Earth Summary Essays - Planetary Science, Astrobiology,

Earth Summary Earth An Inner Terrestrial Planet Size: About 8,000 miles in diameter Distance: 1 A.U. from the Sun Day: About 24 hours Year: About 365 days General Description: Earth may be the most unique of all planets because of the life forms we know exist here and the way they utilize the Suns energy. The Earth is composed of a great amount of water, mostly in the form of oceans, which make up most of its surface. It also contains various gases, of which make it possible for us humans to exist and is a system that exists between plants and animals here. Core/Interior: The Earth has three layers to it's interior, the inner core, outer core, and mantle. Of these the outer core is thought to be liquid. Like most of the terrestrial planets at birth, the Earth has been molten and undergone some differentiation allowing the heavy material which is consisting mostly of an iron, nickel, and cobalt core making it's density five and a half times the density of water. Surface: Earth probably has the most unique surface with all its various landmasses and water systems. It also has polar caps, volcanoes, and continents that have trees and living organisms moving about on its surface. Much of the tectonic activity on Earth created new landforms and changed other landmasses. Atmosphere: The Earth has one of the most versatile atmospheres because of the way the solar system here picks up water and carries it around the Earth for redistribution. We have a thick atmosphere that consists mostly of oxygen and nitrogen that helps plants and animals survive so well here on Earth. We also have a greenhouse effect that warms our atmosphere and it's surface. Satellites: The Moon is the only satellite known to exist to Earth. Magnetic Field: The Earth has a superior magnetic field due to a core consisting of iron and nickel. Currently the rotation of the Earth and its Coriolis effect help to create this pull of the tides from the oceans. The northern lights or lurora Borealis can be seen at various times in a mystifying view of beauty. When Discovered: N/A Notes: By far the most unique item found on Earth is the Fact that life is known to exist here and successfully grow, cultivate and prosper due to our oxygen content. Mostly due to the fact that we exist in a system of gases that are exchanged between plants and animals. Nowhere else is there such a known diverse system of travel that allows us to explore our planet. Astronomy Essays

Essay about Black Band Disease

Essay about Black Band Disease Essay about Black Band Disease Black Band Disease By Mitchell Jones Tolerating a very narrow range of environmental conditions including temperature, salinity, and solar radiation, reefs are very sensitive to damage from environmental changes. Corals, in particular, are susceptible to a number of diseases including black band disease, white band disease, and coral bleaching. Black band disease was first described in the early 1970s as a black band moving on the surface of star corals and brain corals. It destroys live tissue as it moves over the surface of the colonies, leaving behind bare white skeleton. This disease may kill entire colonies within a matter of a few months, however tissue loss from a colony can be only partial with recovery after the black band disappears. This black band consists primarily of the filamentous cyanobacterium Phormidium corallyticum along with other microorganisms. Research has shown that the death of coral tissue is caused by lack of oxygen as well as exposure to hydrogen sulfide in the tissue adjacent to this black bacterial band The black band microbial consortium consists of an assortment of photosynthetic and non-photosynthetic bacteria that co-exist synergistically. The consortium has three functionally and physically dominant members as well as numerous heterotrophic members whose role in the disease is as yet unknown. The three functionally dominant members are populations of cyanobacteria and sulfide-oxidizing and sulfate-reducing bacteria. The black band disease microbial consortium is structurally and functionally identical to cyanobacterial-dominated microbial mats found in other illuminated, sulfide-rich environments. Black band disease occurs when corals are stressed by environmental factors including sedimentation, nutrient levels, pollution, and high water temperatures but a main cause is cyanobacteria. Several species of cyanobacteria have been found associated with black band disease, the most well-known of which is Phormidium corallyticum. Sulfide-oxidizing bacteria, dominated by Beggiatoa, are present in well-developed bands and exhibit visible vertical migrations within the band matrix. When present on the band surface Beggiatoa appears white due to intracellular

Free to choose Assignment Example | Topics and Well Written Essays - 1500 words

Free to choose - Assignment Example It is natural that different people may form diverse opinions of a person and therefore, the necessity to consider their opinion as a part of identity rises. As the most significant and well-known part of King’s legacy we will consider the famous speech â€Å"I have a dream† to examine people’s attitude towards racial identity. Identity of an individual is formed under the influence of numerous factors – social, political and cultural – that predetermine the way he/she will present him/herself to the society and his/her perceptions of various aspects of life. Moreover, in conditions of the modern culture, people tend to form their identities following the trends or adopting the legacy of certain prominent figures. Pop icons and mass media shape people’s views and behaviors and thus offer a wide range of opportunities for identity expression. Particularly, racial identity is the phenomenon that typically develops in close connection to such concepts as equality and segregation. This aspect of identity implies the way one feels about his or her race and, of course, the way society feels about it. On the other hand, one’s attitude towards certain race-related issue or figure might be subjected to this/her position in the historical and social contexts. Here, the issue of racial ide ntity for ethnic minorities like African Americans attracts much attention in this respect, as it used to be the issue of controversy and oppression for many years before African Americans succeeded in the struggle for their rights. Currently, the figure discussed is Martin Luther King, who made an immense contribution to formation of many people’s racial identity and proclamation of total racial equality. The personality of Martin Luther King is of extraordinary significance in the long struggle against racial discrimination and violation of human rights, which took so many years from the racial minorities.