Abstract
This paper examines recent discoveries in the search for extrasolar planets. The author also discusses how this has become a viable area of research in astronomy. This study is divided into six sections. They include: definition of planets, how planets form, methods of detection, properties of extrasolar planets, and future implications of detection. The paper concludes acknowledging how extrasolar planetary research has opened up avenues of thought and possibilities that were seen as impossible just a few decades ago.

Outline:
Introduction and History
Definition of Planets and Extrasolar Planets
How Extrasolar Planets Form
Methods of Detection
Properties of Extrasolar Planets
Future Implications of Detection
Conclusion

From the Paper
"The search for extrasolar planets has a long history. The notion that there might be other worlds existing in the heavens can be demonstrated as far back as ancient Greece. In more modern times, a Catholic monk was condemned for heresy in 1584 for suggesting that the sky was populated by countless suns and countless other Earths ("From Intuition" par. 1). The purpose of this essay is to describe and analyze the current search for extrasolar planets that has produced significant results within the last decade. What was once a fanciful possibility in astronomy has become a viable avenue of research, with new extrasolar planets being discovered every year. The remainder of this study will be divided into six sections. They include: definition of planets, how planets form, methods of detection, properties of extrasolar planets, future implications of detection, and conclusions."

Tags:extrasolar, planets, astronomy, stars, galaxies

Abstract
This paper discusses the consensus reached by the International Astronomical Union in 2006 on the official definition of a planet, and the consequent reclassification of Pluto as a "dwarf planet." The writer explains what is known about Pluto today and describes the background to the controversy and the discoveries that led to the challenging of Pluto's status as a planet. Many scientists today still believe that Pluto is in fact a planet, and support a more expansive definition of what are called planets. The paper concludes that, as our knowledge of what constitutes planets continues to expand, Pluto may once again be considered a planet.

From the Paper
"The recent controversy over Pluto's status as a planet reveals the fact that quite often, what seems like a scientific certainty is still quite contentious within the scientific community, when new discoveries are made through improved technology. In 1995, discoveries of large planets around other stars, plus new objects that are neither planet nor star, and free-floating objects in space that look like planets but do not orbit stars forced astronomers to reformulate definitions of what constituted a planet (Britt 2000). Extrasolar planets may originate as brown dwarf stars, lack light, and are even in some cases as large as Jupiter, yet they orbit stars like planets (Britt 2000). In defining whether these burnt-out brown dwarfs were planets in the early 90s were planets, the issue of Pluto's planetary status again came to the forefront of scientific debate."

Tags:comet, solar system, trans-Neptunian extrasolar, Kuiper Belt, asteroid universe orbit satellite

Abstract
This paper compares eight planets in the solar system -- Venus, Mercury, Mars, Jupiter, Saturn, Neptune, Uranus and Pluto-- to the planet Earth in terms of structure, atmosphere, chemical composition, and possibility of life at some time.

From the Paper
"The Earth is the third planet and the most massive of the inner planets. (Encrenaz, Bibring and Blanc) Its average density differs from that of the silicates that form most of the superficial rock surface. Seismic measurements and natural volcanic eruptions indicate that the internal structure consists of several distinct layers, a central core with a radius surrounded by a mantle and then a thin crust. There is a discontinuity between the crust lithosphere and the mantle asthenosphere. The mantle is..."

Tags:planetary comparison, planets, Solar, Venus, Mercury, Mars, Jupiter, Saturn, Neptune, Uranus, Pluto, Earth

Abstract
This paper argues that the use of astrobiology to explore life on other planets is a waste of resources that would be better applied to resolving problems here on Earth. It includes a Summary, Analysis, Evaluation, and Definition.

From the Paper
"From NASA's point of view astro-biology is the best approach for exploring life on other planets. Their reasons for asserting this are threefold. First NASA's proven and reliable Deep Space Network astro-biology technology has been in operation for years. Second NASA's technology is not only reliable but increasingly sophisticated having grown through the years to meet the new demands. Third pitted against comparable equipment NASA's Deep Space Network is the most sensitive and reliable deep space ..."

Tags:astrobiology, NASA, SETI, alien, planets, space exploration

Abstract
This paper examines three planets namely Venus, Saturn and Jupiter and provides some factual information about them and their motion relative to earth. For each planet in turn, it provides information on the history of its name, examines its atmosphere and composition, missions to the particular planet as well as providing a comparison of the chemical and physical makeup of the planets with Earth.

From the Paper
"It takes Saturn 29.5 years to complete one revolution around the Sun. As it circles the Sun, the angle of the Saturn's rings relative to the Sun varies by 27.3 degrees. During this motion a very peculiar phenomenon is observed. Twice during the 29.5 years, the rings are edge-on to the Sun. Since, as seen from Saturn, the Earth appears not more then 6 degrees from the Sun, it too crosses the ring plane at around the same time. Since Saturn's rings are so thin, when they are edge-on to the Earth, they appear to disappear when viewed with a small telescope."

Tags:atmosphere, earth, magnetosphere, missions, moons

Abstract
This paper begins with a definition and description of the planets within our solar system and then goes on to discuss extra-solar planets and the ongoing search for them. The paper describes some of the technology and techniques employed in this search, a discovery of an extra-solar planet by scientists at the Geneva Observatory in Switzerland, and recent advances in locating extra-solar planetary objects.

From the Paper
"The word planet means "wanderer" in Greek. It derives from the fact that planets within our solar system seem generally to wander eastward about the so-called fixed stars across the zodiac constellations (Kolb). There is no clear consensus precisely defining what constitutes a planet, as distinguished from brown dwarfs, which are the material remnants of burned out ancient stars whose masses where too small to form white dwarfs or collapse completely, forming black holes in the manner that stars much larger than ten solar masses, or ten times the mass of our sun (Hawking)."

Tags:body, emits, light, energy, orbits, star, reflecting, size, mass, jupiter, mars, pluto, terrestrial

Abstract
A detailed survey of the planets. The author looks at the space age and how knowledge has developed over time. Includes a detailed discussion of each era from 1957 when the Soviet Union launched Sputnik to the present.

From the Paper
"Think of how exciting it must have been to live in the days when the telescope was first turned to the heavens. Every part of the sky offered a new surprise. The planets were transformed from specs of light to globes with unique characteristics. Could there be a more thrilling time of planetary discovery than those days of Galileo and the first telescopes? Yes, we live in such a time. How could the glimpses those early telescopes gave compare in richness to the dozens upon dozens of photographs and storehouses full of other data collected in the past few decades? Thanks to the spacecraft, we have finally started to know the planets as real places, both like and unlike Earth."

Tags:planets, stars, telescope, moon, earth, spacecraft

Abstract
This paper examines why Earth is the only planet in our solar system capable of sustaining life and how it is the only planet that has plentiful liquid water and an atmosphere that can protect the planet from the harmful ultra-violet rays of the Sun. The paper attempts to determine what makes Earth so special by using comparative planetology to understand what makes Earth a habitat for life and what makes it so different from the other planets in our solar system.

Outline:
Terrestrial Planets
Jovian Planets
Conclusion

From the Paper
"If we were to look at Earth as a starting point to compare the other eight planets in our solar system, the first thing we notice from space is the magnificent blue color and swirls of clouds. This is an inviting sight and is the first hint at why life is found on our planet. Earth has many features that the other planets do not have. Earth has many features that make it unique. Earth is made of rock and metal. It is one of the four terrestrial planets and has the largest Moon in the solar system. Earth has abundant volcanic activity because of its size in comparison to the other terrestrial planets. With the abundance of water and oxygen, Earth's atmosphere stays in balance and is able to continue supporting life. The liquid oceans help to remove carbon dioxide from the atmosphere and the presence of a stratosphere helps protect the surface from the deadly ultra-violet rays of the Sun. Another unique feature of Earth is plate tectonics. Plate tectonics acts as giant conveyor belt that moves the mantle of Earth around, which constantly changes the look of our planet. Although Earth's interior needs much more exploration, scientists can tell about the composition of the deepest regions of Earth by using seismic waves following an earthquake. By reading this seismic data carefully, scientists get a better understanding of interior Earth."

Tags:jupiter, sun, moon, jovian

Abstract
The paper reveals how politics determine the direction planetary classification will take in astronomy. More than that, the paper looks at how the current debate over Pluto evolved, who was invested in what, and the history of mankind's efforts to arrive at a working typology for the solar system. Additionally, the paper considers the implications of the new classification structure.

From the Paper
"What is a dwarf planet? Answer: A dwarf planet is an object that does not gravitationally dominate its small region of the solar system, is not a satellite, and is nearly round. Looking at the items discussed in one of the sidebars found within the article, it is clear that the twelve dwarf planets are not really planets but are, instead, dwarfs for the simple reason that at least one of them is spherical rather than round and the rest do not appear to be items that dominate their sector of the solar system. Admittedly, though, there is some question about whether or not the current definition of..."

Tags:planets, pluto, classification