The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research. NASA was established in 1958; the new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles; the agency is responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA science is focused on better understanding Earth through the Earth Observing System. From 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1.
In the early 1950s, there was challenge to launch an artificial satellite for the International Geophysical Year. An effort for this was the American Project Vanguard. After the Soviet launch of the world's first artificial satellite on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts; the US Congress, alarmed by the perceived threat to national security and technological leadership, urged immediate and swift action. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge be met by an energetic program of research and development for the conquest of space... It is accordingly proposed that the scientific research be the responsibility of a national civilian agency...
NACA is capable, by rapid extension and expansion of its effort, of providing leadership in space technology. While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency was created in February 1958 to develop space technology for military application. On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA; when it began operations on October 1, 1958, NASA absorbed the 43-year-old NACA intact. A NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA. A significant contributor to NASA's entry into the Space Race with the Soviet Union was the technology from the German rocket program led by Wernher von Braun, now working for the Army Ballistic Missile Agency, which in turn incorporated the technology of American scientist Robert Goddard's earlier works. Earlier research efforts within the US Air Force and many of ARPA's early space programs were transferred to NASA.
In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology. The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee is associated with the President's political party, a new administrator is chosen when the Presidency changes parties; the only exceptions to this have been: Democrat Thomas O. Paine, acting administrator under Democrat Lyndon B. Johnson, stayed on while Republican Richard Nixon tried but failed to get one of his own choices to accept the job. Paine was confirmed by the Senate in March 1969 and served through September 1970. Republican James C. Fletcher, appointed by Nixon and confirmed in April 1971, stayed through May 1977 into the term of Democrat Jimmy Carter. Daniel Goldin was appointed by Republican George H. W. Bush and stayed through the entire administration of Democrat Bill Clinton.
Robert M. Lightfoot, Jr. associate administrator under Democrat Barack Obama, was kept on as acting administrator by Republican Donald Trump until Trump's own choice Jim Bridenstine, was confirmed in April 2018. Though the agency is independent, the survival or discontinuation of projects can depend directly on the will of the President; the first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research; the second administrator, James E. Webb, appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's Moon la
Avera is an associated commune on the island of Rurutu, in French Polynesia. It is the smaller of two villages in French Polynesia with this name, the other being located on the island of Raiatea. According to the 2017 census, it had grown to a population 919 people, it is in the Pacific/Tahiti UTC timezone
A cave or cavern is a natural void in the ground a space large enough for a human to enter. Caves form by the weathering of rock and extend deep underground; the word cave can refer to much smaller openings such as sea caves, rock shelters, grottos, though speaking a cave is exogene, meaning it is deeper than its opening is wide, a rock shelter is endogene. Speleology is the science of study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called caving, potholing, or spelunking; the formation and development of caves is known as speleogenesis. Caves can range in size, are formed by various geological processes; these may involve a combination of chemical processes, erosion by water, tectonic forces, microorganisms and atmospheric influences. Isotopic dating techniques can be applied to cave sediments, to determine the timescale of the geological events which formed and shaped present-day caves, it is estimated that a cave cannot exceed 3,000 metres in depth due to the pressure of overlying rocks.
For karst caves the maximum depth is determined on the basis of the lower limit of karst forming processes, coinciding with the base of the soluble carbonate rocks. Most caves are formed in limestone by dissolution. Caves can be classified in various other ways as well, including a contrast between active and relict: active caves have water flowing through them. Types of active caves include inflow caves, outflow caves, through caves. Solutional caves or karst caves are the most occurring caves; such caves form in rock, soluble. Rock is dissolved by natural acid in groundwater that seeps through bedding planes, faults and comparable features. Over time cracks enlarge to become caves and cave systems; the largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3 and occurring organic acids; the dissolution process produces a distinctive landform known as karst, characterized by sinkholes and underground drainage.
Limestone caves are adorned with calcium carbonate formations produced through slow precipitation. These include flowstones, stalagmites, soda straws and columns; these secondary mineral deposits in caves are called speleothems. The portions of a solutional cave that are below the water table or the local level of the groundwater will be flooded. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed to be examples of another type of solutional cave, they were formed by H2S gas rising from below. This gas mixes with groundwater and forms H2SO4; the acid dissolves the limestone from below, rather than from above, by acidic water percolating from the surface. Caves formed at the same time. Lava tubes are the most common primary caves; as lava flows downhill, its surface solidifies. Hot liquid lava continues to flow under that crust, if most of it flows out, a hollow tube remains; such caves can be found in the Canary Islands, Jeju-do, the basaltic plains of Eastern Idaho, in other places.
Kazumura Cave near Hilo, Hawaii is a remarkably deep lava tube. Lava caves are not limited to lava tubes. Other caves formed through volcanic activity include rifts, lava molds, open vertical conduits, blisters, among others. Sea caves are found along coasts around the world. A special case is littoral caves, which are formed by wave action in zones of weakness in sea cliffs; these weaknesses are faults, but they may be dykes or bedding-plane contacts. Some wave-cut caves are now above sea level because of uplift. Elsewhere, in places such as Thailand's Phang Nga Bay, solutional caves have been flooded by the sea and are now subject to littoral erosion. Sea caves are around 5 to 50 metres in length, but may exceed 300 metres. Corrasional or erosional caves are those that form by erosion by flowing streams carrying rocks and other sediments; these can form in any type including hard rocks such as granite. There must be some zone of weakness to guide the water, such as a fault or joint. A subtype of the erosional cave is the aeolian cave, carved by wind-born sediments.
Many caves formed by solutional processes undergo a subsequent phase of erosional or vadose enlargement where active streams or rivers pass through them. Glacier caves are formed by flowing water within and under glaciers; the cavities are influenced by the slow flow of the ice, which tends to collapse the caves again. Glacier caves are sometimes misidentified as "ice caves", though this latter term is properly reserved for bedrock caves that contain year-round ice formations. Fracture caves are formed when layers of more soluble minerals, such as gypsum, dissolve out from between layers of less soluble rock; these rocks fracture and collapse in blocks of stone. Talus caves are formed by the openings among large boulders that have fallen down into a random heap at the bases of cliffs; these unstable deposits are called talus or scree, may be subject to frequent rockfalls and landslides. Anchialine ca
Tubuai or Tupua'i is the main island of the Tubuai Island group, located at 23°23′00″S 149°27′00″W, 640 km south of Tahiti. In addition to Tubuai, the group of islands include Rimatara, Rurutu and the uninhabited Îles Maria, they are part of the Austral Islands in the far southwest of French Polynesia in the south Pacific Ocean. Tubuai island sustains a population of 2,217 people on 45 km² of land. Due to its southerly position, Tubuai has notably cooler weather than Tahiti; the island is ringed by a lagoon formed by an encircling coral reef. A break in the reef that enables passage for ships is located on the north side of the island. Tubuai has two volcanic domes, with Mt Taita'a, being 422 meters. Six or seven islets called; these were described in the late 1700s as having an abundance of Toa trees, which the native islanders used in housebuilding and in making war clubs and spears due to the wood's density. Carbon-dating of archaeological remains allows settlement of these islands to be traced back to AD 1200–1450.
There exists on the island today the stone ruins of a “great number of structures, house platforms, marae complexes, cemeteries...” According to David Stanley's South Pacific Handbook: "The Austral islands were one of the great art areas of the Pacific, represented today in many museums. The best-known artifacts are tall sharkskin drums, wooden bowls, fly whisks, tapa cloth." Tubuai was first viewed by Europeans when it was mapped by Captain James Cook in 1777, although his party did not disembark. Cook discovered the island's name, "Toobouai", from the natives who surrounded his ship in their canoes; the next Europeans to arrive were the mutineers of the HMS Bounty in 1789. Mutineer Fletcher Christian, in looking for an island on which to permanently hide, had "scoured" Bligh's maps and nautical charts and decided on Tubuai. Upon arrival at Tubuai, a conflict arose while the mutineers were still on their ship and several islanders were killed in their canoes; the site of this event in the lagoon on the north side of the island is called Baie Sanglant.
Mutineer James Morrison wrote: "The Island is full of Inhabitants for its size and may Contain 3000 souls." After only ten days on the island, the mutineers sailed for Tahiti to get women and livestock in which they were only nominally successful. When they returned to Tubuai they built a fort on the northeast part of the island at Ta'ahueia, manned with cannon and swivel gun which they named Fort George; the mutineer leader, Fletcher Christian, knew that settling on Tahiti was sure to mean the mutineers' eventual discovery and arrest, so despite being viewed as intruders, Christian was reluctant to view permanent settlement on Tubuai as unfeasible. Christian favoured using diplomacy over time to obtain wives, but many of the other mutineers insisted on raiding parties to take wives by force; the islanders of Tubuai did not want to allow their women to stay at the mutineer camp, or to allow them to become wives. They were not disposed to trade food, it was not long before armed parties of mutineers started burning houses and desecrating marae during skirmishes to obtain women.
More battles ensued. One mutineer tattooed Thomas Burkett was speared in the side by one of the islanders during one of the skirmishes. After only two months since their first arrival on Tubuai the mutineers left for good. Increased contact with Europeans meant more exposure to diseases to which the islanders had no immunity; this proved devastating to the population of Tubuai. At some point during the 30 years from when the mutineers left the island on September 17, 1789, the early 1820s when accounts by Christian missionaries began to be recorded, the population, estimated by the mutineer Morrison to be 3000 was now reduced to no more than 300 people. One Protestant minister when visiting a congregation on Tubuai on January 3, 1824, wrote that several islanders were still suffering from a devastating illness, he noted that several hundred had died within the previous four years. Tupua'i is located at 23°23′00″S 149°27′00″W, just above the Tropic of Capricorn; the island is at the centre of Austral Islands, located 195 km from Ra'ivāvae, 210 km from Rurutu, 700 km from Rapa Iti and 640 km south of Tahiti.
It consists of two former sets of volcanic peaks on Mount Taita'a which are separated by the collar of Huahine. Its area is 45 square kilometres, surrounded by a large lagoon; the barrier reef that surrounds it in effect creates a lagoon of 85 square kilometres, an area double that of the island. It sometimes reaches 5 kilometres wide, its depth is leading to a characteristic colour of turquoise or jade. For a large part, its depth is around 6 metres. However, it can reach up to 25 metres in some parts of the south-east; the waters are replenished via a rather strong and constant ocean current, contributing to the preservation of the lagoon habitat and the health of the coral in the reef. The cooler waters and until very low pollution have helped sustain this environment. Many small streams run through the island, though they empty into swamps rather than the sea; these swamps represent a large portion of the island. Only the river Vaiohuru has any real flow. Eight offshore islands motu in Tahitian, surround the main island: Motu One (also known as îlot d
Bass Islands (French Polynesia)
The Bass Islands consist of Rapa Iti and Marotiri. They are considered to be the southernmost of the Austral Islands, although this classification is more one of geographic and political expediency than because of similarities between them and the rest of the Austral Islands; the Bass Islands, lying several degrees outside the tropics, are the southernmost islands in French Polynesia. Geologically, the Bass Islands are distinguished from the Austral Islands in that their vulcanism appears to be much more recent. Culturally, the Bass Islands appear to have been colonized about the same time as Tahiti and the Marquesas, the culture and language appear to have diverged about the same time as well, indicating that they developed in relative isolation from the time of first settlement. Rapa, sometimes called Rapa Iti, is the largest and only inhabited island of the Bass Islands. An older name for the island is Oparo, its area is 38.5 km2 with a population of 530 and a max elevation of 650 m. Its main town is Ahuréi.
Marotiri is a group of four uninhabited volcanic rocks protruding from the sea, forming the southeastern end of the Austral Islands of French Polynesia. Marotiri is known as Bass Rocks, maybe according to the name of the European explorer George Bass. Marotiri is isolated, located at 27°55′00″S 143°26′00″W, about 725 miles west-south-westward of Pitcairn Island; the closest island is Rapa Iti, 75 km further northwest, but separated from it by an ocean depth of more than 1,500 meters. The rocks are part of the municipality of uninhabitable by people, they form an important bird sanctuary. French overseas departments and territories Administrative divisions of France Islands controlled by France in the Indian and Pacific oceans List of islands of France
Macdonald seamount is a seamount in Polynesia, southeast of the Austral Islands. It rises 4,200 metres from the seafloor to a depth of about 40 metres, but the height of its top appears to vary with volcanic activity; the seamount was discovered in 1967 and has been periodically active with gas release and seismic activity since then. The seamount features a flat top with several subsidiary cones and is located in the neighbourhood of a system of seamounts. Macdonald seamount is the active expression of Macdonald hotspot, a volcanic hotspot that has formed Macdonald seamount and some other volcanoes. Eruptions occurred in 1967, 1977, 1979–1983 and 1987–1989. Earthquake activity was recorded in 2007; the activity has modified the morphology of the volcano and may lead to the formation of an island in the future. Macdonald seamount was discovered in 1967; the seamount was named in 1970 after Gordon A. MacDonald, it is known as Tamarii, while Macdonald appears to be a misspelling. The Pacific Ocean is characterized by the long island chains, which extend from the southeast to the northwest in direction of the motion of the Pacific Plate.
Such chains begin in the southeast with volcanoes such as Hawaii that become progressively more eroded northwestward and end as series of atolls. This has led to the suggestion that they are formed by deep sources over which the Pacific Plate drifts and carries the volcano away from its magma source; these sources are known as "hotspots" and there may be 42–117 in total on Earth. Hotspots may be formed by cracks propagating in the crust, such hotspots would not show an age progression. Macdonald seamount is located off the southeastern end of the Austral Islands; the Austral Islands extend away from the southern Cook Islands to Îles Maria and Marotiri southeastward, including the islands Rimatara, Tubuai and Rapa. A large gap separates Marotiri from the Macdonald volcano; the Ngatemato seamounts and Taukina seamounts lie north of Macdonald, they are older and appear to have a different origin. Farther southeast lies the Foundation seamount chain, the associated hotspot may have generated some of the seamounts close to Macdonald.
Macdonald seamount lies close to the southeastern end of an area of shallower ocean, which extends northwestward towards Marotiri, includes Annie seamount, Simone seamount and President Thiers Bank. The 3,000 metres high Ra seamount rises 100 kilometres northwest of Macdonald to a depth of 1,040 metres. A smaller seamount, rises from the southern foot of Macdonald 850 metres to depths of 3,150 metres. Additional small seamounts that appear to have formed at the East Pacific Rise are found in the area; the crust beneath Macdonald is of Eocene age, away from the area of shallower ocean it is covered with hills and sediment. Macdonald seamount rises 4,200 metres from the seafloor to a depth of about 40 metres below sea level. Other sources indicate a surface area of 2.4 square kilometres for the summit plateau. Ongoing volcanic activity may have modified the topography of the summit of Macdonald between surveys in 1975 and 1982, forming another elliptical pinnacle reaching a depth of 29 metres at the northwestern margin of the plateau and raising the summit plateau to depths of 50–34 metres.
By the time of a new survey in 1986, the pinnacle had been replaced by a pile of rocks which only reached a depth of 42 metres. The upper parts of the edifice are covered by 50 centimetres thick lapilli with lava flows underneath; some hydrothermal alteration products are found, a thick ash cover occurs to depths of 2,000 metres. Aside from these lapilli deposits, scoriaceous lava flows are exposed on the edifice as well. Farther down, lava flow fronts form scarps which become noticeable at depths of 620–1,000 metres, except on the northern flank. Deeper, pillow lavas predominate. Below the summit area, the slopes fall down steeply to a depth of 600 metres and flatten out. Save for a debris-covered ridge to the northwest, Macdonald has a circular shape, with a width of 45 kilometres at a depth of 3,900 metres; the slopes of Macdonald display radial ridges which may reflect tectonically-controlled rift zones, as well as isolated parasitic cones. The volume of the whole edifice has been estimated to be 820 cubic kilometres.
Macdonald seamount bears traces of landslides, including collapse scars up on the edifice and smooth terrain formed by debris on its lower slopes. The seafloor further shows evidence including ripples. Geomagnetic analysis of the edifice has demonstrated the existence of a magnetized structure at the base of the volcano and an additional anomaly which seems to be the magma chamber at a depth of 2 kilometres within the edifice, close to the northern flank. Data obtained in gabbroic rocks expelled by the volcano during its eruptions suggest that another magma reservoir exists at depths of 5 kilometres, within the crust beneath Macdonald. Macdonald has principally erupted basalt; this basalt cont
Statue of A'a from Rurutu
The Statue of A'a from Rurutu is a famous wooden sculpture of the god A'a, made on the Pacific island of Rurutu in the Austral archipelago. In the early nineteenth century, the sculpture was given by the islanders to the London Missionary Society to mark their conversion to Christianity. Following this, it was brought back to England to be displayed, first in the museum of the LMS and in the British Museum; the figure of A'a is famous as one of the finest surviving pieces of Polynesian sculpture, in the twenty-first century the sculpture is, according to Julie Adams, curator of the Oceania collection at the British Museum "an international celebrity". The statue of A'a is a wooden anthropomorphic figure, 117 cm high and 36 cm wide, it is, in the estimation of Alfred Gell, "arguably the finest extant piece of Polynesian sculpture". The figure is hollow, has a removable back panel allowing access to the interior; the sculpture's arms are carved in high relief. The figure has no feet or base, it is unknown if it did when it was created.
The lower legs, right buttock, left arm of the sculpture are damaged, the penis has been broken off completely. While the other damage could be the result of deterioration over time, the severing of the figure's penis appears to have been deliberate, though it is not known whether it was by British missionaries or Polynesian converts. Thirty smaller figures are carved on the surface of the statue. Many of these are positioned to mark features on the human body, such as the eyes and mouth, though some do not correspond with any human feature; the figures are carved in two distinct styles. These two distinct styles of figure are intended to represent male and female forms respectively; these figures are symmetrically distributed across A'a, with the exception of those on the lower abdomen, where there is an upright figure on the right side of A'a and a splayed figure on the left. It is not clear; the earliest records of A'a date to 1821, when the statue was presented to the missionaries of the LMS on Ra'iatea, the second largest of the Society Islands in French Polynesia.
It had been brought there from Rurutu. The sculpture itself could be much older: radiocarbon dating carried out in 2015 suggests that A'a was created between 1591 and 1647. According to Rurutuan tradition, A'a is made from the wood of the pua keni keni, native to islands in the eastern Pacific, though tests conducted in 2015 suggested that the figure is in fact made from sandalwood Santalum insulare. A'a was made using stone-bladed tools, though if it was made after the arrival of Europeans to Polynesia in the 1760s iron tools may have been used in its construction. Ray or shark skin rasps, breadfruit leaves, cowrie shells and coconut oil would have been used to finish and polish the statue. According to a Rurutuan tradition, A'a was carved by Amaiterai, who had visited London and encountered the Christian god there; the cavity according to this story, held three figures, representing the three elements of the Trinity – God the Father, God the Son, God the Holy Spirit. It has been suggested that Amaiterai in this story was in fact Omai, who in 1774 had become the second Pacific Islander known to visit Europe.
The name "Amaiterai", the legendary creator of A'a, may be a corruption of "Omaiterai", or "Omai the Great". In 1821, A'a was given to missionaries from the London Missionary Society based on the island of Ra'iatea, as a symbol of the islanders' conversion to Christianity, it was sent back to London by these missionaries, became part of the collection of the LMS museum. From 1890, the LMS loaned much of their collection of Polynesian art, including A'a, to the British Museum, it is not on display in the museum, but since the 1980s has been exhibited around the world, including in New York, Canberra and London. The works acquired by the British Museum from the London Missionary Society make up some of the best-known works of Polynesian art, including A'a. A'a itself, though part of a corpus of Polynesian god-figures with features such as the smaller figures on the body, large head, rounded stomach, is according to Julie Adams "recognized by experts as a unique figure in Polynesian art". A god figure from Rarotonga in the collection of the British Museum, has three male humanoid figures carved in high relief on its torso, similar to those which cover A'a.
When A'a was brought to the LMS missionaries in 1821, 24 "small gods" were found inside its cavity. It has long been believed that A'a was constructed to hold these small gods. However, the size and shape of the cavity suggest that it was created to hold some other objects – an assortment of small gods could have been housed in a much simpler cavity. Anthropologist Steven Hooper argues that in fact A'a was created as a casket to house the bones of a revered ancestor. John Williams, one of the missionaries who witnessed A'a being presented to the LMS on Ra'iatea, identified the sculpture as representing the god "Aa", both in a letter of 1822 to the directors of the LMS informing them that the sculpture was being delivered, in his 1837 book about his experiences in Polynesia. Lancelot Threlkeld – another missionary, whose boat brought the gods of Rurutu to Raiatea – described the figure as "the great god Aa". However, in 1824 the LMS' publication Missionary Sketches referred to the sculpture as