Cytherocentric orbit

Animation of JAXA probe Akatsuki's trajectory around Venus from 1 December 2015
   Akatsuki ·   Venus

A Cytherocentric orbit is an orbit around the planet Venus. Venus has no moon, but several man-made objects orbit the planet.

The name is analogous to the term geocentric orbit for an orbit around Earth and heliocentric orbit for an orbit around the Sun. The apsides of an Cytherocentric orbit are pericytherion, the pericenter (analogous to perigee), and the apocenter is named apocytherion (analogous to apogee).

Etymology

The Cythero prefix is derived from Kythira or "Cythera." In Greek mythology, Cythera was an island associated with the goddess Aphrodite, who is the equivalent of the Roman goddess Venus. Therefore, naming an orbit around Venus "cytherocentric" is a way of referencing Venus' association with this goddess.[citation needed]

Satellites in Cytherocentric orbit

Venera 9 was the first satellite to achieve Venus orbit in 20 October 1975. Akatsuki was the latest probe to achieve Venus orbit in 2015.[1]

Eight probes have achieved Venus orbit:

In order to enter Venus orbit, a satellite has to perform an engine burn to reduce the speed. Otherwise, the probe moves too fast to achieve orbit and will be a flyby. A noteworthy case is that of Japanese probe Akatsuki, which failed to enter orbit around Venus on 6 December 2010.[2] JAXA stated on 8 December that the probe's orbital insertion maneuver had failed,[3] because of a defect in the orbital insertion burn. After the craft orbited the Sun for five years, engineers successfully placed it into an alternative Venusian elliptic orbit on 7 December 2015 by firing its attitude control thrusters for 20 minutes.

Magellan was the first interplanetary probe to use aerobraking to reduce the apocytherion.[4] By passing through the dense atmosphere, a probe can reduce its speed and attain the necessary delta-v. Venus's thick atmosphere supports aerobraking. This reduces fuel needs.

Stationary and synchronous orbits

A satellite with revolutionary period that matches the planet's rotational period appears fixed at a position in the sky relative to an observer on the planet. Such an orbit on Earth is a Geostationary orbit.[5]

The height of a stationary or synchronous orbit can be calculated as follows:

[6]

where G is the gravitational constant, m2 is the mass of the celestial body, and T is the sidereal rotational period of the body.

By this formula one can find the geostationary-analogous cytherostationary orbit. Around Venus, such an orbit would be 1,536,600 km or about 253 Venus radii from the planet's surface. This is because Venus has the slowest rotation rate of any planet. The slower the rotation, the farther away a satellite must be in order to be stationary. The hill sphere of a celestial body describes the region in which the gravity of that body is dominant. The hill sphere radius of Venus is about 1 million kilometers; and as the cytherostationary orbital distance lies outside of it, no stable cytherostationary satellite can exist.

See also

References

  1. ^ "Exploration: Venus". The National Aeronautics and Space Administration. 2010.
  2. ^ JAXA's press briefing, 22:00, 7 December 2010 JST
  3. ^ "Japan's Venus Probe Fails to Enter Orbit". ABC News. Retrieved 8 December 2010.
  4. ^ Lyons, Daniel T.; Saunders, R. Stephen; Griffith, Douglas G. (1 May 1995). "The Magellan Venus mapping mission: Aerobraking operations". Acta Astronautica. 35 (9): 669–676. Bibcode:1995AcAau..35..669L. doi:10.1016/0094-5765(95)00032-U. ISSN 0094-5765.
  5. ^ "Space Today Online - Answers To Your Questions". Spacetoday.org. 2010.
  6. ^ "Calculating the Radius of a Geostationary Orbit - Ask Will Online". Ask Will Online. 2012-12-27. Retrieved 2017-11-21.

Read other articles:

Koja, Jakarta Utara

KojaKecamatanPantai Cilincing tahun 1932Peta lokasi Kecamatan KojaKojaPeta lokasi Kecamatan KojaTampilkan peta IndonesiaKojaKoja (Indonesia)Tampilkan peta IndonesiaKoordinat: 6°07′02″S 106°54′07″E / 6.117256°S 106.901989°E / -6.117256; 106.901989Negara IndonesiaProvinsiDKI JakartaKota AdministrasiJakarta UtaraPemerintahan • CamatAde Himawan[1]Populasi (2021)[2] • Total352.306 jiwa • Kepadatan26.4...

 

Pelagic zone

Unobstructed water in the body of the sea that is neither close to the surface nor to the sea floor Pelagic and Open sea redirect here. For the writer, see Vasa Pelagić. For the marketplace, see OpenSea. For ocean not controlled by any sovereign territory, also called the high seas, see International waters. Layers of the pelagic zone (scaled) Marine habitats Coastal habitats Littoral zone Intertidal zone Estuaries Mangrove forests Seagrass meadows Kelp forests Coral reefs Continental shelf ...

 

Человек прямоходящий

† Человек прямоходящий Научная классификация Домен:ЭукариотыЦарство:ЖивотныеПодцарство:ЭуметазоиБез ранга:Двусторонне-симметричныеБез ранга:ВторичноротыеТип:ХордовыеПодтип:ПозвоночныеИнфратип:ЧелюстноротыеНадкласс:ЧетвероногиеКлада:АмниотыКлада:Синапсиды�...

Atlanta Opera

Cobb Energy Performing Arts Centre The Atlanta Opera is an opera company located in the Atlanta metropolitan area. Founded in 1979, it produces mainstage opera productions and arts education programs for Metropolitan Atlanta and the Southeast.[1] In 2007, The Atlanta Opera moved into its new performance home at the Cobb Energy Performing Arts Centre where it produces four mainstage productions each season.[2] History In the late 1970s, the Metropolitan Opera stopped touring to...

 

Bau (album)

2006 studio album by MinaBauStudio album by MinaReleased26 November 2006 (2006-11-26)Recorded2006StudioStudi GSU, LuganoGenrePoprock[1]Length59:57LanguageItalianEnglishLabelPDUProducerMassimiliano PaniMina chronology Ti amo...(2006) Bau(2006) Todavía(2007) Singles from Bau Mogol Battisti Alibi Bau is a studio album by Italian singer Mina, released on 26 November 2006 by PDU and distributed by Sony Music. The album was first released in a limited edition on viny...

 

Grain trade

Trade in cereals and other food grains The grain trade refers to the local and international trade in cereals such as wheat, barley, maize, and rice, and other food grains. Grain is an important trade item because it is easily stored and transported with limited spoilage, unlike other agricultural products. Healthy grain supply and trade is important to many societies, providing a caloric base for most food systems as well as important role in animal feed for animal agriculture. The grain tra...

Egri VK

Tigra-ZF-EgerFull nameEgri Vízilabda KlubFounded24 September 1910; 113 years ago (1910-09-24)LeagueOrszágos Bajnokság IBased inEger, HungaryArenaBitskey Aladár Uszoda(Capacity: 1,500)ColorsBlue and white   PresidentZoltán SzécsiManagerPéter BirosChampionships3 Hungarian Championships4 Hungarian Cups2021–22Országos Bajnokság I,10th of 14Websiteegrivizilabda.hu Egri Vízilabda Klub (English: Water Polo Club of Eger) is a Hungarian water polo club based in ...

 

Puy de Lassolas

The Puy de Lassolas (Occitan: L'Assolelhat, the sunburnt [mountain]) is a volcano in the Chaîne des Puys in France, peaking at 1187 metres. It forms, with the Puy de la Vache, a group of volcanic craters. Together, they thus form two half craters. Their lava flows created several lakes by crossing valleys, including Lake Cassière to the north and Lake Aydat to the south in the Veyre valley. A view of the summit of the Puy de Lassolas References This article does not cite any sources. P...

 

New Conservative Party (South Korea)

2019–2020 political party in South Korea Not to be confused with New Conservative Party for Reform. New Conservative Party 새로운보수당LeaderYoo Seong-minFoundedSeptember 30, 2019 (2019-09-30) (as Emergency Action for Change and Innovation)December 12, 2019 (2019-12-12) (as New Conservative Party)DissolvedFebruary 17, 2020 (2020-02-17)Split fromBareunmirae PartyMerged intoUnited Future PartyIdeologyConservatism (South Korean)Polit...

大字 (数字)

この項目には、一部のコンピュータや閲覧ソフトで表示できない文字が含まれています（詳細）。 数字の大字（だいじ）は、漢数字の一種。通常用いる単純な字形の漢数字（小字）の代わりに同じ音の別の漢字を用いるものである。 概要 壱万円日本銀行券（「壱」が大字） 弐千円日本銀行券（「弐」が大字） 漢数字には「一」「二」「三」と続く小字と、「壱」「�...

 

Duck decoy (model)

Man-made object resembling a real duck This article is about the carved wildfowl model. For the large structure for catching wildfowl, see Duck decoy (structure). This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article's tone or style may not reflect the encyclopedic tone used on Wikipedia. See Wikipedia's guide to writing better articles for suggestions. (April 2014) (Learn how and ...

 

Kungkuni

Kungkuni Baccaurea tetrandra Herbarium specimenStatus konservasiRisiko rendahIUCN135804457 TaksonomiDivisiTracheophytaSubdivisiSpermatophytesKladAngiospermaeKladmesangiospermsKladeudicotsKladcore eudicotsKladSuperrosidaeKladrosidsKladfabidsOrdoMalpighialesFamiliPhyllanthaceaeTribusAntidesmeaeGenusBaccaureaSpesiesBaccaurea tetrandra Müll.Arg., 1866 Tata namaSinonim takson Adenocrepis tetrandra Baill. Baccaurea brevipedicellata Pax & K.Hoffm. Baccaurea stipulata J.J.Sm. Baccaurea terminali...

فري فورم

فري فورم   معلومات عامة المالك شركة والت ديزني  تاريخ التأسيس 29 أبريل 1977[1]  البلد الولايات المتحدة  المقر الرسمي لوس أنجلوس  الموقع الرسمي الموقع الرسمي (الإنجليزية)  صفحة فيسبوك Freeform  صفحة تويتر FreeformTV  الجوائز جائزة بيبودي  [لغات أخرى]‏  (2...

 

Henry Howard, 15th Earl of Arundel

English nobleman The Right HonorableThe Earl of ArundelPC(Ire)Born15 August 1608Died17 April 1652(1652-04-17) (aged 43)BuriedArundel Castle, Arundel, West Sussex, EnglandNoble familyHowardSpouse(s)Lady Elizabeth StuartIssue12, including:Thomas Howard, 5th Duke of NorfolkHenry Howard, 6th Duke of NorfolkLord Philip HowardLord Charles HowardLord Bernard HowardFatherThomas Howard, 14th Earl of ArundelMotherAlethea Talbot Henry Frederick Howard, 15th Earl of Arundel PC(Ire) (15 August 1608&#...

 

梅拉蒂·达伊瓦·奥克塔维亚尼

梅拉蒂·达伊瓦·奥克塔维亚尼Melati Daeva Oktavianti基本資料代表國家/地區 印度尼西亞出生 (1994-10-28) 1994年10月28日（29歲）[1] 印度尼西亞万丹省西冷[1]身高1.68米（5英尺6英寸）[1]握拍右手[1]主項：女子雙打、混合雙打職業戰績48勝–27負（女雙）109勝–56負（混雙）最高世界排名第4位（混雙-普拉文·喬丹）（2020年3月17日[2]）現時世界排名第...

A Night of Neglect

A Night of NeglectEpisode GleeNomor episodeMusim 2Episode 17SutradaraCarol BankerPenulisIan BrennanTanggal siar19 April 2011 (2011-04-19)Bintang tamu Gwyneth Paltrow sebagai Holly Holliday Cheyenne Jackson sebagai Dustin Goolsby Stephen Tobolowsky sebagai Sandy Ryerson Charice sebagai Sunshine Corazon Harry Shum, Jr. sebagai Mike Chang Chord Overstreet sebagai Sam Evans Darren Criss sebagai Blaine Anderson Ashley Fink sebagai Lauren Zizes Max Adler sebagai Dave Karofsky James Earl s...

 

2011 World Judo Championships – Women's team

Judo competition Judo Women's team at the 2011 World Judo ChampionshipsVenueAccor ArenaLocation Paris, FranceDate28 AugustMedalists   France (2nd title)  Japan  Germany  CubaCompetition at external databasesLinksEJU • JudoInside← Antalya 2010Salvador 2012 → 2011 World Judo ChampionshipsMenWomen60 kg48 kg66 kg52 kg73 kg57 kg81 kg63 kg90 kg70 kg100 kg78 kg+100 kg+78 kgteamteamvte The women's team competition of the 2...

 

مقاومة مغناطيسية نفقية

مقاومة مغناطيسية نفقية مقاومة مغناطيسية نفقية (بالإنجليزية: tunnel magnetoresistance)‏ في الفيزياء هو تأثير مقاومة مغناطيسية يحدث في توصيلات مغناطيسية نفقية، والنفقية هنا يرجع إلى نفق ميكانيكا الكم الذي تفسره ميكانيكا الكم . أي أن تأثير المقاومة المغناطيسية النفقية هو تاثير كمومي ل...

Bristol underground scene

Bristol cultural movement since early 1980s Bristol underground sceneA work by Bristol graffiti artist BanksyDateEarly 1980s–presentLocationBristol, EnglandOutcome Creation of trip hop music Rise of graffiti Publicity of social issues Rise of independent media The Bristol underground scene is a cultural movement in Bristol beginning in the early 1980s. The scene was born out of a lack of mainstream clubs catering for the emergence of hip hop music, with street and underground parties a main...

 

Doctor of Psychology

Doctoral degree The examples and perspective in this article deal primarily with the United States and do not represent a worldwide view of the subject. You may improve this article, discuss the issue on the talk page, or create a new article, as appropriate. (December 2021) (Learn how and when to remove this message) Karen Weaver is a Doctor of Psychology and former mayor of Flint, Michigan The Doctor of Psychology (Psy.D. or D.Psych.) is a professional doctoral degree intended to prepare gr...