Editing Eugene Merle Shoemaker (section)

== Scientific contributions ==
[[File:Gene shoemaker with rocket belt.jpg|thumb|150px|Eugene Shoemaker wearing a [[Bell Rocket Belt]] while training astronauts.]]

The [[United States Geological Survey]] (USGS) hired Shoemaker in 1950, and he maintained an association with the organisation for the rest of his career.<ref name="Kieffer"/> His first assignment was to search for uranium deposits in Utah and Colorado. His next mission was to study volcanic processes, since other investigators had already noticed that uranium deposits were often located in the vents of ancient volcanoes. This study led him to explore the [[Hopi Buttes]] of Northern Arizona, which happened to be near [[Meteor Crater]].<ref name="Kieffer"/>

[[Daniel Barringer (geologist)|Daniel Barringer]], an entrepreneur and mining engineer who had discovered Meteor Crater in 1891, had postulated that it had been caused by the impact of a meteor. About the same time, [[Grove Karl Gilbert|G. K. Gilbert]], the chief geologist of the USGS, examined the crater and announced that it had been created by an explosive venting of volcanic steam. A majority of scientists accepted Gilbert's explanation of the cause of the crater, and it remained the conventional wisdom until Shoemaker's investigations half a century later.<ref name="Kieffer"/>

For his PhD degree at [[Princeton University|Princeton]] (1960), under the guidance of [[Harry Hammond Hess]], Shoemaker studied the impact dynamics of [[Meteor Crater|Barringer Meteor Crater]].  Shoemaker noted Meteor Crater had the same form and structure as two [[explosion crater]]s created from [[Nuclear weapon|atomic bomb]] tests at the [[Nevada Test Site]], notably [[Operation Buster-Jangle|Jangle U]] in 1951 and [[Operation Teapot|Teapot Ess]] in 1955. In 1960, [[Edward C. T. Chao]] and Shoemaker identified shocked quartz ([[coesite]]) at Meteor Crater, proving the crater was formed from an impact generating extremely high temperatures and pressures.  They followed this discovery with the identification of coesite within [[suevite]] at [[Nördlinger Ries]], proving its impact origin.<ref name="Levy">{{cite book |last=Levy |first=David |title=Shoemaker by Levy: The man who made an impact |date=2002 |publisher=Princeton University Press |location=Princeton |isbn=978-0691113258}}</ref>{{rp|69, 74–75, 78–79, 81–85, 99–100}}

===Astrogeology and Apollo===

[[File:Shoemaker training astronauts at Brooks Camp, Katmai National Park.png|thumb|right|Shoemaker training astronauts at [[Brooks Camp]], [[Katmai National Park]]<ref>{{cite book |last1=Phinney |first1=William |title=Science Training History of the Apollo Astronauts |date=2015 |publisher=NASA SP -2015-626 |page=65}}</ref>]]

In 1960, Shoemaker directed a team at the [[USGS]] center in [[Menlo Park, California]], to generate the first [[geological map]] of the Moon using photographs taken by [[Francis G. Pease]].  Shoemaker also helped pioneer the field of [[Planetary geology|astrogeology]] by founding the [[Astrogeology Research Program]]. He was prominently involved in the [[Ranger program|Lunar Ranger]] missions to the Moon, joining the television imaging team of [[Harold Urey]] and [[Gerard Kuiper]], which turned into a preparatory mission for the future crewed landing.  Shoemaker was then chosen to be the [[principal investigator]] for the [[Surveyor program]]'s television experiment, and then the lunar geology principal investigator for [[Apollo 11]], [[Apollo 12]], and [[Apollo 13]].<ref name=Levy/>{{rp|85–86, 92–97, 101, 119, 136}}

Shoemaker was also involved in the training of the American [[astronaut]]s.  He himself was a possible candidate for an [[Apollo program|Apollo]] Moon flight and was set to be the first geologist to walk on the Moon but was disqualified due to being diagnosed with [[Addison's disease]], a disorder of the [[adrenal gland]].  Shoemaker would train astronauts during field trips to [[Meteor Crater]] and [[Sunset Crater]] near Flagstaff.<ref>{{cite web|url=https://astrogeology.usgs.gov/About/AstroHistory/astronauts.html|title=About – USGS Astrogeology Science Center|website=astrogeology.usgs.gov|access-date=31 March 2018|archive-date=November 17, 2011|archive-url=https://web.archive.org/web/20111117022504/http://astrogeology.usgs.gov/About/AstroHistory/astronauts.html|url-status=live}}</ref> He was a [[CBS News]] television commentator on the early Apollo missions, especially the [[Apollo 8]] and [[Apollo 11]] missions, appearing with [[Walter Cronkite]] during live coverage of those flights.<ref name="Astronomy obit">{{cite journal
 | last        = Graham
 | first       = Rex
 | title       = Making an exceptional impact. (planetary scientists Eugene and Carolyn Shoemaker)
 | journal     = Astronomy
 |date=May 1998
 | url         = http://business.highbeam.com/136942/article-1G1-20461558/making-exceptional-impact
 | archive-url = https://web.archive.org/web/20130509131721/http://business.highbeam.com/136942/article-1G1-20461558/making-exceptional-impact
 | url-status    = dead
 | archive-date = 2013-05-09
 | access-date  = 2013-02-12
 | page        = 36
 | publisher   = Kalmbach Publishing Co.
 | location    = Waukesha, Wisconsin
 | issn        = 0091-6358
}}
</ref>

According to [[David H. Levy]], just before the crewed Moon landings,
{{blockquote|"With humanity about to set forth upon this new world, geologists and astronomers were divided as to whether the lunar surface was a result of volcanic forces from beneath, or cosmic forces from above.  In 1949, Ralph Baldwin had articulated that the Moon's craters were mostly of impact origin and Gene Shoemaker revived the idea again around 1960.  He saw craters on the Moon as logical impact sites that were formed not gradually, in [[geologic time scale|eons]], but explosively, in seconds."<ref name=Levy/>{{rp|58–59}}
}}

He was awarded the [[John Price Wetherill Medal]] from the [[Franklin Institute]] in 1965. Coming to [[California Institute of Technology|Caltech]] in 1969, he started a systematic search for Earth orbit-crossing [[asteroid]]s, which resulted in the discovery of several families of such asteroids, including the [[List of Apollo asteroids|Apollo asteroids]]. Shoemaker advanced the idea that sudden geologic changes can arise from [[asteroid]] strikes and that asteroid strikes are common over geologic time periods.  Previously, [[Impact crater|astrobleme]]s were thought to be remnants of extinct volcanoes&nbsp;– even on the Moon.

===Comet Shoemaker–Levy 9===
In 1993, he co-discovered [[Comet Shoemaker–Levy 9]] using the 18-inch Schmidt camera at [[Palomar Observatory]].  This comet was unique in that it provided the first opportunity to observe the planetary impact of a comet.  Shoemaker–Levy 9 collided with Jupiter in July 1994. The resulting impact caused a massive "scar" on the face of [[Jupiter]].