Courtesy: http://www.phantichkinhte123.com/p/blog-page_16.html
What makes Earth unique?
Our planet earth is one of the smaller planets of the solar system. The Earth is much closer to a perfect sphere. The Earth is probably also unique in the amount of water it possesses. One of the characteristic of the earth that makes it stand out among other planets is its weight.Earth is one special planet.It has liquid water, plate tectonics, and an atmosphere that shelters it from the worst of the sun’s rays. But many scientists agree our planet’s most special feature might just be us.
Earth is one special planet.
It has liquid water, plate tectonics, and an atmosphere that shelters it from the worst of the sun’s rays. But many scientists agree our planet’s most special feature might just be us.
The Earth is the only planet circling our sun on which life as we know it could (and does) exist. A brief glance at the Earth and all other known planets finds many startling contrasts. The Earth as a planet consists mostly of iron, oxygen, sulfur, silicon, magnesium, and nickel (total, 98%), with the other two percent consisting of about a hundred other elements. Like no other planet, ours is covered with green vegetation, blue-green seas, streams, rivers, mountains, and deserts which produce a spectacular variety of color and texture—all other known planets are covered with lifeless soil which varies only according to slight movements made by wind or mild air currents. Completely barren, the surface of most planets is totally in contrast to the Earth’s with its blue lakes, green oceans, huge land masses and 500,000 islands. Even from a distance, its colors are quite lively—bright greens, blues and whites—whereas the surface of all other known planets are rather dull.
Some type of life is found in every niche on the Earth. Even in the extremely cold Antarctica, hardy microscopic beings exist in ponds, tiny wingless insects live in patches of moss and lichen, and even two types of plants flower yearly. From the top of the atmosphere to the bottom of the oceans, from the coldest part of the poles to the warmest part of the equator, life persists here. To this day no sign of life has been found on any other planet.
The Earth is immense—8,000 miles in diameter and weighing roughly 6.6 x 1021 tons. If the Earth traveled much faster in its 292-million-mile-long orbit around the sun, centrifugal force would pull it away from the sun, and if too far, all life would cease to exist. If it traveled slightly slower, the Earth would move closer to the sun, and if it moved too close, all life would likewise perish. The Earth’s 365 day, 5-hour, 48-minute and 45.51-second-round-trip is accurate to a thousandth of a second! If the yearly average temperature on Earth rose or fell only a few degrees, most life on it would soon roast or freeze. This change would upset the water-ice and other balances, with disastrous results. If it rotated on its axis slower, all life would die in time, either by freezing at night because of lack of heat from the sun, or by burning during the day from too much sun.As far as science “knows,” the planet earth is unique in the entire universe. Certainly this is true in our own solar system. Nothing that we have observed leads us to believe that there is any other planet like earth.
haideelucernaxx 
Recent Comments