Excerpt from Essay :

Of those 1,235, 68 are estimated to be Earth-size; 288 are super Earth-size; 662 are Neptune-size; 165 are the size of Jupiter, and 19 are larger than Jupiter (Science Daily).

Of the 54 planet candidates that have been found in the habitable zone, five are near Earth-size. The other 49 left in the habitable zone range from super-Earth-size (up to twice the size of the Earth) -- to larger than Jupiter (Science Daily). All of these findings came from observations between May 12 to September 17, 2009 of more than 156,000 stars in Kepler's view (approximately 1/400 of the sky) (Science Daily).

This research has shown that the fact that so many candidates for planets have been found in such a tiny fraction of the sky (1/400) suggests that there are more planets orbiting sun-like stars in our galaxy -- many more than we can imagine (Science Daily). William Borucki of NASA's Ames Research Center in Moffett Field, California believes that some of these planet candidates in the habitable zone could potentially have moons with liquid water (Science Daily).

A new instrument called HARPS-North will help complement Kepler by helping to confirm and characterize Kepler's planetary Candidates (SIFY). HARPS stands for "High-Accuracy Radial velocity Planet Searcher" and it was created to detect the tiny radial-velocity signal induced by planets as small as Earth (SIFY). The Kepler mission gives the size of the planet based on light it blocks when it moves in front of stars, but planets need to have their planetary masses measured so that density can be measured. This will make it so rocky planets and water worlds can be identified -- as opposed to those that have atmospheres of hydrogen and helium (SIFY).

HARPS-North will look at the most interesting targets that Kepler finds. They will work as partners to find worlds that are similar to Earth and might be able to support life like human life (SIFY). A spectrograph operates by splitting the light from a star into its component wavelengths or colors (kind of like a prism) (Space Daily). Chemical elements absorb light of specific colors, leaving dark lines in the star's spectrum. Those lines change position slightly because of the Doppler shift created by the gravitation tug of an orbiting planet on its star (Science Daily).

1. Briefly relate several possible courses for the future of the universe and the kinds of observation that would be necessary to resolve the issue. Will the universe last forever or will it end? There is the possibility that the universe will come to an end in the opposite way of which it started. The opposite of the Big Bang is called the Big Crunch. The Big Crunch would happen when there is enough matter in the Universe that the gravitational forces will stop its expansion. Gravity will then cause the universe to change directions and begin to collapse under its own weight. It could even collapse into a giant black hole. There are some that believe if the universe did collapse into a giant black hole, it could then turn into another Big Bang. In this way, the universe could, potentially, live forever, but it would simply be going through these phases of contraction and expansion forever.

2. Outline the stellar nebula theory, and explain how the characteristic properties of the solar system provide evidence that supports that theory. The stellar nebula theory is the most widely used theory when it comes to explaining how our solar system was formed and how it evolved. It was first just applied to our own solar system, but it is now applied to the entire universe. According to the theory, stars form in massive and dense clouds of molecular hydrogen. The clouds are unstable gravitationally speaking and matter merges into smaller and more dense clumps inside. The clouds then collapse and they form stars. This can be the beginning of planets when the situation is right. Planets are believed to form thus as a direct and natural result of star formation.

3. Earth is considered a unique planet due to the five sub-spheres or sub-systems it has operating on it. These are Earth's lithosphere, hydrosphere, cryosphere...

Compare and contrast the planets Venus and Mars with regard to their either having or not having these sub-spheres. See the list below.

Atmosphere: Mars' lack of atmosphere has locked it in a deep freeze, while the greenhouse effect has made Venus frightfully hot (AIP).

O2CO2: Venus probably started out with the same CO2 as the Earth. Carl Sagan believed that though they may have started out the same, on Earth, most of the carbon was locked up in minerals and buried in sediments. The surface of Venus, however, was so hot and dry that carbon-bearing compounds evaporated rather than remaining in rocks (AIP). All CO2 is in the air on Venus while frozen water and most CO2 is in the soil.

Hydrosphere: Mars wasn't always a dead world; in fact, there is satellite evidence that suggests that there was once an active hydrosphere on Mars (which is where there has been talk of reviving it) (Think Quest).

H2O liquid/H2O Gas: On Venus, all water vapor and greenhouse heat surface bakes the CO2 out of rocks, which then creates more greenhouse and CO2 in air. On Mars, water vapor and liquid water and CO2 combined with rock; the temperature then dropped and frozen water was left in the soil (as well as (CO2) (Astronomy Notes).

4. Discuss the minor members of the solar system such as comets, meteors, and asteroids. Include in your answer their origin, properties, and geology, where it applies. The sun and the planets are the major players of the solar system, but not the only players in the solar system. There are thousands of asteroids and several tens of comets. These are remnants of the planetesimals that formed at the beginning of our solar system. They are more rocky objects with different shapes and dimensions and they orbit around the sun (PD Astro). Asteroids are sometimes referred to as minor planets and there is some controversy over the distinction between asteroids and comets. They are both made of volatile material. A meteoroids are the smallest rocks orbiting the sun (in order to distinguish them from larger asteroids). When one of them enters the Earth's atmosphere, the friction gets heated up and is disrupted. This luminous strip that is created in the sky is called a meteor, while the rock debris that hits the ground is called a meteorite (PD Astro).

Works Cited

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http://www.aip.org/history/climate/Venus.htm

Astronomy Notes. "Earth-Venus-Mars Comparison." Astronomy Notes. Accessed on February

17, 2011: http://www.astronomynotes.com/solarsys/EVMcomp.htm

Cain, F. "Radio galaxies." Universe Today, 2009. Web. Accessed on February 17, 2011:

http://www.universetoday.com/30590/radio-galaxies/

Nave, C.R. "Supernovae." Hyper Physics, 2011. Web. Accessed on February 17, 2011:

http://hyperphysics.phy-astr.gsu.edu/hbase/astro/snovcn.html

PD Astro. "Minor Bodies of the Solar System." Astro PD. 2011. Web. Accessed on February 17,

2011: http://www.pd.astro.it/E-MOSTRA/NEW/A2030MIN.htm

Science Daily. "NASA Finds Earth-Size Planet Candidates in Habitable Zone, Six Planet

System." Science News. Accessed on February 17, 2011:

http://www.sciencedaily.com/releases/2011/02/110202133321.htm

SIFY. "New Device to Help Confirm Kepler's Planetary Candidates." SIFY News. Accessed on February 17, 2011: http://www.sify.com/news/new-device-to-help-confirm-kepler-s-planetary-candidates-news-scitech-lcpnucecbfb.html

Soper, D.E. "Determining Distances Through the Moving Cluster Method." Institute of Theoretical Science, University of Oregon, 2007. Web. Accessed on February 17, 2011:

http://physics.uoregon.edu/~soper/Stars/movingcluster.html

Space Daily. "New Instrument Will Help Confirm Kepler Planet Finds." Space Daily. Accessed on February 17, 2011:

http://www.spacedaily.com/reports/New_Instrument_Will_Help_Confirm_Kepler_Planet_Finds_999.html

Think Quest. "Mars Terraformation." Think Quest. 2011. Web. Accessed on February 17, 2011:

http://library.thinkquest.org/C003763/index.php?page=mars04