Editing Tycho (lunar crater)

{{short description|Prominent lunar impact crater}}{{use dmy dates|date=March 2023}}
{{Infobox Lunar crater
| name        = Tycho
| image       = Tycho LRO.png
| image_size  = 
| caption     = Tycho seen by [[Lunar Reconnaissance Orbiter]] (rotate display if you see a [[crater illusion]] due to the atypical position of the light source). [[NASA]]
| coordinates = {{coord|43.31|S|11.36|W|globe:moon_type:landmark|display=inline,title}}
| diameter    = 85&nbsp;km (53.4&nbsp;miles)
| depth       = {{convert|4.7|km|mi|abbr=on}}<ref name="Margot99">{{cite journal |last1=Margot |first1=Jean-Luc |last2=Campbell |first2=Donald B. |last3=Jurgens |first3=Raymond F. |last4=Slade |first4=Martin A. |title=The topography of Tycho Crater |journal=Journal of Geophysical Research: Planets |date=25 May 1999 |volume=104 |issue=E5 |pages=11875–11882 |doi=10.1029/1998JE900047|bibcode=1999JGR...10411875M }}</ref>
| colong      = 12
| eponym      = [[Tycho Brahe]]
}}
[[File:Tycho area Si - Ferruggia Zetta.jpg|left|thumb|The crater area in selenochromatic format<ref>{{cite web |title=Selenocromatica |url=https://www.gawh.it/main/selenocromatica |access-date=19 January 2025 |website=GAWH}}</ref>]]
[[Image:Lage des Mondkraters Tycho.jpg|thumb|right|Location of Tycho as seen from the [[Northern Hemisphere]]]]
[[File:Tycho.stl|thumb|3D model of Tycho crater]]

'''Tycho''' ({{IPAc-en|ˈ|t|aɪ|k|oʊ}}) is a prominent [[Lunar craters|lunar impact]] [[impact crater|crater]] located in the southern lunar highlands, named after the Danish astronomer [[Tycho Brahe]] (1546–1601).<ref name=gpn>{{gpn|6163}}, accessed 19 February 2019</ref> It is estimated to be 108 million years old.<ref name="lro">{{cite web |title=The floor of Tycho crater |series=[[Lunar Reconnaissance Orbiter]] |publisher=[[NASA]] |url=https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc-20100114-tycho.html |date=3 August 2017 |access-date=1 July 2018 |archive-date=30 March 2017 |archive-url=https://web.archive.org/web/20170330203111/https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc-20100114-tycho.html |url-status=dead }}</ref>

To the south of Tycho is the crater [[Street (crater)|Street]], to the east is [[Pictet (crater)|Pictet]], and to the north-northeast is [[Sasserides (crater)|Sasserides]]. The surface around Tycho is replete with craters of various sizes, many overlapping still older craters. Some of the smaller craters are secondary craters formed from larger chunks of [[ejecta]] from Tycho.
It is one of the [[Moon]]'s brightest craters,<ref name=lro/> with a diameter of {{cvt|85|km}}<ref>{{cite news |last=Wood |first=Charles A. |date=2006-08-01 |title=Tycho: The metropolitan crater of the Moon |magazine=[[Sky & Telescope]] |url=http://www.skyandtelescope.com/observing/celestial-objects-to-watch/tycho-the-metropolitan-crater-of-the-moon/ |access-date=2018-06-19}}</ref> and a depth of {{cvt|4700|m}}.<ref name=Margot99></ref>

==Age and description==
Tycho is a relatively young crater, with an estimated age of 108&nbsp;million years ([[Annum|Ma]]), based on analysis of samples of the crater ray recovered during the {{nobr|[[Apollo 17]]}} mission.<ref name=lro/> This age initially suggested that the impactor may have been a member of the [[Baptistina family]] of asteroids, but as the composition of the impactor is unknown this remained conjecture.<ref>
{{cite news
 | date=September 5, 2007
 | title=Breakup event in the main asteroid belt likely caused dinosaur extinction 65 million years ago
 | publisher=[[Physorg]]
 | url=http://www.physorg.com/news108218928.html
 | access-date=2007-09-06
}}
</ref>
However, this possibility was ruled out by the [[Wide-field Infrared Survey Explorer]] in 2011, as it was discovered that the Baptistina family was produced much later than expected, having formed approximately 80 million years ago.<ref>{{cite news |last=Plotner |first=Tammy |date=2015-12-24 |title=Did asteroid Baptistina kill the dinosaurs? Think other-WISE |website=[[Universe Today]] |url=https://www.universetoday.com/89050/did-asteroid-baptistina-kill-the-dinosaurs-think-other-wise/#more-89050}}</ref>

The crater is sharply defined, unlike older craters that have been degraded by subsequent impacts. The interior has a high [[albedo feature|albedo]] that is prominent when the Sun is overhead, and the crater is surrounded by a distinctive [[ray system]] forming long spokes that reach as long as 1,500&nbsp;kilometers. Sections of these rays can be observed even when Tycho is illuminated only by [[planetshine|earthlight]]. Due to its prominent rays, Tycho is mapped as part of the [[Copernican period|Copernican System]].<ref>{{cite report |author1=McCauley, John F. |author2=Trask, Newell J. |year=1987 |title=The Geologic History of the Moon |editor-link=Donald Wilhelms |editor=Wilhelms, D.E. |publisher=[[United States Geological Survey]] |series=Professional Paper |volume=1348 |at=Plate&nbsp;11: Copernican system |url=https://pubs.er.usgs.gov/publication/pp1348 }}</ref>

[[Image:Tycho Crater.jpg|thumb|left|250px|The large [[ray system]] centered on Tycho]]
The ramparts beyond the rim have a lower albedo than the interior for a distance of over a hundred kilometers, and are free of the ray markings that lie beyond. This darker rim may have been formed from minerals excavated during the impact.

Its inner wall is slumped and [[Terrace (geology)|terraced]], sloping down to a rough but nearly flat floor exhibiting small, knobby domes. The floor displays signs of past volcanism, most likely from rock melt caused by the impact. Detailed [[Astrophotography|photograph]]s of the floor show that it is covered in a criss-crossing array of cracks and small hills. The central peaks rise {{convert|1600|m|ft|sp=us}} above the floor, and a lesser peak stands just to the northeast of the primary [[massif]].

Infrared observations of the lunar surface during an eclipse have demonstrated that Tycho cools at a slower rate than other parts of the surface, making the crater a "hot spot". This effect is caused by the difference in materials that cover the crater.

[[Image:Tycho Crater Panorama.jpg|thumb|Panoramic view of the lunar surface taken by {{nobr|[[Surveyor 7]],}} which landed about {{convert|29|km|mi|abbr=on}} from the rim of Tycho]]

The rim of this crater was chosen as the target of the {{nobr|[[Surveyor 7]]}} mission. The robotic spacecraft safely touched down north of the crater in January&nbsp;1968. The craft performed chemical measurements of the surface, finding a composition different from the maria. From this, one of the main components of the highlands was theorized to be [[anorthosite]], an [[aluminium]]-rich mineral. The crater was also imaged in great detail by {{nobr|[[Lunar Orbiter 5]].}}

From the 1950s through the 1990s, NASA aerodynamicist Dean Chapman and others advanced the lunar origin theory of [[tektite]]s. Chapman used complex orbital computer models and extensive wind tunnel tests to support the theory that the so-called Australasian tektites originated from the Rosse ejecta ray of Tycho. Until the Rosse ray is sampled, a lunar origin for these tektites cannot be ruled out, though tektites are now generally considered to have been produced by terrestrial impact events.

This crater was drawn on lunar maps as early as 1645, when [[Antonius Maria Schyrleus de Rheita|A.M.S. de&nbsp;Rheita]] depicted the bright ray system.

== Names ==
Tycho is named after the Danish astronomer [[Tycho Brahe]].<ref name=gpn/> Like many of the craters on the Moon's near side, it was given its name by the [[Society of Jesus|Jesuit]] astronomer [[Giovanni Battista Riccioli|G.B. Riccioli]], whose 1651 nomenclature system has become standardized.{{sfn|Whitaker|2003|pp=61}}<ref>[[:commons:File:Riccioli1651MoonMap.jpg|Riccioli map of the Moon (1651)]]</ref> Earlier lunar cartographers had given the feature different names. [[Pierre Gassendi]] named it Umbilicus Lunaris ('the [[navel]] of the Moon').{{sfn|Whitaker|2003|pp=33}} [[Michael van Langren|van&nbsp;Langren]]'s 1645 map calls it "Vladislai IV" after [[Władysław IV Vasa]], [[King of Poland]].{{sfn|Whitaker|2003|pp=198}}<ref>[[:commons:File:Langrenus map of the Moon 1645.jpg|Langren's map of the Moon (1645)]]</ref> And [[Johannes Hevelius]] named it 'Mons Sinai' after [[Mount Sinai]].<ref>[[:commons:File:Hevelius Map of the Moon 1647.jpg|Hevelius map of the Moon (1647)]]</ref>

== Satellite craters ==

By convention, these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Tycho.

{| class="wikitable sortable" style="text-align:center"
|-
! Tycho
! class="unsortable" | Coordinates
! Diameter, km
|-
|A
|{{Coord|39.94|S|12.07|W|globe:moon|name=Tycho A}}
|29
|-
|B
|{{Coord|43.99|S|13.92|W|globe:moon|name=Tycho B}}
|14
|-
|C
|{{Coord|44.12|S|13.46|W|globe:moon|name=Tycho C}}
|7
|-
|D
|{{Coord|45.58|S|14.07|W|globe:moon|name=Tycho D}}
|26
|-
|E
|{{Coord|42.34|S|13.66|W|globe:moon|name=Tycho E}}
|13
|-
|F
|{{Coord|40.91|S|13.21|W|globe:moon|name=Tycho F}}
|17
|-
|H
|{{Coord|45.29|S|15.92|W|globe:moon|name=Tycho H}}
|8
|-
|J
|{{Coord|42.58|S|15.42|W|globe:moon|name=Tycho J}}
|11
|-
|K
|{{Coord|45.18|S|14.38|W|globe:moon|name=Tycho K}}
|6
|-
|P
|{{Coord|45.44|S|13.06|W|globe:moon|name=Tycho P}}
|7
|-
|Q
|{{Coord|42.50|S|15.99|W|globe:moon|name=Tycho Q}}
|20
|-
|R
|{{Coord|41.91|S|13.68|W|globe:moon|name=Tycho R}}
|4
|-
|S
|{{Coord|43.47|S|16.30|W|globe:moon|name=Tycho S}}
|3
|-
|T
|{{Coord|41.15|S|12.62|W|globe:moon|name=Tycho T}}
|14
|-
|U
|{{Coord|41.08|S|13.91|W|globe:moon|name=Tycho U}}
|20
|-
|V
|{{Coord|41.72|S|15.43|W|globe:moon|name=Tycho V}}
|4
|-
|W
|{{Coord|43.30|S|15.38|W|globe:moon|name=Tycho W}}
|21
|-
|X
|{{Coord|43.84|S|15.25|W|globe:moon|name=Tycho X}}
|12
|-
|Y
|{{Coord|44.12|S|15.93|W|globe:moon|name=Tycho Y}}
|22
|-
|Z
|{{Coord|43.23|S|16.35|W|globe:moon|name=Tycho Z}}
|23
|}

== Fictional references ==
* There is a chapter entitled "Tycho" in Jules Verne's ''[[Around the Moon]]'' ([[Around the Moon|''Autour de la Lune'']], 1870) which describes the crater and its ray system.

* In [[Robert A. Heinlein|R.A. Heinlein]]'s 1940 short story "[[Blowups Happen]]", a character speculates that Tycho may have been the location of a sentient race's main atomic power plant, in a past time when the Moon was still habitable—and that the plant exploded, causing the craters, the rays spreading from Tycho, and the death of all life on the Moon.

* [[Clifford Simak|C.D. Simak]] set his 1961 novelette ''The Trouble with Tycho'', at the lunar crater. He also postulated that the crater's rays were composed of volcanic glass ([[tektites]]) akin to a theory postulated by NASA researchers Dean Chapman and John O'Keefe in the 1970s.

* In [[Robert A. Heinlein|Heinlein]]'s 1966 book ''[[The Moon Is a Harsh Mistress]]'', Tycho is the location of the lunar habitat named "Tycho Under".

* Tycho was the location of the [[Tycho Magnetic Anomaly]] (TMA-1), and subsequent excavation of an alien monolith, in [[2001: A Space Odyssey (novel)|''2001: A Space Odyssey'']], the seminal 1968 science-fiction film by [[Stanley Kubrick]] and book by [[Arthur C. Clarke]].

* In the 1987 film ''[[Can't Buy Me Love (film)|Can't Buy Me Love]]'', Cindy notices Tycho while looking through a telescope on her final "contractual" date with Ronny in the Airplane Graveyard.

* It also serves as the location of "Tycho City" in the 1996 film ''[[Star Trek: First Contact]]''; a lunar metropolis by the 24th&nbsp;century.

* In [[Jack Williamson]]'s 2001 novel ''Terraforming Earth'', the crater is utilized for "Tycho Base", a self-sustaining, robot-controlled installation aimed at restoring life to the (dead) planet Earth after an asteroid sterilizes the biosphere.

* In the 2019 film [[Ad Astra (film)|''Ad Astra'']], the Moon base is situated in the Tycho crater. This is Roy's first stop on his journey to Mars.

* Crater Tycho figures prominently in the [[Matthew Looney]] and [[Maria Looney]] series of children's books set on the Moon, authored by [[Jerome Beatty]].

* In [[Roger Macbride Allen|R.M. Allen's]] ''Hunted Earth'' novels, the 'naked purples' own a former penal colony in or around Tycho crater known as "Tycho Purple Penal" (see ''[[The Ring of Charon]]'').

* Tycho is referenced in the band [[Cojum Dip]]'s song, Waltz in E&nbsp;Major, Op.&nbsp;15 "Moon Waltz".

* Tycho is referenced in the 2022 game ''[[Horizon Forbidden West]]'' as the site of a Helium-3 mine.

==Gallery==
<gallery widths="230px" heights="220px" perrow="4">
Image:Lunar2007 eclipse-LiamG.jpg|March 2007 [[lunar eclipse]]. The advancing shadow of Earth brings out detail on the lunar surface. The huge ray system emanating from Tycho is shown as the dominant feature on the southern hemisphere.
Image:LRO Tycho Central Peak 0.25.jpg|Central peak complex of crater Tycho, taken at sunrise by the [[Lunar Reconnaissance Orbiter]] in 2011.
File:Tycho crater 4119 h2.jpg|[[Lunar Orbiter 4]] image from 1967
File:Tycho crater floor 5125 h2.jpg|[[Lunar Orbiter 5]] image of the northeastern crater floor, showing irregular surface of cracked impact melt.  Illumination is from lower right.
File:AS15-95-12997 contast enhanced.jpg|Tycho was not photographed up-close during the Apollo program, but [[Apollo 15]] captured this distant oblique view.
File:Radar_Image_of_Tycho_Crater_from_Jean-Luc_Margot%27s_PhD_work.png|Radar image of Tycho Crater.
</gallery>

==See also==
*[[1677 Tycho Brahe]], minor planet
*[[Tycho Brahe (Martian crater)]]
*[[Tycho's Nova]], bright supernova

==References==
{{reflist|25em}}

----

{{refbegin|25em|small=y}}
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}}
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 | year = 1971
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{{refend}}

==External links==
{{commons category|Tycho (lunar crater)}}
* {{cite web |title=Tycho |website=Moon Wiki |url=https://the-moon.us/wiki/Tycho}}
* {{cite AV media |author=Doran, Seán |title=Sunset on Tycho |website=[[flickr]] |medium=artificial video |quote=based on [[Lunar Reconnaissance Orbiter|LRO]] data |url=https://www.flickr.com/photos/136797589@N04/38721495941/ |url-access=subscription}}. For more, see {{cite AV media |title=album |website=[[flickr]] |medium=artificial images |url=https://www.flickr.com/photos/136797589@N04/albums/72157686992929766/with/35498090194/ |url-access=subscription}} 
* {{APOD |date=8 November 2003|title=Eclipsed Moon in Infrared}}
* {{APOD |date=5 March 2005|title=Tycho and Copernicus: Lunar Ray Craters}}
* {{APOD |date=4 January 2013|title=Sunrise at Tycho}}
* {{APOD |date=May 7, 2018|title=The Unusual Boulder at Tycho's Peak}}

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[[Category:Impact craters on the Moon]]
[[Category:Tycho Brahe]]