scholarly journals Geodetic Applications of Grazing Occultations

1971 ◽  
Vol 2 ◽  
pp. 592-600
Author(s):  
D. W. Dunham

Up to about a century ago, occultations were often used to measure differences in geographical longitude. Extensive geodetic surveys, accurate chronometers, telegraphic communications, and later short-wave radio time services obviated the geodetic need for occultation observations, which are affected by geodetically severe uncertainties of stellar and lunar positions, lunar limb irregularities, and observers’ personal equations. More sophisticated methods of observation would be needed before the Moon could again be useful to geodesy.During this century, cinematography of Bailey’s beads and the flash spectrum during total solar eclipses have been used to obtain the relative apparent position of the Sun and Moon to an accuracy which could be useful to geodesy. But observational opportunities were rare and few results of geodetic significance have been obtained.

1991 ◽  
Vol 29 (5) ◽  
pp. 319-319
Author(s):  
Mark Littman ◽  
Ken Willcox ◽  
Edward Pascuzzi
Keyword(s):  
The Sun ◽  
The Moon ◽  

1857 ◽  
Vol 3 ◽  
pp. 135-136
Author(s):  
William Swan
Keyword(s):  
The Sun ◽  
The Moon ◽  

The object of this communication is to discuss the evidence afforded by various observations of the eclipse which occurred on the 28th July 1851, as to the nature of the rose-coloured prominences which are seen round the moon during the total phase of solar eclipses.In order to render the inquiry into the nature of the red prominences as complete as possible, the author has not confined himself to the consideration of such hypotheses only as have been formally stated regarding them; but has also included in his examination such other views as he thought might probably be entertained regarding those remarkable objects.


1853 ◽  
Vol 20 (3) ◽  
pp. 445-459
Author(s):  
William Swan

The red prominences seen during total solar eclipses, are conspicuous rose-coloured objects which appear round the dark edge of the moon, as soon as the last rays of the sun have disappeared. In preparing my account of the total eclipse of the 28th July 1851, it was at first my intention to have stated some hypothetical views which I had formed regarding those remarkable objects, and other appearances I had observed during the total phase of the eclipse. I found, however, that the mere description of phenomena extended to so great a length, as to render such a course inexpedient; and I have since delayed resuming the subject, in order that by comparing a number of other observations with my own, I might be enabled, either to confirm or to modify my views.


Author(s):  
Alexander P. D. Mourelatos

The comment endorses and reinforces Daniel W. Graham’s highly original and attractive proposal that early Greek cosmology develops in two stages. In what Graham calls the “meteorological stage” of the sixth century BCE, celestial objects are explained as formations either from fire or from watery exhalations in a roughly planar model of the cosmos. In the “lithic stage” of the mid- and late fifth century introduced by Anaxagoras, the model is that of a central earth around which solid stone-like celestial objects revolve held aloft in a vortex. The change to the lithic stage comes about, according to Graham, as the implications of Parmenides’ epoch-making discovery that the moon is illuminated by the sun (heliophotism) come to be understood and are then theoretically exploited. The present comment also proposes that the false explanations of lunar phases and lunar and solar eclipses in the meteorological-stage cosmologies, respectively, of Xenophanes and of Heraclitus may have played a helpful heuristic role in the theoretical breakthrough to heliophotism.


2018 ◽  
Vol 3 (2) ◽  
pp. 207-216 ◽  
Author(s):  
David Fisher ◽  
Lionel Sims

Claims first made over half a century ago that certain prehistoric monuments utilised high-precision alignments on the horizon risings and settings of the Sun and the Moon have recently resurfaced. While archaeoastronomy early on retreated from these claims, as a way to preserve the discipline in an academic boundary dispute, it did so without a rigorous examination of Thom’s concept of a “lunar standstill”. Gough’s uncritical resurrection of Thom’s usage of the term provides a long-overdue opportunity for the discipline to correct this slippage. Gough (2013), in keeping with Thom (1971), claims that certain standing stones and short stone rows point to distant horizon features which allow high-precision alignments on the risings and settings of the Sun and the Moon dating from about 1700 BC. To assist archaeoastronomy in breaking out of its interpretive rut and from “going round in circles” (Ruggles 2011), this paper evaluates the validity of this claim. Through computer modelling, the celestial mechanics of horizon alignments are here explored in their landscape context with a view to testing the very possibility of high-precision alignments to the lunar extremes. It is found that, due to the motion of the Moon on the horizon, only low-precision alignments are feasible, which would seem to indicate that the properties of lunar standstills could not have included high-precision markers for prehistoric megalith builders.


Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 8
Author(s):  
Pyrrhon Amathes ◽  
Paul Christodoulides

Photography can be used for pleasure and art but can also be used in many disciplines of science, because it captures the details of the moment and can serve as a proving tool due to the information it preserves. During the period of the Apollo program (1969 to 1972), the National Aeronautics and Space Administration (NASA) successfully landed humans on the Moon and showed hundreds of photos to the world presenting the travel and landings. This paper uses computer simulations and geometry to examine the authenticity of one such photo, namely Apollo 17 photo GPN-2000-00113. In addition, a novel approach is employed by creating an experimental scene to illustrate details and provide measurements. The crucial factors on which the geometrical analysis relies are locked in the photograph and are: (a) the apparent position of the Earth relative to the illustrated flag and (b) the point to which the shadow of the astronaut taking the photo reaches, in relation to the flagpole. The analysis and experimental data show geometrical and time mismatches, proving that the photo is a composite.


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