Abstract This paper examines asteroids. This paper examines the history of their discovery and analysis and concludes with consideration of Potentially Hazardous Asteroids (PHA) and asteroid impacts.
Abstract This paper explains that asteroids are the most significant threat to the human race, not population growth, because asteroids are powerful enough to devastate, if not destroy, all advanced life on the planet in a single blow, and our knowledge and ability to detect these space bullets are limited both in ability and in funding. The author points out that the risk of a catastrophic event occurring because of an outer space object is much higher than many of us would like to believe; asteroids pose a greater probability of occurring on a smaller scale than many other natural disasters like volcano eruptions or hurricanes. The paper stresses the claim that population growth will destroy the human race is mostly unwarranted because of the many internal checks against this growth, such as the decreasing birth rates in many industrialized nations, AIDS, and advancing science and political ideas.
From the Paper "Approximately 65 million years ago, an asteroid 10 kilometers across caused an impact releasing more energy than a million H-bombs. This impact resulted in the Chicxulub Crater in Mexico and was supposed to have caused the extinction of the dinosaurs. It wouldn't take anything larger to cause similar extinction of the human race. Asteroids could potentially produce more destruction to our planet than any amount of nuclear devices we could detonate. Even asteroids that are too small to make it through our atmosphere could cause major damage in populated areas. The Tunguska meteorite exploded and vaporized in the upper atmosphere over Siberia, but the speed of the meteorite caused the explosion to devastate thousands of square kilometers of forest. If that meteorite were aimed at Beijing or New York there could have been millions killed without effective evacuation measures."
Tags: detection, disasters, extinction, crater, population
Abstract This paper discusses the asteroid which scientists believe caused the extinction of dinosaurs and the probability of another event such as this occurring. It also discuss the measurements government has taken to prevent a damaging impact and the different methods they will use to deter such an asteroid if one should come too near the Earth.
From the Paper "Luckily for us, impacts that would cause massive destruction occur on Earth only about once ever 100,000 years (NASA Ames Space Science Division). According to NASA, these dangerous asteroids capable of wreaking global havoc are extremely rare."
Abstract The paper looks at the role of asteroid impact on the extinction of the dinosaurs and the Great Dying of the Permian period. It looks at direct and indirect physical evidence.
From the Paper "he article under review is titled "Repeated Blows: Did Extraterrestrial Collisions Capable of Causing Widespread Extinctions Pound the Earth Not Once, But Twice-Or Even Several Times." It was published in the March 2002 issue of the Scientific American...."
Abstract The paper details the similarities between Earth and Mars explaining that Mars once had its own water cycle. The paper explains what an asteroid is and asserts that asteroids probably destroyed Mars. It speculates whether an asteroid can destroy Earth and discusses ways to prevent this from happening.
From the Paper "A billion or so years ago, a frozen lake covered the plains that were alive. Most of the other volcanoes had stopped spewing gases, the temperature and atmospheric pressure on Mars were so low that ice from the lake surface sublimated. These formed into vapor without melting as water. The water vapor formed clouds that dropped snow onto the volcano's slopes. The volcano's magma chamber warmed the slopes enough to melt the bottom layers of the deep snow pack."
Abstract The paper relates that, in 1930, the Lowell Observatory announced the discovery of the ninth planet, Pluto, but then, in 2006, the scientific community decided that Pluto would lose its status as a planet. The paper then explains that this decision was based on the scientific community's discovery that Pluto is more akin to the making of an asteroid than it is to a planet. The paper also looks at the opinion of people who think Pluto should still be a planet and posits that the many questions about Pluto will be answered when the New Horizons space satellite arrives at Pluto in 2015.
From the Paper "In 1930, the Lowell Observatory announced the discovery of a small planetary body beyond the planet Neptune (Gingerich, 2007, 137). It was named Pluto, following the suggestion of a young girl who thought that name was right because the first two letters incorporated the initials of the scientist for whom the Lowell Observatory was named for (Gingerich, 137). In hindsight, the rush to bestow planetary status on the tiny heavenly body was perhaps more a need for the Lowell Observatory to have a role in the discovery of something scientifically significant than in something that met the standards of scientific theory and research."
Abstract The following paper discusses how man needs to treat the earth with respect if he is to survive. The writer is of the opinion that the extinction of the human species, if it ever occurs, will be due to the mismanagement of the earth's resources rather than the effect of an asteroid hitting the earth, which is believed to have caused the extinction of the dinosaurs.
From the Paper "Man is the most intelligent and enterprising of all the animals. Man has always had a desire to explore and understand the phenomena around him. This in turn has fueled his desire to scale Mount Everest, reach the North Pole, and in an astounding demonstration of technological prowess coupled with determination, walk on the moon. Great inventions in science and technology have been achieved due to man's constant desire to improve his living conditions and his quality of life. Every generation has constantly refined and modified operations and function to make it easier and more effective.The earth is full of changes too. Many of the changes are too subtle and slow for man to observe and recognize, the movement of glaciers for example, a few centimeters or less in a day. Records show that the glaciers, which were almost intact for hundreds of years, are retreating faster since the mid-1800s and the rate of retreat is accelerating with each passing year (Wright, 2002). Darwinian theory states that all plants and animals undergo changes and mutations-we are constantly evolving. Man's influence has however, impacted the habitats and the living condition of many plants and animals. Extinction of a species is many times attributed to the effects of man's encroachment on their habitats. The clearing of forests, contamination of the rivers and lakes due to the run off of fertilizers used in agriculture and uncontrolled hunting for food and sport."
Abstract This paper explains that the fossil records tell us that, through out the geological history of earth, mass extinctions have been the norm rather than the exception. This paper states that a better understanding of the role extinction plays in evolution is essential. The author concludes that human beings are uniquely adaptable; they invent procedures as medicine that give them extended control over their environments.
From the Paper "Of course, the most famous extinction event is that of the dinosaurs, about 65 million years ago. Such events appear in the fossil record as far back as Precambrian time when it is believed that life first began. Ideas of mass extinction has been an issue of controversy between many geologists towards the idea that it is related to intermittent catastrophes such as the striking of the earth's surface by a large asteroid or comet. Many paleontologists and evolutionary theorists reject such ideas and believe them to be unjustified."
Abstract This paper examines the recent interest in life on Mars. Since the discovery of an asteroid of Martian origins with potentially organic fossils in it in the Antarctic in 1996, this theory has been revived. Scientists now cast doubt on this theory but five missions to Mars are still planned for 2003.
This paper explains that global warming and cooling of the earth's atmosphere have shaped the destiny of mankind since the beginning of time; however, today's climatic fluctuations may be man-made.
Abstract This paper relates that historians and archaeologists can trace numerous events to smaller climatic fluctuations, such as Europe's "Little Ice Age," which happened in the early Middle Ages bringing strange weather that caused famines, uprisings and withdrawal of northern Icelandic and Greenland colonies. The author points out that some people believe that the major threat to humanity is not diseases, crazed terrorist or the earth being bombarded by asteroids but rather world population growth. Environmental experts are concerned over how many people the earth's atmosphere can support. The paper stresses that a scientific consensus says the most direct result of the many gas emissions is a "global warming" of 1.5 to 4.5 degrees over the next millennium, and that is in addition to a more than evident temperature increase of half a degree.
From the Paper "The Maldives, a chain of 1,180 islands in the Indian Ocean now sits three feet above the ocean's surface. In his Los Angeles Times article, "Maldives Faces Global Warming Goliath," writer Dexter Filkins says that "the entire nation could vanish, Atlantis-like, into the sea." Last winter, these island states crusaded for marked reductions in global greenhouse gases. While the US has proposed that industrialized nations began to reduce emissions in 2008 (at 1990 levels), the 35 nations Alliance of Small Island States insists on a 20 % cutback by 2005. While the exact danger (and its arrival) is unknown, island countries are anxious about a five-year study by the International Panel of Climate Change that predicts that by 2100, sea levels could rise from 6 inches to 3 feet. If such a dire forecast comes true, the ocean will swallow most of the Maldives. The country's main economic activity, tourism, would be devastated."
Abstract This paper describes the origin of meteors, their composition and properties. The author explains the source of light and color of meteors, their speed and size. The paper gives some features of major meteor showers such as the Leonid and Perseid.
From the Paper "The smallest units in the solar system, which can be observed with the naked eye, are meteoroids and they range in size from large fragments of asteroids and comets to small micro-meteoroids. Most meteoroid streams come from..."
Abstract This paper discusses the consensus reached by the International Astronomical Union in 2006 on the official definition of a planet, and the consequent reclassification of Pluto as a "dwarf planet." The writer explains what is known about Pluto today and describes the background to the controversy and the discoveries that led to the challenging of Pluto's status as a planet. Many scientists today still believe that Pluto is in fact a planet, and support a more expansive definition of what are called planets. The paper concludes that, as our knowledge of what constitutes planets continues to expand, Pluto may once again be considered a planet.
From the Paper "The recent controversy over Pluto's status as a planet reveals the fact that quite often, what seems like a scientific certainty is still quite contentious within the scientific community, when new discoveries are made through improved technology. In 1995, discoveries of large planets around other stars, plus new objects that are neither planet nor star, and free-floating objects in space that look like planets but do not orbit stars forced astronomers to reformulate definitions of what constituted a planet (Britt 2000). Extrasolar planets may originate as brown dwarf stars, lack light, and are even in some cases as large as Jupiter, yet they orbit stars like planets (Britt 2000). In defining whether these burnt-out brown dwarfs were planets in the early 90s were planets, the issue of Pluto's planetary status again came to the forefront of scientific debate."
Tags: comet, solar system, trans-Neptunian extrasolar, Kuiper Belt, asteroid universe orbit satellite
Abstract This paper defines what is meant by mass extinction and discusses a few that have occurred on our planet and some of the theories that have attempted to explain them. The writer explains that while some believe in meteorites or comet showers, and others in volcanism, variations in sea level, global climate changes and changes in ocean levels of oxygen, still a third group of scientists believe it was likely a combination of two or more of these events. The paper concludes that it is still unclear exactly what caused mass extinctions, and because of the elapsed time it is doubtful that we will ever know for sure.
From the Paper "Most of us are, of course most familiar with the extinction of the dinosaurs. Practically every child is fascinated by these huge beasts that roamed our planet at one time and now do not exist at all. In 1979 Berkeley scientists discovered a piece of pink and white limestone which contained evidence of what the scientists called "the great dying." (Rogers 1). The rock was found near Gubbio, Italy, and was at one time under the sea. To make an involved story short, the Cretaceous limestone has many fossils of tiny crustaceans while these little crustacean fossils are entirely absent from the clay layer, reappearing again in the Tertiary limestone. The scientist measured the presence of iridium, and found a substantial increase in the clay--twenty five times more than normal."
