Planetary Comparison Essay

Man first came to live by finding ways to sustain his life. He could think, decide, create an opinion and work with his bare hands. After many years of survival, he became more curious at the things around him. He saw the moon, the sun and the stars. It was when the man was curious that human life was considered intelligent life. Without man’s curiosity, he wouldn’t care about the planet that he is hosting his life. Without his brain, he wouldn’t know that other planets and other heavenly bodies exist aside from the planet Earth. The properties of planet Earth include its shape, density, reflection of light and age. The shape of the Earth resembles that of a sphere. It is a spherical planet because of gravity. What makes the Earth spherical is the bulging characteristic it has on the equator. The bulges exist on this part of the planet because of rotation. Properties of the Earth Density – As of the Earth’s density, it refers to the â€Å"mass per unit volume† of the planet. The density of the Earth can be better imagined if compared to the density of iron, rock or water. The density of is 8 grams per cubic centimeter, 2. 5 grams per cubic centimeter for a rock. With water, it is just a gram per cubic centimeter. Deep down the planet is surely a dense section of the Earth (Newman, 2000, p. 267). † Reflection of Light – Another property is reflection of light. The Earth has 37% albedo, which means that it has 37% of light that it is capable of reflecting. Again, to get the clearer picture, the reflection of light of the Earth can be compared to that of dirt, clouds and ice. Dirt can only reflect around 10%, while water and clouds have just enough albedo. When albedo is moderate, it means that the reflection of light ranges from 40 to 60 percent. Meanwhile, ice has a high albedo because its reflection of light is almost a solid one hundred percent (Hamilton, 2001). Age of the Earth – The age of the Earth is also another property of the planet. Planet Earth is as old as billions of years. With the help of radioactive dating of stones, scientists and geologists discovered that the Earth existed 3. to 4. 5 billion years ago (Hamilton, 2001). The Earth’s Interior The Earth’s interior is characterized by explosions, earthquakes and seismic waves. There are waves that travel in both solid and liquid parts of the Earth. There are also waves that run only on solid ground (Hamilton, 2001). Inside the Earth’s interior, one can find nickel, iron and solid in the inner core. In the Earth’s outer core are nickel, iron and liquid. It s mantle are oxygen and silicon, which, when combined, form silicate rocks. The temperature inside the Earth’s core is hotter than the surface of the sun because of radioactivity and collisions. During the early years of history, the Earth is molded by numerous collisions and the heat from this activity contributed to the 6500K temperature of the planet’s core (Hamilton, 2001). Surface Changes It is a fact that the surface of the Earth changes constantly. One activity that contributes in the surface change of the planet is continental drift. Continental drift, as its name implies, refers to the drifting apart of the Earth’s continents. The continents move over time, and such movements were better understood and explained as the Plate Tectonics Theory came out, describing the lithosphere of the planet (Hamilton, 2001). If the lithosphere breaks, tectonic plates are built. In this planet, there are plenty of minor tectonic plates. With major tectonic plates, there are only seven. There is movement among these plates at different kinds of boundaries which include transform boundaries, spreading or divergent boundaries and collision or convergent boundaries. These boundaries pave way to the formation of oceanic trenches, mountains, volcanic activities and even earthquakes. Imagine two pieces of large lands collide (Hamilton, 2001). The tension caused by the collision alters the shape of the pieces of land. This is what happens to planet Earth. Whatever type of activity there is, the surface of the Earth will always be affected (Hamilton, 2001). Even erosion affects the surface of the Earth. Erosion happens when particles like rock, soil and sediments are displaced or moved to other places. What cause the displacement are agents like water, living organisms and wind. Ice is also another cause of displacement because of the downward slope (Hamilton, 2001). The Earth and the Other Nine It cannot be denied that the Earth is special because compared to other planets in the solar system; it is only the Earth that is capable of sustaining life. It has an atmosphere. It has displacement of lands. It has plate tectonics. It has water. It has humans. The one thing that separates the Earth from the other planets is the human being and human life. There may be signs of the existence of life in Mars, and that there are other forms of life in the moon of Saturn, but only Earth is capable of supporting and maintaining life (Moskowitz, 2008). Intelligent Life – Even if it may be proven in the future that there are indeed organisms living in Mars, it is still safe to say that the Earth is home to intelligent life. Other planets may be able to host life, but only the planet Earth is capable of hosting the intelligent kind (Moskowitz, 2008). Life on other planets would not even be possible without the planet Earth, according to Gregory Laughlin. Laughlin is a planet hunter and an astrophysicist at the prestigious University of California, Santa Cruz. Gregory was able to say this because the Earth delicately transferred some of its materials to the other planets. These tiny materials can be found in the planet’s crust (Moskowitz, 2008). Water – Another feature of the Earth which cannot be found in other planets is water. The planet is indeed a place conducive for evolution because it has water in it, in that amount. The amount of water on Earth is almost magical. The amount of water present in this planet is just enough to keep a desert alive. There is not too much water to drown the Earth’s mountains (Moskowitz, 2008). Water on Earth is different from the water in the other planets because the water in the other planets either fry or freeze. This can be explained through the distance between the planet earth and the sun (Moskowitz, 2008). Distance – Distance, of course, is a unique feature of the planet. The Earth indeed has the best location in the solar system because if we depend on too much sun, then the distance between the planet and then sun is just right enough to match the Earth’s geological timescales (Moskowitz, 2008). It is the temperature we get from the sun that regulates the Earth’s atmosphere. It is the distance between the Earth and the sun that keeps the temperature of the Earth’s surface around the temperature of the waters (Moskowitz, 2008). Size – The size of the Earth is also another unique feature of the planet. A smaller Earth will not leave space for the planet to hold on to the atmosphere. A bigger Earth may be a hotter Earth for humans. Hotter in this sense means the kind of warmness which humans will not be able to tolerate (Moskowitz, 2008). Getting More Detailed Mercury is the nearest planet to the Sun. Among all the other planets, it is the eighth largest. It has two moons namely Titan and Ganymede. While these moons are smaller than Mercury, they are more massive than the planet. Mercury, compared to the Earth, is closer to the sun (Arnett, 2008). Venus, on the other hand, is the sixth largest planet in the solar system. It is also nearer to the sun compared to the Earth. It is an inferior planet with phases easily seen through a telescope from the Earth (Arnett, 2008). Aside from the Earth, Mars stands out to be a popular planet since the early times. Today, there are observatories that are ground-based just to study Mars. The size of Mars is a barrier in studying it, but the planet still shows features that can host life (Arnett, 2008). The biggest planet in the solar system is Jupiter. When it comes to mass, this planet is doubly massive compared to the Earth and to the other planets as well. In fact, when compared to the Earth’s mass, Jupiter has 318 times more (Arnett, 2008). Saturn is a popular planet since the prehistoric years because there was Galileo in 1610, holding a telescope, observing this planet with rings. Galileo knew that Saturn looked different and he thought that the Earth passes through the rings after some years on a regular basis (Arnett, 2008). If the Earth is spherical, then the planet Uranus is ecliptic. Unlike the Earth, Uranus’ poles are hotter than its equator. The poles of this planet are more receptive to the sun’s energy than the equator (Arnett, 2008). Neptune is far from the sun, but its core measures the same as that of the mass of the Earth. Its core is made of rocks. It does not have a unique internal layering like that of Saturn and Jupiter, but the composition is nonetheless distinct. Whatever heat it receives from the sun is nothing compared to the heat it can generate itself through its core (Arnett, 2008). Pluto is the smallest planet in the solar system. It has an eccentric orbit, which makes it closer to the sun at times than Neptune. Unlike the Earth and all the other planets, this heavenly body rotates in the opposite direction (Arnett, 2008). Above all these, it is still the Earth that stands out. All these pieces of information would not be known without the human mind, made possible with life, sustained by the Earth.