Editing Impact event (section)

==References==
{{reflist|30em
| refs =

<ref name="US-Congress-20130410">{{cite web |author=U.S.Congress |title=Threats From Space: a Review of U.S. Government Efforts to Track and mitigate Asteroids and Meteors (Part I and Part II) – Hearing Before the Committee on Science, Space, and Technology House of Representatives One Hundred Thirteenth Congress First Session |url=http://www.gpo.gov/fdsys/pkg/CHRG-113hhrg80552/pdf/CHRG-113hhrg80552.pdf |date=Spring 2013 |type=Hearings held 19 March 2013 and 10 April 2013 |page=147 |work=[[United States Congress]] |access-date=3 May 2014 }}</ref>

<ref name="Earth-impact">{{cite web
  |date=2010
  |title=Earth Impact Effects Program
  |publisher=Imperial College London / Purdue University
  |author1=Robert Marcus |author2=H. Jay Melosh |author3=Gareth Collins |url=http://impact.ese.ic.ac.uk/ImpactEffects/
  |access-date=2013-02-04}} (solution using 2600kg/m^3, 17km/s, 45 degrees)</ref>

<ref name="UCB2013">{{cite web
  |date=February 7, 2013
  |title=New evidence comet or asteroid impact was last straw for dinosaurs
  |publisher=UC Berkeley News Center
  |author=Robert Sanders
  |url=http://newscenter.berkeley.edu/2013/02/07/new-evidence-comet-or-asteroid-impact-was-last-straw-for-dinosaurs/
  |access-date=2013-02-11}}</ref>

<!-- <ref name="science">{{cite web
  |date=Jan 28, 2013
  |title=Record Setting Asteroid Flyby
  |publisher=NASA Science
  |url=https://science.nasa.gov/science-news/science-at-nasa/2013/28jan_2012da/
  |access-date=2013-01-29}}</ref>

<ref name="Tunguska">{{cite web
  |date=June 30, 2008
  |title=The Tunguska Impact – 100 Years Later
  |publisher=NASA Science News
  |author= Tony Phillips
  |url=https://science.nasa.gov/science-news/science-at-nasa/2008/30jun_tunguska/
  |access-date=2013-02-12}}</ref>
 -->
}}