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WELCOME TO FREDRIK ANTHONY GARCIAS HOMEPAGE ON THE INTERNET | ||
| THIS SITE CONTAINS INFORMATION ABOUT SOME PLANETS IN OUR SOLAR SYSTEM | ||
  MERCURY 
You are standing on the blistering surface of Mercury. To the east, you can see the Sun rise. It appears much larger than it does on Earth, because Mercury is less than half Earth's distance from the Sun. You watch as the boiling sphere rises just above the horizon and hangs there in the sky. Soon you notice that the Sun seems to be expanding, growing larger and larger. Time passes, and the Sun expands to its full size. Then it shrinks slowly back to its original form. Suddenly, it travels quickly to the west. You think it is about to set, but you are amazed to see it rise, waver, and rush eastward! As it rises to the zenith and stops, you notice that it begins to grow larger and larger. Finally, it travels west again to set, oscillating as it disappears below the horizon. This entire spectacle takes 88 Earth days from sunrise to sunset. From another location on Mercury's surface, you can see the Sun rise and set twice in the same amount of time. Why does the Sun dance so strangely across the Mercurian sky? What makes it seem to move west, then east, then swing west again to set? As you watch this strange pattern, you understand what sets it in motion. It takes 59 Earth days for Mercury to rotate once on its axis. It takes 88 Earth days for Mercury to complete its journey around the Sun. After two Mercurian years, the planet will have rotated three times. It is this two-to-three ratio that creates the odd solar movements across Mercury's sky. Sometimes Mercury's orbit around the Sun and its revolution on its axis are "in sync" with each other, creating the illusion that the Sun has halted completely in the sky. Soon afterwards, the orbit around the Sun overtakes the planet's revolution. The Sun then appears to be moving backward. You also notice that the path Mercury takes around the Sun is unusually elliptical. At its closest point, Mercury is less than one-third Earth's distance from the Sun. At its farthest point, it is a little less than half that distance. This orbital variation is what makes the Sun appear to grow and shrink in size. Standing on the surface of Mercury and looking at your surroundings, it seems to you that it is a hellish world. When the Sun ignited, the gases held by this planet's feeble gravity were ripped away. There is no atmosphere to speak of -- Mercury is almost a vacuum. Everything is eerily silent. You toss a rock across the barren surface, but there is no sound. There is not enough atmosphere to carry sound across the surface. You know that the enormous core of this planet is mostly iron. Will some future space expedition try to mine this rich deposit? The surface gives no clue to its hidden riches. It is as barren and pock-marked as Earth's Moon. Without a protective atmosphere, Mercury has stood naked before the violent meteorite bombardments of the early solar system. Temperatures on the planet's surface range from boiling to freezing. During the day, temperatures rise as high as 400 degrees Fahrenheit. It can be even hotter at the equator, where the rays of the Sun linger. At night, temperatures drop as low as minus 300 degrees Fahrenheit, as the heat of the day drifts off into space. Without an atmosphere, Mercury can't hold onto any warmth after the Sun sets. You look up into the night sky and see two brilliant stars that are bright enough to cast shadows. You know, however, that these bright objects are not really stars. They are Venus and Earth. Looking closely, you can see our Moon -- a tiny pinpoint of light next to its brighter host. It is Venus that draws your attention, however. Venus shines brighter than any other object in the night sky, and you wonder what that world is like. You command yourself to travel, and suddenly you are there. To read about our sister planet, TURN TO THE NEXT TOPIC. 
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VENUSYou are standing on the surface of Venus. Before you is a bleak wasteland, a barren plain of crumbling rock. Although it is noon, there is little light. The creamy yellow clouds that completely cover the surface reflect 98 percent of the Sun's rays. Lightning flashes in the distance as an acid rainstorm forms to the west. The rain never reaches the surface, but it is almost constantly falling. It evaporates before it hits the ground, only to condense and fall again. There is no water on Venus -- only sulphur rain and carbon dioxide. Looking up through the darkness, you are aware of clouds rushing overhead. You are standing on the day side of the planet. Because Venus rotates only once every 243 Earth days, the Sun superheats the clouds, causing them to race around the planet almost three times faster than hurricane force winds on Earth. The clouds of Venus float much higher above the surface than Earth's clouds. The high carbon dioxide content of the thick atmosphere traps the Sun's heat, creating a greenhouse effect that keeps the surface blisteringly hot. You suspect the temperature is more than 800 degrees Fahrenheit. The surface is very still. You detect very little wind, since most of the wind is found in the upper cloud levels. An occasional surface breeze can knock you off your feet, however. The clouds compact the atmospheric gases so tightly that they have a liquid consistency. As you feel the thick weight of this atmosphere, you feel as if you were half a kilometer beneath one of Earth's oceans. Objects in the distance appear to ripple and shimmer. You find yourself using swimming motions when you try to walk. Out of curiosity, you reach into your pocket and take out a quarter. Holding it high over your head, you drop it and watch it float lazily to the ground. Looking around the surface, you see many strange formations. There are many domes of rock dotting the surface. As you move closer, you notice that these domes are volcanoes. Many of the volcanoes on the planet's surface are active, contributing to the high levels of carbon dioxide in the oppressive atmosphere. You travel to a huge stretch of mountains. Some of these are taller than Earth's Mount Everest. The mountains range across an area larger than Australia, and many are volcanic. This world puzzles you. Venus and Earth are about the same size, and Venus is only 30 percent closer to the Sun. Why are they so different if they both formed an atmosphere through the same volcanic processes? The answer is water. When Earth developed its atmosphere, much of the carbon dioxide was absorbed by its oceans. But Venus was too close to the Sun to hold on to its water. As the carbon dioxide in the atmosphere increased, the greenhouse effect became increasingly pronounced, and the oceans slowly boiled away. You are now floating above the planet Venus, looking down at the beautiful yellow clouds that reflect the sunlight like a shining jewel. The clouds are rushing madly beneath you now. It is time to move on. To learn about Mars, the red planet, TURN TO THE NEXT TOPIC. | |
 
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MARS
Mars is a quiet world. As quiet as a tomb. Mars has no life, although it may have been able to support life in its distant past. The potential for life may still remain, locked away in its rocks and polar caps. Mars is only one-third Earth's size, but its surface features dwarf those on Earth. Its mountains and volcanoes tower over Earth's tallest peaks. One mountain, named "Olympus Mons," is three times taller than Mount Everest. The Martian surface is scarred by impact craters, evidence of the same violent bombardments that marred the surfaces of the other rocky worlds. Rocky debris litters the Martian landscape. Some of the canyons on Mars are much deeper than Earth's Grand Canyon. They were carved out by huge rivers that once flowed across the Martian landscape. Now, the rivers are gone. Any remaining water is frozen. The atmosphere is so thin and the temperatures so cold that water cannot exist as a liquid. It quickly evaporates. Water is locked in the polar ice caps and in a layer of permafrost beneath the Martian surface. Moisture is locked in the soil itself. If you scoop up a handful of the rocky soil, you can see tiny droplets of water quickly evaporating in the thin air. Snow covers the polar ice caps, but it is not water. This snow is made from frozen carbon dioxide. These blankets of dry ice cover the frozen water locked in the polar caps. Why is Mars a dead planet? It once had water. What happened to it? In its formative years, Mars was a volcanic world like Venus and Earth. Perhaps, for a time, the heat and gases from volcanic activity allowed water to flow as a liquid. Torrents of water once formed the ravines and riverbeds still visible on its surface. Because Mars is much smaller than Earth, its gravity is too weak to hold on to an atmosphere, and the gases slowly dispersed into space. Without a protective blanket to capture the Sun's heat, the water evaporated and froze. Occasional periods of volcanic activity may have melted the ice caps for a time, spreading water across the landscape once again. An alternating pattern of volcanic activity and quiet may have created the complex, intricate formations you see on the Martian surface. Although they have been quiet for eons, Martian volcanoes may still be active. If so, the atmosphere-generating process may begin again. To learn about the gas giants of our solar system, TURN TO THE NEXT SECTION. 
MORE INFORMATION ABOUT OUR SOLARSYSTEM
This site contains information about the big planet in our solar system |
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WELCOME TO FREDRIK ANHTONY GARCIAS HOMEPAGE
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