Friday, January 07, 2000

will explain the four scenarios astronomers consider for Earth-Moon binary system formation. Moreover, this paper will tell what the main points of each scenario are including modern view and why that is. For the second section of atmosphere composition and characterizes, this paper will describe some of the important factors. These important factors tell the shaping, the surface and atmospheric conditions for the inner region planets and Earth's moon. Earth's moon is twice the size of Mercury.

There are four scenarios astronomers considered for the Earth-Moon binary system formation which are the following: the adopted-cousin theory, the sister theory, the daughter theory and the chip-off-the-old-block theory. The adopted cousin theory says that a small planet was captured by Earth's gravity. The sister theory says it is a double planet. The daughter theory states the moon broke apart from the spinning original Earth also known as primordial Earth. The chip-off-the-old-block theory was originated by computers simulation of the solar system. Billions of years ago, the evolving Earth had nearby neighbors called planetesimals (large mountain sized debris that was orbiting around Earth). I like the bull’s-eye concept in the book. From the initial supernova gave birth to the solar nebula with its orbiting cloud of gases and other elements such as iron, magnesium and sulfur. There was ice crystals that formed water molecules and combined over millions of years. The orbiting cloud of elements contained gases such as hydrogen, helium, oxygen, nitrogen, and carbon and other elements such as iron, silicon, magnesium and sulfur. The lighter gases evaporated from the sun’s radiation. It depended on the distance from the sun; which has eventually left the heavier elements such as rocks and metals which then formed the planetesimals that formed Mars, Mercury, Venus and Earth. Planetesimals were made in million years of evolution. It was the collision of one of these planetesimals with Earth which caused spewing matter from the Earth crust and material from the planetesimals to fly into space. Scientists have concluded the moon is actually a by-product of this earlier collision. To substantiate this theory, moon samples were obtained from Astronauts and other space exploratory devices. Moon rock is different from Earth rock. The chip-of-the-old block has become a de-facto modern theory accepted today. The chip-off-the-old-block theory pretty much debunks the other three theories. (Universe and Beyond, pp 22-23, 2004)

There are important factors that shape the surface and atmospheric conditions on the four inner region planets Earth-Moon, Mars, Venus and Mercury. In the following paragraphs, I will address these factors.

The Earth is the only planet to this day known to have life. There are three factors that helps maintain Earth's atmospheric composition which are as follows: the decomposition of the air molecules that takes place from the Sun's rays, the volcanic activity and the Earth's gravity. Over the early years, Earth had been bombarded by the elements from space and gradually over time, volcanic activity and collisions with comets has provided the Earth with atmospheric gases. Gravity helps maintain the gases and how much escapes through evaporation from the Sun's rays; therefore, Earth has been blessed with just the right atmospheric chemistry in order to maintain life. As far as geological landscape, the Earth landscape has evolved over the years, because of the wind, the rain, the volcano activity. We now have oceans, rivers, streams, mountains, and vegetation that prospers on Earth as we know it. The Earth's temperature is mostly maintained through our permeable cloud cover, Earth's mass and axis tilt and the atmospheric exchange of gases. (Universe and Beyond, pg 24, pp 36-37, 2004)

The moon has no atmosphere, no gases and minimal gravity to maintain its environment. If once there was volcanic activity on the moon, any gases derived from that volcanic activity would dissipate into space. This is mostly due to the moon's minimal gravity and the sun's assistance with evaporation. The moon is pretty much a battle scared, lifeless Antarctica. The temperature varies from space cold in the hemispheric section away from the Sun compared to sizzling hot in the hemisphere facing the Sun. (Universe and Beyond, pp 22-24, 2004)
The Mars atmosphere is less than 1% of Earth's of which carbine dioxide pretty much fulfills the 1%. Ultra-violet light dominates the planet due to the thin atmosphere. The temperature on Mars is cold all year around. In the winter, it is so cold, the atmosphere forms frozen CO2 crystals. It is obvious that there is no liquid form on Mars. Again, the temperature is relevant the thin atmospheric radiation exchange from the Sun. The terrain has a combination of sand dunes, canals, and rock surfaces. Mars is very windy especially in summer which might have gust of 300 KM per hour. Through satellite and pictures taken from robotic rovers, the landscape takes on a orange like hue. This is because the dust particles are stirred up by this windy planet. There is evidence that the planet once held liquid, but at present, scientists believe it is frozen deep into the ground. However, there are signs at one time liquid water did exist since space rovers have recovered sedimentary rock specimens which can easily be found in Earth's lakes and streams. One interesting fact about Mars, is that the tilt of the axis point is closely related to the Earth's. A day in Mars is 24.6 hours vs. Earth's 24 hours. Mars has a larger orbit area; therefore, one year on Mars equals 1.9 Earth years.
Mars is ½ the size of Earth, but 1/10 its mass. (Universe and Beyond, pp 24-30, 2004)
Venus, not like the Roman Goddess Venus, is comparable to Earth in size, mass and surface gravity; however, the temperature far exceeds our boiling point at 460 degrees Celsius hotter than melting lead. The atmosphere is 90% denser than Earth's and composed with mostly carbon dioxide. Since the atmosphere is so dense with carbon dioxide ,the constant volcanic activity produces additional gases enough to produce a greenhouse effect. This greenhouse cloud covering in the upper atmosphere then traps the gases and prevents the sun's infrared radiation from escaping. This makes the planet sizzling hot. The landscape is dominated with active volcanoes. The rotation of Venus is so slow that a day for Venus is equal to 59 Earth days, and the nights are equally long. The snail like rotation does not provide a magnetic field like the Earth's rotation does. (Universe and Beyond, pp 30-33, 36, 37, 2004)

Mercury, the closest to the sun, has temperatures of 400 degrees Celsius. Mercury's atmosphere is completely missing. It also has one third the Earth's gravity. Mercury is half the size of the moon. The landscape looks very much like the moon cratered by the insults of space debris. Mercury has little gravity and rotates slower than Venus. It rotates its axis three times the same time it orbits the Sun twice. One Mercury day equals 176 Earth days. (Universe and Beyond pp 38-39, 2004)

This paper showed the four scenarios astronomers consider for the Earth-Moon binary system formation. Second it showed the main points of each scenario are including modern view and why that is. The paper also concludes the atmosphere composition and characterizes, and described some of the important factors including shaping, the surface and atmospheric conditions.

Dickinson, T. (Ed.). (2004). "Chapter 2"
The Universe and Beyond, 4th Edition. (pg 22-23) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 24) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 36-37) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 24-30) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 30-33) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 36) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 37) Canada: Firefly Book, Inc.
Dickinson, T. (Ed.). (2004). " Chapter 2"
The Universe and Beyond, 4th Edition. (pg 38-39) Canada: Firefly Book, Inc.

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