Comets is cloud remains a theory only, as it has never been directly detected. The Kuiper Belt is a region that was first proposed by the Dutch-American astronomer Gerard Kuiper in 1951. Seeing that Oort’s cloud of comets did not really explain the reason for the population of comets with short orbital periods (making complete orbits around the sun in less than 200 years), Kuiper thought that a belt of comets probably existed outside the orbit of Neptune within the range of 30 to 50 astronomical units (2.8 to 4.6 billion miles) from the sun. Collisions and perturbations by the planets of our solar system are believed to be the reasons for the ejection of bodies from this belt.
Around 1988, astronomers David Jewitt (University of Hawaii) and Jane Luu (University of California at Berkeley) began searching for members of the Kuiper belt using modern electronic cameras attached to a large telescope on Mauna Kea, Hawaii. The equipment was capable of detecting extremely faint objects. After nearly 5 years of systematic searching they found a distinct image on 1992 August 30, which was subsequently designated 1992 QB1. The object was moving very slowly, and calculations eventually revealed the object took 291 years to orbit the sun at an average distance of 43 AU. Since, the discoveries of that object over three dozen additional objects had been found as of the end of 1996.
Some astronomers estimate that there are over 30,000 icy objects bigger than 100 kilometers in diameter in the Kuiper belt. The total mass of the belt is believed to be hundreds of times bigger than the asteroid belt between Mars and Jupiter. Comets are one of the more exciting things to study in astronomy because of a number of reasons. One of these reasons is because they are unpredictable. Comets can suddenly brighten or fade away in just a few hours.
They can also lose their tail, or even develop more tails. Another thing is they can split into pieces, so multiple comets can be observed traveling together. Another reason why comets are interesting to study is because they have some of the oldest and untouched objects in the solar system. The comets composition represent how things were originally, and also what made the sun and the planets how they are today. Studies have recently shown that comets are what formed life on Earth.
Collisions between Earth and comets in earlier times brought water to the Earth, which resulted in oceans forming. After the oceans were formed, it enabled life to begin. However, as easily as comets can begin life, they just as easily can end it. The way that the dinosaurs became extinct was from collisions from comets.
Most of the comets that are seen from Earth only come by once every few millions of years. Some do, however, come back within around 200 years. These types of comets are called short-period comets. These comets, which have shorter orbits, are believed by scientists to come from the Kuiper belt.
The reason why this is believed is because there are some small, icy objects that orbit near and beyond Pluto that have been detected. Since the orbits of short-period comets are shorter, they pass the Sun more often, which makes it start to disappear. The ice and gasses start evaporating, which leaves the dust and other solids left. When this happens, meteors are formed. The orbit of planets and comets are alike because they travel in an ellipse with the sun as the center point.
However, for the planets the orbit is more in a circular shape. Also, the planets orbit the sun on the same plane. However, most comets, including comet Hyakutake, which was visible in 1996, and Hale-Bopp that was in 1997, have elliptical orbits of that are very large in size, and are shaped more like an oval than a circle shape. The foci of these comets are very far apart from each other. The plane of comet Hyakutake’s orbit intersected the planetary orbit plane at a steep angle. The plane of Hale-Bopp is nearly perpendicular to the plane of earth’s orbit.
One of the most well known comets is Halleys comet. This comet has been known since around 240 BC, and maybe even as early as 1059 BC. Its most famous appearance was in the year 1066 AD, when it was seen right before the Battle of Hastings. The comet was named after Edmund Halley, who is the one who calculated its orbit. He figured that the comets that were seen in 1531 and 1607 were the same thing, which meant it had an orbit of 76 years. Halley died, however in 1742, so he never lived to see his if he was right.
His prediction did come true though when the comet came back on Christmas Eve in 1758. Halley’s Comet came in the years 1835 and 1910. Then in 1984 to 1985, five spacecraft from the USSR, Japan and Europe were sent to make observations and study Halley’s Comet in 1986. One of the deep space satellites from NASA was changed so it could observe the solar wind upstream from the comet Halley. Only three comets have ever been studied from a spacecraft.
Comet Giacobini-Zinner was one of the comets studied from space; it was in 1985. Comet Halley was studied in 1986. Comet Grigg-Skjellerup was studied on July 10th, 1992. The study of comets is very important because it is important to know what they are, and also it can explain a lot of unanswered questions about the origins of life. Some people who do not fully understand what comets are and what they do can be led to believe in many bad things, which can result in a tragedy. An example of such a tragedy would be the Heavens Gate incident.
There were many people who believed that the comet Hale-Bopp was going to cause something very bad to happen, so they all committed suicide. If people can have a better understanding of what comets are, things like this could possibly be prevented. The roles that comets have played in the earth and in life as it is today are really big and important. If it had not been for comets, then life could possibly not have even existed now. Also, many creatures, for example the dinosaurs, have become extinct because of the comets colliding with the earth. If the comets had never made these creatures go extinct, then life would without a doubt be different.
