Introduction

Shooting stars is one of the most beautiful phenomenon, so that most people would make efforts to see this view and scientists have done many researches about it. Many reasons of shooting stars are consist of comets, asteroids, meteors and meteoroids. However, behind this beautiful phenomenon, these four kinds of stars can make unpredictable influence and in different level of damages to the universe. Comets are invisible except unless they near the sun. Comets are mixture of ice (water and frozen gas) and dust, comets have several distinct parts, including nucleus, coma, hydrogen cloud, dust tail and ion tail. The main body of comet is called the nucleus, which can contain water, methane, nitrogen and other ice. Asteroids is a small rocky body orbiting the sun large numbers of these, ranging enormously in size, are found between the orbits of mars and Jupiter, though some have more eccentric orbits. Asteroids are minor planets, especially that inner solar system. The larger ones have also been called planetoid. Meteors are formed as dusts, also called as meteoroids. When they rub with atmosphere, they will create light and heat, and finally burn as light. This phenomenon is called meter shower. The meteorites are the central part of Meteors or Asteroids and it is major material about human research universe at first time (Sun, 2017).

Comets

A comet is a small part of solar system main, mainly by the ice and a small amount of dust and rock mixed (SPACE FACTS, 2017). Comets have several different parts: nucleus, coma, hydrogen cloud, dust tail, and ion tail (NINE PLANTS. 1994-2015). The nucleus is usually considered a solid part of the centre of the comet, the core is constituted of rock, dust and frozen gas into a small asteroid. The coma is the evaporation of the nucleus, whose shape and size are closely related to the distance from the sun. In general, the closer to the sun, the greater the coma, the diameter of up to hundreds of thousands of kilometres, and sometimes with the sun, or even more than the sun (The Plants 2010-2017). In the coma outside the composition of the cloud by the hydrogen atoms, this is a hydrogen clouds. The Dust tail is composed of dust, collar is yellow, is the sun’s photon under the radiation pressure to repulsion the formation of dust, this is the most protruding part of the comet. The ion tail consists of ionic gases, such as carbon monoxide, hydrogen, carbon dioxide, carbon, hydrogen and other ionized molecules (Calvin J. Hamilton. 1995-2010). The comet’s orbit is mostly parabolic or hyperbolic, with a few oval-shaped. At present, it has been found that there are more than 1700 comets running around the sun. The famous Halley comet around the sun week for 76 years (SPACE. 2017). The comet is made up of frozen gases, rock and dust, and when the comet approaches the star, the comet material sublimates, forming a hazy coma around the ice nucleus and a tail of a thin matter stream. Due to the pressure of the solar wind, the tail is always pointing to the direction of the sun to form a very long tail. Comet tail is generally tens of millions of kilometres long, up to hundreds of millions of kilometres. The shape of a comet like a broom, so commonly known as broom stars(Sea and Sky 1998-2016).The comet does not have a fixed volume, it is very small when it is away from the sun; close to the sun, the coma becomes bigger than before, the comet becomes longer and the volume becomes very large. The maximum length of the tail can reach more than 200 million kilometres. The quality of the comet is very small, and the average density of the comet is 1 gram per cubic centimetre. Coma and comet material is extremely thin, its quality only the total mass of 1 to 5%, or even small (Bill Dunford. 2011).

Asteroids

Asteroid is a little rough body circling the sun substantial quantities of these, running hugely in size, are found between the circles of blemishes and Jupiter, however some have more unusual circles. Space rocks are minor planets, particularly that internal close planetary system. The bigger ones have additionally been called planetoids. These terms have truly been connected to any galactic protest circling the sun that did not demonstrate the plate of a planet and was not saw to have the qualities of a dynamic comet. As minor planets in external close planetary system were found and found to unstable based surfaces that look like those of comets, they were frequently recognized from space rocks of the space rocks belt. Space rocks allude to the minor planets of the inward close planetary system incorporating that co-orbital with Jupiter.

Ceres was the principal space rock to be found, it was found in 1801 by Giuseppe Piazzi and it was thought to be another planet. This was escorted by the revelation of other comparable bodies, which, with the gear of time, had all the earmarks of being purposes of light, similar to stars, demonstrating next to zero planetary plate, however promptly recognizable from stars because of their obvious movements (NASA, 2010). Trojans are incorporated bodies caught in Jupiter’s fourth and fifth LaGrange focuses, centaurs (bodies in circle amongst Jupiter and Neptune), and trans-Neptunian objects(orbiting past Neptune) in our meaning of “space rock” as utilized on the site, despite the fact that they may all the more accurately be called “minor planets” rather than space rocks(NASA, 2010).

The principle contrast amongst space rocks and comets is their organization, as in what they are made of. Space rock are comprised of metals and rough material. Both space rocks and comets were framed right on time in the historical backdrop of the close planetary system around 4.5 billion years prior. Space rocks framed significantly nearer to the sun, where it was too warm for frosts to stay strong. Comets framed more distant from the sun where frosts would not dissolve. Comets which approach the sun lose material with each circle since some of their ice melts and vaporizes to shape a tail.

Meteors

Meteor is a particle which is broken from an asteroid, orbiting the Sun, and it is also called meteoroid. Meteor will burn itself as it reaches the atmosphere of Earth. At the same time, this action produces a shooting stars’ effect. Besides, if a meteor has not completely disintegrated when it enter the atmosphere, it will become a meteorite which is the core of meteor (Collins, 2010).

Meteor is normally formed by many different sources, including the dusts of comets and asteroids, and more, this is because, when these sources pass through the Earth, they would create dust (Clain). Each day, scientists estimate that there are between 1000 to 10000 tons of meteors which will hit the atmosphere of the Earth. Before they hit the surface of the Earth, they would burn out and become shooting stars (8 Planets).

Moreover, meteor will create a light path when it enters the atmosphere. Sometimes, the light, which is created by the action and also called fireball, would bright than the brightest planet, Venus. However, this light disappeared as soon as the meteor burnt out (Sun, 2017).

According to NASA, scientists usually name a new meteor shower from the constellation it comes from. Take Perseids as an example, Perseids occurs in Perseus, as a result, it is named Perseids. In addition, there are approximately 30 meteor showers, which are visible to the observers on Earth, occurring annually. Some of these meteor showers might have been approximately a hundred years. For instance, the Perseid meteor shower, which was first discovered and recorded 2000 years ago in Chinese annals, occurs in every August.

Compared to asteroids, comets and meteorites, meteors could not create as huge damages as asteroids, to the Earth or universe as it just simply made up of dust. Besides, meteors and meteorites can pass through the atmosphere, while comets and asteroids cannot. However, the time when asteroids pass through the atmosphere and reach the Earth and it caused the extinction of dinosaurs (Carr, 2016). According to a scientist Nicola David (2013), although there is an explosion which happened in Russia in 2013, but there are a few solutions to solve this problem is that to change the orbit of the meteor temporarily in order to avoid its collision with the Earth. However, this solution cannot be made sure that this meteor would hit the Earth again months or years later.

Meteorites

We can say meteorites is meteor, but the meteorite is the central part of meteor or asteroids because it is planetary embryos that didn’t grow big enough to become planets in their own right. Actually, the meteorites major divide four kinds-stony meteorite, pallasite, iron meteorite and mix meteorite (Heide, 1964).

It will be born when the meteor through Earth’s atmosphere, meteor’s shell is dust so it will be broken. Stony meteorite’s major element is rock, iron meteorite’s major elements are different metal, pallasite meteorite is belong mix meteorite (Heide, 1964). Pallasites are a beautiful olivine crystal formed in rock or metal meteorites. (Sun.org, 2017). Some of stony meteorites- Is a kind of meteorite from the universe formed by the ball, from the space floating dust and stone, meteorite attracts these things with itself to form a larger object, such as asteroids and meteorites (Heide, 1964).

Meteorites’ research value is very high, some of them will be 400 million years ago, the protection of their own meteorite particles so it retained a lot of dust is the original information of our early solar system, so it is very important for the universe research (Sun.org, 2017).

Pallasites are especially fascinating. The olivine crystals in a metal or rock matrix are the boundary between the silicate mantle and the centre of the mantles (Sun.org, 2017). If cut into thin slices, it will be showing different colour from yellow to green (Sun.org, 2017). Per the speculation that meteorites from universe used by the scientists, the core of the earth is form by iron and nickel (Sun.org, 2017).

Meteorites is major research resources for scientists to do some research (Dalrymple, 1991), because It is like a tree of the same record of their own life course, through research, scientists can get information on the surrounding earth space around the sample (Lauretta and McSween, 2006). Scientists want meteorites to research since they are first material that was formed in our early solar system, almost 4.6 billion years ago, We will never be able to hold a piece of core in our hands, but we can explore the metal cores of protoplanets and asteroids (Sun.org, 2017). The same metal meteorites also has some slight radiation, so he can also be used for radiation research.

Conclusion

To summarise, comets, asteroids, meteors and meteorites are essential particles to form the universe. Comets characteristics are orbit and distance between the comet and the sun. The comet’s orbit is divided into three kinds, parabolic, hyperbolic and oval-shaped. On the other hand, comets are more close to the sun, the volume is bigger than before, however the comet and the sun have long distance, the comet volume is small. Meteors are consisted of dust which from comets and asteroids. Besides, it will create a light trail when it enters the atmosphere. Compared to asteroids, meteors can make less damage to the Earth. Meteorite is the core of meteor, but their size is not big enough to form a planet. Because of the material of meteorite, many scientists would be interested to do research about it.

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