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List Of Extraterrestrial Dune Fields
This is a list of dune fields not on Earth which have been given official names by the International Astronomical Union. Dune fields are named according to the IAU's rules of planetary nomenclature. The relevant descriptor term is undae. As of now, the only two Solar System planets, besides Earth, with named dune fields are Venus and Mars. Dune fields have also been discovered on Saturn's moon Titan, Pluto and comet 67P/Churyumov–Gerasimenko. Venus There are three officially named dune fields on Venus. They are named after desert goddesses, as per the IAU's rules. They are listed below. * Al-Uzza Undae 67.7N, 90.5E – named after Uzza, an Arabian desert goddess * Menat Undae 24.8S, 339.4E * Ningal Undae 9.0N, 60.7E – named after Ningal, the wife of the Sumerian desert god Sin Mars There are six officially named dune fields on Mars, which are named after nearby classical albedo features in accordance with the IAU's rules. Five of them lie between 75°N to 85°N, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Sand Cascades On Mars
Darkness, the direct opposite of lightness, is defined as a lack of illumination, an absence of visible light, or a surface that absorbs light, such as black or brown. Human vision is unable to distinguish colors in conditions of very low luminance. This is because the hue sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision. The emotional response to darkness has generated metaphorical usages of the term in many cultures, often used to describe an unhappy or foreboding feeling. Referring to a time of day, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. Scientific Perception The perception of darkness differs from the mere absence of light due to the effects of after images on perception. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a complementary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Albedo Features On Mars
The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the features they could see. The most popular system of nomenclature was devised by Giovanni Schiaparelli, who used names from classical antiquity. Today, the improved understanding of Mars enabled by space probes has rendered many of the classical names obsolete for the purposes of cartography; however, some of the old names are still used to describe geographical features on the planet. History Observing albedo features Early telescopic astronomers, observing Mars from a great distance through primitive instruments (though they were advanced for their day), were limited to studying albedo contrasts on the surface of the planet. These lighter and darker patches rarely correspond to topographic features and in many cases obscure them. The o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gusev Crater
Gusev is a crater on the planet Mars and is located at and is in the Aeolis quadrangle. The crater is about 166 kilometers in diameter and formed approximately three to four billion years ago. It was named after Russian astronomer Matvey Gusev (1826–1866) in 1976. Prior to the exploration of the crater by the Spirit Rover, the crater was postulated to be an ancient lakebed with Ma'adim Vallis draining into it, of volcaniclastic origin, or a combination of both. These interpretations were based on ''Viking'' orbiter imagery, MOC imagery, THEMIS thermal mapping, and MOLA elevation mapping. However, Spirit did not find any lacustrine deposits, instead Spirit found alkaline volcanic rocks, including olivine basalt, comminuted basaltic debris, lavas, and pyroclastic rocks, but no eruption centers. More recently, satellite images showed the trails of dust devils on Gusev's floor. The ''Spirit'' rover later photographed dust devils from the ground, and likely owes much of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Husband Hill
Husband Hill is one of the Columbia Hills in Gusev crater, Mars, which are close to the landing site of NASA's ''Spirit'' rover. It was named in honor of Rick Husband, the commander of the Space Shuttle ''Columbia'' when it disintegrated upon atmospheric reentry (see Space Shuttle ''Columbia'' disaster). In 2005, the ''Spirit'' rover, as part of its exploration of its landing site, slowly climbed to the top of Husband Hill. It reached the summit on August 21, 2005, and began its descent on September 25, 2005, after spending nearly two months examining the outcrops and views of the summit plateau before moving on. Named areas on the hill include the " Cumberland Ridge", where rocks with higher than normal phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ... content exi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rover (space exploration), rovers to explore the Martian surface and Geology of Mars, geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Timekeeping on Mars#Sols, Martian solar days: MER-A ''Spirit'' was active until March 22, 2010, while MER-B ''Opportunity'' was active until June 10, 2018. Objectives The mission's scientific objective was to search for and characterize a wide range of rock (geology), rocks and soils that hold clues to past Water on Mars, water activity on Mars. The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997. The total cost o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GeekWire
GeekWire is an American technology news website that covers startups and established technology companies. The site launched in March 2011 and is based in Seattle. It was founded by journalists Todd Bishop and John Cook with investment from Jonathan Sposato. GeekWire founders John Cook and Todd Bishop were former technology reporters at the Seattle Post-Intelligencer and the Puget Sound Business Journal. Bishop and Cook joined the Puget Sound Business Journal to create TechFlash in September 2008, leaving to start GeekWire on March 7, 2011. GeekWire is regularly featured on the Techmeme Techmeme is a technology news aggregator. The website has been described as "a one-page, aggregated, filtered, archiveable summary in near real-time of what is new and generating conversation". Overview Gabe Rivera was a compiler software engin ... leaderboard as one of the sources most frequently posted to that site. References External links * American technology news websites Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siton Undae
Siton Undae is one of the largest and densest dune fields in the vicinity of Planum Boreum, the Martian northern polar ice-cap. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU on 20 March 2007. It extends from latitude 73.79°N to 77.5°N and from longitude 291.38°E to 301.4°E (43.98°W – 57.08°W). Its centre is located at latitude 75.55°N, longitude 297.28E (62.72°W), and has a diameter of . Siton Undae is part of a cluster of sand-seas (undae), which along with Hyperboreae, and Abalos Undae, overlay the lowlands of Vastitas Borealis. Siton Undae superposes the deepest basin of the northern region of Mars and contains amorphous silica-coated glass-rich dunes. It is theorised that the formation of Siton Undae may have occurred during early erosion incidents of the Planum Boreum cavi unit, and that Rupes Tenuis may also have been a sand source, although it is now depleted. Other dune fields sharing the same formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olympia Undae
Olympia Undae is a vast dune field in the north polar region of the planet Mars. It consists of a broad "sand sea" or erg that partly rings the north polar plateau (Planum Boreum) from about 120° to 240°E longitude and 78° to 83°N latitude. Stretching about across and covering an area of 470,000 km2, Olympia Undae is the largest continuous dune field on Mars. It is similar in size to the Rub' Al Khali in the Arabian Peninsula, the largest active erg on Earth. Olympia Undae lies within the informally named Borealis basin (also called the north polar basin), the largest of three topographic basins that occur in the northern lowlands of Mars. The average elevation in Olympia Undae is about 4,250 m below datum ( martian "sea" level). The 19-km-diameter crater Jojutla lies near the geographic center of Olympia Undae at 81.63°N latitude and 169.65°E longitude. This crater was named by Andres Eloy Martinez Rojas, Mexican astronomer and science writer. ''Unda'' (pl. ''undae' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ogygis Undae
Ogygis Undae is the only named southern hemisphere dune field on Mars. It is named after one of the classical albedo features on Mars, ''Ogygis Regio''. Its name, which refers to Ogyges, a primeval mythological ruler in ancient Greece, was officially approved by the International Astronomical Union (IAU) on September 17, 2015. It is situated just outside Argyre Planitia, a plain located in the southern highlands of Mars. The dunes of Ogygis Undae extend from latitude −49.94°N to −49.37°N and from longitude 292.64°E to 294.93°E (65.07°W – 67.36°W). They are centered at latitude −49.66°N, longitude 293.79°E (66.21°W), and extend approximately 87 km to the east and west from there. Ogygis Undae has an area of 1904 km2, and due to its large size is a primary subject for research on Martian dune morphology and sand composition. Morphology Ogygis Undae is the final sink of an extended sand transport system that was imaged with the HRSC camera onboard ESA M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperboreae Undae
Hyperboreae Undae (Latin: "Far Northern Waves/Dunes") is one of the largest and densest dune fields of Planum Boreum, the Martian North Pole. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU in 1988. It extends from latitude 77.12°N to 82.8°N and from longitude 302.92°E to 316.02°E (43.98°W – 57.08°W). Its centre is at latitude 79.96°N, longitude 49.49°W, and has a diameter of . Hyperboreae Undae is southwest of the Boreum Cavus depression, an arc-like depression at the northeastern boundary of Chasma Boreale. From there, Hyperboreae Undae continues in a southwestern direction through Chasma Boreale, and into the lowlands of Vastitas Borealis. It overlays the eastern part of Hyperboreae Lingua and the region above Escorial crater. Hyperboreae Undae is well known for the barchanoid and linear dunes that have formed at its location, although they are seemingly incompatible. Research has been ongoing to explain the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspledon Undae
Aspledon Undae is one of the named northern circumpolar dune fields in the vicinity of Planum Boreum, the Martian North pole. It is named after one of the classical albedo features on Mars. Its name was officially approved by the International Astronomical Union (IAU) on 20 March 2007. Its name is Greek, and derives from the name of a town in Boeotia, Ancient Greece, which, in turn, took its name from Aspledon ( grc, Ασπληδών), son of Poseidon, the ancient Greek god of the sea. The dunes of Aspledon Undae extend from latitude 71.47°N to 75.14°N and from longitude 305.83°E to 315.04°E (44.96°W – 54.17°W). Its centre is located at latitude 73.06°N, longitude 309.65°E (50.35°W), and has a diameter of 215.2 km. Aspledon Undae is the southernmost of the albedo-named dune fields of Planum Boreum, and lies to the south of Hyperboreae Undae and southeast of Siton Undae. It is theorised that the formation of Aspledon Undae may have occurred during early erosion in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
