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
In physics, an orbit is the gravitationally curved trajectory of an object, such as the trajectory of a planet around a star or a natural satellite around a planet. Orbit refers to a repeating trajectory, although it may refer to a non-repeating trajectory. To a close approximation and satellites follow elliptic orbits, with the central mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbital motion; the apparent motions of the planets were described by European and Arabic philosophers using the idea of celestial spheres. This model posited the existence of perfect moving spheres or rings to which the stars and planets were attached.
It assumed the heavens were fixed apart from the motion of the spheres, was developed without any understanding of gravity. After the planets' motions were more measured, theoretical mechanisms such as deferent and epicycles were added. Although the model was capable of reasonably predicting the planets' positions in the sky and more epicycles were required as the measurements became more accurate, hence the model became unwieldy. Geocentric it was modified by Copernicus to place the Sun at the centre to help simplify the model; the model was further challenged during the 16th century, as comets were observed traversing the spheres. The basis for the modern understanding of orbits was first formulated by Johannes Kepler whose results are summarised in his three laws of planetary motion. First, he found that the orbits of the planets in our Solar System are elliptical, not circular, as had been believed, that the Sun is not located at the center of the orbits, but rather at one focus. Second, he found that the orbital speed of each planet is not constant, as had been thought, but rather that the speed depends on the planet's distance from the Sun.
Third, Kepler found a universal relationship between the orbital properties of all the planets orbiting the Sun. For the planets, the cubes of their distances from the Sun are proportional to the squares of their orbital periods. Jupiter and Venus, for example, are about 5.2 and 0.723 AU distant from the Sun, their orbital periods about 11.86 and 0.615 years. The proportionality is seen by the fact that the ratio for Jupiter, 5.23/11.862, is equal to that for Venus, 0.7233/0.6152, in accord with the relationship. Idealised orbits meeting these rules are known as Kepler orbits. Isaac Newton demonstrated that Kepler's laws were derivable from his theory of gravitation and that, in general, the orbits of bodies subject to gravity were conic sections. Newton showed that, for a pair of bodies, the orbits' sizes are in inverse proportion to their masses, that those bodies orbit their common center of mass. Where one body is much more massive than the other, it is a convenient approximation to take the center of mass as coinciding with the center of the more massive body.
Advances in Newtonian mechanics were used to explore variations from the simple assumptions behind Kepler orbits, such as the perturbations due to other bodies, or the impact of spheroidal rather than spherical bodies. Lagrange developed a new approach to Newtonian mechanics emphasizing energy more than force, made progress on the three body problem, discovering the Lagrangian points. In a dramatic vindication of classical mechanics, in 1846 Urbain Le Verrier was able to predict the position of Neptune based on unexplained perturbations in the orbit of Uranus. Albert Einstein in his 1916 paper The Foundation of the General Theory of Relativity explained that gravity was due to curvature of space-time and removed Newton's assumption that changes propagate instantaneously; this led astronomers to recognize that Newtonian mechanics did not provide the highest accuracy in understanding orbits. In relativity theory, orbits follow geodesic trajectories which are approximated well by the Newtonian predictions but the differences are measurable.
All the experimental evidence that can distinguish between the theories agrees with relativity theory to within experimental measurement accuracy. The original vindication of general relativity is that it was able to account for the remaining unexplained amount in precession of Mercury's perihelion first noted by Le Verrier. However, Newton's solution is still used for most short term purposes since it is easier to use and sufficiently accurate. Within a planetary system, dwarf planets and other minor planets and space debris orbit the system's barycenter in elliptical orbits. A comet in a parabolic or hyperbolic orbit about a barycenter is not gravitationally bound to the star and therefore is not considered part of the star's planetary system. Bodies which are gravitationally bound to one of the planets in a planetary system, either natural or artificial satellites, follow orbits about a barycenter near or within that planet. Owing to mutual gravitational perturbations, the eccentricities of the planetary orbits vary over time.
Mercury, the smallest planet in the Solar System, has the most eccentric orbit
An equinox is regarded as the instant of time when the plane of Earth's equator passes through the center of the Sun. This occurs 23 September. In other words, it is the moment at which the center of the visible Sun is directly above the Equator; the word is derived from aequus and nox. On the day of an equinox and nighttime are of equal duration all over the planet, they are not equal, due to the angular size of the Sun, atmospheric refraction, the changing duration of the length of day that occurs at most latitudes around the equinoxes. Long before conceiving this equality primitive cultures noted the day when the Sun rises due East and sets due West and indeed this happens on the day closest to the astronomically defined event. In the northern hemisphere, the equinox in March is called the Spring Equinox; the dates are variable, dependent as they are on the leap year cycle. Because the Moon cause the motion of the Earth to vary from a perfect ellipse, the equinox is now defined by the Sun's more regular ecliptic longitude rather than by its declination.
The instants of the equinoxes are defined to be when the longitude of the Sun is 0° and 180°. Systematically observing the sunrise, people discovered that it occurs between two extreme locations at the horizon and noted the midpoint between the two, it was realized that this happens on a day when the durations of the day and the night are equal and the word "equinox" comes from Latin Aequus, meaning "equal", Nox, meaning "night". In the northern hemisphere, the vernal equinox conventionally marks the beginning of spring in most cultures and is considered the start of the New Year in the Assyrian calendar and the Persian calendar or Iranian calendars as Nowruz, while the autumnal equinox marks the beginning of autumn; the equinoxes are the only times. As a result, the northern and southern hemispheres are illuminated. In other words, the equinoxes are the only times when the subsolar point is on the equator, meaning that the Sun is overhead at a point on the equatorial line; the subsolar point crosses the equator moving northward at the March equinox and southward at the September equinox.
When Julius Caesar established the Julian calendar in 45 BC, he set 25 March as the date of the spring equinox. Because the Julian year is longer than the tropical year by about 11.3 minutes on average, the calendar "drifted" with respect to the two equinoxes – so that in AD 300 the spring equinox occurred on about 21 March, by AD 1500 it had drifted backwards to 11 March. This drift induced Pope Gregory XIII to create the modern Gregorian calendar; the Pope wanted to continue to conform with the edicts of the Council of Nicaea in AD 325 concerning the date of Easter, which means he wanted to move the vernal equinox to the date on which it fell at that time, to maintain it at around that date in the future, which he achieved by reducing the number of leap years from 100 to 97 every 400 years. However, there remained a small residual variation in the date and time of the vernal equinox of about ±27 hours from its mean position all because the distribution of 24-hour centurial leap days causes large jumps.
This in turn raised the possibility that it could fall on 22 March, thus Easter Day might theoretically commence before the equinox. The astronomers chose the appropriate number of days to omit so that the equinox would swing from 19 to 21 March but never fall on 22 March; the dates of the equinoxes change progressively during the leap-year cycle, because the Gregorian calendar year is not commensurate with the period of the Earth's revolution about the Sun. It is only after a complete Gregorian leap-year cycle of 400 years that the seasons commence at the same time. In the 21st century the earliest March equinox will be 19 March 2096, while the latest was 21 March 2003; the earliest September equinox will be 21 September 2096 while the latest was 23 September 2003. Vernal equinox and autumnal equinox: these classical names are direct derivatives of Latin; these are the universal and still most used terms for the equinoxes, but are confusing because in the southern hemisphere the vernal equinox does not occur in spring and the autumnal equinox does not occur in autumn.
The equivalent common language English terms spring equinox and autumn equinox are more ambiguous. It has become common for people to refer to the September equinox in the southern hemisphere as the Vernal equinox. March equinox and September equinox: names referring to the months of the year in which they occur, with no ambiguity as to which hemisphere is the context, they are still not universal, however, as not all cultures use a solar-based calendar where the equinoxes occur every year in the same month. Although the terms have become common in the 21st century, they were sometimes used at least as long ago as the mid-20th century. Northward equinox and southward equinox: names referring to the appare
James Bradley FRS was an English astronomer and priest who served as Astronomer Royal from 1742, succeeding Edmond Halley. He is best known for two fundamental discoveries in astronomy, the aberration of light, the nutation of the Earth's axis; these discoveries were called "the most brilliant and useful of the century" by Jean Baptiste Joseph Delambre, historian of astronomy, mathematical astronomer and director of the Paris Observatory, in his history of astronomy in the 18th century, because "It is to these two discoveries by Bradley that we owe the exactness of modern astronomy..... This double service assures to their discoverer the most distinguished place above the greatest astronomers of all ages and all countries." Bradley was born at Sherborne, near Cheltenham in Gloucestershire, to William Bradley and Jane Pound in March 1693. After attending Westwood's Grammar School at Northleach in Gloucestershire, he entered Balliol College, Oxford, on 15 March 1711, took degrees of B. A. and M.
A. in 1714 and 1717 respectively. His early observations were made at the rectory of Wanstead in Essex, under the tutelage of James Pound, his uncle and a skilled astronomer. Bradley was elected a fellow of the Royal Society on 6 November 1718, he took orders on becoming vicar of Bridstow in Herefordshire in the following year, a small sinecure living in Wales was procured for him by his friend Samuel Molyneux. He resigned his ecclesiastical preferments in 1721, when appointed to the Savilian chair of astronomy at Oxford, while as reader on experimental philosophy from 1729 to 1760, he delivered 79 courses of lectures at the Ashmolean Museum. In 1742, Bradley was appointed to succeed Edmond Halley as Astronomer Royal. A crown pension of GB£250 a year was conferred upon him in 1752. Bradley retired in broken health, nine years to the Cotswold village of Chalford in Gloucestershire, he had medical attention from a local doctor, Daniel Lysons from Oxford. He died at Skiveralls House on 13 July 1762.
He was buried in Minchinhampton in Gloucestershire. In 1722 Bradley measured the angular diameter of Venus with a large aerial telescope with an objective focal length of 212 ft. Bradley's discovery of the aberration of light was made while attempting to detect stellar parallax. Bradley worked with Samuel Molyneux until Molyneux's death in 1728, trying to measure the parallax of Gamma Draconis; this stellar parallax ought to have shown up, if it existed at all, as a small annual cyclical motion of the apparent position of the star. However, while Bradley and Molyneux did not find the expected apparent motion due to parallax, they found instead a different and unexplained annual cyclical motion. Shortly after Molyneux's death, Bradley realised that this was caused by what is now known as the aberration of light; the basis on which Bradley distinguished the annual motion observed from the expected motion due to parallax, was that its annual timetable was different. Calculation showed that if there had been any appreciable motion due to parallax the star should have reached its most southerly apparent position in December, its most northerly apparent position in June.
What Bradley found instead was an apparent motion that reached its most southerly point in March, its most northerly point in September. A story has been told apocryphally, that the solution to the problem occurred to Bradley while he was in a sailing-boat on the River Thames, he noticed that when the boat turned about, a small flag at the top of the mast changed its direction though the wind had not changed. Bradley worked out the consequences of supposing that the direction and speed of the earth in its orbit, combined with a consistent speed of light from the star, might cause the apparent changes of stellar position that he observed, he found that this fitted the observations well, gave an estimate for the speed of light, showed that the stellar parallax, if any, with extremes in June and December, was far too small to measure at the precision available to Bradley. This discovery of what became known as the aberration of light was, for all realistic purposes, conclusive evidence for the movement of the Earth, hence for the correctness of Aristarchus' and Kepler's theories.
The theory of the aberration gave Bradley a means to improve on the accuracy of the previous estimate of the speed of light, estimated by the work of Ole Rømer and others. The earliest observations upon which the discovery of the aberration was founded were made at Molyneux's house on Kew Green, were continued at the house of Bradley's uncle James Pound in Wanstead, Essex. After publication of his work on the aberration, Bradley continued to observe, to develop and check his second major discovery, the nutation of the Earth's axis, but he did not announce this in print until 14 February 1748, when he had tested its reality by minute observations during an entire revol
The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process, it is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometers, or 109 times that of Earth, its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System. Three quarters of the Sun's mass consists of hydrogen; the Sun is a G-type main-sequence star based on its spectral class. As such, it is informally and not accurately referred to as a yellow dwarf, it formed 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System; the central mass became so hot and dense that it initiated nuclear fusion in its core. It is thought that all stars form by this process.
The Sun is middle-aged. It fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result; this energy, which can take between 10,000 and 170,000 years to escape from its core, is the source of the Sun's light and heat. In about 5 billion years, when hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand to become a red giant, it is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, render Earth uninhabitable. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, no longer produce energy by fusion, but still glow and give off heat from its previous fusion; the enormous effect of the Sun on Earth has been recognized since prehistoric times, the Sun has been regarded by some cultures as a deity.
The synodic rotation of Earth and its orbit around the Sun are the basis of solar calendars, one of, the predominant calendar in use today. The English proper name Sun may be related to south. Cognates to English sun appear in other Germanic languages, including Old Frisian sunne, Old Saxon sunna, Middle Dutch sonne, modern Dutch zon, Old High German sunna, modern German Sonne, Old Norse sunna, Gothic sunnō. All Germanic terms for the Sun stem from Proto-Germanic *sunnōn; the Latin name for the Sun, Sol, is not used in everyday English. Sol is used by planetary astronomers to refer to the duration of a solar day on another planet, such as Mars; the related word solar is the usual adjectival term used for the Sun, in terms such as solar day, solar eclipse, Solar System. A mean Earth solar day is 24 hours, whereas a mean Martian'sol' is 24 hours, 39 minutes, 35.244 seconds. The English weekday name Sunday stems from Old English and is a result of a Germanic interpretation of Latin dies solis, itself a translation of the Greek ἡμέρα ἡλίου.
The Sun is a G-type main-sequence star. The Sun has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way, most of which are red dwarfs. The Sun is heavy-element-rich, star; the formation of the Sun may have been triggered by shockwaves from more nearby supernovae. This is suggested by a high abundance of heavy elements in the Solar System, such as gold and uranium, relative to the abundances of these elements in so-called Population II, heavy-element-poor, stars; the heavy elements could most plausibly have been produced by endothermic nuclear reactions during a supernova, or by transmutation through neutron absorption within a massive second-generation star. The Sun is by far the brightest object in the Earth's sky, with an apparent magnitude of −26.74. This is about 13 billion times brighter than the next brightest star, which has an apparent magnitude of −1.46. The mean distance of the Sun's center to Earth's center is 1 astronomical unit, though the distance varies as Earth moves from perihelion in January to aphelion in July.
At this average distance, light travels from the Sun's horizon to Earth's horizon in about 8 minutes and 19 seconds, while light from the closest points of the Sun and Earth takes about two seconds less. The energy of this sunlight supports all life on Earth by photosynthesis, drives Earth's climate and weather; the Sun does not have a definite boundary, but its density decreases exponentially with increasing height above the photosphere. For the purpose of measurement, the Sun's radius is considered to be the distance from its center to the edge of the photosphere, the apparent visible surface of the Sun. By this measure, the Sun is a near-perfect sphere with an oblateness estimated at about 9 millionths, which means that its polar diameter differs from its equatorial diameter by only 10 kilometres; the tidal effect of the planets is weak and does not affect the shape of the Sun. The Sun rotates faster at its equator than at its poles; this differential rotation is caused by convective motion
In astronomy and celestial navigation, the hour angle is one of the coordinates used in the equatorial coordinate system to give the direction of a point on the celestial sphere. The hour angle of a point is the angle between two planes: one containing Earth's axis and the zenith, the other containing Earth's axis and the given point; the angle may be expressed as negative east of the meridian plane and positive west of the meridian plane, or as positive westward from 0° to 360°. The angle may be measured in time, with 24h = 360 ° exactly. In astronomy, hour angle is defined as the angular distance on the celestial sphere measured westward along the celestial equator from the meridian to the hour circle passing through a point, it may be given in time, or rotations depending on the application. In celestial navigation, the convention is to measure in degrees westward from the prime meridian, from the local meridian or from the first point of Aries; the hour angle is paired with the declination to specify the location of a point on the celestial sphere in the equatorial coordinate system.
The local hour angle of an object in the observer's sky is LHA object = LST − α object or LHA object = GST + λ observer − α object where LHAobject is the local hour angle of the object, LST is the local sidereal time, α object is the object's right ascension, GST is Greenwich sidereal time and λ observer is the observer's longitude. These angles can be measured in degrees -- one or the other, not both. Negative hour angles indicate the time until the next transit across the meridian. Observing the sun from earth, the solar hour angle is an expression of time, expressed in angular measurement degrees, from solar noon. At solar noon the hour angle is 0.000 degree, with the time before solar noon expressed as negative degrees, the local time after solar noon expressed as positive degrees. For example, at 10:30 AM local apparent time the hour angle is -22.5°. The cosine of the hour angle is used to calculate the solar zenith angle. At solar noon, h = 0.000 so cos=1, before and after solar noon the cos term = the same value for morning or afternoon, i.e. the sun is at the same altitude in the sky at 11:00AM and 1:00PM solar time, etc.
The sidereal hour angle of a body on the celestial sphere is its angular distance west of the vernal equinox measured in degrees. An alternate definition is that SHA of a celestial body is the arc of the Equinoctial or the angle at the celestial pole contained between the celestial meridian of the First point of Aries and that through the body, measured westward from Aries; the SHA of a star changes and the SHA of a planet doesn't change quickly, so SHA is a convenient way to list their positions in an almanac. SHA is used in celestial navigation and navigational astronomy. Clock position
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In other words, if the axis of rotation of a body is itself rotating about a second axis, that body is said to be precessing about the second axis. A motion in which the second Euler angle changes is called nutation. In physics, there are two types of precession: torque-induced. In astronomy, precession refers to any of several slow changes in an astronomical body's rotational or orbital parameters. An important example is the steady change in the orientation of the axis of rotation of the Earth, known as the precession of the equinoxes. Torque-free precession implies. In torque-free precession, the angular momentum is a constant, but the angular velocity vector changes orientation with time. What makes this possible is a time-varying moment of inertia, or more a time-varying inertia matrix.
The inertia matrix is composed of the moments of inertia of a body calculated with respect to separate coordinate axes. If an object is asymmetric about its principal axis of rotation, the moment of inertia with respect to each coordinate direction will change with time, while preserving angular momentum; the result is that the component of the angular velocities of the body about each axis will vary inversely with each axis' moment of inertia. The torque-free precession rate of an object with an axis of symmetry, such as a disk, spinning about an axis not aligned with that axis of symmetry can be calculated as follows: ω p = I s ω s I p cos where ωp is the precession rate, ωs is the spin rate about the axis of symmetry, Is is the moment of inertia about the axis of symmetry, Ip is moment of inertia about either of the other two equal perpendicular principal axes, α is the angle between the moment of inertia direction and the symmetry axis; when an object is not solid, internal vortices will tend to damp torque-free precession, the rotation axis will align itself with one of the inertia axes of the body.
For a generic solid object without any axis of symmetry, the evolution of the object's orientation, represented by a rotation matrix R that transforms internal to external coordinates, may be numerically simulated. Given the object's fixed internal moment of inertia tensor I0 and fixed external angular momentum L, the instantaneous angular velocity is ω = R I 0 − 1 R T L Precession occurs by recalculating ω and applying a small rotation vector ω dt for the short time dt; the errors induced by finite time steps tend to increase the rotational kinetic energy: E = ω ⋅ L 2 this unphysical tendency can be counteracted by applying a small rotation vector v perpendicular to both ω and L, noting that E ≈ E + ⋅ v Another type of torque-free precession can occur when there are multiple reference frames at work. For example, Earth is subject to local torque induced precession due to the gravity of the sun and moon acting on Earth's axis, but at the same time the solar system is moving around the galactic center.
As a consequence, an accurate measurement of Earth's axial reorientation relative to objects outside the frame of the moving galaxy must account for a minor amount of non-local torque-free precession, due to the solar system's motion. Torque-induced precession is the phenomenon in which the axis of a spinning object des