Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics and chemistry in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, stars, nebulae and comets. More all phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject is physical cosmology, the study of the Universe as a whole. Astronomy is one of the oldest of the natural sciences; the early civilizations in recorded history, such as the Babylonians, Indians, Nubians, Chinese and many ancient indigenous peoples of the Americas, performed methodical observations of the night sky. Astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy, the making of calendars, but professional astronomy is now considered to be synonymous with astrophysics. Professional astronomy is split into theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, analyzed using basic principles of physics.
Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain observational results and observations being used to confirm theoretical results. Astronomy is one of the few sciences in which amateurs still play an active role in the discovery and observation of transient events. Amateur astronomers have made and contributed to many important astronomical discoveries, such as finding new comets. Astronomy means "law of the stars". Astronomy should not be confused with astrology, the belief system which claims that human affairs are correlated with the positions of celestial objects. Although the two fields share a common origin, they are now distinct. Both of the terms "astronomy" and "astrophysics" may be used to refer to the same subject. Based on strict dictionary definitions, "astronomy" refers to "the study of objects and matter outside the Earth's atmosphere and of their physical and chemical properties," while "astrophysics" refers to the branch of astronomy dealing with "the behavior, physical properties, dynamic processes of celestial objects and phenomena."
In some cases, as in the introduction of the introductory textbook The Physical Universe by Frank Shu, "astronomy" may be used to describe the qualitative study of the subject, whereas "astrophysics" is used to describe the physics-oriented version of the subject. However, since most modern astronomical research deals with subjects related to physics, modern astronomy could be called astrophysics; some fields, such as astrometry, are purely astronomy rather than astrophysics. Various departments in which scientists carry out research on this subject may use "astronomy" and "astrophysics" depending on whether the department is affiliated with a physics department, many professional astronomers have physics rather than astronomy degrees; some titles of the leading scientific journals in this field include The Astronomical Journal, The Astrophysical Journal, Astronomy and Astrophysics. In early historic times, astronomy only consisted of the observation and predictions of the motions of objects visible to the naked eye.
In some locations, early cultures assembled massive artifacts that had some astronomical purpose. In addition to their ceremonial uses, these observatories could be employed to determine the seasons, an important factor in knowing when to plant crops and in understanding the length of the year. Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye; as civilizations developed, most notably in Mesopotamia, Persia, China and Central America, astronomical observatories were assembled and ideas on the nature of the Universe began to develop. Most early astronomy consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, the nature of the Sun and the Earth in the Universe were explored philosophically; the Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the geocentric model of the Ptolemaic system, named after Ptolemy.
A important early development was the beginning of mathematical and scientific astronomy, which began among the Babylonians, who laid the foundations for the astronomical traditions that developed in many other civilizations. The Babylonians discovered. Following the Babylonians, significant advances in astronomy were made in ancient Greece and the Hellenistic world. Greek astronomy is characterized from the start by seeking a rational, physical explanation for celestial phenomena. In the 3rd century BC, Aristarchus of Samos estimated the size and distance of the Moon and Sun, he proposed a model of the Solar System where the Earth and planets rotated around the Sun, now called the heliocentric model. In the 2nd century BC, Hipparchus discovered precession, calculated the size and distance of the Moon and inven
Surveying or land surveying is the technique and science of determining the terrestrial or three-dimensional positions of points and the distances and angles between them. A land surveying professional is called a land surveyor; these points are on the surface of the Earth, they are used to establish maps and boundaries for ownership, such as building corners or the surface location of subsurface features, or other purposes required by government or civil law, such as property sales. Surveyors work with elements of geometry, regression analysis, engineering, programming languages, the law, they use equipment, such as total stations, robotic total stations, theodolites, GNSS receivers, retroreflectors, 3D scanners, handheld tablets, digital levels, subsurface locators, drones, GIS, surveying software. Surveying has been an element in the development of the human environment since the beginning of recorded history; the planning and execution of most forms of construction require it. It is used in transport, communications and the definition of legal boundaries for land ownership.
It is an important tool for research in many other scientific disciplines. The International Federation of Surveyors defines the function of surveying as: A surveyor is a professional person with the academic qualifications and technical expertise to conduct one, or more, of the following activities. Surveying has occurred since humans built the first large structures. In ancient Egypt, a rope stretcher would use simple geometry to re-establish boundaries after the annual floods of the Nile River; the perfect squareness and north-south orientation of the Great Pyramid of Giza, built c. 2700 BC, affirm the Egyptians' command of surveying. The Groma instrument originated in Mesopotamia; the prehistoric monument at Stonehenge was set out by prehistoric surveyors using peg and rope geometry. The mathematician Liu Hui described ways of measuring distant objects in his work Haidao Suanjing or The Sea Island Mathematical Manual, published in 263 AD; the Romans recognized land surveying as a profession.
They established the basic measurements under which the Roman Empire was divided, such as a tax register of conquered lands. Roman surveyors were known as Gromatici. In medieval Europe, beating the bounds maintained the boundaries of a village or parish; this was the practice of gathering a group of residents and walking around the parish or village to establish a communal memory of the boundaries. Young boys were included to ensure the memory lasted as long as possible. In England, William the Conqueror commissioned the Domesday Book in 1086, it recorded the names of all the land owners, the area of land they owned, the quality of the land, specific information of the area's content and inhabitants. It did not include maps showing exact locations. Abel Foullon described a plane table in 1551, but it is thought that the instrument was in use earlier as his description is of a developed instrument. Gunter's chain was introduced in 1620 by English mathematician Edmund Gunter, it enabled plots of land to be surveyed and plotted for legal and commercial purposes.
Leonard Digges described a Theodolite that measured horizontal angles in his book A geometric practice named Pantometria. Joshua Habermel created a theodolite with a compass and tripod in 1576. Johnathon Sission was the first to incorporate a telescope on a theodolite in 1725. In the 18th century, modern techniques and instruments for surveying began to be used. Jesse Ramsden introduced the first precision theodolite in 1787, it was an instrument for measuring angles in vertical planes. He created his great theodolite using an accurate dividing engine of his own design. Ramsden's theodolite represented a great step forward in the instrument's accuracy. William Gascoigne invented an instrument that used a telescope with an installed crosshair as a target device, in 1640. James Watt developed an optical meter for the measuring of distance in 1771. Dutch mathematician Willebrord Snellius introduced the modern systematic use of triangulation. In 1615 he surveyed the distance from Alkmaar to Breda 72 miles.
He underestimated this distance by 3.5%. The survey was a chain of quadrangles containing 33 triangles in all. Snell showed, he showed how to resection, or calculate, the position of a point inside a triangle using the angles cast between the vertices at the unknown point. These could be measured more than bearings of the vertices, which depended on a compass, his work established the idea of surveying a primary network of control points, locating subsidiary points inside the primary network later. Between 1733 and 1740, Jacques Cassini and his son César undertook the first triangulation of France, they included a re-surveying of the meridian arc, leading to the publication in 1745 of the first map of France constructed on rigorous principles. By this time triangulation methods were well established for local map-making, it was only towards the end of the 18th century that detailed triangulation network surveys mapped whole countries. In 1784, a team from Gene
West Virginia is a state located in the Appalachian region in the Southern United States, considered to be a part of the Middle Atlantic States. It is bordered by Pennsylvania to the north, Maryland to the east and northeast, Virginia to the southeast, Kentucky to the southwest, Ohio to the northwest. West Virginia is the 41st largest state by area, is ranked 38th in population; the capital and largest city is Charleston. West Virginia became a state following the Wheeling Conventions of 1861, after the American Civil War had begun. Delegates from some Unionist counties of northwestern Virginia decided to break away from Virginia, although they included many secessionist counties in the new state. West Virginia was admitted to the Union on June 20, 1863, was a key border state during the war. West Virginia was the only state to form by separating from a Confederate state, the first to separate from any state since Maine separated from Massachusetts, was one of two states admitted to the Union during the American Civil War.
While a portion of its residents held slaves, most of the residents were yeomen farmers, the delegates provided for gradual abolition of slavery in the new state Constitution. The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States; however the Bureau of Labor Statistics classifies West Virginia as a part of the Mid-Atlantic. The northern panhandle extends adjacent to Pennsylvania and Ohio, with the West Virginia cities of Wheeling and Weirton just across the border from the Pittsburgh metropolitan area, while Bluefield is less than 70 miles from North Carolina. Huntington in the southwest is close to the states of Ohio and Kentucky, while Martinsburg and Harpers Ferry in the Eastern Panhandle region are considered part of the Washington metropolitan area, in between the states of Maryland and Virginia; the unique position of West Virginia means that it is included in several geographical regions, including the Mid-Atlantic, the Upland South, the Southeastern United States.
It is the only state, within the area served by the Appalachian Regional Commission. The state is noted for its mountains and rolling hills, its significant logging and coal mining industries, its political and labor history, it is known for a wide range of outdoor recreational opportunities, including skiing, whitewater rafting, hiking, mountain biking, rock climbing, hunting. Many ancient man-made earthen mounds from various prehistoric mound builder cultures survive in the areas of present-day Moundsville, South Charleston, Romney; the artifacts uncovered in these give evidence of village societies. They had a tribal trade system culture. In the 1670s during the Beaver Wars, the powerful Iroquois, five allied nations based in present-day New York and Pennsylvania, drove out other American Indian tribes from the region in order to reserve the upper Ohio Valley as a hunting ground. Siouan language tribes, such as the Moneton, had been recorded in the area. A century the area now identified as West Virginia was contested territory among Anglo-Americans as well, with the colonies of Pennsylvania and Virginia claiming territorial rights under their colonial charters to this area before the American Revolutionary War.
Some speculative land companies, such as the Vandalia Company, the Ohio Company and Indiana Company, tried to legitimize their claims to land in parts of West Virginia and present day Kentucky, but failed. This rivalry resulted in some settlers petitioning the Continental Congress to create a new territory called Westsylvania. With the federal settlement of the Pennsylvania and Virginia border dispute, creating Kentucky County, Kentuckians "were satisfied, the inhabitants of a large part of West Virginia were grateful."The Crown considered the area of West Virginia to be part of the British Virginia Colony from 1607 to 1776. The United States considered this area to be the western part of the state of Virginia from 1776 to 1863, before the formation of West Virginia, its residents were discontented for years with their position in Virginia, as the government was dominated by the planter elite of the Tidewater and Piedmont areas. The legislature had electoral malapportionment, based on the counting of slaves toward regional populations, the western white residents were underrepresented in the state legislature.
More subsistence and yeoman farmers lived in the west and they were less supportive of slavery, although many counties were divided on their support. The residents of this area became more divided after the planter elite of eastern Virginia voted to secede from the Union during the Civil War. Residents of the western and northern counties set up a separate government under Francis Pierpont in 1861, which they called the Restored Government. Most voted to separate from Virginia, the new state was admitted to the Union in 1863. In 1864 a state constitutional convention drafted a constitution, ratified by the legislature without putting it to popular vote. West Virginia abolished slavery by a gradual process and temporarily disenfranchised men who had held Confederate office or fought for the Confederacy. West Virginia's history has been profoundly affected by its mountainous terrain and vast river valleys, rich natural resources; these were all factors driving its economy and the lifestyles of its residents, who tended to live in many small isolated communities in the mountain valleys.
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Cape of Good Hope
The Cape of Good Hope is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is; this misconception was based on the misbelief that the Cape was the dividing point between the Atlantic and Indian Oceans. Contemporary geographic knowledge instead states the southernmost point of Africa is Cape Agulhas about 150 kilometres to the east-southeast; the currents of the two oceans meet at the point where the warm-water Agulhas current meets the cold-water Benguela current and turns back on itself. That oceanic meeting point fluctuates between Cape Point; when following the western side of the African coastline from the equator, the Cape of Good Hope marks the point where a ship begins to travel more eastward than southward. Thus, the first modern rounding of the cape in 1488 by Portuguese explorer Bartolomeu Dias was a milestone in the attempts by the Portuguese to establish direct trade relations with the Far East. Dias called the cape Cabo das Tormentas, the original name of the "Cape of Good Hope".
As one of the great capes of the South Atlantic Ocean, the Cape of Good Hope has long been of special significance to sailors, many of whom refer to it as "the Cape". It is a waypoint on the Cape Route and the clipper route followed by clipper ships to the Far East and Australia, still followed by several offshore yacht races; the term Cape of Good Hope is used in three other ways: It is a section of the Table Mountain National Park, within which the cape of the same name, as well as Cape Point, falls. Prior to its incorporation into the national park, this section constituted the Cape Point Nature Reserve, it was the name of the early Cape Colony established by the Dutch on the Cape Peninsula. Just before the Union of South Africa was formed, the term referred to the entire region that in 1910 was to become the Cape of Good Hope Province. Eudoxus of Cyzicus was a Greek navigator for Ptolemy VIII, king of the Hellenistic Ptolemaic dynasty in Egypt, who found the wreck of a ship in the Indian Ocean that appeared to have come from Gades, rounding the Cape.
When Eudoxus was returning from his second voyage to India, the wind forced him south of the Gulf of Aden and down the coast of Africa for some distance. Somewhere along the coast of East Africa, he found the remains of the ship. Due to its appearance and the story told by the natives, Eudoxus concluded that the ship was from Gades and had sailed anti-clockwise around Africa, passing the Cape and entering the Indian Ocean; this inspired him to attempt a circumnavigation of the continent. Organising the expedition on his own account he set sail from Gades and began to work down the African coast; the difficulties were too great, he was obliged to return to Europe. After this failure he again set out to circumnavigate Africa, his eventual fate is unknown. Although some, such as Pliny, claimed that Eudoxus did achieve his goal, the most probable conclusion is that he perished on the journey. In the 1450 Fra Mauro map, the Indian Ocean is depicted as connected to the Atlantic. Fra Mauro puts the following inscription by the southern tip of Africa, which he names the "Cape of Diab", describing the exploration by a ship from the East around 1420: "Around 1420 a ship, or junk, from India crossed the Sea of India towards the Island of Men and the Island of Women, off Cape Diab, between the Green Islands and the shadows.
It sailed for 40 days in a south-westerly direction without finding anything other than wind and water. According to these people themselves, the ship went some 2,000 miles ahead until - once favourable conditions came to an end - it turned round and sailed back to Cape Diab in 70 days". "The ships called junks that navigate these seas carry four masts or more, some of which can be raised or lowered, have 40 to 60 cabins for the merchants and only one tiller. They can navigate without a compass, because they have an astrologer, who stands on the side and, with an astrolabe in hand, gives orders to the navigator". Fra Mauro explained that he obtained the information from "a trustworthy source", who traveled with the expedition the Venetian explorer Niccolò da Conti who happened to be in Calicut, India at the time the expedition left: "What is more, I have spoken with a person worthy of trust, who says that he sailed in an Indian ship caught in the fury of a tempest for 40 days out in the Sea of India, beyond the Cape of Soffala and the Green Islands towards west-southwest.
Thus one can believe and confirm what is said by both these and those, that they had therefore sailed 4,000 miles". Fra Mauro comments that the account of the expedition, together with the relation by Strabo of the travels of Eudoxus of Cyzicus from Arabia to Gibraltar through the southern Ocean in Antiquity, led him to believe that the Indian Ocean was not a closed sea and that Africa could be circumnavigated by her southern end; this knowledge, together with the map depiction of the African continent encouraged the Portuguese to intensify their effort to round the tip of Africa. I
The Moon is an astronomical body that orbits planet Earth and is Earth's only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, the largest among planetary satellites relative to the size of the planet that it orbits; the Moon is after Jupiter's satellite Io the second-densest satellite in the Solar System among those whose densities are known. The Moon is thought to have formed not long after Earth; the most accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia. The Moon is in synchronous rotation with Earth, thus always shows the same side to Earth, the near side; the near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the second-brightest visible celestial object in Earth's sky, its surface is dark, although compared to the night sky it appears bright, with a reflectance just higher than that of worn asphalt.
Its gravitational influence produces the ocean tides, body tides, the slight lengthening of the day. The Moon's average orbital distance is 1.28 light-seconds. This is about thirty times the diameter of Earth; the Moon's apparent size in the sky is the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly during a total solar eclipse; this matching of apparent visual size will not continue in the far future because the Moon's distance from Earth is increasing. The Moon was first reached in September 1959 by an unmanned spacecraft; the United States' NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, six manned landings between 1969 and 1972, with the first being Apollo 11. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon's origin, internal structure, the Moon's history. Since the Apollo 17 mission in 1972, the Moon has been visited only by unmanned spacecraft.
Both the Moon's natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences can be found in language, lunar calendar systems and mythology; the usual English proper name for Earth's natural satellite is "the Moon", which in nonscientific texts is not capitalized. The noun moon is derived from Old English mōna, which stems from Proto-Germanic *mēnô, which comes from Proto-Indo-European *mḗh₁n̥s "moon", "month", which comes from the Proto-Indo-European root *meh₁- "to measure", the month being the ancient unit of time measured by the Moon; the name "Luna" is used. In literature science fiction, "Luna" is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of Earth's moon; the modern English adjective pertaining to the Moon is lunar, derived from the Latin word for the Moon, luna. The adjective selenic is so used to refer to the Moon that this meaning is not recorded in most major dictionaries.
It is derived from the Ancient Greek word for the Moon, σελήνη, from, however derived the prefix "seleno-", as in selenography, the study of the physical features of the Moon, as well as the element name selenium. Both the Greek goddess Selene and the Roman goddess Diana were alternatively called Cynthia; the names Luna and Selene are reflected in terminology for lunar orbits in words such as apolune and selenocentric. The name Diana comes from the Proto-Indo-European *diw-yo, "heavenly", which comes from the PIE root *dyeu- "to shine," which in many derivatives means "sky and god" and is the origin of Latin dies, "day"; the Moon formed 4.51 billion years ago, some 60 million years after the origin of the Solar System. Several forming mechanisms have been proposed, including the fission of the Moon from Earth's crust through centrifugal force, the gravitational capture of a pre-formed Moon, the co-formation of Earth and the Moon together in the primordial accretion disk; these hypotheses cannot account for the high angular momentum of the Earth–Moon system.
The prevailing hypothesis is that the Earth–Moon system formed after an impact of a Mars-sized body with the proto-Earth. The impact blasted material into Earth's orbit and the material accreted and formed the Moon; the Moon's far side has a crust, 30 mi thicker than that of the near side. This is thought to be; this hypothesis, although not perfect best explains the evidence. Eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, Jeff Taylor challenged fellow lunar scientists: "You have eighteen months. Go back to your Apollo data, go back to your computer, do whatever you have to, but make up your mind. Don't come to our conference unless you have something to say about the Moon's birth." At the 1984 conference at Kona, the giant impact hypothesis emerged as the most consensual theory. Before the conference, there were parti
Delaware is one of the 50 states of the United States, in the South-Atlantic or Southern region. It is bordered to the south and west by Maryland, north by Pennsylvania, east by New Jersey and the Atlantic Ocean; the state takes its name from Thomas West, 3rd Baron De La Warr, an English nobleman and Virginia's first colonial governor. Delaware occupies the northeastern portion of the Delmarva Peninsula. It's the sixth most densely populated. Delaware's largest city is Wilmington; the state is divided into the lowest number of any state. From north to south, they are New Castle County, Kent County, Sussex County. While the southern two counties have been predominantly agricultural, New Castle County is more industrialized. Before its coastline was explored by Europeans in the 16th century, Delaware was inhabited by several groups of Native Americans, including the Lenape in the north and Nanticoke in the south, it was colonized by Dutch traders at Zwaanendael, near the present town of Lewes, in 1631.
Delaware was one of the 13 colonies participating in the American Revolution. On December 7, 1787, Delaware became the first state to ratify the Constitution of the United States, has since been known as "The First State"; the state was named after the Delaware River, which in turn derived its name from Thomas West, 3rd Baron De La Warr, the ruling governor of the Colony of Virginia at the time Europeans first explored the river. The Delaware Indians, a name used by Europeans for Lenape people indigenous to the Delaware Valley derive their name from the same source; the surname de La Warr is of Anglo-Norman origin. It came from a Norman lieu-dit La Guerre; this toponymic could derive from the Latin word ager, from the Breton gwern or from the Late Latin varectum. The toponyms Gara, Gaire appear in old texts cited by Lucien Musset, where the word gara means gore, it could be linked with a patronymic from the Old Norse verr. Delaware is 96 miles long and ranges from 9 miles to 35 miles across, totaling 1,954 square miles, making it the second-smallest state in the United States after Rhode Island.
Delaware is bounded to the north by Pennsylvania. Small portions of Delaware are situated on the eastern side of the Delaware River sharing land boundaries with New Jersey; the state of Delaware, together with the Eastern Shore counties of Maryland and two counties of Virginia, form the Delmarva Peninsula, which stretches down the Mid-Atlantic Coast. The definition of the northern boundary of the state is unusual. Most of the boundary between Delaware and Pennsylvania was defined by an arc extending 12 miles from the cupola of the courthouse in the city of New Castle; this boundary is referred to as the Twelve-Mile Circle. Although the Twelve-Mile Circle is claimed to be the only territorial boundary in the United States, a true arc, the Mexican boundary with Texas includes several arcs, many cities in the South have circular boundaries; this border extends all the way east to the low-tide mark on the New Jersey shore continues south along the shoreline until it again reaches the 12-mile arc in the south.
To the west, a portion of the arc extends past the easternmost edge of Maryland. The remaining western border runs east of due south from its intersection with the arc; the Wedge of land between the northwest part of the arc and the Maryland border was claimed by both Delaware and Pennsylvania until 1921, when Delaware's claim was confirmed. Delaware is with the lowest mean elevation of any state in the nation, its highest elevation, located at Ebright Azimuth, near Concord High School, is less than 450 feet above sea level. The northernmost part of the state is part of the Piedmont Plateau with rolling surfaces; the Atlantic Seaboard fall line follows the Robert Kirkwood Highway between Newark and Wilmington. A ridge about 75 to 80 feet in elevation extends along the western boundary of the state and separates the watersheds that feed Delaware River and Bay to the east and the Chesapeake Bay to the west. Since all of Delaware is a part of the Atlantic coastal plain, the effects of the ocean moderate its climate.
The state lies in the humid subtropical climate zone. Despite its small size, there is significant variation in mean temperature and amount of snowfall between Sussex County and New Castle County. Moderated by the Atlantic Ocean and Delaware Bay, the southern portion of the state has a milder climate and a longer growing season than the northern portion of the state. Delaware's all-time record high of 110 °F was recorded at Millsboro on July 21, 1930; the all-time record low of −17 °F was recorded at Millsboro on January 17, 1893. The transitional climate of Delaware supports a wide variety of vegetation. In the northern third of the state are found Northeastern coastal forests and mixed oak forests typical of the northeastern United States. In the southern two-thirds of the state are found Middle Atlantic coastal forests. Trap Pond State Park, along with areas in other parts of Sussex County, for example, support
The Rev Dr Nevil Maskelyne DD FRS FRSE was the fifth British Astronomer Royal. He held the office from 1765 to 1811, he was the first person to scientifically measure the weight of the planet Earth. Maskelyne was born in London, the third son of Edmund Maskelyne of Purton and his wife, Elizabeth Booth. Maskelyne's father died. Maskelyne attended Westminster School and was still a pupil there when his mother died in 1748, his interest in astronomy had begun while at Westminster School, shortly after the eclipse of 14 July 1748. Maskelyne entered St Catharine's College, Cambridge in 1749, graduating as seventh wrangler in 1754. Ordained as a minister in 1755, he became a fellow of Trinity College, Cambridge in 1756 and a Fellow of the Royal Society in 1758. Pursuing his career as a minister he was Rector of Shrawardine from 1775 to 1782 and Rector of North Runcton from 1782. In 1784 he was elected a Fellow of the Royal Society of Edinburgh, his proposers were John Robison and Dugald Stewart. On 21 August 1784 Maskelyne married Sophia Rose of St Andrew Holborn, Middlesex.
Their only child, was the mother of Mervyn Herbert Nevil Story-Maskelyne professor of mineralogy at Oxford. Maskelyne's sister, married Robert Clive. Nevil Maskelyne is buried in the churchyard of St Mary the Virgin, the parish church of the village of Purton, England. In 1760 the Royal Society appointed Maskelyne as an astronomer on one of their expeditions to observe the 1761 transit of Venus, he and Robert Waddington were sent to the island of St. Helena; this was an important observation since accurate measurements would allow the accurate calculation of Earth's distance from the Sun, which would in turn allow the actual rather than the relative scale of the solar system to be calculated. This would allow, it was argued, the production of more accurate astronomical tables, in particular those predicting the motion of the Moon. Bad weather prevented observation of the transit, but Maskelyne used his journey to trial a method of determining longitude using the position of the moon, which became known as the lunar distance method.
He returned to England, resuming his position as curate at Chipping Barnet in 1761, began work on a book, publishing the lunar-distance method of longitude calculation and providing tables to facilitate its use in 1763 in The British Mariner's Guide, which included the suggestion that to facilitate the finding of longitude at sea, lunar distances should be calculated beforehand for each year and published in a form accessible to navigators. In 1763 the Board of Longitude sent Maskelyne to Barbados in order to carry out an official trial of three contenders for a Longitude reward, he was to carry out observations on board ship and to calculate the longitude of the capital, Bridgetown by observation of Jupiter's satellites. The three methods on trial were John Harrison's sea watch, Tobias Mayer's lunar tables and a marine chair made by Christopher Irwin, intended to help observations of Jupiter's satellites on board ship. Both Harrison's watch and lunar-distance observations based on Mayer's lunar tables produced results within the terms of the Longitude Act, although the former appeared to be more accurate.
Harrison's watch had produced Bridgetown's longitude with an error of less than ten miles, while the lunar-distance observations were accurate to within 30 nautical miles. Maskelyne reported the results of the trial to the Board of Longitude on 9 February 1765. On 26 February 1765 he had been appointed Astronomer Royal following the unexpected death of Nathaniel Bliss in 1764; the Commissioners understood that the timekeeping and astronomical methods of finding longitude were complementary. The lunar-distance method could more be rolled out, with Maskelyne's proposal that tables like those in his "The British Mariner's Guide" be published for each year; this proposal led to the establishment of The Nautical Almanac, the production of which, as Astronomer Royal, Maskelyne oversaw. Taking occasional astronomical observations was the only way to check that a timekeeper was keeping good time over the course of a long voyage; the Commissioners needed to know that more than one sea watch could be made, that Harrison's methods could be communicated to other watchmakers.
The Board of Longitude therefore decided that rewards should be given Harrison and others involved in helping to develop the lunar-distance method. Harrison was told that a further reward of £10,000 would be forthcoming if he could demonstrate the replicability of his watch, it is worth noting that although Harrison and his son accused Maskelyne of bias against the timekeeping method, charges repeated by authors such as Dava Sobel and Rupert Gould, Maskelyne never submitted a method or an idea of his own for consideration by the Board of Longitude. He was to play a significant role in having marine timekeepers, as well as the lunar-distance method, developed and used on board voyages of exploration. Since the observations that fed into the Nautical Almanac were made at the Royal Observatory, the Greenwich meridian became the reference for measurements of longitude in the Royal Navy, on British Admiralty charts, it was recommended for adoption as the international Prime Meridian in 1884. Maskelyne took a great interest in various geodetical operations, including the measurement of the length of a degree of latitude in Maryland and Pennsylvania, executed by Mason and Dixon in 1766 – 1768, the determination of the relative longitude of Greenwi