Solar System

            The solar system consists of the sun and all the planets and other bodies that revolve around it. It is shaped like a disk with the sun at its center.

            The largest objects orbiting the sun are the nine planets, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Some planets have moons – natural bodies that revolve around them. Other bodies orbiting the sun include thousands of tiny objects called asteroids and comets – chunks of ice, rock, and dust. The solar system also contains dust and gases left over from when it was formed.

            All the planets and most asteroids revolve around the sun in nearly circular orbits (paths) that are in nearly the same plane. They all move in counterclockwise orbits, as seen from “above.” Some moons have clockwise motion.

Theories about the solar system

            Five planets – Mercury, Venus, Mars, Jupiter, and Saturn – are regularly visible from Earth and have been known since ancient times. Around 300 B.C. some ancient Greek scientists suggested that the sun was the center of the solar system. Until the mid-1500s, however, most people believed that the Earth was the center of the solar system, and that everything else revolved around it. Then, in 1543 the Polish astronomer Nicolaus Copernicus (1473-1543) figured out that the Earth and the other planets traveled around the sun in circular orbits.

            By 1618 further discoveries by the German astronomer Johannes Kepler (1571-1630) led to what became known as Kepler’s three laws of planetary motion. The English scientist Isaac Newton (1642-1727) used a form of math called calculus to show that gravity, the force that holds objects to the Earth, also holds the planets in their orbits round the sun.

            The German astronomer Johannes Bode (1747-1826) discovered a mathematical relationship in the distances of the planets from the sun. In 1781, when the English astronomer William Herschel (1738-1822) discovered Uranus, it fit into Bode’s pattern, as did many asteroids when they were discovered. Astronomers discovered Neptune in 1846 and Pluto in 1930.

Astronomy

Astronomy is older than recorded history. It was first used to figure out when the seasons would change. Today it is used to calculate the age of the universe.

Astronomy is the study of everything in the universe beyond Earth. It is one of the oldest sciences. For thousands of years people have gazed at the sky to try to learn about the stars, the planets, and everything else in the universe.

The night sky changes as the year passes. Starting about 10,000 years ago, people studied the changing positions of the sun and the stars to decide when to plant and harvest crops. The earliest astronomers lived before recorded history. Our first knowledge of ancient astronomy dates from about 2,500 years ago, when Greek astronomers carefully recorded what they had learned. They believed that the Earth was at the center of the universe and that the stars and other planets circled the Earth.

Beginning of modern astronomy

            The Polish scientist Nicolaus Copernicus (1473-1543) was the first person to suggest correctly that the Earth revolved around the sun, not the other way around. The Italian astronomer Galileo Galilei (1564-1642) was the first to use a telescope to study the sky, and he saw things no one else had seen. Although Galileo believed, like Copernicus, that the planets orbited the sun, he could not explain why.

            The person who answered that question was the English mathematician Isaac Newton (1642-1727). Newton discovered that all objects possess a force called gravity that attracts other objects. A large object such as the sun produces enough gravity to hold the planets in orbit around it. Moons orbit planets for the same reason. Because of Newton’s discoveries scientists came to accept the idea that the Earth and other planets revolve around the sun.

Ecological and Economical Importance of Coral Reefs and Mangroves

     Coral is made from the skeletons of billions of tiny sea animals called polyps. Coral reefs form when polyps anchor themselves to undersea volcanic islands. Over millions of years more polyps attach themselves to the skeletons of dead polys until they form a structure that resembles a giant rock, called a reef. Reefs can reach lengths of 1,000 miles (1,600km) and are the biggest structures made by nonhuman animals. Coral reefs are very fragile and can easily be destroyed by global warming, pollution or mining.

     Any diver can tell you that coral reefs are beautiful. They are like undersea cities, filled with colorful fish, intricate formations and wondrous sea creatures. The importance of coral reefs, however, extends far beyond the pleasure it brings to those who explore it. Coral reefs play an essential role in everything from water filtration and fish reproduction to shore line protection and erosion prevention.

·          Most corals and sponges are filter feeders, which means that they consume particulate matter suspended in the water column. This contributes to enhanced quality and clarity of our near shore waters.

• Coral reefs support a phenomenal diversity of species and provide irreplaceable sources of food and shelter. Tropical rainforests play a similar role on the land.
• Coral reef ecosystems support a variety of human needs. They are important for subsistence, fisheries, tourism, shoreline protection, and yield compounds that are important in the development of new medicines.

·         Coral reefs form natural barriers that protect nearby shorelines from the eroding forces of the sea, thereby protecting coastal dwellings, agricultural land and beaches.

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes 25° N and 25° S. Mangroves are found in tropical and subtropical tidal areas. Areas where mangals occur include estuaries and marine shorelines. The mangrove biome, or mangel, is a distinct saline woodland  habitat characterized by a depositional coastal environments, where fine sediments which is often with high organic content collect in areas protected from high-energy wave action. Mangroves dominate three quarters of tropical coastlines. The saline conditions tolerated by various mangrove species range from brackish water, through pure seawater (30 to 40 ppt), to water concentrated by evaporation to over twice the salinity of ocean seawater (up to 90 ppt).

          Mangrove forests are among the most productive terrestrial eco systems and are natural and are a renewable        resource. Mangroves are not a marvel just for their adaptations but also for the significant role they play in our        environment.

·         Mangroves are also a source of a vast range of wood and non-wood forest products including timber, fuel wood, charcoal, fodder, honey, pulp, tannin, medicine and thatch etc.

·         The ecosystem has a very large unexplored potential for natural products useful for medicinal purposes & also for salt production, apiculture, fisheries products fuel and fodder, etc.

·         Mangroves also provide opportunities for education, scientific research and eco tourism.

·         It is essential to systematically conserve the biodiversity in the mangrove ecosystem and manage well for the use of mankind.

Reshaping the Earth

            As what I have read in the encyclopedia, “Air and water are essential to life on Earth. Human activity, can sometimes damage their purity and make them polluted or dirty.”

Air Pollution:

Air is considered to be polluted when it contains enough harmful impurities to affect the health, safety, or comfort of living things. The term pollution, usually means damage to the environment caused by human activity. Vehicles such as cars and airplanes give out exhaust fumes. Factories burn fossil fuels, such as coal, and chemicals, and release waste matter into the air.

            When people use fossil fuels such as gasoline, oil, and coal, carbon dioxide and other gases are released into the air. These gases act like the glass in a greenhouse which traps the heat from the sun. This “greenhouse effect” causes the atmosphere to warm and world temperatures continue to rise.

Water pollution:

            Water just like air is polluted when it contains harmful impurities that affect living things. Pollution of water can also have natural causes. Storms can cause soil and other debris to dissolve in water. But, as with air pollution, human activity causes the most damage to water supplies. Factories release harmful chemicals into rivers and lakes. Sewage which is the household waste from toilets, sinks and bathtubs, pumps into the oceans. If an oil tanker sinks, thousands of tons of oil can cover the surface of the sea and the shore. As a result, fish, birds and other wildlife die. Waste material on land can also pollute groundwater because groundwater contains soil and rocks. Dangerous material can pass into the food cycle through crops or animal feed.

The Geosciences

fairy.rhevanz11@gmail.com

            Earth science is also known as geoscience, the geosciences or the Earth sciences. The third planet from the sun: Earth, is the only known as the “life-bearing planet”- the planet we live on and Science is the study of events in the world that is trying to explain in a logical and orderly way on how everything happens, a system of acquiring knowledge and it is systematic and organized body of knowledge. In this case, if you will combine the two, Earth + Science makes it the Earth Science which means the term for the sciences related to the planet Earth. The geosciences may include the study of the atmosphere, oceans and biosphere, and also the solid earth.

The following are the fields of science which are generally categorized within the geosciences.

* Geology is a very wide field of study because geology is split into many minor sciences which describes the rocky parts of the Earth’s crust or lithosphere and its development.

* Geophysics and Geodesy investigate the shape of the Earth, its reaction to forces and its gravity.

* Soil science or pedosphere covers the outermost layer of the Earth’s crust which is the soil formation.

* Oceanography and hydrology describe the marine and freshwater domains of the watery parts of the Earth or hydrosphere.

* Glaciology covers the icy parts of the Earth or the cryosphere.

* Atmospheric sciences cover the gaseous parts of the Earth or atmosphere between the surface and the exosphere.

* A very important linking sphere is the biosphere, the zone of life on Earth, the global ecological system integrating all living beings and their relationships including their interaction with the elements of the lithosphere, hydrosphere and atmosphere create the conditions that can support life.