Meteorite Impacts: Mankind's Doom?

Content

Abstract.............................................................2

Situational Analysis...............................................3

Premise..............................................................11

Definitions..........................................................

Study Limitations..................................................12

Work Plan...........................................................12

Study and Findings.................................................12

Conclusion...........................................................16

Premise Assessment................................................16

Recommendations for Future Studies............................17

Recommendations for Unit Studied..............................17

Reference............................................................18

Abstract

The rich Mesopotamian marshlands almost completely disappeared, with only 10 percent of the important ecosystem still remaining, according to a study based on satellite images of the region. The marshlands lie in the confluence Tigris and Euphrates in southern Iraq and extend into Iran. Scientists at the U.N. Environment Program (UNEP) found that the marshy area has almost completely dried up over the past three decades and is now mainly desert with large salt-encrusted patches. A small northern fringe of marsh that straddles the Iraq-Iran border is all that remains. The damage is a result of to extensive damming upstream and drainage schemes implemented since the 1970s. More recently, a major factor contributing to the problem is a massive drainage works program installed in southern Iraq in the early 1990s.

According to the UNEP study, due to be published later this year, the marshlands previously totaled an area of 15,000 to 20,000 square kilometers (5,800 to 7,700 square miles) but now cover less than 1,500 to 2,000 square kilometers (580 to 770 square miles). 1

An indigenous group of people known as Ma'dan-who trace their culture to ancient Sumerians and Babylonians-have been displaced by the loss of the marshlands. The major ecological changes have also put several species of migratory birds and waterfowl at risk, while mammals unique to the region, such as the smooth-coated otter, are now considered extinct. Coastal fisheries in the northern Gulf, which depend on the marshlands for spawning grounds, have experienced a sharp decline.

The U.N. and a team of scientists assembled by the Iraqi Foundation are urging Iraq, Syria, Turkey, and Iran (all countries with the Tigris-Euphrates river basin) to develop a joint program to manage the water supply and halt further environmental damage. The team of scientists is also developing a restoration plan for the Mesopotamian marshlands; this effort is being called Eden Again.

Situation Analysis

History of Meteorites 32

Meteorites or sometimes referred to as meteors have been around since the beginning of our solar system. Approximately 4.5 billion years ago these "rocks that fall from the sky" were formed. Comprised of most of the same materials that comprises rocks found on earth, meterorites have traveled from long distances with evidence of materials that are found on stars.

In ancient times, objects in the night sky conjured superstition and were associated with gods and religion. But the misunderstandings about meteors lasted longer than those of most celestial objects. Meteorites were long ago thought to be cast down as gifts from angels. Others thought the gods were displaying their anger. As late as the 17th Century, many believed they fell from thunderstorms (they were nicknamed \"thunderstones\"). Many scientists were skeptical that stones could fall from the clouds or the heavens, and often they simply didn\'t believe the accounts of people who claimed to have seen such things.

However, in 1807, a fireball exploded over Connecticut, and several meteorites rained down. By then, the first handful of asteroids had been discovered, and a new theory emerged suggesting meteorites were broken bits off asteroids or other planets. (A theory that still holds today) .

One of the most significant meteorite events in recent history destroyed hundreds of square miles of forest in Siberia on June 30, 1908. Across hundreds of miles, witnesses of the Tunguska event saw a ball of fire streak through the sky, suggesting the meteor entered the atmosphere at an oblique angle. It exploded, emitting hot winds producing loud noises and shaking the ground enough to break windows in nearby villages. Small particles blown into the atmosphere lit the night sky for several days. No meteorite was ever found, and for years many scientists thought the devastation was caused by a comet. Now, the prevailing theory holds that a meteor exploded just above the surface.

The largest meteorite recovered in the United States fell in a wheat field in southern Nebraska in 1948. Witnesses observed a giant fireball in the afternoon that some said was brighter than the sun. The meteorite was found buried 10 feet deep in the ground. It weighed 2,360 pounds. The most famous meteorite crater in the United States is misnamed Meteor Crater. Located near Flagstaff Arizona this crater is almost a mile wide and 600 feet deep. The rim rises approximately 150 feet from the surrounding plain showing the awesome power of its effect. It is believed that impact destroyed all life with a 3-5k radius with winds that carried temperatures of over 1000 degrees. It was the first crater proved to be caused by a meteorite impact, which occurred between 20,000 and 50,000 years ago.

Written records have existed for over 2500 years in China and Europe. Eclipses, planets, and comets are mentioned and have brought about refinements to the current understanding of the long-term motion of these bodies especially for comets such as Halley and Swift-Tuttle. Several meteor showers have also been identified which brought about a better understanding of their