There are about 5 very bright stars that I believe would be visible almost anywhere, but some of the stars were more difficult to discern and I had to look carefully to determine if they were stars or other forms of night sky light, like an airplane. 2. Exoplanets, or extrasolar planets, are planets that orbit stars other than the sun. Do a web search on exoplanets. How many of these planets are thought to have been detected? 843 as of November 2, 2012

How were they detected? Most were detected using high-power telescopes and the radial velocity method, which helps differentiate the light from those planets from the light of the suns that they orbit.

Do any of these planets orbit stars similar to the sun? Yes.

Are any of these planets similar to Earth in terms of size and mass? Yes, in the Kepler 20 star system

List some of the issues that make human space travel within the solar system difficult. The sheer distance between astronomical bodies makes human space travel within the solar system difficult; the time required to cover the space is so extensive that it is difficult, if not impossible, to equip a vehicle with enough resources to provide for human passengers for the duration of a flight of that length is also a challenge. Furthermore, the human body deteriorates during space travel and a space traveler would lose muscle tone if in space long enough to travel to distant astronomical bodies.

What are the factors that make human interstellar space travel unlikely even for the distant future? The deterioration...

(2012, March 11). Characteristics of the sun. Retrieved November 5,
2012 from Universe Today website: http://www.universetoday.com/94252/characteristics-of-the-sun/

Coffey, J. (2008, June 18). Size of Jupiter. Retrieved November 5, 2012 from Universe Today

website: http://www.universetoday.com/15149/size-of-jupiter/

Enchanted Learning. (2010). "Jupiter's moons." Jupiter. Retrieved November 5, 2012 from Enchanted Learning website: http://www.enchantedlearning.com/subjects/astronomy/planets/jupiter/moons.shtml

Pandian, J. (2002). "How does the location of sunrise and sunset change throughout the year?"

Curious About Astronomy: Ask an Astronomer. Retrieved November 5, 2012 from Cornell University website: http://curious.astro.cornell.edu/question.php?number=186

The Planetary Society. (2012). Extrasolar Planets. Retrieved November 5, 2012 from the

Planetary Society website: http://www.planetary.org/explore/space-topics/exoplanets/

Seligman, C. (Unk.) "The Motion of the Moon." The Sky. Retrieved November 5, 2012…