Editing Trieste (bathyscaphe) (section)

==The Mariana Trench dives==

[[File:Bathyscaphe Trieste with USS Lewis (DE-535) over the Marianas Trench, 23 January 1960 (NH 96797).jpg|thumb|left| ''Trieste'' just before the Mariana dive 23 January 1960, seen escorted by [[USS Lewis (DE-535)|USS ''Lewis'']]]]
''Trieste'' departed San Diego on 5 October 1959 for [[Guam]] aboard the freighter ''Santa Maria'' to participate in ''Project Nekton'', a series of very deep dives in the Mariana Trench.

On 23 January 1960, it reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard and Don Walsh.<ref>{{cite web|url=http://www.history.navy.mil/danfs/t8/trieste.htm|title=Trieste|access-date=11 October 2005|archive-date=17 March 2010|archive-url=https://web.archive.org/web/20100317120249/http://www.history.navy.mil/danfs/t8/trieste.htm|url-status=dead}}</ref> This was the first time a vessel, crewed or uncrewed, had reached the deepest known point of the Earth's oceans. The onboard systems indicated a depth of {{convert|11521|m|ft|0}}, although this was revised later to {{convert|10916|m|ft|0}}; fairly recently, more accurate measurements have found Challenger Deep to be between {{convert|10911|m|ft|0}} and {{convert|10994|m|ft|0}} deep.<ref>{{cite news |title=Oceans' deepest depth re-measured |first=Jonathan |last=Amos |url=https://www.bbc.co.uk/news/science-environment-15845550 |newspaper=BBC News |date=7 December 2011 |access-date=7 December 2011}}</ref>

The descent to the ocean floor took 4 hours 47 minutes at a descent rate of {{convert|0.9|m/s|km/h mph}}.<ref>NGC: On the sea floor</ref><ref>[http://www.ocean.udel.edu/extreme2004/geology/trieste.html To the Depths in ''Trieste''] {{Webarchive|url=https://web.archive.org/web/20080208104443/http://www.ocean.udel.edu/extreme2004/geology/trieste.html |date=8 February 2008 }}, University of Delaware College of Marine Studies</ref> After passing {{convert|9000|m|ft|}}, one of the outer Plexiglas window panes cracked, shaking the entire vessel.<ref>{{Cite web |url=http://bjsonline.com/watches/articles/0022_3.shtml |title=Rolex Deep Sea Special |access-date=25 February 2007 |archive-url=https://web.archive.org/web/20070202144233/http://bjsonline.com/watches/articles/0022_3.shtml |archive-date=2 February 2007 |url-status=dead }}, ''Rolex Deep Sea Special'', Written January 2006.</ref> The two men spent twenty minutes on the ocean floor. The temperature in the cabin was 7&nbsp;°C (45&nbsp;°F) at the time. While at maximum depth, Piccard and Walsh unexpectedly regained the ability to communicate with the support ship, [[USS Wandank (ATA-204)#Mariana Islands service.2C 1955-1967|USS ''Wandank'' (ATA-204)]], using a [[sonar]]/[[hydrophone]] voice communications system.<ref>{{cite web | url=http://www.historycentral.com/navy/Tug/Wanduck%20II.html | title=Wandank (ATA-204) | publisher=historycentral.com | access-date=3 June 2009}}</ref> At a speed of almost {{convert|1|mi/s|km/s|order=flip|abbr=on}} &ndash; about five times the speed of sound in air &ndash; it took about seven seconds for a voice message to travel from the craft to the support ship and another seven seconds for answers to return.

While at the bottom, Piccard and Walsh reported observing a number of [[sole (fish)|sole]] and [[flounder]] (both [[flatfish]]).<ref>{{cite video | year = 2012 | title = Meet the only man alive who has been to the deepest ocean | url = https://www.bbc.co.uk/news/science-environment-17060355 | publisher = [[BBC]] | access-date =24 February 2012}}</ref><ref>{{cite news | url=http://news.bbc.co.uk/1/hi/8426132.stm | title=Meet the creatures that live beyond the abyss | publisher=[[BBC]] | access-date=24 February 2012 | date=22 January 2010}}</ref> The accuracy of this observation has later been questioned and recent authorities do not recognize it as valid.<ref>{{cite journal |last1=Linley |first1=Thomas D. |last2=Gerringer |first2=Mackenzie E. |last3=Yancey |first3=Paul H. |last4=Drazen |first4=Jeffrey C. |last5=Weinstock |first5=Chloe L. |last6=Jamieson |first6=Alan J. |title=Fishes of the hadal zone including new species, in situ observations and depth records of Liparidae |journal=Deep Sea Research Part I: Oceanographic Research Papers |date=1 August 2016 |volume=114 |pages=99–110 |doi=10.1016/j.dsr.2016.05.003 |bibcode=2016DSRI..114...99L |language=en |issn=0967-0637|doi-access=free }}</ref> The theoretical maximum depth for fish is at about {{convert|8000-8500|m|ft|abbr=on}}, beyond which they would become [[hyperosmotic]].<ref name=Wolff1961>{{cite journal|author=Wolff, T.|year=1961|title=The deepest recorded fishes|journal=Nature|volume=190|issue=4772|pages=283–284|doi=10.1038/190283a0|bibcode=1961Natur.190..283W|doi-access=free}}</ref><ref name=Jamieson2012>{{cite journal|author1=Jamieson, A.J.|author-link = Alan Jamieson |author2=P.H. Yancey|year=2012|title=On the Validity of the Trieste Flatfish: Dispelling the Myth|journal=The Biological Bulletin|volume=222|issue=3|pages=171–175|doi=10.1086/BBLv222n3p171|pmid=22815365|s2cid=31549749}}</ref><ref>{{cite journal|author1=Yancey, P.H.|author2=E.M. Gerringer |author3=J.C. Drazen|author4=A.A. Rowden|author5=A. Jamieson |year=2014 |title=Marine fish may be biochemically constrained from inhabiting the deepest ocean depths|journal=PNAS|volume=111|issue=12|pages=4461–4465|doi=10.1073/pnas.1322003111|pmc=3970477|pmid=24591588|bibcode=2014PNAS..111.4461Y|doi-access=free}}</ref> Invertebrates such as [[sea cucumber]]s, some of which potentially could be mistaken for flatfish, have been confirmed at depths of {{convert|10000|m|ft|abbr=on}} and more.<ref name=Wolff1961/><ref>{{cite book |first=Alan J. |last = Jamieson |author-link = Alan Jamieson |year=2015|title=The Hadal Zone: Life in the Deepest Oceans|publisher=Cambridge University Press|pages=285–318|isbn=978-1-107-01674-3}}</ref> Walsh later said that their original observation could be mistaken as their knowledge of biology was limited.<ref name=Jamieson2012/> Piccard and Walsh noted that the floor of the Challenger Deep consisted of "[[diatom]]aceous ooze". The ascent took 3 hours and 15 minutes. The National Museum of the Navy commemorated the 60th anniversary of the dive in January 2020.<ref name=":2">{{Cite web|title=Navy Museum Commemorates 60th Anniversary of Trieste|url=https://www.history.navy.mil/content/history/nhhc/news-and-events/news/2020/navy_museum_commemorates_60th_anniversary_trieste.html|archive-url=https://web.archive.org/web/20240604145245/https://www.history.navy.mil/content/history/nhhc/news-and-events/news/2020/navy_museum_commemorates_60th_anniversary_trieste.html|url-status=dead|archive-date=4 June 2024|access-date=2022-01-28|website=NHHC|language=en-US}}</ref>