Sources:
title: Science Explorer Focus on Physical Science
Author: David V. Frank, Peter Kahan, John G. Little, Steve Miller, jay M.Pasachoff, Camille L. Wainwright
http://www.space.com/3-international-space-station.html
Stephen Hawking: Questioning the universe
http://www.ted.com/talks/stephen_hawking_asks_big_questions_about_the_universe.html
http://www.nasa.gov/mission_pages/station/main/iss_top_10.html
http://nineplanets.org/kboc.html
http://www.cnn.com/2013/10/22/world/international-space-station-fast-facts/
http://solarsystem.nasa.gov/index.cfm
Author: David V. Frank, Peter Kahan, John G. Little, Steve Miller, jay M.Pasachoff, Camille L. Wainwright
http://www.space.com/3-international-space-station.html
Stephen Hawking: Questioning the universe
http://www.ted.com/talks/stephen_hawking_asks_big_questions_about_the_universe.html
http://www.nasa.gov/mission_pages/station/main/iss_top_10.html
http://nineplanets.org/kboc.html
http://www.cnn.com/2013/10/22/world/international-space-station-fast-facts/
http://solarsystem.nasa.gov/index.cfm