The Solar System Essay Research Paper Our — страница 2

  • Просмотров 201
  • Скачиваний 5
  • Размер файла 18

The surface temperature is approximately 750 K, even hotter than Mercury’s noon temperatures. The large amount of carbon dioxide in Venus’ atmosphere accounts for the extremely high temperatures near the planet’s surface and the greenhouse effect that traps and absorbs the sun’s heat. Because of the clouds, only 15% of the sun’s light reach the planet’s surface. Days on Venus are dim and overcast. Some places on Venus the surface has been severely fractured and folded by stress caused by the convection of the Venusian mantle, the part of the planet just above the core. The highest mountain on Venus, Maxwell Montes, is about 7 1/2 miles high and might possibly be a volcano. After Venus is our planet, Earth. Earth is the 5th largest planet and 149,600,000 km from the

sun. Earth is divided into several layers that have distinct chemical and seismic properties. The crust varies considerably in thickness, it is thinner under the oceans, thicker under the continents. The inner core and crust are solid; the outer core and mantle layers are plastic or semi-fluid. The various layers are separated by, which are evident in seismic data; the best known of these is the discontinuity between the crust and upper mantle. Most of the mass of the Earth is in the mantle, most of the rest is in the core. The core is probably composed mostly of iron though it is possible that some lighter elements may be present, too. Temperatures at the center of the core may be as high as 7500 K. The lower mantle is probably mostly silicon, magnesium and oxygen with some

iron, calcium and aluminum. Unlike the other planets, Earth’s crust is divided into several separate solid plates, which float around independently on top of the hot mantle below. There are (at present) eight major plates and twenty more small plates. The Earth’s surface is covered with 71% water, which is also responsible for most of the erosion and weathering of the Earth’s continents. Earth’s temperature is relatively stable. The atmosphere of the Earth is 77% nitrogen , 21% oxygen, with traces of argon, carbon dioxide and water. The greenhouse effect raises the average surface temperature about 35 degrees C above what it would be without the oceans would freeze and live we know it would be impossible. Earth only has one natural satellite, but thousands of small

artificial satellites have also been place in orbit around the Earth. Mars, the fourth planet from the Sun, is also the seventh largest. Mares are 277,940,000 km from the Sun. Named after the Greek god of War, Mars has been known since prehistoric times as an object of great interest to astronomers. Unlike Venus, Mars generally has no obscuring layer of clouds. In addition, it passes relatively close the Earth in its orbit. Mars is about half the size of the Earth and its atmosphere is composed mostly of carbon dioxide. The temperature at the planet’s surface varies widely during the course of a Martian day, form about 190 K just before dawn to about 240 K in the afternoon. At the center of the planet is probably a small iron or iron sulfide core. If Mars has a magnetic field,

it is so week that no instrument has been able to detect it. Mars like the Earth is tilted on its rotational axis. Liquid water cannot exist on Mars’s surface because of the low temperature and pressure’ water exists only as ice deposited at the poles and perhaps trapped below the surface and as vapor in the atmosphere. Mars is very desolate and barren and is covered in craters and are prone to violent sandstorms. The UV radiation of Mars would kill any known life. Mars has the largest volcano in the solar system, Olympus Mons, at a height of 17 miles, the volcano is three times higher than Earth’s Mount Everest. Valk Marineris, a 2,000-mile canyon that is three times deeper than the Grand Canyon. Mars has a very thin atmosphere composed mostly of the tiny amount of

remaining carbon dioxide plus nitrogen, argon, and traces of oxygen and water. Mars has two moons Phobos and Demos. Between Mars and Jupiter there is the Asteroid Belt. An Asteroid is a small rocky chunk of mater that range in size from579 miles and in diameter to less than .6 miles in diameter. Most of them are small and are believed to be planetesimals ancient chunks of matter that originated with the solar system. There are 5,000 tracked and documented asteroids, 13,000 are identified, and there are an estimated 1,000,000 of them. Objects that cross the Earths orbit and could possible hit earth are called Apollo Objects Jupiter the largest of the planets and is the fifth planet from the Sun. Jupiter is 1300 times larger than the Earth and more than twice as all the other