Essay On Our Planet Earth

The Earth As A Living Planet

The Earth as a living planet

You can easily identify living things around you. Earth has life on its surface. Scientists are trying hard to find out whether life exists elsewhere also in the universe, but, till date they could not find any.

The earth is a living planet where many complex systems run perfectly without stopping at all. When compared to other planets, it is evident that in all its aspects the earth is specially designed for human life. Built on some important balances, life prevails in every spot of this planet, from the atmosphere to the depths of the earth. However, even a minor change in any one of these arrangements would create very severe problems regarding the existence and survival of humankind.The Earth is a large habitat for living organisms. Many birds, animals, plants and micro-organisms live here. Some of them live in water, some in land and some in atmosphere.

Exploring only a few of the millions of these balances would be sufficient to show that the world we live in is specially designed for us.

One of the most important balances in our planet is revealed in the atmosphere that surrounds us. The atmosphere of the earth holds the most appropriate gasses in the most appropriate ratio needed for the survival not only of human beings, but also of all the living beings on the earth.

For life to exist on a celestial body, some conditions are necessary. There must be the presence of some elements such as carbon (C), oxygen (O2), Nitrogen (N2) and hydrogen (H2) which are involved in the basic structures of complex molecules forming living cells. The 77% of nitrogen, 21% of oxygen and 1% of carbon dioxide as well as other gasses readily available in the atmosphere represent the ideal figures necessary for the survival of living beings. Oxygen, a gas that is vital for living beings, helps food to be burned and converted into energy in our bodies.

If the oxygen percentage in the atmosphere were greater than 21%, the cells in our body would soon start to suffer great damages. The vegetation and hydrocarbon molecules needed for life would also be destroyed. If this percentage were any less, this would cause difficulties in our respiration, and the food we eat would not be converted into energy. Therefore, the 21% of oxygen in the atmosphere is the most ideal quantity determined for life.

No less than oxygen, other gasses like nitrogen and carbon dioxide are also arranged in the ideal quantity for the needs of living beings and the continuity of life. The amount of nitrogen in the atmosphere has the ideal ratio to balance the harmful and burning effects of oxygen. This ratio represents the most appropriate value required for photosynthesis, which is...

Loading: Checking Spelling

0%

Read more

The Weight of the World: Overpoluation on Planet Earth

1212 words - 5 pages According to the World census, as of 2012 there are seven billion people on planet Earth. Currently the weight of the population is relatively close to 300 million tons. All seven billion are contributing to an ever evolving world such as: technologically, medically, socially, and economically. Unfortunately having such luxuries at our fingertips it is only natural to take things like electricity and even water for granted, we are not looking at...

Report on the Religious Life on Planet Earth

967 words - 4 pages Report on the Religious Life of Planet EarthReport on the Religious Life on Planet EarthxxxxxxxxxProfessor Philip VanVleckWorld ReligionsNovember 8, 2012Report on the Religious Life of Planet EarthThis is a report based on my research and findings on whether planet Earth is a religious planet or not. In order for me to start my research I had to find out what makes a person...

The Importance of Ocean Currents to Survival on Planet Earth

1959 words - 8 pages Earth has been called the blue planet and not without reason. The ocean covers about three quarters of the earth’s surface and plays a vital role in our survival. It bounty feeds millions of people daily. Its surface absorbs more than ninety five percent of the solar radiation that reaches our planet. It is integral to the water cycle and it regulates our planets climate. But none of these roles would be fulfilled without the movement of the...

Children of the Sun- A fantasy short story about a young girl and her brother living on a foreign planet.

2077 words - 8 pages Children of The SunBrabe awoke with sharp pains running through his body. The Sun! He hadn't had any sunlight for almost a day."Lela," he said, shaking her, "we must get out of here, wherever we are."Lela didn't move, she just laid there like a rag doll thrown in a heap on the floor. Then it hit him. Like the blow of one of Kyrria's...

A Planet for the Taking

954 words - 4 pages This essay was written as a critical analysis of David Suzuki's essay "A Planet for the Taking" -In the essay 'A Planet for the Taking,' David Suzuki describes Canadians' odd appreciation for this great natural bounty we call our own. He is an internationally acclaimed scientist who is concerned about the welfare of

Essay about a new solar system discovered in June 2002. In addition, it talks about the planet "55 Cnc d" and how it's similar to Earth.

750 words - 3 pages Recent Cosmic DiscoveryFor many years, people thought that the planet Earth was the only planet of its kind. In addition, it was believed that the Milky Way was the only galaxy that contained planets like ours. A significant amount of time and money has gone into this quest for the unknown. Over 90 extrasolar planets have...

Marijuana as a Gift from Mother Earth

1049 words - 4 pages Marijuana as a Gift from Mother Earth When and where will the senseless persecutions of America’s Marijuana users end? These Marijuana smokers are typically middle class males, between the ages of 17 and 39, and one in three have no prior felony charges on their records. (HRW World Report) However, each year, hundreds of thousands of them are arrested and thrown into jail, alongside murderers, rapists, and child molesters. The “Marihuana...

How the Properties of Water are Related to Its Roles in Living Organisms and as a Living Environment for Living Organisms

1044 words - 4 pages How the Properties of Water are Related to Its Roles in Living Organisms and as a Living Environment for Living Organisms Over 70% of the world’s surface is covered by water, 95% of which consists of salty oceans; water is essential to all life forms. A molecule of water consists of two hydrogen atoms covalently bound to one atom of oxygen which gives a formula of H2O. When water molecules are close together their positive...

Describe the advantages and disadvantages of living in a world such as that depicted in "Gattaca"

865 words - 3 pages Describe the advantages and disadvantages of living in a world such as that depicted in GATTACA. Secondly, imagine that you live in this world. Describe how you envisage your life, including the good and bad. Include the kinds of issues that people living in this world would have to deal with everyday.The film Gattaca is based on the theme of a eugenic society in which...

How Living as a Christian Disciple May Influence the Lives of Christians Today

3004 words - 12 pages How Living as a Christian Disciple May Influence the Lives of Christians Today Christianity is an entire way of life. It's not only a part of your life it is your whole life. It is a sense of being with God. It is not a one way system, but in fact a two way bond. Being a disciple of God gives you a sense of who you are. You have the position of being part of God's children as well as being a child of your parents. This is an...

Being a Vegetarian is Better For the Planet

942 words - 4 pages Albert Einstein once said, "Nothing will benefit human health and increase chances of survival for life on earth as much as the evolution to a vegetarian diet." As people move into a more health conscious society, vegetarianism is becoming a popular choice. While some people cannot imagine a day without meat, others are convinced that a vegetarian lifestyle is the better option. There are numerous benefits of being a vegetarian. Some...

Earth seen from a satellite

Names
Other namesTerra,[1]
the World
Orbit
Reference dateJ2000.0
Longest distance from the Sun152,097,701 km
1.0167103335 AU[2]
Shortest distance from the Sun147,098,074 km
0.9832898912 AU[2]
Longest distance from the center of its orbital path
("semi-major axis")
149,597,887.5 km
1.0000001124 AU[2]
How long it takes to complete an orbit365.256366 days
1.0000175 yr[2]
Average speed29.783 km/s
107,218 km/h[2]
Angle above the reference plane
("inclination")
1°34'43.3"
to the invariable plane[3]
Size and other qualities
Average radius6,371.0 km (3,958.8 mi)[4]
Surface area510,072,000 km²
Volume1.08321 × 10¹² km³
Mass5.9736 × 1024 kg
Average density5.515 g/cm³
Surface gravity0.99732 g
Escape velocity11.186 km/s
Avg. surface temp.14°C

Earth is the planet we live on. It is the third planet from the sun. It is the only planet known to have life on it. Lots of scientists think the earth formed around 4.5 billion years ago.[5] It is one of four rocky planets on the inside of the Solar System. The other three are Mercury, Venus and Mars.

The large mass of the sun makes Earth move around it, just as the mass of Earth makes the moon move around it. Earth also turns around in space, so that different parts face the sun at different times. Earth goes around the sun once (one "year") for every 365¼ times it turns all the way around (one "day").

Earth is the only planet in our solar system that has a large amount of liquidwater.[6] About 71% of the surface of Earth is covered by oceans. Because of this, people sometimes call it "blue planet".[7]

Because of its water, Earth is home to millions of species of plants and animals.[8][9] The things that live on Earth have changed its surface greatly. For example, early cyanobacteria changed the air and gave it oxygen. The living part of Earth's surface is called the "biosphere".[10]

Orbit and turning[change | change source]

Earth is part of the eight planets and many thousands of small bodies that move around the Sun as its solar system. The Solar System is moving through the Orion Arm of the Milky Waygalaxy now, and will be for about the next 10,000 years.[11]

Earth is generally 150,000,000 kilometers or 93,000,000 miles away from the sun (this distance is named an "Astronomical Unit"). Earth moves along its way at an average speed of about 30 km or 19 mi a second.[12] Earth turns all the way around about 365¼ times in the time it takes for Earth to go all the way around the sun.[13] To make up this extra bit of a day every year, an additional day is used every four years. This is named a "leap year".

The Moon goes around Earth at an average distance of 400,000 kilometers (250,000 mi). It is locked to Earth, so that it always has the same half facing Earth; the other half is called the "dark side of the moon". It takes about 27⅓ days for the Moon to go all the way around Earth, but because Earth is moving around the Sun at the same time, it takes about 29½ days for the Moon to go from dark to bright to dark again. This is where the word "month" came from, even though most months now have 30 or 31 days.

History of Earth[change | change source]

See also: Historical geology, Age of the Earth, Giant impact hypothesis, and Great Oxygenation Event

Earth and the other planets formed about 4.6 billion years ago.[14][15] They were made of the leftover gas from the nebula that made the Sun. The Moon may have been formed after a collision between the early Earth and a smaller planet (sometimes called Theia). Scientists believe that parts of both planets broke off — becoming (by gravity) the Moon.[16]

Earth's water came from different places. Condensingwater vapour, and comets and asteroids hitting Earth, made the oceans. Within a billion years (that is at about 3.6 billion years ago) the first lifeevolved, in the Archaeanera.[17] Some bacteria developed photosynthesis, which lets plants make food from the Sun's light and water. This released a lot of oxygen, which was first taken up by iron in solution. Eventually, free oxygen got into the atmosphere or air, making Earth's surface suitable for aerobic life (see Great Oxygenation Event). This oxygen also formed the ozonelayer which protects Earth's surface from bad ultravioletradiation from the Sun. Complex life on the surface of the land did not exist before the ozone layer.

Earth was very different in the distant past. Long ago, almost all land was in one place. This is called a supercontinent. The earliest known supercontinent was called Vaalbara. Much later, there was a time (the Cryogenian) when Earth was almost entirely covered by thick ice sheets (glaciers).[18] This is called the Snowball Earththeory.[18]

What it is made of[change | change source]

Earth is rocky. It is the largest of the rocky planets moving around the sun by mass and by size. It is much smaller than the gas giants such as Jupiter.

Chemical make-up[change | change source]

Overall, Earth is made of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%). The 1.2% left over is made of many different kinds of other chemicals. Chemicals that are very uncommon (such as gold and platinum) can be very valuable.

The structure of Earth changes from the inside to the outside. The center of earth (Earth's core) is mostly iron (88.8%), nickel (5.8%), sulfur (4.5%), and less than 1% other things.[19] The Earth's crust is largely oxygen (47%). Oxygen is normally a gas but it can join with other chemicals to make compounds like water and rocks. 99.22% of rocks have oxygen in them. The most common oxygen-having rocks are silica (made with silicon), alumina (made with aluminium), rust (made with iron), lime (made with calcium), magnesia (made with magnesium), potash (made with potassium), and sodium oxide, and there are others as well.[20]

Shape[change | change source]

Earth's shape is a spheroid: not quite a sphere because it is slightly squashed on the top and bottom. The shape is called an oblate spheroid. As Earth spins around itself, the centrifugal force forces the equator out a little and pulls the poles in a little. The equator, around the middle of Earth's surface, is about 40,075 kilometers or 24,900 miles long.

The highest mountain above sea level—the well-known Mount Everest (which is 8.8 km or 5.5 mi above sea level)—is not actually the one that is the farthest away from the center of the Earth. Instead, the sleeping volcanoMount Chimborazo in Ecuador is; it is only 6.3 km or 3.9 mi above sea level but it is almost at the equator. Because of this, Mount Chimborazo is 6,384.4 km or 3,967.1 mi from the center of the Earth, while Mount Everest is 2.1 kilometers or 1.3 miles closer to it.[21][22][23] Similarly, the lowest point below sea level that we are conscious of is the Challenger Deep in the Mariana Trench in the Pacific Ocean. It is about 10.9 km or 6.8 mi below sea level,[24] but, again, there are probably places at the bottom of the Arctic Ocean that are nearer to the center of the Earth.

[change | change source]

The deepest hole ever dug is only about 12.3 kilometers or 7.6 miles. We know something about the inside of the Earth, though, because we can learn things from earthquakes and the times when volcanoeserupt. We are able to see how quickly the shock waves move through Earth in different places.

The inside of Earth is very different from the outside. Almost all of Earth's liquid water is in the seas or close to the surface. The surface also has a lot of oxygen, which comes from plants. Small and simple kinds of life can live far under the surface, but animals and plants only live on the surface or in the seas. The rocks on the surface of Earth (Earth's crust) are well known. They are thicker where there is land, between 30 to 50 km or 19 to 31 mi thick. Under the seas they are sometimes only 6 km or 3.7 mi thick.[25] There are three groups of rocks that make up most of the Earth's crust. Some rock is made when the hot liquid rock comes from inside the earth (igneous rocks); another type of rock is made when sediment is laid down, usually under the sea (sedimentary rocks); and a third kind of rock is made when the other two are changed by very high temperature or pressure (metamorphic rocks). A very few rocks also fall out of the sky (meteorites).

Below the crust is warm and almost-liquid rock that is always moving around (the Earth's mantle). Then, there is a thin liquid layer of heated rock (the outer core). This is very hot: 7,000 °C or 13,000 °F.[26] The middle of the inside of the Earth would be liquid as well but all the weight of the rock above it pushes it back into being solid. This solid middle part (the inner core) is almost all iron. This is what makes the Earth magnetic.

Pieces of the crust form plates[change | change source]

Main article: Plate tectonics

The Earth's crust is solid but made of parts which move very slowly.[27] The thin level of hard rock on the outside of the Earth rests on hot liquid material below it in the deeper mantle.[28] This liquid material moves because it gets heat from the hot center of the earth. The slow movement of the plates is what causes earthquakes, volcanoes and large groups of mountains on the Earth.

There are three ways plates can come together. Two plates can move towards each other ("convergent" plate edges). This can form islands (such as Japan), volcanoes, and high mountain ranges (such as the Andes and Himalayas).[29] Two plates can move away from each other ("divergent" plate edges). This gives the warm liquid rock inside the earth a place to come out. This makes special mountain ranges below the sea or large low lands like Africa's Great Rift Valley.[30][31] Plates are able to move beside each other as well ("transform" plate edges, such as the San Andreas Fault). This makes their edges crush against each other and makes many shocks as they move.[32]

Surface[change | change source]

The outside of the Earth is not even. There are high places called mountains, and high flat places called plateaus. There are low places called valleys and canyons. For the most part, moving air and water from the sky and seasdamages rocks in high places and breaks them into small pieces. The air and water then move these pieces to lower places. Because of this, the Earth would have been very flat a long time before now. The fundamental cause of the differences in the Earth's surface is plate tectonics.

All places on Earth are made of, or are on top of, rocks. The outside of the Earth is usually not uncovered rock. Over 70% of the Earth is covered by seas full of salty water.[33] This salty water makes up about 97½% of all Earth's water. The fresh water people can drink is mostly ice. Only a very small amount is in rivers and under the Earth for people to drink and use.[34] The air above the Earth stops the water from going away into outer space. Also, much of the land on Earth is covered with plants, or with what is left from earlier living things. Places with very little rain are dry wastes called deserts. Deserts usually have few living things, but life is able to grow very quickly when these wastes have rainfall. Places with large amounts of rain may be large woods. Lately, people have changed the environment of the Earth a great deal.

Air[change | change source]

Main article: Atmosphere

All around the Earth is a large amount of air (the atmosphere). The mass of the Earth pulls the gasses in the air down and does not let them go into outer space. The air is mostly made of nitrogen (about 78%) and oxygen (about 21%) but there are a few other gasses as well.[35] Most living things need the air (or parts of the air gripped in the water) to breathe and live. They use the gasses—especially oxygen and carbon dioxide—to make and use sugar and to give themselves power.

The air animals and plants use to live is only the first level of the air around the Earth (the troposphere). The day to day changes in this level of air are named weather; the changes between places far away from each other and from year to year are named the climate. Rain and storms are both in this level. Both come about because this part of the air gets colder as it goes up. Cold air becomes thicker and falls, and warm air becomes thinner and goes up.[36] The turning Earth moves the air as well and air moves north and south because the middle of the Earth generally gets more power from the Sun and is warmer than the north and south points. At the same time, air over water (specially very warm water) gets water in it but, because cold air is not able to take in as much water, it starts to make clouds and rain as it gets colder. The way water moves around in a circle like this is called the water cycle.[36]

Above this first level, there are four other levels. The air gets colder as it goes up in the first level; in the second level (the stratosphere), the air gets warmer as it goes up. This level has a special kind of oxygen called ozone. The ozone in this air keeps living things safe from damaging rays from the Sun. The power from these rays is what makes this level warmer and warmer. The middle level (the mesosphere) gets colder and colder with height; the fourth level (the thermosphere) gets warmer and warmer; and the last level (the exosphere) is almost outer space and has very little air at all. It reaches about half the way to the Moon. The three outer levels have a lot of electric power moving through them; this is called the ionosphere and is important for radio and other electric waves in the air. It is also where the Northern Lights are.

Even though air seems very light, the weight of all of the air above the outside of the Earth (air pressure) is important. Generally, from sea level to the top of the outer level of the air, a space of air one square centimeter across has a mass of about 1.03 kg and a space of air one square inch across has a weight of about 14.7 pounds. The mass of the air also keeps the Earth safe when rocks (meteorites) hit it from outer space. Without the air, the damage meteorites do would be much greater. Because of the air, meteorites generally burn up long before they get to the earth.

The air also keeps the Earth warm, specially the half turned away from the Sun. Some gasses – especially methane and carbon dioxide – work like a blanket to keep things warm.[37]In the past, the Earth has been much warmer and much colder than it is now. Since people have grown used to the heat we have now, though, we do not want the Earth to be too much warmer or colder. Most of the ways people create electric power use burning kinds of carbon—especially coal, oil, and natural gas. Burning these creates new carbon dioxide and can cause more warming. A large discussion is going on now about what people should do about the Earth's latest warming, which has gone on for about 150 years. So far, this warming has been good for people: plants have grown better and the weather has been better than when it was colder before. Some people who learn about science, though, say that many bad things will possibly come about if the warming goes on.

People[change | change source]

Main article: Human

About seven billion people live on Earth. They live in about 200 different lands called countries. Some (like Russia) are large with many large cities. Others (like the Vatican) are small. The five countries with the most people are China, India, the United States, Indonesia, and Brazil. About 90% of people live in the north half of the world, which has most of the land. Scientists think that people originally came from Africa. Now, 70% of all people do not live in Africa but in Europe and Asia.[38]

People change the Earth in many ways. They have been able to grow plants for food and clothes for about ten thousand years. When there was enough food, they were able to build towns and cities. Near these places, men and women were able to change rivers, bring water to farms, and stop floods (rising water) from coming over their land. People found useful animals and bred them so they were easier to keep.

Related pages[change | change source]

References[change | change source]

  1. ↑By International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather than for the planet Earth. Cf.Blue, Jennifer (July 5, 2007). "Descriptor Terms (Feature Types)". Gazetteer of Planetary Nomenclature. USGS. Retrieved 2007-07-05. 
  2. 2.02.12.22.32.4Williams, Dr. David R. "Earth Fact Sheet". NASA. Retrieved 2011-02-03. 
  3. Allen, Clabon Walter; Cox, Arthur N. (2000). Allen's Astrophysical Quantities. Springer. p. 294. ISBN 0387987460. 
  4. Various (2000). David R. Lide, ed. Handbook of Chemistry and Physics (81st ed.). CRC. ISBN 0-8493-0481-4. 
  5. "The age of the Earth in the twentieth century- a problem (mostly) solved". Geological Society, London, Special Publications. Retrieved 2009-07-28. 
  6. "Rover reveals Mars was once wet enough for life". Microsoft. Retrieved 28 July 2009. 
  7. Blue Planet is a poetic title for the Earth used in movies, in cheap paper books, in poetry, and in government reports (such as the European Space Agency's "Exploring the water cycle of the 'Blue Planet'")
  8. "How many species are there on Earth". Harvard University. Retrieved 2009-07-28. 
  9. Purves, William Kirkwood; et al. (2001). Life, the science of biology. Macmillan. p. 455. ISBN 0716738732. 
  10. "Origins of life on Earth". Space.com. Retrieved 2009-07-28. 
  11. "Earth's location in the Milky Way". NASA. Retrieved 2009-08-06. 
  12. "NASA- an Earth fact sheet". NASA. Retrieved 2009-08-06. 
  13. Staff (2007-08-07). "Useful Constants". International Earth Rotation and Reference Systems Service. Retrieved 2008-09-23. 
  14. ↑Cite error: Invalid tag; no text was provided for refs named .
  15. ↑Dalrymple, G. Brent (2001). "The age of the Earth in the twentieth century: a problem (mostly) solved". Special Publications, Geological Society of London190 (1): 205–221. doi:10.1144/GSL.SP.2001.190.01.14. 
  16. "Origin of the Moon in a giant impact near the end of the Earth's formation". Nature.com. Retrieved 2009-07-28. 
  17. "Earth life appeared on land 1.5 billion years earlier than previously thought". SpaceRef.com. Retrieved 2009-07-03. 
Earth turns at an angle (an "axial tilt") in relation to its path around the Sun.
A picture of the inside of the Earth, showing the different levels. In fact, the air and the outside levels are much thinner than shown here
A picture showing the Earth's largest and most important plates.

0 Replies to “Essay On Our Planet Earth”

Lascia un Commento

L'indirizzo email non verrà pubblicato. I campi obbligatori sono contrassegnati *