The Shakespeare quadrangle is a region of Mercury running from 90 to 180° longitude and 20 to 70° latitude. It is called Caduceata. Prior to the images taken by MESSENGER, the only spacecraft images of Mercury were those taken by the Mariner 10 spacecraft, which made three passes of the planet in 1974–75. Most images used in mapping the geology of the Shakespeare quadrangle were taken during the near-equatorial first pass, with close encounter or the dark side of the planet; the second, south-polar pass did not image the Shakespeare quadrangle at high resolution. High-resolution images of small areas within the quadrangle were obtained during the third pass, when the spacecraft was on a near-encounter north-polar trajectory; because the spacecraft viewed the same areas from different positions during the first and second passes, stereoscopic pictures are available for certain areas of the southern hemisphere. All of the Mariner 10 passes occurred under similar lighting conditions. Across the Shakespeare quadrangle, these conditions varied from low light at the terminator near the west boundary to higher sun at the east boundary.
Lighting conditions were favorable for determining fine-scale relief in the west, but progressively less so toward the east. Conversely, albedo features such as bright crater rays, which are conspicuous in the eastern part, become difficult to recognize westward toward the terminator; this range of lighting conditions across the quadrangle results in inconsistent geologic mapping, because topography and surface texture are critical for characterizing individual materials units. The average resolution of the pictures used from the first pass is just over 1 km; the dominant feature in the Shakespeare quadrangle is 1,300 km in diameter. This impact basin is the largest and best preserved on the hemisphere of Mercury observed by Mariner 10; the entire eastern half of the basin is in the Raditladi quadrangle. Surrounding Caloris is a discontinuous annulus of its ejecta deposits, called the Caloris Group. Caloris ejecta are embayed and covered by a plains unit that lies in large circular depressions, some of which may be ancient degraded basins.
This plains material occurs in the floors of old craters and in small irregular topographic lows. The eastern part of the Shakespeare quadrangle consists of cratered terrain and intercrater plains. Over the whole of the mapped area are scattered fresh craters superposed on other units; the oldest recognizable unit in the quadrangle is the intercrater plains material. These plains were described by Trask and Guest as intercrater plains; the unit has a surface expression of rolling to hummocky plains in the areas between large craters and is exposed in the eastern part of the mapped area. The surface of the unit is pockmarked with craters, many of which are small and shallow. Trask and Guest concluded that the surface of these plains represents a primordial surface of Mercury on which craters have been superposed; the large extent of this surface compared to its counterpart on the Moon was thought to reflect the restricted distribution of ejecta around each individual crater caused by the high gravity on Mercury.
Because of this high gravity, considerable areas were unaffected by basin ejecta. However and Guest and O’Donnell have shown that in some areas the intercrater plains overlie degraded craters, a relation suggesting either that the intercrater plains were formed during a specific time in Mercury’s history and that cratering occurred both before and after their emplacement, or, that the intercrater plains were formed by a continuous process throughout cratering history. In several parts of the quadrangle on the margins of large expanses of smooth plains materials, is a unit of smoother and less rolling plains that have a lower crater density. Following Schaber and McCauley, this unit is called intermediate plains material, it is difficult to map with precision because it grades into both the intercrater plains and the smooth plains. Its recognition depends on lighting conditions that vary across the mapped areas east of longitude 120°; the presence of this unit suggests that the plains-forming process spanned much of the early geologic history of Mercury and continued long after the peak of cratering.
In the southern part of Sobkou Planitia, intermediate plains have a lower albedo than the adjacent plains. In some places, they may represent areas of intercrater plains that have been flooded by the younger smooth plains material. Lineated plains material was recognized by Trask and Guest as forming terrain consisting of lines of hills and valleys, some of which are as much as 300 km long; this unit modified intercrater plains. Its features are similar to those of the lunar Imbrium sculpture and to the hills and valleys radial to the Nectaris Basin on the Moon; the lineations were formed in a similar way to those of the Imbrium sculpture, which resulted from excavation by projectiles ejected at low angles from the Imbrium Basin.
The Victoria quadrangle is a region on Mercury from 0 to 90° longitude and 20 to 70 ° latitude. It is designated the "H-2" quadrangle, is known as Aurora after a large albedo feature. Most of the Victoria quadrangle lies within an area that appears bright on telescopic images of the planet, the bright-albedo feature Aurora, which coincides with the east half of the quadrangle; as is common with most of the imaged portions of Mercury, the Victoria quadrangle is dominated by basins and large craters, with plains materials occupying the areas between them. All the pictures acquired by Mariner 10 that were used for mapping were obtained during the first encounter: those covering the southeast half of the quadrangle are incoming close-encounter images, those covering the north-west corner are outgoing close-encounter images. At the time the pictures were obtained, the terminator was at about long 7° to 8°, within the eastern part of the quadrangle. A large gap in coverage between the incoming and outgoing images appears as a northeast-trending diagonal blank strip on the base map.
A small part of this gap was filled in the southwestern part of the quadrangle by poor second-encounter images. No images provide a vertical view; the high obliquity of the images, the wide range in sun-elevation angles, the complete transection of the quadrangle by the gap in coverage hamper geologic mapping. Only in about 15 percent of the quadrangle, near the southeast corner, do data permit separation of units with the confidence possible in other quadrangles on Mercury. Three widespread units are recognized within the Victoria quadrangle; these are, from oldest to youngest, intercrater plains material, intermediate plains material, smooth plains material. In addition, central peak, floor and ejecta materials related to the numerous craters and basins larger than about 20 km in diameter are mapped; the simplicity of the stratigraphic scheme is at least in part due to deficiencies in the data base. About half of the intercrater area consists of material characterized by a high density of small degraded craters, an irregular to rough surface.
Superposition relations suggest that this unit is about the same age as, or older than, all mappable craters and basins. The origin of intercrater plains material is enigmatic; some of the more plainslike areas included within this unit may well have an origin similar to that of intermediate plains material. Within the 5° overlap area with the Kuiper quadrangle to the south, an area has been mapped that displays moderately rough to rough terrain and a high density of degraded craters; this unit is similar to intercrater plains material, cannot be distinguished from it anywhere else in the Victoria quadrangle. Most of the cratered plains material is volcanic in origin, but some of it may consist of impact breccias. Smooth to moderately irregular plains occupy most of the area between large craters not underlain by intercrater plains material; these plains superficially resemble the plains of the lunar maria. Like the lunar maria, the two younger mercurian plains units have been ascribed to volcanic activity, although this interpretation has been questioned.
A volcanic origin seems most probable, but no compelling evidence exists in the Victoria quadrangle to support this opinion. The elongate ridges, though associated with intermediate plains material, are not restricted to it. Locally, ridges extend into intercrater plains material adjacent to intermediate plains material, large young craters superposed on the intermediate plains material are transected by these ridges. Filling most craters is plains material, smoother and less densely cratered than intermediate plains material; because most areas underlain by this unit are enclosed within craters, contacts between smooth plains and older plains units are rare. Smooth plains material thus is defined entirely by texture and apparent crater density. Few superposition data directly support the inferred age sequence, but the relative youth of the smooth plains unit is indicated by its presence on the floors of craters that are superposed on intermediate plains material; the smooth plains unit includes materials of a wide range in age, but the exposed areas are too small to test this possibility quantitatively.
Although a volcanic origin cannot be ruled out for all or part of the smooth plains material, it is more a mixture of ejecta from small craters and colluvium mass wasted from crater walls. The ridges associated with the intermediate plains unit are best interpreted as tectonic in origin because they extend into adjacent exposures of intercrater plains material and, more because they transect ejecta and floors of craters; the ridges range in length from about 50 km to many hundreds of kilometers, are sinuous to lobate in plan, trend about north-south. Most are asymmetric, with one slope steeper than the other, at places they can be more logically referred to as rounded scarps. An individual ridge changes along trend from symmetric ridge to asymmetric ridge to roun
Abū Nuwās al-Ḥasan ibn Hānī al-Ḥakamī,a known as Abū Nuwās, was a classical Arabic poet. Born in the city of Ahvaz in modern-day Iran, to an Arab father and a Persian mother, he became a master of all the contemporary genres of Arabic poetry. Abu Nuwas has entered the folkloric tradition, he appears several times in The Book of One Thousand and One Nights. Abu Nuwas's father, Hānī, whom the poet never knew, was an Arab, a descendant of the Jizani tribe Banu Hakam, a soldier in the army of Marwan II, his Persian mother, named Jullaban, worked as a weaver. Biographies differ on the date of Abu Nuwas' birth, ranging from 747 to 762; some sources say he was born at Basra, but other accounts report he was born in Damascus, Busra, or at Ahwaz. His given name was al-Hasan ibn Hani al-Hakami,'Abu Nuwas' being a nickname. "Father of the Lock of Hair" referred to the two long sidelocks. Ismail bin Nubakht: "I never saw a man of more extensive learning than Abu Nuwas, nor one who, with a memory so richly furnished, possessed so few books.
After his death we searched his house, could only find one book-cover containing a quire of paper, in, a collection of rare expressions and grammatical observations." Abu Nuwas was forced to flee to Egypt for a time, after he wrote an elegiac poem praising the elite Persian political family of the Barmakis, the powerful family, toppled and massacred by the caliph, Harun al-Rashid. He returned to Baghdad in 809 upon the death of Harun al-Rashid; the subsequent ascension of Muhammad al-Amin, Harun al-Rashid's twenty-two-year-old libertine son was a mighty stroke of luck for Abu Nuwas. In fact, most scholars believe, his most famous royal commission was a poem. "According to the critics of his time, he was the greatest poet in Islam." Wrote F. F. Arbuthnot in Arabic Authors, his contemporary Abu Hatim al Mekki said that the deepest meanings of thoughts were concealed underground until Abu Nuwas dug them out. Abu Nuwas was imprisoned when his drunken, libidinous exploits tested al-Amin's patience. Amin was overthrown by his puritanical brother, Al-Ma'mun, who had no tolerance for Abu Nuwas.
Some accounts claim that fear of prison made Abu Nuwas repent his old ways and become religious, while others believe his penitent poems were written in hopes of winning the caliph's pardon. It was said that al-Ma'mun's secretary Zonbor tricked Abu Nuwas into writing a satire against Ali, the fourth Caliph and son-in-law of the Prophet, while Nuwas was drunk. Zonbor deliberately read the poem aloud in public, ensured Nuwas's continuing imprisonment. Depending on which biography is consulted, Abu Nuwas either died in prison or was poisoned by Ismail bin Abu Sehl, or both. Abu Nuwas is considered one of the greats of classical Arabic literature, he influenced many writers, to mention only Omar Khayyám, Hafiz — both of them Persian poets. A hedonistic caricature of Abu Nuwas appears in several of the One Nights tales. Among his best known poems are the ones ridiculing the "Olde Arabia" nostalgia for the life of the Bedouin, enthusiastically praising the up-to-date life in Baghdad as a vivid contrast.
He is one of various people credited with inventing the literary form of the mu‘ammā, a riddle, solved'by combining the constituent letters of the word or name to be found'. His freedom of expression on matters forbidden by Islamic norms, continues to excite the animus of censors. While his works were in circulation until the early years of the twentieth century, in 1932 the first modern censored edition of his works appeared in Cairo. In January 2001, the Egyptian Ministry of Culture ordered the burning of some 6,000 copies of books of homoerotic poetry by Abu Nuwas. Any mention of pederasty was omitted from his entry in the Saudi Global Arabic Encyclopedia. In 1976, a crater on the planet Mercury was named in honor of Abu Nuwas. A fictionalised Abu Nuwas is the protagonist of the novels The Father of Locks and The Khalifah's Mirror by Andrew Killeen, in which he is depicted as a spy working for Ja'far al-Barmaki. In the Sudanese novel Season of Migration to the North by Tayeb Salih, Abu Nuwas's love poetry is cited extensively by one of the novel's protagonists, the Sudanese Mustafa Sa'eed, as a means of seducing a young English woman in London: "Does it not please you that the earth is awaking,/ That old virgin wine is there for the taking?"
Al-Khatib al-Baghdadi, the author of The History of Baghdad, wrote that Abu Nuwas was buried in Shunizi cemetery in Baghdad. The city has several places named for the poet. Abū Nuwās Street runs along the east bank of the Tigris, once the city’s showpiece. Abu Nuwas Park is located there on the 2.5-kilometer stretch between the Jumhouriya Bridge and a park that extends out to the river in Karada near the 14th of July Bridge. In East Africa's Swahili culture the name "Abu Nuwas" is quite popular as Abunuwasi. Here it is connected to a number of stories which otherwise go by names like Nasreddin, Guha or "the Mullah" in folktale and literature of Islamic societies. In the tales Abunuwasi avenges the poor people; the Tanzanian artist Godfrey Mwampembwa created a Swahili comic book called Abunuwasi, which has adaptations of three of the Abunuwasi stories. The book was published by Sasa Sema Publications in 1996. Dīwān Abū Nu’ās, khamriyyāt Abū Nu’ās, ed. by ‘Alī Najīb ‘Aṭ
The Beethoven quadrangle is located in the equatorial region of Mercury, in the center of the area imaged by Mariner 10. Most pictures of the quadrangle were obtained at high sun angles as the Mariner 10 spacecraft receded from the planet. Geologic map units are described and classified on the basis of morphology and albedo, they are assigned relative ages based on stratigraphic relations and on visual comparisons of the density of superposed craters. Crater ages are established by relative freshness of appearance, as indicated by topographic sharpness of their rim crests and degree of preservation of interior and exterior features such as crater floors and ejecta aprons. Topography appears subdued because of the sun angle, boundaries between map units are not defined. Impact craters. Unlike many basins on the Moon, the two obvious basins in the quadrangle and Raphael, are not multiringed, whereas well-developed rings encircle many craters of lesser diameters. Remnant ejecta blankets around parts of the Beethoven and Raphael basins are subdued in appearance and their margins poorly defined in places.
However, where they can be recognized, these extensive aprons allow a generalized regional stratigraphic sequence to be determined. A third basin subdued but probable, is centered at latitude 0°, longitude 130°. Mariner 10 images in the northeastern part of the quadrangle are poor to unusable; this area therefore contains only a few crater outlines and mapped materials. Another difficulty in mapping is the poor match in topographic bases between Beethoven and adjacent quadrangles. Mismatches are common along the borders with the Kuiper and Discovery quadrangles to the east and southeast. Major divisions of rock units in the quadrangle are plains crater and basin materials. Surfaces of the plains units range in morphology from level but rough to nearly flat and smooth. Plains materials are identified in part by surface texture and their relative ages determined by density of superposed craters. Intercrater plains material, one of the two oldest plains units, was described by Trask and Guest, it covers large areas in the western and southeastern parts of the quadrangle.
There, as in other regions of Mercury, its surface reveals the outlines of many buried crater rim crests and knobby remnants of an older resurfaced terra. This unit has been scoured by many secondary craters that have formed overlapping chains and troughs that contribute to its hummocky texture; the intercrater plains unit is inferred to consist of crater and basin ejecta deposits, volcanic flows, possible pyroclastic deposits that have resurfaced and smoothed older cratered, crustal rocks. The unit appears to be gradational laterally eastward with plains and terra material and vertically with intermediate plains material; the intercrater plains material is about the same age as the ejecta blanket around Beethoven basin: both units have a high crater density. That the plains unit is younger than Beethoven may be indicated in some areas where the basin’s ejecta blanket appears to be obscured by the overlap or embayment of plains material. Spudis and Prosser have suggested that Beethoven may be late c3 in age or as old as early c2.
The age of the plains and terra material, undivided is equivalent to that of the intercrater plains material, to at least part of the intermediate plains material, though it was not found in contact with the latter. The plains and terra unit, occurring in the central and eastern parts of the quadrangle, was mapped to the east in the Kuiper quadrangle; the term was there applied where differences in image quality prevent clear distinctions between plains and terra materials. The name was adopted in the Beethoven quadrangle for the same reason; the unit intergrades to the west and south with intercrater plains material and is interpreted to be of the same origin and composition. The intermediate plains material and smooth plains material also consist of mixtures of fine crater ejecta and volcanic materials that appear to form a continuous sequence. Both units are thicker than the intercrater plains unit; the intermediate plains material is widespread in intercrater areas in the west half of the quadrangle and fills floors of older craters and basins in the southern part.
Smooth plains material, the youngest plains unit, occurs as scattered patches in low areas and covers the floors of many craters of c4 age and older. In some crater floors smaller ones, differentiation between smooth plains and intermediate plains materials is difficult and the choice becomes arbitrary. Aside from a few small patches of dark material, areas covered by bright rays around and emanating from c5 craters, all plains units and the exterior rim materials of many craters have albedos in the intermediate range. Collectively, these materials impart a homogeneous appearance to the surface of the planet, unlike the contrast in bright highlands and dark maria of the Moon. No terra material similar to that in the Kuiper quadrangle was recognized in the Beethoven quadrangle, its absence may be due, in part, to fewer clusters of large young craters whose coalesced ejecta blankets could have yielded the coarsely textured, rough surfaces that characterize the unit in the Kuiper area. The visible effect of roughness is diminished by the higher sun angle at which the Beethoven images were
Adventure Rupes is an escarpment on Mercury 270 kilometres long located in the southern hemisphere of Mercury. Discovered by the Mariner 10 spacecraft in 1974, it was formed by a thrust fault, thought to have occurred due to the shrinkage of the planet's core as it cooled over time. Adventure Rupes has an arcuate shape with the scarp face on convex side of the arc, it has a relief of about 1.3 km and is a continuation of Resolution Rupes and Discovery Rupes along a rough arc, which extends for more than 1000 km. Adventure Rupes is separated from Resolution Rupes by a high relief ridge informally named Rabelais Dorsum, which crosscuts the scarps; this means that Resolution Rupes and Adventure Rupes may be parts of one large structure similar in length to Discovery Rupes. The scarp is named after HMS Adventure, one of James Cook's ships on his second voyage to the Pacific, 1772–1775
International Astronomical Union
The International Astronomical Union is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy. Among other activities, it acts as the internationally recognized authority for assigning designations and names to celestial bodies and any surface features on them; the IAU is a member of the International Council for Science. Its main objective is to promote and safeguard the science of astronomy in all its aspects through international cooperation; the IAU maintains friendly relations with organizations that include amateur astronomers in their membership. The IAU has its head office on the second floor of the Institut d'Astrophysique de Paris in the 14th arrondissement of Paris. Working groups include the Working Group for Planetary System Nomenclature, which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies, the Working Group on Star Names, which catalogs and standardizes proper names for stars.
The IAU is responsible for the system of astronomical telegrams which are produced and distributed on its behalf by the Central Bureau for Astronomical Telegrams. The Minor Planet Center operates under the IAU, is a "clearinghouse" for all non-planetary or non-moon bodies in the Solar System; the Working Group for Meteor Shower Nomenclature and the Meteor Data Center coordinate the nomenclature of meteor showers. The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council held in Brussels, Belgium. Two subsidiaries of the IAU were created at this assembly: the International Time Commission seated at the International Time Bureau in Paris and the International Central Bureau of Astronomical Telegrams seated in Copenhagen, Denmark; the 7 initial member states were Belgium, France, Great Britain, Greece and the United States, soon to be followed by Italy and Mexico. The first executive committee consisted of Benjamin Baillaud, Alfred Fowler, four vice presidents: William Campbell, Frank Dyson, Georges Lecointe, Annibale Riccò.
Thirty-two Commissions were appointed at the Brussels meeting and focused on topics ranging from relativity to minor planets. The reports of these 32 Commissions formed the main substance of the first General Assembly, which took place in Rome, Italy, 2–10 May 1922. By the end of the first General Assembly, ten additional nations had joined the Union, bringing the total membership to 19 countries. Although the Union was formed eight months after the end of World War I, international collaboration in astronomy had been strong in the pre-war era; the first 50 years of the Union's history are well documented. Subsequent history is recorded in the form of reminiscences of past IAU Presidents and General Secretaries. Twelve of the fourteen past General Secretaries in the period 1964-2006 contributed their recollections of the Union's history in IAU Information Bulletin No. 100. Six past IAU Presidents in the period 1976–2003 contributed their recollections in IAU Information Bulletin No. 104. The IAU includes a total of 12,664 individual members who are professional astronomers from 96 countries worldwide.
83% of all individual members are male, while 17% are female, among them the union's former president, Mexican astronomer Silvia Torres-Peimbert. Membership includes 79 national members, professional astronomical communities representing their country's affiliation with the IAU. National members include the Australian Academy of Science, the Chinese Astronomical Society, the French Academy of Sciences, the Indian National Science Academy, the National Academies, the National Research Foundation of South Africa, the National Scientific and Technical Research Council, KACST, the Council of German Observatories, the Royal Astronomical Society, the Royal Astronomical Society of New Zealand, the Royal Swedish Academy of Sciences, the Russian Academy of Sciences, the Science Council of Japan, among many others; the sovereign body of the IAU is its General Assembly. The Assembly determines IAU policy, approves the Statutes and By-Laws of the Union and elects various committees; the right to vote on matters brought before the Assembly varies according to the type of business under discussion.
The Statutes consider such business to be divided into two categories: issues of a "primarily scientific nature", upon which voting is restricted to individual members, all other matters, upon which voting is restricted to the representatives of national members. On budget matters, votes are weighted according to the relative subscription levels of the national members. A second category vote requires a turnout of at least two-thirds of national members in order to be valid. An absolute majority is sufficient for approval in any vote, except for Statute revision which requires a two-thirds majority. An equality of votes is resolved by the vote of the President of the Union. Since 1922, the IAU General Assembly meets every three years, with the ex
Discovery Rupes is an escarpment on Mercury 650 kilometers long and 2 kilometres high, located at latitude 56.3 S and longitude 38.3 W. It was formed by a thrust fault, thought to have occurred due to the shrinkage of the planet's core as it cooled over time; the scarp cuts through Rameau crater. It was discovered by Mariner 10; the rupes are named after the ship used by explorer James Cook on his third voyage. "Discovery Rupes Discovery Region, Mercury". The Solar System in 3-D. Lunar and Planetary Institute. Retrieved 2006-10-25