query: when the moon 's declination is maximum north which of the following will occur

pos: Lunar standstill − 5° =) 18.5° to (23.5° + 5° =) 28.5°. At the minor lunar standstill, the Moon will change its declination during the nodal period from +18.5° to −18.5°, for a total range of 37°. Then 9.3 years later, during the major lunar standstill, the Moon will change its declination during the nodal period from +28.5° to −28.5°, which totals 57° in range. This range is enough to bring the Moon's altitude at culmination from high in the sky to low above the horizon in just two weeks (half an orbit). Strictly speaking, the lunar standstill is a moving position

pos: Orbit of the Moon of the sun sets at the lunar north pole and rises at the lunar south pole. Every 18.6 years, the angle between the Moon's orbit and Earth's equator reaches a maximum of 28°36′, the sum of Earth's equatorial tilt (23°27′) and the Moon's orbital inclination (5°09′) to the ecliptic. This is called "major lunar standstill". Around this time, the Moon's declination will vary from −28°36′ to +28°36′. Conversely, 9.3 years later, the angle between the Moon's orbit and Earth's equator reaches its minimum of 18°20′. This is called a "minor lunar standstill". The last lunar standstill was a minor standstill

pos: Lunar standstill − 5° =) 18.5° to (23.5° + 5° =) 28.5°. At the minor lunar standstill, the Moon will change its declination during the nodal period from +18.5° to −18.5°, for a total range of 37°. Then 9.3 years later, during the major lunar standstill, the Moon will change its declination during the nodal period from +28.5° to −28.5°, which totals 57° in range. This range is enough to bring the Moon's altitude at culmination from high in the sky to low above the horizon in just two weeks (half an orbit). Strictly speaking, the lunar standstill is a moving position

pos: Lunar standstill in the sky in each period of 24 hours when it reaches the observer's meridian. During the month, these culmination altitudes vary so as to produce a greatest value and a least value. The following table shows these altitudes at different times in the lunar nodal period for an observer at 55° north. The greatest and least culminations occur about two weeks apart. The following table shows some occasions of a lunar standstill. The times given are for when the Moon's node passed the equinox—the Moon's greatest declination occurs within a few months of these times, depending on its detailed

pos: Moon year. The full moon is highest in the sky during winter (for each hemisphere). The 18.61-year nodal cycle has an influence on lunar standstill. When the ascending node of the lunar orbit is in the vernal equinox, the lunar declination can reach up to plus or minus 28° each month. This means the Moon can pass overhead if viewed from latitudes up to 28° north or south (of the Equator), instead of only 18°. The orientation of the Moon's crescent also depends on the latitude of the viewing location; an observer in the tropics can see a smile-shaped crescent Moon.

pos: Lunar standstill to the moonrise or moonset on the days of lunar standstills can be found in ancient sites of other ancient cultures, such as at Chimney Rock in Colorado and Hopewell Sites in Ohio. The term "lunar standstill" was apparently first used by archeologist Alexander Thom in his 1971 book "Megalithic Lunar Observatories". The term "solstice", which derives from the Latin "solstitium": "sol"- (sun) + -"stitium" (a stoppage), describes the similar extremes in the Sun's varying declination. Neither the Sun nor the Moon stands still, obviously; what stops, momentarily, is the change in declination. The word "tropic", as in Tropic of

neg: Sun path of Capricorn 23.44°S and a vertical stick will cast no shadow along that point. But north of the Tropic of Capricorn solar noon shadows will point towards true north and south of the Tropic of Capricorn shadows will point towards true south. The solar noon shadows of objects on points beyond and below subsolar points will point towards true north and true south respectively only when the solar declination has its maximum positive (δ☉ = +23.44°) or maximum negative (δ☉ = −23.44°) value. On the other hand, on the equinoxes when the sun is neither declined north nor south (δ☉

neg: Lunar standstill relatively close to the Earth, lunar parallax alters declination up to 0.95° when observed from Earth's surface versus geocentric declination, the declination of the Moon from the center of the Earth. Geocentric declination may be up to about 0.95° different from the observed declination. The amount of this parallax varies with latitude, hence the observed maximum of each standstill cycle varies according to position of observation. Atmospheric refraction – the bending of the light from the Moon as it passes through the Earth's atmosphere – alters the observed declination of the Moon, more so at low elevation, where the atmosphere

neg: Pole star takes about 25,770 years to complete a cycle. Polaris' mean position (taking account of precession and proper motion) will reach a maximum declination of +89°32'23", which translates to 1657" (or 0.4603°) from the celestial north pole, in February 2102. Its maximum apparent declination (taking account of nutation and aberration) will be +89°32'50.62", which is 1629" (or 0.4526°) from the celestial north pole, on 24 March 2100. Precession will next point the north celestial pole at stars in the northern constellation Cepheus. The pole will drift to space equidistant between Polaris and Gamma Cephei ("Errai") by 3000 AD, with Errai reaching

neg: Colatitude 42°, so the distance from the zenith (overhead point) to Polaris is . Adding the declination of a star to the observer's colatitude gives the maximum latitude of that star (its angle from the horizon at culmination or upper transit). For example, if Alpha Centauri is seen with a latitude of 72° north (108° south) and its declination is known (60°S), then it can be determined that the observer's colatitude is (i.e. their latitude is ). Stars whose declinations exceed the observer's colatitude are called circumpolar because they will never set as seen from that latitude. If an object's declination

neg: Orbit of the Moon in October, 2015. At that time the descending node was lined up with the equinox (the point in the sky having right ascension zero and declination zero). The nodes are moving west by about 19° per year. The sun crosses a given node about 20 days earlier each year. When the inclination of the Moon's orbit to the Earth's equator is at its minimum of 18°20′, the centre of the Moon's disk will be above the horizon every day from latitudes less than 71°40' (90° − 18°20') north or south. When the inclination is at its maximum of 28°36', the

neg: Lunar standstill the "minimum" lunar declination, as seen from the centre of the Earth, was at 16:54 UTC on 22 March, when the Moon reached an apparent declination of −28:43:23.3. The next two best contenders were 20:33 on 29 September, at a declination of −28:42:38.3 and 13:12 on 2 September at declination −28:42:16.0. The "maximum" lunar declination, as seen from the centre of the Earth, was at 01:26 on 15 September, when the declination reached +28:43:21.6. The next highest was at 07:36 on 4 April, when it reaches +28:42:53.9 However, these dates and times do not represent the maxima and minima for

neg: Lunar standstill in space relative to the direction of Earth's axis and to the rotation of the Moon's orbital nodes (lunar nodal precession) once every 18.6 years. The standstill position does not persist over the two weeks that the Moon takes to move from its maximum (positive) declination to its minimum (negative) declination, and it most likely will not exactly coincide with either extreme. However, because the 18.6-year cycle of standstills is so much longer than the Moon's orbital period (about 27.3 days) that the change in the declination range over periods as short as half an orbit is very small. The

neg: Lunar standstill major standstill (e.g., in 2005-2006), the declination of the Moon varied during each month from about –("e" + "i") = –28.5° to +("e" + "i") = 28.5°. However, an additional subtlety further complicates the picture. The Sun's gravitational attraction on the Moon pulls it toward the plane of the ecliptic, causing a slight wobble of about 9 arcmin within a 6-month period. In 2006, the effect of this was that, although the 18.6-year maximum occurred in June, the maximum declination of the Moon was not in June but in September, as shown in the third diagram. Because the Moon is

neg: Meridian (geography) can be averaged to give the time of meridian passage. Navigators utilized the sun’s declination and the sun’s altitude at local meridian passage, in order to calculate their latitude with the formula. Latitude = (90o – noon altitude + declination) The declination of major stars are their angles north and south from the celestial equator. It is important to note that the Meridian passage will not occur exactly at 12 hours because of the inclination of the earth. The meridian passage can occur within a few minutes of variation. Many of these instruments rely on the ability to measure the

neg: Lunar standstill lower above the horizon, and back. The Moon differs from most natural satellites around other planets in that it remains near the ecliptic (the plane of Earth's orbit around the Sun) instead of Earth's equatorial plane. The Moon's maximum and minimum declination vary because the plane of the Moon's orbit around Earth is inclined about 5.14° with respect to the ecliptic plane, and the spatial direction of the Moon's orbital inclination gradually changes over an 18.6-year cycle, alternately adding to or subtracting from the 23.5° tilt of Earth's axis. Therefore, the maximum declination of the Moon varies roughly from (23.5°

neg: Lunar node "Ketu". In Tibetan Astrology (partially based on the Kalachakra Tantra) the descending node is named Kalagni. The Moon's orbit is inclined about 5.14° to the ecliptic; hence, the Moon can be up to about 5° north or south of the ecliptic. The ecliptic is inclined about 23.44° to the celestial equator, whose plane is perpendicular to the rotational axis of Earth. As a result, once during the 18.6-year nodal period (when the ascending node of the Moon's orbit coincides with the vernal equinox), the Moon's declination reaches a maximum and minimum (northern and southern extremes): about 28.6° from the celestial

neg: Magnetic declination The angle between magnetic and grid meridians is called grid magnetic angle, grid variation, or grivation.” By convention, declination is positive when magnetic north is east of true north, and negative when it is to the west. "Isogonic lines" are lines on the Earth's surface along which the declination has the same constant value, and lines along which the declination is zero are called "agonic lines". The lowercase Greek letter δ (delta) is frequently used as the symbol for magnetic declination. The term "magnetic deviation" is sometimes used loosely to mean the same as magnetic declination, but more correctly it

neg: Balsamic Moon made to the earthly events that occur during such an astrological configuration. The balsamic moon also is said to relate to healing and rest, since it is the last phase before the New Moon. Balsamic Moon In astrology, a balsamic Moon is said to occur when the Moon is less than 45 degrees behind the natal Sun. For example, if a person has a natal Sun positioned at 10 degrees Aquarius then a balsamic Moon will occur when the Moon reaches 25 degrees Sagittarius. It will stay balsamic as it transits through Capricorn and then Aquarius, until it reaches 10

neg: July 2018 lunar eclipse July 2018 lunar eclipse A total lunar eclipse occurred on 27 July 2018. The Moon passed through the center of Earth's shadow in what was the first central lunar eclipse since 15 June 2011. It was also the second total lunar eclipse in 2018, after the one on 31 January. The eclipse occurred when the Moon was near its maximum distance from Earth, which caused the Moon to appear smaller than normal (a phenomenon sometimes called a micromoon), and to travel at its slowest speed in its orbit around Earth. This was the longest total lunar eclipse that will occur

neg: Geostationary ring km below GEO to 75 km above GEO and from -15 degrees to 15 degrees declination. Geostationary ring The geostationary ring is a volume segment around the geostationary orbit defined by variations in altitude and declination that can occur for uncontrolled objects left in the geostationary orbit. The geostationary orbit is subject to orbit perturbations caused by anomalies in the gravitational field of the Earth, by the gravitational effects of Sun and Moon, and by solar radiation pressure. A precessional motion of the orbit plane is caused by the oblatedness of the Earth (formula_1), and the gravitational effects of Sun

neg: Mecca Time clear what the speakers at the conference meant by "perfect alignment with the North Magnetic Pole". As the geomagnetic field of the earth continuously changes the deviation of the compass needle from true north (known as the magnetic declination) also slowly changes. In the past there were epochs when the compass needle at Mecca pointed true north (and there will be future epochs when this is true again) but at the moment the line of no compass deviation is located somewhat to the southeast of Mecca. In 2015 the (predicted) magnetic declination of Mecca is 3.3° East and will continue

neg: Lunar standstill is thicker (deeper). Not all the maxima are observable from all places in the world – the Moon may be below the horizon at a particular observing site during the maximum, and by the time it rises, it may have a lower declination than an observable maximum at some other date. Note that all dates and times in this section, and in the table, are in UTC, all celestial positions are in topocentric apparent coordinates, including the effects of parallax and refraction, and the lunar phase is shown as the fraction of the Moon's disc which is illuminated. In 2006,

neg: Heliocentric Julian Day Belt objects would be 5 s, and for objects in the main asteroid belt it would be 100 s. In this calculation, the Moon – which is closer than the Sun – can be wrongly placed on the far side of the Sun, resulting in an error of about 15 min. In terms of the vector formula_1 from the heliocentre to the observer, the unit vector formula_2 from the observer toward the object or event, and the speed of light formula_3: formula_4 When the scalar product is expressed in terms of the right ascension formula_5 and declination formula_6 of the

neg: Balsamic Moon Balsamic Moon In astrology, a balsamic Moon is said to occur when the Moon is less than 45 degrees behind the natal Sun. For example, if a person has a natal Sun positioned at 10 degrees Aquarius then a balsamic Moon will occur when the Moon reaches 25 degrees Sagittarius. It will stay balsamic as it transits through Capricorn and then Aquarius, until it reaches 10 degrees Aquarius. The balsamic Moon is said to relate to one's commitment to destiny, so whenever the Moon is placed in this position it is at a very crucial point, and attention should be

neg: Magnetic declination them aligned with magnetic north to allow pilots to use their magnetic compasses for accurate and reliable in-plane navigation. Runways are designated by a number between 01 and 36, which is generally one tenth of the magnetic azimuth of the runway's heading: a runway numbered 09 points east (90°), runway 18 is south (180°), runway 27 points west (270°) and runway 36 points to the north (360° rather than 0°). However, due to magnetic declination, changes in runway designators have to occur at times to keep their designation in line with the runway's magnetic heading. An exception is made for

neg: Lunar node Lunar node A lunar node is either of the two orbital nodes of the Moon, that is, the two points at which the orbit of the Moon intersects the ecliptic. The "ascending" (or "north") node is where the Moon moves into the northern ecliptic hemisphere, while the "descending" (or "south") node is where the Moon enters the southern ecliptic hemisphere. A lunar eclipse can occur only when the full Moon is near (within 11° 38' ecliptic longitude) either lunar node, while a solar eclipse can occur only when the new Moon is near (within 17° 25') either lunar node. Because

neg: Position of the Sun is directed toward the north celestial pole ), in astronomical units: Where the obliquity of the ecliptic is not obtained elsewhere, it can be approximated: for use with the above equations. The Sun appears to move northward during the northern spring, contacting the celestial equator on the March equinox. Its declination reaches a maximum equal to the angle of Earth's axial tilt (23.44°) on the June solstice, then decreases until reaching its minimum (−23.44°) on the December solstice, when its value is the negative of the axial tilt. This variation produces the seasons. A line graph of the Sun's declination

neg: The Tunnel Thru the Air; Or, Looking Back from 1940 Saturn was at maximum North declination in March. Since Saturn’s sidereal year is 29.457 years, it is very uncommon for it to be at maximum North declination in March. Like the weather rules above, the astrological “sign” occurs in the spring. Also, on page 202, Gann discussed the great bull market from 1924 through 1927, “He went back into the stock market and in the great Coolidge Bull Campaign from 1924 to 1927 was again a dominant factor in General Motors and other stocks and was reputed to have made fifty millions, or more.” Checking the geocentric ephemeris, and Hill

neg: Declination Earth. (An ellipsoid is an approximation to sea level that is mathematically manageable). For the moon this discrepancy can reach 0.003 degrees; the Sun and planets are hundreds of times more distant and for them the discrepancy is proportionately smaller (and for the stars is immeasurable). Declination In astronomy, declination (abbreviated dec; symbol δ) is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of the celestial equator, along the hour circle passing through the point in question. The

neg: Geostationary ring Geostationary ring The geostationary ring is a volume segment around the geostationary orbit defined by variations in altitude and declination that can occur for uncontrolled objects left in the geostationary orbit. The geostationary orbit is subject to orbit perturbations caused by anomalies in the gravitational field of the Earth, by the gravitational effects of Sun and Moon, and by solar radiation pressure. A precessional motion of the orbit plane is caused by the oblatedness of the Earth (formula_1), and the gravitational effects of Sun and Moon. This motion has a period of about 53 years. The two parameters describing the

neg: Eclipse the Earth (the ecliptic), eclipses can occur only when the Moon is close to the intersection of these two planes (the nodes). The Sun, Earth and nodes are aligned twice a year (during an eclipse season), and eclipses can occur during a period of about two months around these times. There can be from four to seven eclipses in a calendar year, which repeat according to various eclipse cycles, such as a saros. Between 1901 and 2100 there are the maximum of seven eclipses in: Excluding penumbral lunar eclipses, there are a maximum of seven eclipses in: As observed from

neg: Solar eclipse of July 5, 2168 Solar eclipse of July 5, 2168 A total solar eclipse will occur on July 5, 2168. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Lasting a maximum of 7 minutes, 26 seconds, it will

neg: Solar eclipse of June 13, 2132 Solar eclipse of June 13, 2132 A total solar eclipse will occur on June 13, 2132. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Lasting a maximum of 6 minutes, 55 seconds, it will

neg: Equinox zero. Its latitude will not be exactly zero, since Earth is not exactly in the plane of the ecliptic. Its declination will not be exactly zero either. (The ecliptic is defined by the barycenter of Earth and the Moon combined.) The modern definition of equinox is the instants when the Sun's apparent geocentric longitude is 0° (northward equinox) or 180° (southward equinox). See the adjacent diagram. Because of the precession of the Earth's axis, the position of the vernal point on the celestial sphere changes over time, and the equatorial and the ecliptic coordinate systems change accordingly. Thus when specifying

neg: Conjunction (astronomy) are close together upon the celestial sphere. In the vast majority of such cases, one of the planets will appear to pass north or south of the other. However, if two celestial bodies attain the same declination at the time of a conjunction in right ascension (or the same ecliptic latitude at a conjunction in ecliptic longitude), the one that is closer to the Earth will pass in front of the other. In such a case, a syzygy takes place. If one object moves into the shadow of another, the event is an eclipse. For example, if the Moon passes

neg: Eclipse season every new moon, and all solar eclipses would be the same type. An eclipse season is the only time during which the Sun (from the perspective of the Earth) is close enough to one of the Moon's nodes to allow for an eclipse to occur. During the season, whenever there is a full moon a lunar eclipse will occur and whenever there is a new moon a solar eclipse will occur. If the Sun is close enough to a node, then a total eclipse will occur. Each season lasts from 31 to 37 days, recurring about every 6 months. At

neg: Ganita-yukti-bhasa ascension, declination, longitude, etc., determination of time, place, direction, etc., from gnomonic shadow, eclipses, Vyatipata (when the sun and moon have the same declination), visibility correction for planets and phases of the moon. Ganita-yukti-bhasa Ganita-yukti-bhasa (also written as Ganita Yuktibhasa) is either the title or a part of the title of three different books: This edition of Yuktibhasa has been divided into two volumes, even though the original Malayalam text has no such division. Volume I deals with mathematics and Volume II treats astronomy. Each volume is divided into three parts: First part is an English translation of the relevant

neg: Geomantic figures Cauda Draconis and Caput Draconis, which were assigned to the northern and southern lunar nodes instead. Traditionally, the energies and manifestations of the planets were different based on their declination or motion; for the planets Mercury, Venus, Mars, Jupiter, and Saturn, the diurnal energy represents the planet in direct motion, while the nocturnal energy refers to the retrograde motion of the planets. For the Moon, this was illustrated by the waxing or waning periods of the Moon, respectively; the Sun's figures were based on the Sun during the day (or northern declination) or during the night (southern declination). The zodiacal

neg: Solar compass small convex lens. Opposite to each lens on the brass plates there is attached a small silver plate, by means of three small screws and on each of these, lines are drawn at a suitable distance apart to embrace the sun's image, which falls upon each from the lenses. It will be seen, by inspecting this part of the instrument, that it must be used one end towards the sun, when he has north declination, and the other end for south declination. To gain a better understanding of the set of parts of the solar apparatus just described one should

neg: Lunar standstill the Moon's orbit either adds to (major standstill) or subtracts from (minor standstill) the inclination of earth's rotation axis (23.439°). The effect of this on the declination of the Moon is shown in the second diagram. During the course of the nodal period, as the Moon orbits the Earth, its declination swings from –"m"° to +"m"°, where "m" is a number in the range ("e" – "i") ≤ "m" ≤ ("e" + "i"). At a minor standstill (e.g., in 2015), its declination during the month varies from –("e" – "i") = –18.5° to +("e" – "i") = 18.5°. During a

neg: Solar eclipse of December 25, 1935 the maximum possible. The next time this will occur is 2206. Solar eclipse of December 25, 1935 An annular solar eclipse occurred on December 25, 1935. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands

neg: Saros (astronomy) 13 common years + 5 leap years + 10.321 days), is useful for predicting the times at which nearly identical eclipses will occur. Three periodicities related to lunar orbit, the synodic month, the draconic month, and the anomalistic month coincide almost perfectly each saros cycle. For an eclipse to occur, either the Moon must be located between the Earth and Sun (for a solar eclipse) or the Earth must be located between the Sun and Moon (for a lunar eclipse). This can happen only when the Moon is new or full, respectively, and repeat occurrences of these lunar phases result

neg: Will Rogers phenomenon Will Rogers phenomenon The Will Rogers phenomenon is obtained when moving an element from one set to another set raises the average values of both sets. It is based on the following quote, attributed (perhaps incorrectly) to comedian Will Rogers: The effect will occur when both of these conditions are met: Consider the sets R and S The arithmetic mean of R is 2.5, and the arithmetic mean of S is 7. However, if 5 is moved from S to R, producing then the arithmetic mean of R increases to 3, and the arithmetic mean of S increases to 7.5.

neg: Lunar eclipse not decrease appreciably within the changes in the Moon's orbital distance. Thus, the concurrence of a totally eclipsed Moon near apogee will lengthen the duration of totality. A central lunar eclipse is a total lunar eclipse during which the Moon passes through the centre of Earth's shadow, contacting the antisolar point. This type of lunar eclipse is relatively rare. A selenelion or selenehelion occurs when both the Sun and an eclipsed Moon can be observed at the same time. This can occur only just before sunset or just after sunrise, when both bodies will appear just above the horizon at

neg: Solar eclipse the Earth is inclined at an angle of just over 5 degrees to the plane of the Earth's orbit around the Sun (the ecliptic). Because of this, at the time of a new moon, the Moon will usually pass to the north or south of the Sun. A solar eclipse can occur only when new moon occurs close to one of the points (known as nodes) where the Moon's orbit crosses the ecliptic. As noted above, the Moon's orbit is also elliptical. The Moon's distance from the Earth can vary by about 6% from its average value. Therefore, the Moon's

neg: Solar compass an angle to the above described plane or lines, with the Earth's center, equal to the amount of the sun's declination north or south. Then it will be seen, that when the sun has north or south declination, and the earth is regarded as the center of its revolutions the plane just mentioned becomes conical. This apparent conical motion of the sun may be further explained by the spoked wheels of a covered wagon. The rim representing the sun's apparent path, the hub, the earth, and the spokes, lines drawn from the sun's path. Then it may be seen that

neg: North Magnetic Pole runs from the North Magnetic Pole down through Lake Superior and southward into the Gulf of Mexico (see figure). Along this line, true north is the same as magnetic north. West of the agonic line a compass will give a reading that is east of true north and by convention the magnetic declination is positive. Conversely, east of the agonic line a compass will point west of true north and the declination is negative. As a first-order approximation, the Earth's magnetic field can be modelled as a simple dipole (like a bar magnet), tilted about 10° with respect to the

neg: Lunisolar calendar Gregorian calendar has a lunisolar calendar, which is used to determine the date of Easter. The rules are in the Computus. The following is a list of lunisolar calendars: Lunisolar calendar A lunisolar calendar is a calendar in many cultures whose date indicates both the moon phase and the time of the solar year. If the solar year is defined as a tropical year, then a lunisolar calendar will give an indication of the season; if it is taken as a sidereal year, then the calendar will predict the constellation near which the full moon may occur. As with all

neg: True polar wander True polar wander True polar wander is a solid-body rotation of a planet or moon with respect to its spin axis, causing the geographic locations of the north and south poles to change, or "wander". In a stable state, the largest moment of inertia axis is aligned with the spin axis, with the smaller two moments of inertia axes lying in the plane of the equator. When this is not the case, true polar wander will occur: the planet or moon will rotate as a rigid body to realign the largest moment of inertia axis with the spin axis. The

neg: Solar eclipse of July 2, 2038 in 2038 (the maximum possible), included four penumbral lunar eclipses: January 21, June 17, July 16, and December 11. Solar eclipse of July 2, 2038 An annular solar eclipse will occur on July 2, 2038. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a

neg: Solar eclipse of January 5, 2038 2038 (the maximum possible), included four penumbral lunar eclipses: January 21, June 17, July 16, and December 11. Solar eclipse of January 5, 2038 An annular solar eclipse will occur on January 5, 2038. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial

neg: Solar eclipse of December 26, 2038 Solar eclipse of December 26, 2038 A total solar eclipse will occur on December 26, 2038. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. <BR>Animated path There are 7 eclipses in 2038 (the maximum

neg: North applicable declination, can solve all the problems. But simple generalizations on the subject should be treated as unsound, and as likely to reflect popular misconceptions about terrestrial magnetism. Maps intended for usage in orienteering by compass will clearly indicate the local declination for easy correction to true north. Maps may also indicate grid north, which is a navigational term referring to the direction northwards along the grid lines of a map projection. The visible rotation of the night sky around the visible celestial pole provides a vivid metaphor of that direction corresponding to up. Thus the choice of the north

neg: Axial precession be approximated by the following polynomials for negative and positive time from the present in "/a, where "T" is in billions of Julian years (Ga): Precession will be greater than "p" by the small amount of +0.135052"/a between and . The jump to this excess over "p" will occur in only beginning now because the secular decrease in precession is beginning to cross a resonance in Earth's orbit caused by the other planets. According to Ward, when, in about 1,500 million years, the distance of the Moon, which is continuously increasing from tidal effects, has increased from the current 60.3

neg: S5 0014+81 on the mass of S5 0014+81's supermassive black hole predict that it will live for roughly years (near the end of the Black Hole Era of the universe, when it is more than 10 times its current age), before it dissipates by the Hawking radiation. However, it is undergoing accretion, so it may take longer than the stated time for it to dissipate. S5 0014+81 S5 0014+81 is a distant, compact, hyperluminous, broad-absorption-line quasar, or blazar, located near the high declination region of the constellation Cepheus, near the North Equatorial Pole. The object is a blazar; in fact, an OVV

neg: Solar compass and set due west. At noon the sun would be at the highest point, and in the lowest point at midnight. In other words, when the sun has no declination, its apparent revolutions are in a perfect plane with the Earth's equator. If a straight line were drawn from the rising sun to the setting sun, and from the sun at noon and at midnight, both of these lines would pass through the Earth's center and the equator would intersect these lines. This is not so when the sun has north or south declination because its apparent motion will have

neg: Wet moon orbit is inclined 5.14° to the ecliptic, the Moon will always remain within about 5° north or south of the ecliptic. For half of a sidereal month (with respect to the stars), the Moon is either north or south of the ecliptic. The two points where the Moon's orbit intersects that of Earth are called the lunar nodes; at the ascending node, the Moon moves north of the ecliptic, while at the descending node, the satellite moves south. Eclipses occur at these points, hence the name "ecliptic". The nodes precess around the ecliptic axis at the rate of one circuit

neg: Don River (Ontario) very quickly following a moderate to heavy rainfall, up to 1–2 metres inside of three hours. The average base flow for the Don River is about 4 m/s. Peak flows occur in late February and late September which corresponds to seasonal variation in the Toronto region. Maximum flows, based on a Hurricane Hazel level flood have been estimated at nearly 1700 m/s. On August 19, 2005, an unusually strong summer storm caused short term flooding in the Don Valley. Peak flow rates for that event were measured at 55.3 m/s. Since high flow rates occur during storm events, the resulting

neg: Solstice any kind. Unlike the equinox, the solstice time is not easy to determine. The changes in solar declination become smaller as the sun gets closer to its maximum/minimum declination. The days before and after the solstice, the declination speed is less than 30 arcseconds per day which is less than of the angular size of the sun, or the equivalent to just 2 seconds of right ascension. This difference is hardly detectable with indirect viewing based devices like sextant equipped with a vernier, and impossible with more traditional tools like a gnomon or an astrolabe. It is also hard to

neg: Solar eclipse of September 2, 2035 Beijing, China and Pyongyang, North Korea, and will pass north of a third, Tokyo, Japan. Solar eclipse of September 2, 2035 A total solar eclipse will occur on September 2, 2035. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding

neg: Achernar first-magnitude star, although Antares is located in a constellation with many bright second-magnitude stars, whereas the stars surrounding Alpha Eridani and Fomalhaut are considerably fainter. The first star catalogue to contain Achernar in the chart of Eridanus is Johann Bayer's "Uranometria". Bayer did not observe it himself, and it is attributed to Keyser and the voyages of the Dutch. Thus it was the only first-magnitude star not listed in Ptolemy's "Almagest". Alpha Eridani will continue to move north in the next few millennia, rising from Crete about 500 years hence before reaching its maximum northern declination between the 8th and

neg: Will Rogers phenomenon comparisons, and life span statistics before and after a stage migration use different meanings of "unhealthy", as the cutoff for detection is different. Will Rogers phenomenon The Will Rogers phenomenon is obtained when moving an element from one set to another set raises the average values of both sets. It is based on the following quote, attributed (perhaps incorrectly) to comedian Will Rogers: The effect will occur when both of these conditions are met: Consider the sets R and S The arithmetic mean of R is 2.5, and the arithmetic mean of S is 7. However, if 5 is moved

neg: Position of the Sun during a year resembles a sine wave with an amplitude of 23.44°, but one lobe of the wave is several days longer than the other, among other differences. The following phenomena would occur if Earth is a perfect sphere, in a circular orbit around the Sun, and if its axis is tilted 90°, so that the axis itself is on the orbital plane (similar to Uranus). At one date in the year, the Sun would be directly overhead at the North Pole, so its declination would be +90°. For the next few months, the subsolar point would move toward the

neg: Llyn Celyn reservoir is held in reserve to be released down the river for specific whitewater events. Because the reservoir's principal purpose is to support low river flows in the main River Dee, the best conditions for such events occur during long dry spells in summer when maximum releases are made. Usually the dam will release between 9 and 11 m³/s, although releases as low as 2 m³/s and as high as 16 m³/s have been known. During wet weather the releases are usually throttled back to a minimal maintenance flow unless a planned release for recreational activities has been agreed. Its

neg: Ceres (dwarf planet) earlier. These last observations indicated that the north pole of Ceres pointed in the direction of right ascension 19 h 24 min (291°), declination +59°, in the constellation Draco, resulting in an axial tilt of approximately 3°. "Dawn" later determined that the north polar axis actually points at right ascension 19 h 25 m 40.3 s (291.418°), declination +66° 45' 50" (about 1.5 degrees from Delta Draconis), which means an axial tilt of 4°. "Dawn" revealed that Ceres has a heavily cratered surface; nevertheless, Ceres does not have as many large craters as expected, likely due to past geological processes.

neg: Sundial due east and due west. In a similar way, northern hemisphere dials that are partly north-facing and southern hemisphere dials that are south-facing, and which lean forward toward their upward pointing gnomons, will have a similar restriction on the range of declination that is possible for a given reclination value. The critical declination formula_54 is a geometrical constraint which depends on the value of both the dial's reclination and its latitude : As with the vertical declined dial, the gnomon's substyle is not aligned with the noon hour-line. The general formula for the angle formula_21, between the substyle and the

neg: Declination (N.P.D.), which is equivalent to 90 - (declination). For instance an object marked as declination -5 would have a NPD of 95, and a declination of -90 (the south celestial pole) would have a NPD of 180. Declination in astronomy is comparable to geographic latitude, projected onto the celestial sphere, and hour angle is likewise comparable to longitude. Points north of the celestial equator have positive declinations, while those south have negative declinations. Any units of angular measure can be used for declination, but it is customarily measured in the degrees ( ° ), minutes ( ′ ), and seconds

neg: Solar eclipse of March 30, 2052 southeastern states of the United States. Almost all of North America and the northern edge of South America will see a partial eclipse. It will be the 2nd total eclipse visible from the Florida Panhandle and southwest Georgia in 7 years. Solar eclipse of March 30, 2052 A total solar eclipse will occur on March 30, 2052. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's,

neg: Moon of millions of years ago, the Moon would always completely cover the Sun on solar eclipses, and no annular eclipses were possible. Likewise, hundreds of millions of years in the future, the Moon will no longer cover the Sun completely, and total solar eclipses will not occur. Because the Moon's orbit around Earth is inclined by about 5.145° (5° 9') to the orbit of Earth around the Sun, eclipses do not occur at every full and new moon. For an eclipse to occur, the Moon must be near the intersection of the two orbital planes. The periodicity and recurrence of

neg: Peak copper that they can and will continue. Peak copper Peak copper is the point in time at which the maximum global copper production rate is reached. Since copper is a finite resource, at some point in the future new production from mining will diminish, and at some earlier time production will reach a maximum. When this will occur is a matter of dispute. Unlike fossil fuels, copper is scrapped and reused and it has been estimated that at least 80% of all copper ever mined is still available (having been repeatedly recycled). Copper is among the most important industrial metals, valued

neg: Arthur Thomas Doodson of two tidal peaks in a day, though remember that the repeat time is not exactly twelve hours but 12.4206 hours. The two peaks are not equal: the twin tidal bulges beneath the moon and on the far side of the earth are aligned with the moon. Bridgeport is north of the equator, so when the moon is north of the equator also and shining upon Bridgeport, Bridgeport is closer to its maximum effect than approximately twelve hours later when Bridgeport is on the far side of the earth from the moon and the high tide bulge at Bridgeport's longitude

neg: Astronomy on Mars the Earth, a dip in overall brightness would occur, although this would be too small to be noticeable by casual naked eye observers because the size of the Moon is much smaller than that of the Earth and it would cover only a small fraction of the Earth's disk. Mars Global Surveyor imaged the Earth and Moon on May 8, 2003 13:00 UTC, very close to maximum angular elongation from the Sun and at a distance of 0.930 AU from Mars. The apparent magnitudes were given as −2.5 and +0.9. At different times the actual magnitudes will vary considerably depending

neg: Saturn the time, the moon will pass above or below Saturn in the sky, and no occultation will occur. It is only when Saturn lies near the point that the moon’s orbit crosses the "plane of the ecliptic" that occultations can happen – and then they occur every time the moon swings by, until Saturn moves away from the crossing point. Saturn Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius about nine times that of Earth. It has only one-eighth the average density

neg: North Magnetic Pole exactly the direction of the North Magnetic Pole (or of any other consistent location). Instead, the compass aligns itself to the local geomagnetic field, which varies in a complex manner over the Earth's surface, as well as over time. The local angular difference between magnetic north and true north is called the magnetic declination. Most map coordinate systems are based on true north, and magnetic declination is often shown on map legends so that the direction of true north can be determined from north as indicated by a compass. In North America the line of zero declination (the "agonic line")

neg: Contact (mathematics) four-vertex theorem). In general a curve will not have 4th-order contact with any circle. However, 4th-order contact can occur generically in a 1-parameter family of curves, at a curve in the family where (as the parameter varies) two vertices (one maximum and one minimum) come together and annihilate. At such points the second derivative of curvature will be zero. In econometrics it is also possible to consider circles which have two point contact with two points "S"("t"), "S"("t") on the curve. Such circles are "bi-tangent" circles. The centers of all bi-tangent circles form the symmetry set. The medial axis is

neg: Heliacal rising called its "acronychal rising", which for a superior planet signifies an opposition, another type of syzygy. When the Moon has an acronychal rising, it will occur near full moon and thus, in a small number of cases, a noticeable lunar eclipse. Heliacal rising The heliacal rising (, ) or star rise of a star, star cluster, or galaxy occurs annually when it becomes visible above the eastern horizon for a moment before sunrise, after a period of less than a year when it had not been visible. Historically, the most important such rising is that of Sirius, which was an

neg: Equatorial coordinate system sphere. The declination symbol , (lower case "delta", abbreviated dec) measures the angular distance of an object perpendicular to the celestial equator, positive to the north, negative to the south. For example, the north celestial pole has a declination of +90°. The origin for declination is the celestial equator, which is the projection of the Earth's equator onto the celestial sphere. Declination is analogous to terrestrial latitude. The right ascension symbol , (lower case "alpha", abbreviated RA) measures the angular distance of an object eastward along the celestial equator from the vernal equinox to the hour circle passing through the

neg: Peak copper Peak copper Peak copper is the point in time at which the maximum global copper production rate is reached. Since copper is a finite resource, at some point in the future new production from mining will diminish, and at some earlier time production will reach a maximum. When this will occur is a matter of dispute. Unlike fossil fuels, copper is scrapped and reused and it has been estimated that at least 80% of all copper ever mined is still available (having been repeatedly recycled). Copper is among the most important industrial metals, valued for its heat and electrical conductivities

neg: Azimuth compass recorded to calculate the true azimuth. The true azimuth may be compared to the magnetic azimuth to find the magnetic declination, the angle between the direction that the compass indicates as north and the true north direction. An azimuth compass is a magnetic compass where the circumference of the card is divided into 360 degrees. It has two sights, diametrically opposite each other, through which the sun, planet or star is viewed. The sun is typically observed when the sun's center is about one solar diameter above the horizon. Typically the compass will have a stop in the side of

neg: Full moon may appear reddish due to the Rayleigh scattering of blue wavelengths and the refraction of sunlight through Earth's atmosphere. Lunar eclipses happen only during full moon and around points on its orbit where the satellite may pass through the planet's shadow. A lunar eclipse does not occur every month because the Moon's orbit is inclined 5.14° with respect to the ecliptic plane of Earth; thus, the Moon usually passes north or south of Earth's shadow, which is mostly restricted to this plane of reference. Lunar eclipses happen only when the full moon occurs around either node of its orbit (ascending

neg: Asteroid mining the Moon to Ceres would be even more energy-efficient than transportation from Earth to the Moon. Organizations which are working on asteroid mining include the following: According to the Asterank database, the following asteroids are considered the best targets for mining if maximum cost-effectiveness is to be achieved (last updated December 2018): Currently, the quality of the ore and the consequent cost and mass of equipment required to extract it are unknown and can only be speculated. Some economic analyses indicate that the cost of returning asteroidal materials to Earth far outweighs their market value, and that asteroid mining will

neg: Black moon years. When February is without full moon, then the preceding January or December and the following March or April have two full moons. As with the case of two new moons in a month, whether a black moon by this definition occurs depends on the time zone. Calculated in UTC, instances of a month without full moon between 1990 and 2040 are: Another use of the term is for the absence of the new moon in a calendar month. This can occur only in February; it happens about every 19 years. When February is without new moon, then the preceding

neg: Synoeca cyanea the wasps scrape their mandibles on the carton of their nest. In addition, as one of the most aggressive social wasps, "S. cyanea" often will bite and sting when threatened. Their barbed sting often remains in the skin as the wasp pulls away. "S. cyanea" venom is strong enough to cause haemolytic activity. Rhabdomyolysis and hemorrhage may also occur. In mice, abdominal spasms, ataxia, defecation, dyspnoea, hyperactivity, hypoactivity, sweating, and throes were observed following venom injection. "S. cyanea" venom also contains some antibacterial activity. Human accidents with wasps can occur one of two ways. Either a human may receive no

neg: Atlantic Ocean mean depth between 60°N and 60°S is , or close to the average for the global ocean, with a modal depth between . In the South Atlantic the Walvis Ridge and Rio Grande Rise form barriers to ocean currents. The Laurentian Abyss is found off the eastern coast of Canada. Surface water temperatures, which vary with latitude, current systems, and season and reflect the latitudinal distribution of solar energy, range from below to over . Maximum temperatures occur north of the equator, and minimum values are found in the polar regions. In the middle latitudes, the area of maximum temperature

neg: Magnetic deviation Magnetic deviation Magnetic deviation is the error induced in a compass by "local" magnetic fields, which must be allowed for, along with magnetic declination, if accurate bearings are to be calculated. (More loosely, "magnetic deviation" is used by some to mean the same as "magnetic declination". This article is about the former meaning.) Compasses are used to determine the direction of true North. However, the compass reading must be corrected for two effects. The first is magnetic declination or variation—the angular difference between "magnetic North" (the local direction of the Earth's magnetic field) and true North. The second is "magnetic

neg: Circumpolar constellation holds true in the Southern Hemisphere, where certain stars and constellations will always be visible in the southern circumpolar sky. The celestial north pole, currently marked by Polaris less than 1° away, always has an azimuth equal to zero. The pole's altitude for a given latitude Ø is fixed, and its value is given by the following formula: "A" = 90° - Ø. All stars with a declination less than "A" are not circumpolar. As viewed from the North Pole, all fully visible constellations north of the celestial equator are circumpolar, and likewise for constellations south of the celestial equator

neg: Purnima This lunar phase lasts only for a while, when the Sun, Earth, and the Moon are aligned exactly in a straight line, called a syzygy of the Sun–Earth–Moon system. Full moon is considered the third of the four primary phases of the Moon; the other three phases are new moon, first quarter moon, and third quarter moon. The full moon shows 100% illumination, causes high tides, and can concur with lunar eclipses. The following festivals occur on Purnima. Purnima Purnima (also called Poornima, Pournima, Bangla: পূর্ণিমা, Sanskrit: पूर्णिमा (IAST: pūrṇimā)) is the Indian and Nepali word for full moon, while

neg: Lunar phase of the ecliptic). Thus, when new and full moons occur, the Moon usually lies to the north or south of a direct line through the Earth and Sun. Although an eclipse can only occur when the Moon is either new (solar) or full (lunar), it must also be positioned very near the intersection of Earth's orbital plane about the Sun and the Moon's orbital plane about the Earth (that is, at one of its nodes). This happens about twice per year, and so there are between four and seven eclipses in a calendar year. Most of these eclipses are partial;

neg: Navigational triangle be described in terms of 'Latitude' (degrees north or south of the Equator) and Longitude (degrees east or west of the Greenwich Meridian). X is the point where center of celestial body lies on celestial sphere: The Sun, The Moon, The Planets, The Stars. Some of these points appear to move relative to the celestial sphere (The Sun, The Moon, The Planets), but the Stars' declination remain's more or less same as they are very far away but their hour angle(GHA or LHA) change constantly, in fact their hour angle changes by 360 degree in every 23 hour 56 minutes

neg: Edward Victor Appleton is: formula_2 If N is an integer number, then constructive interference will occur, this means a maximum signal will be achieved at the receiving end. If N is an odd integer number of half wavelengths, then destructive interference will occur and a minimum signal will be received. Let us assume we are receiving a maximum signal for a given wavelength λ. If we start to change λ, this is the process called frequency modulation, N will no longer be a whole number and destructive interference will start to occur, meaning the signal will start to fade. Now we keep changing

neg: Solar eclipse Earth and therefore apparently larger, so every solar eclipse was total or partial, and there were no annular eclipses. Due to tidal acceleration, the orbit of the Moon around the Earth becomes approximately 3.8 cm more distant each year. Millions of years in the future, the Moon will be too far away to fully occlude the Sun, and no total eclipses will occur. In the same timeframe, the Sun may become brighter, making it appear larger in size. Estimates of the when the moon will be unable to occlude the entire sun when viewed from the Earth range between 1.4

neg: Brookings Report implications of a discovery of extraterrestrial life. The report touches on the possibility of covering up extraterrestrial life, including the following passages: "While face-to-face meetings with it will not occur within the next twenty years (unless its technology is more advanced than ours, qualifying it to visit Earth), artifacts left at some point in time by these life forms might possibly be discovered through our space activities on the Moon, Mars, or Venus." – pages 182–183 "Anthropological files contain many examples of societies, sure of their place in the universe, which have disintegrated when they have had to associate with

neg: Magnetic declination download and includes a data file updated every five years to account for movement of the magnetic north pole. A magnetic compass points to magnetic north, not geographic north. Compasses of the style commonly used for hiking include a declination adjustment in the form of a bezel which swivels relative to the base plate. To establish a declination the bezel is rotated until the desired number of degrees plus or minus lie between the bezel’s designation N (for North) and the direction indicated by the magnetic end of the needle (usually painted red). This allows the user to establish a

neg: Equation of time onto our celestial equator, along which "clock time" is measured, is a maximum at the solstices, when the yearly movement of the Sun is parallel to the equator (causing amplification of perceived speed) and yields mainly a change in right ascension. It is a minimum at the equinoxes, when the Sun's apparent motion is more sloped and yields more change in declination, leaving less for the component in right ascension, which is the only component that affects the duration of the solar day. A practical illustration of obliquity is that the daily shift of the shadow cast by the Sun

neg: Racemization by simply mixing equal quantities of two pure enantiomers. Racemization can also occur in a chemical interconversion. For example, when ("R")-3-phenyl-2-butanone is dissolved in aqueous ethanol that contains [NaOH] or HCl, a racemate is formed. The racemization occurs by way of an intermediate enol form in which the former stereocenter becomes planar and hence achiral. An incoming group can approach from either side of the plane, so there is an equal probability that protonation back to the chiral ketone will produce either an "R" or an "S" form, resulting in a racemate. Racemization can occur through some of the following

neg: Solar eclipse the total phase of a solar eclipse directly only when the Sun's photosphere is completely covered by the Moon, and not before or after totality. During this period, the Sun is too dim to be seen through filters. The Sun's faint corona will be visible, and the chromosphere, solar prominences, and possibly even a solar flare may be seen. At the end of totality, the same effects will occur in reverse order, and on the opposite side of the Moon. Photographing an eclipse is possible with fairly common camera equipment. In order for the disk of the Sun/Moon to be

neg: Range of a projectile for the time. After several steps of algebraic manipulation The square root must be a positive number, and since the velocity and the sine of the launch angle can also be assumed to be positive, the solution with the greater time will occur when the positive of the plus or minus sign is used. Thus, the solution is Solving for the range once again or, equivalently To maximize the range at any height Checking the limit as formula_26 approaches 0 The angle ψ at which the projectile lands is given by: For maximum range, this results in the following equation:

neg: Absorption spectroscopy overall line is therefore broader yet. Absorption and transmission spectra represent equivalent information and one can be calculated from the other through a mathematical transformation. A transmission spectrum will have its maximum intensities at wavelengths where the absorption is weakest because more light is transmitted through the sample. An absorption spectrum will have its maximum intensities at wavelengths where the absorption is strongest. Emission is a process by which a substance releases energy in the form of electromagnetic radiation. Emission can occur at any frequency at which absorption can occur, and this allows the absorption lines to be determined from

neg: Lunar standstill to latitude). If viewed from a latitude of 50° N on Earth, any star with a declination of +50° would pass directly overhead (reaching the zenith at upper culmination) once every sidereal day (23 hours, 56 minutes, 4 seconds), whether visible at night or obscured in daylight. Unlike the stars, the Sun and Moon do not have a fixed declination. Since Earth's rotational axis is tilted about 23.5° with respect to a line perpendicular to its orbital plane (the ecliptic), the Sun's declination ranges from +23.5° on the June solstice to −23.5° on the December solstice, as Earth orbits the

neg: Astronomical clock later when it goes back down below the ecliptic. These two locations are the ascending and descending lunar nodes. Solar and lunar eclipses will occur only when the moon is positioned near one of these nodes, because at other times the moon is either too high or too low for an eclipse to be noticed from earth. Some astronomical clocks keep track of the position of the lunar nodes with a long pointer that crosses the dial. This so-called dragon hand makes one complete rotation around the ecliptic dial every 19 years. When the dragon hand and the new moon