Works cited
http://www.ugr.es/~mlamolda/congresos/bioeventos/hildebrand.html
http://www.bbspot.com/News/2007/02/giant-meteor-covered-in-germs.html
http://ehttp://dinosaurs.suite101.com/article.cfm/mass_extinction_at_the_cretaceoustertiary_bound
- http://www.knowledgerush.com/kr/encyclopedia/Cretaceous-Tertiary_extinction_event/
- http://www.absoluteastronomy.com/topics/Cretaceous-Tertiary_extinction_event
- http://www.absoluteastronomy.com/topics/Chicxulub_Crater
n.wikipedia.org/wiki/Impact_event
http://www.scienceclarified.com/scitech/Comets-and-Asteroids/When-Comets-and-Asteroids-Strike-Earth.html
http://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event
http://www.youtube.com/watch?v=vdSTE4jWJmk&feature=related
http://en.wikipedia.org/wiki/Holocene_extinction_event
http://www.jpl.nasa.gov/news/features.cfm?feature=8
http://en.wikipedia.org/wiki/Deccan_Traps
http://earthsci.org/education/teacher/basicgeol/meteorn_add/met_extinct.html
http://www.youtube.com/watch?v=SbXDRJtL3d8&feature=related
http://www.n https://muconnect.muohio.edu/owa/redir.aspx?C=8c60193b98754af58fbf72c6074ec763&URL=http%3a%2f%2fwww.lpl.arizona.edu%2fimpacteffects%2fasa.gov/
[1][1] Extraterrestrial Cause for the Cretaceous-Tertiary Extinction
Luis W. Alvarez 1, Walter Alvarez 2, Frank Asaro 3, and Helen V. Michel 4 http://www.sciencemag.org/cgi/content/abstract/208/4448/1095
[2][2] Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards
Nick Bostrom
http://www.nickbostrom.com/existential/risks.html
[3][3] Whew! (Time Magazine) Leon Jaroff http://www.time.com/time/magazine/article/0,9171,138814,00.html?iid=chix-sphere
[4][4] http://neo.jpl.nasa.gov/risk/2007vk184.html
[5][5] Asteroid 1950 DA
http://neo.jpl.nasa.gov/1950da/