IX.—The Lunar Atmospheric Pressure Inequalities at Glasgow

1936 ◽  
Vol 55 ◽  
pp. 91-96
Author(s):  
R. A. Robb ◽  
T. R. Tannahill
Keyword(s):  
Atmospheric Pressure ◽  
The Moon

In several papers by Chapman (1918, p. 271; 1919, p. 113, etc.) the effect of the moon on the atmospheric pressure has been analysed; the chief inequality observed is semi-diurnal, being, for example, 0·0120 sin (2θ+ 114°) millibar at Greenwich, 0·083 sin (2θ+ 68°) millibar at Batavia, and 0·060 sin (2θ+ 60°) millibar at Hongkong;θbeing measured from upper lunar transit.

On the tides at the port of London

1837 ◽  
Vol 3 ◽  
pp. 399-400
Keyword(s):  
Atmospheric Pressure ◽  
High Water ◽  
The Moon ◽  
Mean Time

The discussions of tide observations which the author has hitherto at various times laid before the Society, were instituted with reference to the transit of the Moon immediately preceding the time of high-water; from which the laws of the variation in the interval between the moon’s transit and the time of high-water have been deduced. But the discussion of nineteen years’ observations of the tides at the London Docks, which is given in the present paper, has been made with reference to the moon’s transit two days previously, and proves very satisfactorily that the laws to which the phenomena are subject accord generally with the views propounded long since by Bernouilli, The relations which the author points out between the height of high-water and the atmospheric pressure as indicated by the barometer are particularly interesting and important. The influence of the wind is also considered; and such corrections indicated as are requisite in consequence of the employment by several observers of solar instead of mean time.

scholarly journals Lunisolar Atmospheric Tides. II

1989 ◽  
Vol 42 (4) ◽  
pp. 439 ◽  
Author(s):  
R Brahde
Keyword(s):  
Phase Shift ◽  
Atmospheric Pressure ◽  
Mean Amplitude ◽  
Atmospheric Tides ◽  
The Moon ◽  
Celestial Equator

In an earlier paper (Brahde 1988) it was shown that series of measurements of the atmospheric pressure in Oslo contained information about a one�day oscillation with mean amplitude 0�17 mb. The data consisted of measurements every second hour during the years 1957-67, 1969 and 1977. In the present paper the intervening years plus 1978 and 1979 have been included, increasing the basis from 13 to 23 years. In addition the phase shift occurring when the Moon crosses the celestial equator has been defined precisely, thus making it possible to include all the data.

I. Dynamical considerations - Dynamics of the Moon

1967 ◽  
Vol 296 (1446) ◽  
pp. 245-247 ◽  
Keyword(s):  
Atmospheric Pressure ◽  
Uniform Density ◽  
The Moon ◽  
Homogeneous Body ◽  
Cubic Form ◽  
The Earth ◽  
Change Of State ◽  
Rate Of Increase ◽  
The Mean ◽  
Single Material

We know the mass of the Moon very well from the amount it pulls the Earth about in the course of a month; this is measured by the resulting apparent displacements of an asteroid when it is near us. Combining this with the radius shows that the mean density is close to 3.33 g/cm 3 . The velocities of earthquake waves at depths of 30 km or so are too high for common surface rocks but agree with dunite, a rock composed mainly of olivine (Mg, Fe II ) 2 SiO 4 . This has a density of about 3.27 at ordinary pressures. The veloci­ties increase with depth, the rate of increase being apparently a maximum at depth about 0.055 R in Europe and 0.075 R in Japan. It appeared at one time that there was a discontinuity in the velocities at that depth, corresponding to a transition of olivine from a rhombic to a cubic form under pressure. It now seems that the transition, though rapid, is continuous, presumably owing to impurities, but the main point is that the facts are explained by a change of state, and that the pressure at the relevant depth is reached nowhere in the Moon, on account of its smaller size. There will, however, be some compression, and we can work out how much it would be if the Moon is made of a single material. It turns out that the actual mean density of the Moon would be matched if the density at atmospheric pressure is 3.27—just agreeing with the specimen of dunite originally used for comparison. The density at the centre would be 3.41. Thus for most purposes the Moon can be treated as of uniform density. With a few small corrections the ratio 3 C /2 Ma 2 would be 0.5956 ± 0.0010, as against 0.6 for a homogeneous body. To make it appreciably less would require a much greater thickness of lighter surface rocks than in the Earth.

The vaporization behavior of carbon and hydrogen from the early global magma ocean

2021 ◽  
Author(s):  
Natalia Solomatova ◽  
Razvan Caracas
Keyword(s):  
First Principles ◽  
Atmospheric Pressure ◽  
Considerable Effect ◽  
Early Earth ◽  
The Moon ◽  
Magma Ocean ◽  
Cooling History ◽  
History Of ◽  
Carbon Molecules ◽  
Dense Atmosphere

<p>Estimating the fluxes and speciation of volatiles during the existence of a global magma ocean is fundamental for understanding the cooling history of the early Earth and for quantifying the volatile budget of the present day. Using first-principles molecular dynamics, we predict the vaporization rate of carbon and hydrogen at the interface between the magma ocean and the hot dense atmosphere, just after the Moon-forming impact. The concentration of carbon and the oxidation state of the melts affect the speciation of the vaporized carbon molecules (e.g., the ratio of carbon dioxide to carbon monoxide), but do not appear to affect the overall volatility of carbon. We find that carbon is rapidly devolatilized even under pressure, while hydrogen remains mostly dissolved in the melt during the devolatilization process of carbon. Thus, in the early stages of the global magma ocean, significantly more carbon than hydrogen would have been released into the atmosphere, and it is only after the atmospheric pressure decreased, that much of the hydrogen devolatilized from the melt. At temperatures of 5000 K (and above), we predict that bubbles in the magma ocean contained a significant fraction of silicate vapor, increasing with decreasing depths with the growth of the bubbles, affecting the transport and rheological properties of the magma ocean. As the temperature cooled, the silicate species condensed back into the magma ocean, leaving highly volatile atmophile species, such as CO<sub>2</sub> and H<sub>2</sub>O, as the dominant species in the atmosphere. Due to the greenhouse nature of CO<sub>2</sub>, its concentration in the atmosphere would have had a considerable effect on the cooling rate of the early Earth.</p>

On the lunar atmospheric tide at St. Helena

1851 ◽  
Vol 5 ◽  
pp. 663-663
Keyword(s):  
Atmospheric Pressure ◽  
The Moon ◽  
Atmospheric Tide ◽  
First Case ◽  
Before And After ◽  
The Difference ◽  
St Helena

The results of the observations made by Captain Lefroy, of the Royal Artillery, Director of the Magnetical and Meteorological Ob­servatory at St. Helena, are here given; from which it appears, on the examination of the barometrical changes during seventeen months, that a maximum of pressure corresponds to the moon’s passage over both the inferior and superior meridians, being slightly greater in the latter case, and that a minimum corresponds nearly to the rising and setting, or to six hours before and after the former periods. The average atmospheric pressures are 28·2714 inches in the first case, and 28·2675 in the last; the difference being 0'0039 inch. The height of the cistern of the barometer above the sea is 1764 feet; and the latitude of the Observatory 15° 57' S. These results were still further confirmed by those of a series of observations during two years. These observations also establish the conclusion that the moon exerts a greater influence on the amount of atmospheric pressure at the periods of her perigee than at those of her apogee.

scholarly journals Lunisolar Atmospheric Tides: A New Approach

1988 ◽  
Vol 41 (6) ◽  
pp. 807 ◽  
Author(s):  
R Brahde
Keyword(s):  
Atmospheric Pressure ◽  
Mean Value ◽  
Phase Changes ◽  
Atmospheric Tides ◽  
The Moon ◽  
Pressure Oscillations ◽  
New Approach ◽  
Thermal Origin ◽  
The One ◽  
Tidal Acceleration

In records of the atmospheric pressure in Oslo, at 60' latitude, a one-day oscillation caused by the lunisolar tide has been detected. The amplitude has a mean value of O� 17 mb. This oscillation appears during intervals when the declination of the Moon has high numerical values. When the Moon passes through the equator, the one-day oscillation disappears and only the half-day mode continues. If a maximum coincides with upper culmination, it reappears during the next fortnight at lower culmination. This means that the phase changes approximately 180' or 12h every time the Moon crosses the equator, and this is the main reason why it has not been detected by means of traditional harmonic analysis of the atmospheric pressure oscillations. By means of the correlation between the pressure variation and the magnitude of the tidal acceleration, it was possible to separate the dynamic one-day oscillation from terms of thermal origin.

Electrical properties of planetary surfaces

1977 ◽  
Vol 285 (1327) ◽  
pp. 441-450 ◽  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Lunar Surface ◽  
Atmospheric Pressure ◽  
The Moon ◽  
Laboratory Studies ◽  
Triple Point Of Water ◽  
Lunar Samples ◽  
Frequency Temperature

The electrical properties of the lunar surface are those of very good dielectric insulators. The results of the Apollo programme and laboratory studies on lunar samples have confirmed the predictions of Earth-based and spacecraft measurements of the dielectric properties of the lunar surface, and helped to increase the reliability of such studies of the surfaces of other planetary bodies. It appears that the electrical properties of the surfaces of Mercury, Venus and Mars are all very similar to those found for the Moon. Mercury has no atmosphere and in this sense is very similar to the Moon; Mars has a mean atmospheric pressure and temperature at the surface that is far below the triple point of water; while Venus has surface temperatures and pressures that are far above the critical point of water. This means that water is unlikely to contribute to the dielectric properties of either planet. The dielectric constant of the surface of the Moon is determined largely by the bulk density and is related to the density by the formula = (1.93 ± 0.17) for dielectric constant, k,at density p g/cm3. Thus, most soils have k about 3, while solid rocks have k about 7.5. Loss tangents appear to be dependent upon density, frequency, temperature, and possibly ilmenite content, and thus are more difficult to predict than the dielectric constant. Typical loss tangents are likely about 0.005 for the Moon, Mars and Mercury, and about 0.01 to 0.2 for Venus.

Lidar Technology Role in Future Robotic and Manned Missions to Solar System Bodies

2005 ◽  
Vol 883 ◽  
Author(s):  
Rosemary R. Baize ◽  
Farzin Amzajerdian ◽  
Robert Tolson ◽  
John Davidson ◽  
Richard W. Powell ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
The Moon ◽  
Soft Landing ◽  
Landing Zone ◽  
Control Concept ◽  
Solar System Bodies ◽  
Robotic Missions ◽  
And Control ◽  
Terrain Features ◽  
Better Than

AbstractFuture planetary exploration missions will require safe and precision soft-landing to target scientifically interesting sites near hazardous terrain features, such as escarpments, craters, slopes, and rocks. Although the landing accuracy has steadily improved over time to approximately 35 km for the recent Mars Exploration Rovers due to better approach navigation, a drastically different guidance, navigation and control concept is required to meet future mission requirements. For example, future rovers will require better than 6 km landing accuracy for Mars and better than 1 km for the Moon plus 100 m maneuvering capability to avoid hazards. Laser Radar or Lidar technology can be the key to meeting these objectives since it can provide highresolution 3-D maps of the terrain, accurately measure ground proximity and velocity, and determine atmospheric pressure and wind velocity. These lidar capabilities can enable the landers of the future to identify the pre-selected landing zone and hazardous terrain features within it, determine the optimum flight path, having atmospheric pressure and winds data, and accurately navigate using precision ground proximity and velocity data. This paper examines the potential of lidar technology in future human and robotic missions to the Moon, Mars, and other planetary bodies. A guidance and navigation control architecture concept utilizing lidar sensors will be presented and its operation will be described. The performance and physical requirements of the lidar sensors will be also discussed.

scholarly journals Enigmatic Gravity Effects Observed during Solar Eclipses. Their Analyse by Quantum Model of Inertia and Gravitation

2021 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
Claude Poher
Keyword(s):  
Atmospheric Pressure ◽  
Quantum Model ◽  
The Moon ◽  
Earth Gravity ◽  
Gravity Effects ◽  
Science Academy ◽  
Solar Eclipses ◽  
Oscillation Plane ◽  
Velocity Drift ◽  
Gravity Acceleration

Foucault long pendulums, with spherical suspended mass, show Earth rotation by the constant velocity drift of their oscillation plane. Maurice Allais used a short, 84 centimeters pendulum, with a suspended bronze disc mass. He recorded its oscillation plane drift velocity, during solar eclipses, in 1954 and 1959. Both times, he noticed an anomalous drift of the oscillation plane. Several authors confirmed the effect, during next solar eclipses, with other types of pendulums. Then a group of Geophysicists, from the Science Academy of China, used an accurate digital gravimeter to measure Earth Gravity acceleration during March 09, 1997 solar eclipse. Their gravimeter recorded two drops of Earth Gravity acceleration (respectively 5.02 and 7.7 µ Gals) before and during first and last contacts of the Moon disc. However there was no acceleration drop during eclipse totality. Same phenomena were confirmed later, during next solar eclipses, with the same gravimeter. No classical causes for these facts were found, since modern gravimeters take care of temperature and atmospheric pressure variations. We analyse the effect of Moon rotation, and of solar Corona mass, in the frame of our Quantum model of Inertia and of Gravitation. The model predicts that Moon / Earth Gravity acceleration changes, when the Moon direction is close to the Sun one, as observed from the gravimeter place. That phenomenon should be tied to Quantum fluctuations dispersion by matter. Recorded measurements confirm that interpretation.

scholarly journals Pantheon habitat made from regolith, with a focusing solar reflector

2020 ◽  
Vol 379 (2188) ◽  
pp. 20200142 ◽  
Author(s):  
Nick Woolf ◽  
Roger Angel
Keyword(s):  
Atmospheric Pressure ◽  
Food Production ◽  
Polar Axis ◽  
Building Blocks ◽  
Solar Concentrator ◽  
The Moon ◽  
The Earth ◽  
Human Habitation ◽  
Thin Plastic

We describe a polar Moon base habitat using direct solar energy for construction, food production and atmospheric revitalization. With a growing area as large as 2000 m 2 , it could provide for 40 or more people. The habitat is built like the ancient Roman Pantheon, a stone structure with a top circular oculus, bringing in focused sunlight that is spread out to crops below. The conical, corbelled structure is built from cast regolith blocks, held in compression despite the large internal atmospheric pressure by a regolith overlayer 20–30 m thick. It is sealed on the inside against leaks with thin plastic. A solar mirror concentrator used initially to cast the building blocks is later used to illuminate the habitat through a small pressure window at the oculus. Three years of robotic preparation of the building blocks does not seem excessive for a habitat which can be expected to last for millennia, as has the Treasury of Atreus made by similar dry-stone construction. One goal of returning to the Moon is to demonstrate the practicality of long-term human habitation off the Earth. The off-axis, paraboloidal reflecting mirror is rotated about the vertical polar axis in order to direct horizontal sunlight downward to a focus. In this way, the heavy materials needed from Earth to build and power the habitat are largely limited to the solar concentrator and regolith moving and moulding equipment. By illuminating with a reflector rather than with electricity, the solar collection area is 20 times smaller than would be needed for PV cells. This article is part of a discussion meeting issue ‘Astronomy from the Moon: the next decades’.

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