the solar system, and they were also involved in the formation of the solar system. They help scientist understand how the solar system was formed. For a long time, astronomers have spent a lot of time trying to understand the origin of asteroids and comets and their involvement in the solar system formation. There has been a theory that tries to explain that the asteroids are remains of a planet that exploded long time ago. However, this theory became obsolete with time as it was concluded that asteroids do not have enough mass to make a planet. In addition, it was concluded that asteroids are also found all over the solar system apart from Mars and Jupiter. The reviewed theory brought a new light where the scientist could reevaluate the formation of comets and asteroids and this would consequently help them understand how the solar system was formed (Christiansen & Hamblin 2007).
This new theory fits best in the model that the astronomers have used to explain the origin of the solar system. The new and the bigger model had been developed from a solar nebula hypothesis which had been first suggested by Pierre-Simon Laplace together with Immanuel Kant. The new theory suggests that the solar system was formed approximately 4.5 to 5 billion years ago (National Research Council 1980). It suggests that the solar system was formed from mammoth gas and dust cloud in the space. The materials exerted gravitational pull despite the fact that they very thin and easily dispersed. As they continued to exert the gravitational force, they were pulled together towards each other to form a mass body. While the dust particles were being pulled together, there were other materials, which were falling in the direction of the nebula center. The core continued to grow in size and increase in mass. As a result, more gravitational pull was exerted forcing more particles to come together. In addition, the process of acceleration also increased as the gravitational force increased. As materials continued falling towards the center of nebula, friction increased, most of the heat from the friction was lost causing the central parts of the planet to become warm. The heat continued to increase until it could no longer escape. A nuclear reaction started which then resulted in the formation of the sun (Carr 1983).
It is important to note that the sun, the planets and the smaller objects were formed as a result of a series of complex reactions that took place in the solar nebula. The reactions and processes were rapid. Evolutionary processes were further influenced by the energy that was contained in the larger bodies. In fact, the evolutionary process are said to continue in some of the objects to date. As opposed to the large bodies, asteroids, comets and meteoroids were small in size, and their reaction was slow. They underwent very little evolution as compared to the large bodies (National Research Council 1980). They are, therefore, referred to as primitive bodies since they never under went much evolution. The smaller bodies were mostly formed on the outside regions of the solar system. However, there are some other evolutions that are said to have taken place inside a few larger asteroids. As a result, therefore, it can be concluded that not all asteroids were made up of unaltered, primordial materials that were in existence before the events that led to the formation of the solar system occurred. Since these bodies were too small, and they could not have been able to sustain long term planet evolution similar to that one that occurred in the larger bodies, the primitive objects maintained the evidence that give proof of early evolutionary processes that led to the formation of the solar system material (Christiansen & Hamblin 2007).
The dust components of the nebula are especially important to its subsequent evolution since it has a larger proportion of elements which are heavier than helium. The sources of this dust are “the outer envelopes of carbon rich red giants stars and novae, the expanding shells of supernovae and planetary nebulae” (National Research Council 1980, p. 17). Each dust particle contains elements and isotopes which are different from the composition of the other dust particle. As a result, the composition of these dust particles has information on regarding the originality of elements contained in the solar system. Comets and asteroids, which were formed in areas of the solar nebula where temperatures never went too high to an extent of evaporating dust, are important in the study of this originality since some of these initial dust particles are preserved in them (National Research Council 1980).
Asteroids and comets are varied in their composition as well as locations by they have a commonality in that they give evidence of the processes that took place during the solar system formation. Their physical states and the associated processes also vary considerably. However, the main differences in their compositions are said to have resulted from their formations, which took place in different locations and also under varying physical conditions. Asteroids are said to have been formed in the inner part of the solar system while comets were formed on the outer side of the solar system (National Research Council 1980).
Despite their differences, they all contain primitive bodies from their different places of origin. They have, however, suffered some kind of alteration in their composition. For them to be fully understood, these alterations need to be deciphered. These alterations, as well as the orbital changes due to collisions together with fractionations and differentiations, led to diversity. Iron and stony-iron meteorites are parts and pieces of asteroids that went through a significant processing during formation of the solar system. These meteorites are important to astronomers since they give them a chance of sampling the interior of the differentiated planetary object. The meteorites went through evolution whereby there was melting of metal and silicates, mantle and crust, as well as volcanism. These iron and stony are the only analogue materials available found in the deep interior if the earth and other planets. Iron and stony-iron are said to have originated from the outer space, and they fell during fireballs. They are important in since they provide information regarding the early evolution of the solar system as well as evolution of its solid bodies (Davis 2005).
Most iron and stony-iron meteorites are said to have resulted from the asteroids. They resulted after the steroids were sufficiently heated to complete differentiation. Steroids played an important role in the early evolution processes. The events included among others, melting target areas, which led to completion of disruption of the parent body. The events are recorded in meteorites group. Some important effects of the early solar system led to the remixing of cold and hot materials, which were in the inner side of some parent bodies. These processes had significant impacts for the geochemical evolution of the surviving material. The later impacts acted on the meteorites parent bodies dispersed pieces in the solar system and some of the pieces fell on the Earth. They fell in the form of meteorites. It is these fragments that today provide scientists with the opportunity to how geological evolution took place in the laboratory (Davis 2005).
As it has already been discussed earlier in this paper, comets, asteroids as well as their fragments are in important part of the planet system. Also, the exploration of these bodies is special in that it has contributed greatly to the understanding of the early solar system conditions by scientists. It has also helped to enhance understanding of the processes that took place during the planets formation and the resultant accretion of the planets. Asteroids and comets are complementary in the search for information regarding the early conditions of the solar system. Their fragments are found in some laboratories on the Earth, and they are found in the form of meteorites. An establishment of the link that exist between the meteorites, the comets and the asteroids and how they contributed to the solar system formation will be a great and substantial achievement by the scientists (Davis 2005).
The origin of the solar system has remained mysterious for a long period of time. Astrologists have spent so much time in the laboratories over the year trying to understand where the solar system came from and how it was formed. There is hardly any information that can clearly reveal the originality of the solar system. However, the remains of comets and asteroids are said to have sufficient information that can be used in these studies. Comets and steroids are remains of the solar system formation. They are small objects that were involved in the solar system formation. However, they underwent a slow evolution and, as a result, no much change happened to them. They are actually refereed to as primitive bodies due to their slow evolution. These bodies will provide scientists with the information that will help them in their studies. Over the last one decade, much research has been done, and today, the knowledge about the solar system formation has been better understood.
Carr, M 1983, The geology of the terrestrial planets, American Institute of Aeronautics and Astronautics, New York, NY.
Christiansen, EH & Hamblin, WK 2007, The Solar System. Web.
Davis, A 2005, Meteorites, comets, and planets, Elsevier, Amsterdam.
McFadden, L, Weissman, P & Johnson, T 2007, Encyclopedia of the solar system, Academic, Amsterdam.
National Research Council (United States) 1980, Strategy for the exploration of primitive solar-system bodies – asteroids, comets, and meteoroids: 1980-1990, National Research Council, Washington.
Seeds, M & Backman, D 2012, Horizons: Exploring the universe, Thomson Brooks/Cole, Boston, MA.