Saturn's hexagon
Saturn's hexagon is a persisting hexagonal cloud pattern around the north pole of Saturn, located at about 78°N.[1][2] The sides of the hexagon are about 13,800 km (8,600 mi) long, which is longer than the Earth's diameter.[3] It rotates with a period of 10h 39m 24s, the same period as Saturn's radio emissions from its interior.[4] However, the hexagon does not shift in longitude like other clouds in the visible atmosphere.[5]
Saturn's south pole does not have a hexagon, according to Hubble observations.[6] But it does have a vortex, and there is also a vortex inside the northern hexagon.
Saturn's polar hexagon discovery was made by the Voyager mission in 1981–82,[7] and it was revisited since 2006 by the Cassini mission.[8] Cassini was only able to take thermal infrared images of the hexagon, until it started to become visible by light in January 2009.[9] Cassini also recently was able to take a video of the hexagonal weather pattern, while traveling at the same speed as the planet, therefore recording only the movement of the hexagon.[10]
See also
References
- ^ Godfrey, D. A. (1988). "A hexagonal feature around Saturn's North Pole". Icarus. 76 (2): 335. Bibcode:1988Icar...76..335G. doi:10.1016/0019-1035(88)90075-9.
- ^ Sánchez-Lavega, A.; Lecacheux, J.; Colas, F.; Laques, P. (April 16, 1993). "Ground-based observations of Saturn's north polar SPOT and hexagon". Science. 260 (5106). American Association for the Advancement of Science: 329–32. Bibcode:1993Sci...260..329S. doi:10.1126/science.260.5106.329. PMID 17838249.
- ^ "New images show Saturn's weird hexagon cloud". MSNBC. December 12, 2009. Archived from the original on 2011-10-05. Retrieved 2013-12-05.
{{cite news}}: Unknown parameter|deadurl=ignored (|url-status=suggested) (help) - ^ Godfrey, D. A. (March 9, 1990). "The Rotation Period of Saturn's Polar Hexagon". Science. 247 (4947): 1206–1208. Bibcode:1990Sci...247.1206G. doi:10.1126/science.247.4947.1206. PMID 17809277.
- ^ Baines, Kevin H.; et al. (2009). "Saturn's north polar cyclone and hexagon at depth revealed by Cassini/VIMS". Planetary and Space Science. 57 (14–15): 1671–1681. Bibcode:2009P&SS...57.1671B. doi:10.1016/j.pss.2009.06.026.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ Sánchez-Lavega, S. Pérez-Hoyos (Universidad Pais Vasco (Spain)), R. G. French (Wellesley College), A.; Pérez-Hoyos, S.; French, R. G. (October 8, 2002). "Hubble Space Telescope Observations of the Atmospheric Dynamics in Saturn's South Pole from 1997 to 2002". American Astronomical Society. Archived from the original on September 5, 2008. Retrieved 213-12-05.
{{cite web}}: Check date values in:|accessdate=(help)CS1 maint: multiple names: authors list (link) - ^ Caldwell, John; Benoit, Turgeon; Hua, Xin-Min; Barnet, Christopher D.; Westphal, James A. (April 16, 1993). "The Drift of Saturn's North Polar Spot Observed by the Hubble Space Telescope". Science. 260 (5106). AAAS: 326–329. doi:10.1126/science.260.5106.326. ISSN 0036-8075. PMID 17838248. Retrieved 2013-12-05.
- ^ "Saturn's Strange Hexagon". NASA. March 27, 2007. Retrieved 2013-05-01.
- ^ "Saturn's Mysterious Hexagon Emerges From Winter Darkness". NASA. December 9, 2009. Retrieved 2013-05-01.
- ^ "NASA's Cassini Spacecraft Obtains Best Views of Saturn Hexagon". Jet Propulsion Laboratory (NASA). December 4, 2013. Retrieved 2013-12-05.
External links
- Saturn Revolution 175, Cassini images, November 27, 2012
- Saturn’s Strange Hexagon – In Living Color! - Universe Today
- Edge of the hexagon from Planetary Photojournal
- Saturn's Hexagon Comes to Light , APOD January 22, 2012
- In the Center of Saturn's North Polar Vortex, Astronomy Picture of the Day - December 4, 2012
- Video of hexagon's rotation from NASA
