Enkelad (mesec)
(Preusmjereno sa stranice Enkelad (mjesec))
Enkelad (Enceladus) je prirodni Saturnov satelit kojeg je 1789. otkrio astronom William Herschel. Ime je dobio od giganta Enkelada iz starogrčke mitologije. Ovaj satelit ima drugo ime Saturn II. Satelit Enkelad ophodi Saturn svakih 32 h 53 m 7 s, ima prosječni promjer od 498.9 km i masu od 8.6×1019 kg. Prosječna gustoća Enkelada je 1.3 g/cm3. Raznim mjerenjima iz svemirske letljelice Cassini-Huygens utvrđeno je da je satelit Enkelad napravljen većinom od leda, vode i možda male količine kamena i metala. Početkom 2006. NASA-ina letjelica Cassini snimila je, vjerojatno, tekuću vodu koja izbija iz gejzira na Enkeladusu.
 Encelad - Slika složena slika od dijelova skupljenih prilikom preleta letjelice Cassini-Huygens tokom 2004.-2005. (izvor: NASA) | |
| Otkriće | |
| Otkrio | William Herschel |
|---|---|
| Datum otkrića | 28. kolovoza 1789 |
| Privremena oznaka | Saturn II |
| Matični planet | Saturn |
| Grupa satelita | Unutarnji pravilni sateliti |
| Orbitalni elementi | |
| Ekscentricitet (e) | 0.0045 [1] |
| Prosječna udaljenost | 238,020 km (xxxx AJ) |
| Orbitalni period (P) | 1.370218 d [1] |
| Inklinacija (i) prema - | |
| - ekliptici | |
| - ekvatoru planeta | 0.019° |
| Fizičke osobine | |
| Srednji promjer | 504.2 km (513×503×497 km) [2] |
| Površina | xxxx km² |
| Masa | 1.08×1020 kg [2] |
| Volumen | xxxx km³ |
| Gustoća | 1.61 g/cm³ [2] |
| Gravitacija na površini | 0.113 m/s² (0.0115 g) |
| Brzina oslobađanja | 241 m/s |
| Period rotacije | sinkrona rotacija |
| Albedo | 0.99 |
| Prosječna površinska temperatura |
min: 32.9 K srednja: 75 K max: 145 K [3] |
| Atmosferski pritisak | U tragovima, prostorno varijabilan[4],[5]. Sastav: Vodena para 91% [6] Dusik 4% [5][6] Ugljik dioksid 3.2% [6] Metan 1.7% [6] |
| Nagib osi | 0° |
Izvori
uredi- ↑ 1,0 1,1 Celestia Solar System Definition File Arhivirano 2005-03-09 na Wayback Machine-u. Retrieved March 22, 2006.
- ↑ 2,0 2,1 2,2 C. C. Porco et al., Science 311, 1393 (2006).
- ↑ J. R. Spencer et al., Science 311, 1401 (2006).
- ↑ M. K. Dougherty et al., Science 311, 1406 (2006).
- ↑ 5,0 5,1 C. J. Hansen et al., Science 311, 1422 (2006).
- ↑ 6,0 6,1 6,2 6,3 J. H. Waite et al., Science 311, 1419 (2006).
Literatura
uredi- Brown, Robert H.; et al. (2006). „Composition and Physical Properties of Enceladus' Surface”. Science 311 (5766): 1425-1428.
- Castillo, Julie C.; D.L. Matson, T.V. Johnson, J.I. Lunine, T.B. McCord, C. Sotin, P.C. Thomas, and E.B. Turtle (2005). „26Al in the Saturnian System - New Interior Models for the Saturnian satellites”. Eos Trans. AGU 82 (52): Fall Meet. Suppl.. Abstract P32A-01. Arhivirano iz originala na datum 2007-09-30. Pristupljeno 2015-05-09.
- Castillo, J. C.; D.L. Matson, C. Sotin, T.V. Johnson, J.I. Lunine, and P.C. Thomas (2006). „A New Understanding of the Internal Evolution of Saturnian Icy Satellites from Cassini Observations”. LPSC XXXVII. Abstract 2200.
- Dougherty, M. K.; K.K. Khurana, F.M. Neubauer, C.T. Russell, J. Saur, J.S. Leisner, and M. E. Burton (2006). „Identification of a Dynamic Atmosphere at Enceladus with the Cassini Magnetometer”. Science 311 (5766): 1406-1409.
- Hansen, Candice J.; L. Esposito, A.I.F. Stewart, J. Conwell, A. Hendrix, W. Pryor, D. Shemansky, and R. West (2006). „Enceladus' Water Vapor Plume”. Science 311 (5766): 1422-1425.
- Matson, D.L.; J.C. Castillo, C. Sotin, T.V. Johnson, J.I. Lunine, A.G. Davies, T.B. McCord, P.C. Thomas, and E.P. Turtle (2006). „Enceladus' Interior and Geysers - Possibility for Hydrothermal Geometry and N2 Production”. LPSC XXXVII. Abstract 2219.
- Pappalardo, R.T.; F. Nimmo (2006). „Diapir-Induced Reorientation of Enceladus”. LPSC XXXVII. Abstract 2113.
- Porco, C.C.; et al. (2006). „Cassini Observes the Active South Pole of Enceladus”. Science 311 (5766): 1393-1401.
- Rathbun, Julie A.; E. Turtle, P. Helfenstein, S. Squyres, P. Thomas, J. Veverka, T. Denk, G. Neukum, T. Roatsch, R. Wagner, J. Perry, D. Smith, T. Johnson, and C. Porco (2005). „Enceladus' global geology as seen by Cassini ISS”. Eos Trans. AGU 82 (52): Fall Meet. Suppl.. Abstract P32A-03. Arhivirano iz originala na datum 2008-04-04. Pristupljeno 2015-05-09.
- Rothery, David A. (1999). Satellites of the Outer Planets: Worlds in their own right. Oxford University Press. ISBN 0-19-512555-X.
- Spahn, Frank; et al. (2006). „Cassini Dust Measurements at Enceladus and Implications for the Origin of the E Ring”. Science 311 (5766): 1416-1418.
- Spencer, J. R.; et al. (2006). „Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot”. Science 311 (5766): 1401-1405.
- Turtle, Elizabeth et al. Enceladus, Curiouser and Curiouser: Observations by Cassini's Imaging Science Subsystem Arhivirano 2013-05-01 na Wayback Machine-u. Cassini CHARM Telecon. 28 April 2005. (Adobe Acrobat file).
- Verbiscer, Anne; R. C. French, C. A. McGhee (2005). „The opposition surge of Enceladus: HST observations 338-1022 nm”. Icarus 173: 66-83. DOI:10.1016/j.icarus.2004.05.001.
- Waite Jr., J. Hunter; et al. (2006). „Cassini Ion and Neutral Mass Spectrometer: Enceladus Plume Composition and Structure”. Science 311 (5766): 1419-1422.
Vanjske veze
uredi
- Astronomska sekcija Fizikalnog društva Split - Encelad, saturnov satelit Arhivirano 2008-04-23 na Wayback Machine-u
- NASA - letjelica Cassini snimila vodu na Enceladusu Arhivirano 2005-01-24 na Wayback Machine-u
- Enceladus Profile Arhivirano 2007-08-01 na Wayback Machine-u at NASA's Solar System Exploration site
- Calvin Hamilton's Enceladus page
- The Planetary Society: Enceladus information Arhivirano 2006-05-14 na Wayback Machine-u
- Cassini Mission Enceladus Page. Contains catalog of released Cassini Images of Enceladus
- CHARM: Cassini–Huygens Analysis and Results from the Mission page, contains presentations on recent Enceladus results Arhivirano 2005-12-02 na Wayback Machine-u
- Paul Schenk's 3D images and flyover videos of Enceladus and other outer solar system satellites
Slike
- Cassini images of Enceladus Arhivirano 2011-08-13 na Wayback Machine-u
- Images of Enceladus at JPL's Planetary Photojournal
- Movie of Enceladus' rotation Arhivirano 2010-06-01 na Wayback Machine-u from the National Oceanic and Atmospheric Administration
- Enceladus global Arhivirano 2018-03-08 na Wayback Machine-u and polar Arhivirano 2018-03-08 na Wayback Machine-u basemaps (December 2011) from Cassini images
- Enceladus atlas (May 2010) from Cassini images Arhivirano 2015-08-31 na Wayback Machine-u
- Enceladus nomenclature and Enceladus map with feature names from the USGS planetary nomenclature page
- Small Bodies Atlas: Enceladus. Phil Stooke's Atlas page for Enceladus containing a catalog of Voyager Enceladus images as well as maps based on Voyager Images