Index to Volume 277

1975 ◽  
Vol 277 (1274) ◽  
pp. 649-649
Keyword(s):  
Orbital Motion ◽  
Lunar Orbit ◽  
Artificial Satellites ◽  
Time Interval ◽  
The Sun ◽  
The Moon ◽  
Slight Effect ◽  
The Earth ◽  
Westerly Direction ◽  
Complete Revolution

Dr R. R. Newton has notified the following correction to his contribution. The paragraph at the bottom of page 16 and the top of page 17 should read: The node of the lunar orbit rotates in a westerly direction around the plane of the ecliptic, making a complete revolution in about 18.61 years. This motion, and this time interval, are important in eclipse theory, as we shall discuss in the next section. This motion results almost entirely from the perturbation of the Sun’s gravitation on the Moon’s orbital motion. The Earth’s equatorial bulge, which is almost entirely responsible for the motion of the nodes of artificial satellites near the Earth, has only a slight effect on a satellite as distant as the Moon.

scholarly journals The Lunar orbit paradox

2013 ◽  
Vol 40 (1) ◽  
pp. 135-146
Author(s):  
Aleksandar Tomic
Keyword(s):  
Inertial Mass ◽  
Lunar Orbit ◽  
The Sun ◽  
The Moon ◽  
The Earth ◽  
Three Body ◽  
Origin Of The Moon ◽  
Force Intensity ◽  
Critical Consideration

Newton's formula for gravity force gives greather force intensity for atraction of the Moon by the Sun than atraction by the Earth. However, central body in lunar (primary) orbit is the Earth. So appeared paradox which were ignored from competent specialist, because the most important problem, determination of lunar orbit, was inmediately solved sufficiently by mathematical ingeniosity - introducing the Sun as dominant body in the three body system by Delaunay, 1860. On this way the lunar orbit paradox were not canceled. Vujicic made a owerview of principles of mechanics in year 1998, in critical consideration. As an example for application of corrected procedure he was obtained gravity law in some different form, which gave possibility to cancel paradox of lunar orbit. The formula of Vujicic, with our small adaptation, content two type of acceleration - related to inertial mass and related to gravity mass. So appears carried information on the origin of the Moon, and paradox cancels.

scholarly journals Theory of the Libration of the Moon

1983 ◽  
Vol 74 ◽  
pp. 37-37
Author(s):  
M. Dubois-Moons
Keyword(s):  
Gravity Field ◽  
Orbital Motion ◽  
Lunar Theory ◽  
The Sun ◽  
Lunar Gravity ◽  
The Moon ◽  
Fourth Degree ◽  
Lunar Gravity Field ◽  
The Earth ◽  
Second Degree

AbstractThe paper presents a new theory of the libration of the Moon, completely analytical with respect to the harmonic coefficients of the lunar gravity field. This field is represented through its fourth degree harmonics for the torque due to the Earth (the second degree for the torque due to the Sun). The Moon is assumed to be rigid and its orbital motion is described by the ELP 2000 solution (Chapront and Chapront-Touzé 1981) for the main problem of lunar theory with planetary perturbations and influence of the non-sphericity of the Earth. Comparisons with other theories (Migus 1980 and Eckhardt 1981) are also presented.

scholarly journals Time Scales for Theory and Practice

1992 ◽  
Vol 9 ◽  
pp. 141-149
Author(s):  
Gernot M. R. Winkler
Keyword(s):  
Theory And Practice ◽  
The Sun ◽  
The Moon ◽  
Vernal Equinox ◽  
Perceived Needs ◽  
The Earth ◽  
Cyclical Process ◽  
The Mean ◽  
Complete Revolution ◽  
Early Human

Very early human experience has suggested a practical definition for the measurement of time: We define a unit of time by defining a standard (cyclical) process. Whenever this process completes its cycle identically, a unit of time has elapsed. This is the origin for the various measures of time in classical astronomy. Nature suggests strongly that we use as such standard processes the year (defined as a complete revolution of the earth around the Sun), the month (the completion of a revolution of the moon around the earth), and the day which again can be measured in several different ways. While the sidereal day is measured by a rotation in respect to the vernal equinox, the mean solar day is measured in respect to the mean. Sun. More recently, we have distinguished many more different ways of defining measures of time, partly in response to perceived needs of the applications, but in part also from purely aesthetic principles.

scholarly journals Relation of a Contracting Earth to the Apparent Accelerations of the Sun and Moon

1978 ◽  
Vol 41 ◽  
pp. 87-87
Author(s):  
R.A. Lyttleton
Keyword(s):  
Phase Change ◽  
Change Theory ◽  
Present Theory ◽  
The Other ◽  
Lunar Orbit ◽  
The Sun ◽  
The Moon ◽  
The Earth ◽  
Tidal Theory ◽  
Additional Process

AbstractThe tidal theory of the evolution of the lunar orbit has remained inconsistent with the observational values of the apparent secular accelerations of the Sun and Moon since it was first developed by Jeffreys in 1920. Allowance for a changing moment of inertia of the Earth enables the discrepancy to be completely removed if a decrease is occurring at a rate of just about the amount already required by the phase-change theory of the nature of the terrestrial core. The agreement of the resulting theory with the latest determinations of the lunar acceleration increases confidence in the phase-change hypothesis. On the other hand the theory renders it most unlikely that a changing constant of gravitation will prove necessary to account for the observations. On the present theory of itself the Moon would have been extremely close to the Earth only about 109 years ago which suggests that some additional process may at times have influenced the lunar orbit.

Automated Determination of the Position of Ships by Satellites

1967 ◽  
Vol 20 (03) ◽  
pp. 281-285
Author(s):  
H. C. Freiesleben
Keyword(s):  
Celestial Body ◽  
World Wide ◽  
Artificial Satellites ◽  
Radio Waves ◽  
The Moon ◽  
Position Determination ◽  
The Earth ◽  
Navigational Aids ◽  
Automated Determination

It has recently been suggested that 24-hour satellites might be used as navigational aids. To what category of position determination aids should these be assigned ? Is a satellite of this kind as it were a landmark, because, at least in theory, it remains fixed over the same point on the Earth's surface, in which case it should be classified under land-based navigation aids ? Is it a celestial body, although only one tenth as far from the Earth as the Moon ? If so, it is an astronomical navigation aid. Or is it a radio aid ? After all, its use for position determination depends on radio waves. In this paper I shall favour this last view. For automation is most feasible when an object of observation can be manipulated. This is easiest with radio aids, but it is, of course, impossible with natural stars.At present artificial satellites have the advantage over all other radio aids of world-wide coverage.

scholarly journals High-resolution spectroscopy and spectropolarimetry of the total lunar eclipse January 2019

2020 ◽  
Vol 635 ◽  
pp. A156
Author(s):  
K. G. Strassmeier ◽  
I. Ilyin ◽  
E. Keles ◽  
M. Mallonn ◽  
A. Järvinen ◽  
...  
Keyword(s):  
Large Scale ◽  
Solar Spectrum ◽  
High Resolution Spectroscopy ◽  
Strong Increase ◽  
Lunar Eclipse ◽  
The Sun ◽  
The Moon ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Earth's Atmosphere

Context. Observations of the Earthshine off the Moon allow for the unique opportunity to measure the large-scale Earth atmosphere. Another opportunity is realized during a total lunar eclipse which, if seen from the Moon, is like a transit of the Earth in front of the Sun. Aims. We thus aim at transmission spectroscopy of an Earth transit by tracing the solar spectrum during the total lunar eclipse of January 21, 2019. Methods. Time series spectra of the Tycho crater were taken with the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope in its polarimetric mode in Stokes IQUV at a spectral resolution of 130 000 (0.06 Å). In particular, the spectra cover the red parts of the optical spectrum between 7419–9067 Å. The spectrograph’s exposure meter was used to obtain a light curve of the lunar eclipse. Results. The brightness of the Moon dimmed by 10.m75 during umbral eclipse. We found both branches of the O2 A-band almost completely saturated as well as a strong increase of H2O absorption during totality. A pseudo O2 emission feature remained at a wavelength of 7618 Å, but it is actually only a residual from different P-branch and R-branch absorptions. It nevertheless traces the eclipse. The deep penumbral spectra show significant excess absorption from the Na I 5890-Å doublet, the Ca II infrared triplet around 8600 Å, and the K I line at 7699 Å in addition to several hyper-fine-structure lines of Mn I and even from Ba II. The detections of the latter two elements are likely due to an untypical solar center-to-limb effect rather than Earth’s atmosphere. The absorption in Ca II and K I remained visible throughout umbral eclipse. Our radial velocities trace a wavelength dependent Rossiter-McLaughlin effect of the Earth eclipsing the Sun as seen from the Tycho crater and thereby confirm earlier observations. A small continuum polarization of the O2 A-band of 0.12% during umbral eclipse was detected at 6.3σ. No line polarization of the O2 A-band, or any other spectral-line feature, is detected outside nor inside eclipse. It places an upper limit of ≈0.2% on the degree of line polarization during transmission through Earth’s atmosphere and magnetosphere.

Decapitated Lunar Goddesses in Aztec Art, Myth, and Ritual

1997 ◽  
Vol 8 (2) ◽  
pp. 185-206 ◽  
Author(s):  
Susan Milbrath
Keyword(s):  
Solar Eclipse ◽  
Seasonal Cycle ◽  
Full Moon ◽  
The Sun ◽  
The Moon ◽  
Seasonal Transition ◽  
The Earth ◽  
New Moon ◽  
The Demonic

AbstractAztec images of decapitated goddesses link the symbolism of astronomy with politics and the seasonal cycle. Rituals reenacting decapitation may refer to lunar events in the context of a solar calendar, providing evidence of a luni-solar calendar. Decapitation imagery also involves metaphors expressing the rivalry between the cults of the sun and the moon. Huitzilopochtli's decapitation of Coyolxauhqui can be interpreted as a symbol of political conquest linked to the triumph of the sun over the moon. Analysis of Coyolxauhqui's imagery and mythology indicates that she represents the full moon eclipsed by the sun. Details of the decapitation myth indicate specific links with seasonal transition and events taking place at dawn and at midnight. Other decapitated goddesses, often referred to as earth goddesses with “lunar connections,” belong to a complex of lunar deities representing the moon within the earth (the new moon). Cihuacoatl, a goddess of the new moon, takes on threatening quality when she assumes the form of a tzitzimime attacking the sun during a solar eclipse. The demonic new moon was greatly feared, for it could cause an eternal solar eclipse bringing the Aztec world to an end.

Solar Motion and Lunar Eclipses in Philolaus’ Cosmological System

Apeiron ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Dirk L. Couprie
Keyword(s):  
The Other ◽  
The Sun ◽  
The Moon ◽  
Internal Logic ◽  
Wrong Side ◽  
The Earth ◽  
Solar Motion ◽  
Length Of The Day

Abstract In this paper, three problems that have hardly been noticed or even gone unnoticed in the available literature in the cosmology of Philolaus are addressed. They have to do with the interrelationships of the orbits of the Earth, the Sun, and the Moon around the Central Fire and all three of them constitute potentially insurmountable obstacles within the context of the Philolaic system. The first difficulty is Werner Ekschmitt’s claim that the Philolaic system cannot account for the length of the day (νυχϑήμερον). It is shown that this problem can be solved with the help of the distinction between the synodic day and the sidereal day. The other two problems discussed in this paper are concerned with two hitherto unnoticed deficiencies in the explanation of lunar eclipses in the Philolaic system. The Philolaic system cannot account for long-lasting lunar eclipses and according to the internal logic of the system, during lunar eclipses the Moon enters the shadow of the Earth from the wrong side. It is almost unbelievable that nobody, from the Pythagoreans themselves up to recent authors, has noticed these two serious deficiencies, and especially the latter, in the cosmology of Philolaus the Pythagorean.

scholarly journals Connection of large earthquakes occurring moment with the movement of the Sun and the Moon and with the Earth crust tectonic stress character

2010 ◽  
Vol 10 (7) ◽  
pp. 1629-1633 ◽  
Author(s):  
M. K. Kachakhidze ◽  
R. Kiladze ◽  
N. Kachakhidze ◽  
V. Kukhianidze ◽  
G. Ramishvili
Keyword(s):  
Tectonic Stress ◽  
Point Of View ◽  
The Sun ◽  
Compression Stress ◽  
The Moon ◽  
Caucasus Region ◽  
The Earth ◽  
Triggering Factor ◽  
Exogenous Factors ◽  
Large Earthquakes

Abstract. It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region.

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