PLANET EARTH

Among all planets moving around the sun “Earth” is the third planet from the Sun and the fifth largest: 
                    orbit         :    149,600,000 km (1.00 AU) from Sun

        diameter :    12,756.3 km

        mass        :    5.972e24 kg

Each day is a little life on this earth. Our mother earth if full of with nature of all living or non-living beings and some wonders. Some time the nature speaks, that land speaks the history of it. It speaks all about its 136,755 numbers species of animals, 321,212 number species of plants, 515, 63 numbers of other species, all total about 1,740,330 verities of different species, which account for one million of the earth's species known to science.

Wonder to know that there are 5,490-Mammals, 9,998-Birds, 9,084-Reptiles, 6,433-Amphibians, 31,300-Fishes, 1,000,000-Insects, 102,248-Spiders and scorpions, 85,000-Mollusks, 47,000-Crustaceans, 2,175-Corals, 68,827-Others Invertebrate Animals, 281,821-Flowering plants (angiosperms), 1,021-Conifers (gymnosperms), 12,000-Ferns and horsetails, 16,236-Mosses, 10,134-Red and green algae, 17,000-Lichens, 31,496-Mushrooms, and 3,067-Brown algae greatest species diversity exists on this earth surface.

GEOGRAPHY OF OUR PLANET EARTH

Earth's surface 70% is covered with water, and the remaining 30% is taken up by the seven continental l and masses.

WATER SURFACE OF EARTH:

Earth's water surface or oceanic / marine) waters is divided into a number of principal oceanic areas these divisions are the Atlantic Ocean, Arctic Ocean, Indian Ocean, Pacific Ocean, and Southern Ocean.

• The Pacific Ocean: The Pacific Ocean, the largest of the oceans, also reaches northward from the Southern Ocean to the Arctic Ocean. It spans the gap between Australia, Asia, the Americas and Oceania. The Pacific Ocean meets the Atlantic south of South America at Cape Horn.
• The Atlantic Ocean: The Atlantic Ocean, the second largest, extends from the Southern Ocean between South America, Africa, North America and Europe, to the Arctic Ocean. The Atlantic meets the Indian Ocean south of Africa at Cape Agulhas.
• The Indian Ocean: The Indian Ocean extends northward from the Southern Ocean to India, between Africa and Australia. The Indian Ocean joins the Pacific Ocean to the east, near Australia.
• The Southern Ocean: The Southern Ocean is the ocean surrounding Antarctica, dominated by the Antarctic Circumpolar Current, generally the ocean south of sixty degrees south latitude. The Southern Ocean is partially covered in sea ice, the extent of which varies according to the season. The Southern Ocean is the second smallest of the five named oceans.
• The Arctic Ocean: The Arctic Ocean is the smallest of the five. It joins the Atlantic near Greenland and Iceland, and joins the Pacific at the Bering Strait. It overlies the North Pole, touching North America in the Western hemisphere and Scandinavia and Asia in the Eastern hemisphere. The Arctic Ocean is partially covered in sea ice, the extent of which varies according to the season. Some authorities do not consider the Arctic Ocean a bona fide ocean, because it is largely surrounded by land with only limited exchange of water with the other oceans. Consequently, it is considered by some to be a sea of the Atlantic, referred to as the Arctic Mediterranean Sea or Arctic Sea.

LANDMASSES ON EARTH:

There are several large landmasses on Earth & these are commonly known as continent. It is seen that each continent has a special shape. Some of these continents are connected while the water separates others. They are generally identified by convention rather than any strict criteria, with seven regions commonly regarded as continents. They are 7 continents (from largest in size to smallest): Asia, Africa, North America, South America, Antarctica, Europe, and Australia.

ASIA

Asia being the largest of the continents covers around one-third of the world’s total land area. Asia is known for its vast size and incomparable character. It stretches all the way east from Japan to the Southeast Arabian Peninsula, which is more than 8500 kilometers away.

It is interesting to see the geographical composition of Asia. It encompasses the entire climate and expanse, be it the equatorial rain forest or the arctic tundra. We also get to see the highest and the lowest points of the Earth’s surface in Asia. The highest being, Mount Everest (8,848 meters) and the lowest is the shore of the Dead Sea (397 meters below sea level).

AFRICA

Africa is the second largest of the continents, covers around 22% of the world’s land area. The Equator intersects it and the expansive landmass covers the Sahara, which is the world’s largest desert, and the Nile, the longest river on earth, as well as 53 nations.

 Most of Africa is a desert region. This continent is basically divided into three regions, which are the Northern Plateau, the Central and Southern Plateau, and the Eastern Highlands. This includes plains, swampy coastal regions, lush tropical forests with Savannah's and hilly plateaus inland.

            It is the home for many exotic large mammals, which include the zebras, giraffes, gazelles, elephants, hippopotamuses, and rhinoceroses, antelopes and carnivores such as lions, leopards, hyenas, and panthers.

Africa is famous for it’s diamond, gold, uranium and copper mining.

NORTH AMERICA

 North America is around twice the size of Europe. It stretches from the vast wintry environment of the Arctic regions to the Yucatan Peninsula. America is sort of wedge shaped featuring an exceedingly irregular coastline with many prominent offshore islands, including Greenland, which is the largest island in the world. It is basically divided into five geographical regions.

The North American wildlife was once abundant but after people started inhabiting this land, the numbers have decreased. The large mammals include several kinds of bear, bighorn sheep, caribou, deer, elk, and antelope.

 Bison, which had a population of about 60 million once, are now found only in protected herds. The Gila monster and the beaded lizard of the southwestern United States and Mexico are the only poisonous lizards in the world. We also get to see a great variety of coastal regions as well as the freshwater rivers and lakes of North America. More than 1,700 species of birds live and breed on this continent.

North America has large deposits of many important minerals, including iron ore, copper, nickel, and uranium. Coal is also found in eastern and western Canada and the United States. World’s greatest deposits of Petroleum and Natural Gas are seen in the State of Mexico.

The people are scattered and North America is culturally diverse.

SOUTH AMERICA

South America is the fourth largest continent of the world although it contains less than 12% of the world’s population.

The Andes, world’s second largest mountain range is seen in South America. The second largest river- Amazon also runs through South America. The lowland consists mainly of the Amazon Basin, which is covered in the equatorial region. These areas are of the wet tropical climate and have a dense cover of rain forest. The largest forest area in the world is seen in South America.

South America has diverse mineral resources, like gold, silver, iron, bauxite, tin, lead and zinc many of which have not been thoroughly exploited.

ANTARCTICA

 

Antarctica the sixth largest of the continents, is ice bound through out the year. Penguins and seals, accompanied by a few invertebrates such as mites and ticks—the only land animals that can tolerate the low temperatures, primarily inhabit it. 

The marine life is rich and it includes krill, a shrimp like organism that is a food source for large numbers of whales in the surrounding waters. Antarctica has no trees, flowering plants, or grasses. The sparse vegetation is limited to about 350 species, which mostly encompass lichens, mosses and algae.

Antarctica is a true desert due to its extreme cold climate making it the coldest, windiest, and driest continent. It’s average temperature is around -50°C (-58°F), and the land is swept by hurricanes and the annual rainfall is only around 50 millimeters a year.

This continent has no native civilization but the United Kingdom, Norway, France, Australia, New Zealand, Chile, and Argentina have made territorial claims. Due to the climate it makes it impossible for people to settle down here.

A current critical environmental issue concerning Antarctica is its ozone shield, which protects the earth’s surface from harmful ultraviolet radiation. Measurements indicate that the ozone layer above Antarctica has been reduced to a dangerous level.

EUROPE

Europe is the fifth largest of the continents. It is also conventionally known as "Europa". Europa was the daughter of Phoenix in Greek mythology. Some say it is possibly from "Ereb", a Phoenician word for sunset.

The Ural Mountains, the Ural River, part of the Caspian Sea, and the Caucasus Mountains forms the main boundary between Europe and Asia. Lots of geographers also see the two continents as one and call it EURASIA. Europe has a more or less a radial pattern of drainage. Most streams flow outward from the core of the continent.

A wide variety of mineral resources are found in Europe, including coal, petroleum and natural gas, copper, lead, and tin.

AUSTRALIA

 Australia is the smallest of the seven continents. The interiors of the continent are predominantly plains. The Southeast and the Southwest plains are the most densely settled areas of Australia. The climate of Australia is variable, but weather extremes are rare. The Northern part of Australia has a monsoon sort of climate while in the south it is temperate.

Australia is known for it’s vast wildlife with rare species and it’s known as the land of the kangaroos. Aborigines are the original inhabitants of Australia. Australians are known to have an ethnic sort of origin.  

One of the interesting features of Australia is the "Great Barrier Reef", which is the world’s largest coral reef.

Continent	Area (km²)	Total population	Percent of	Density
			total population	People per
				km²
Asia	43,820,000	3,879,000,000	60%	86.7
Africa	30,370,000	922,011,000	14%	29.3
North America	24,490,000	528,720,588	8%	21
South America	17,840,000	382,000,000	6%	20.8
Antarctica	13,720,000	1,000	0.00%	0.00007
Europe	10,180,000	731,000,000	11.50%	69.7
Australia	9,008,500	31,260,000	0.50%	3.6