Lunar Spectra Research Articles

INDICATION OF LUMINESCENCE FOUND IN THE DECEMBER 1964 LUNAR ECLIPSE

There is considerable evidence that some areas of the lunar surface fluoresce as a result of unimpaired bombardment by shortwavelength and corpuscular solar radiation. Dubois1'2 and Kozyrev3 sought the effect that this luminescence would have upon the depths and profiles of the Fraunhofer lines in the lunar spectrum. Both obtained some positive results. Dubois found that the light contribution of the luminescence was generally greater on the maria than on the continents and that in any given region it varied appreciably with time.2 He obtained contributions ranging as high as 25 percent. Another possible manifestation of this luminescence appears during lunar eclipses, when it is often observed that the moon's brightness within the innermost part of the penumbra is greater than expected from theoretical considerations. Link studied 16 recent eclipses for which reliable photometric data were available and found that 12 exhibited this excess.4 He suggested that this excess be interpreted as luminescence, which becomes observationally more prominent during the inner penumbral phase because the corona (assumed to be the primary source of the exciting radiation) is actually out of eclipse at that time. He concluded that about 10 percent of the moon's optical radiation is caused by luminescence.

Atmospheric Temperatures from Infrared Emission Spectra of the Moon and Earth. I. The Ozone Layer.

view Abstract Citations (2) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Atmospheric Temperatures from Infrared Emission Spectra of the Moon and Earth. I. The Ozone Layer. Adel, Arthur Abstract A fundamental and independent method of determining the temperature of the ozone layer is applied to previously published infrared emission spectra of the moon, the earth, and the atmosphere. The method is a general one and is applicable as well to the atmospheric constituents H20, N20, and CO2. The emis- sivity of atmospheric ozone in the band ~2 at 9.6 ~ is provided by the lunar spectrum. A gray-body com- parison, in the spectral region occupied by the band, is then made between the radiation intensity of the earth's surface (thermocouple) to space and the return radiation intensity of the ozone layer. The method is a promising one, for, even preliminary, very low resolution spectra yield essentially correct tem- peratures. The temperature of the ozone layer is found to be -44° and -53° C for the evenings of Sep- tember 5, 1941, and November 3, 1941, respectively Publication: The Astrophysical Journal Pub Date: May 1947 DOI: 10.1086/144915 Bibcode: 1947ApJ...105..406A full text sources ADS |

On Some Solar and Lunar Spectra Taken in Little America, Antarctica

Solar spectra were taken with a small quartz spectrograph at noon on November 13, 1929, and January 25, 1930, in Little America, Antarctica, by Malcolm P. Hanson of the Byrd Antarctic Expedition. The ultraviolet limit of these spectra was at about $304\ensuremath{\mu}\ensuremath{\mu}$ which was the same as the ultraviolet limit of noon solar spectra taken at Washington, D.C., in December and January. Assuming that the ultraviolet limit of the solar spectra was due to ozone in the upper atmosphere and that the amount of ozone in Washington was the same as that measured by Dobson, Harrison, and Lawrence at Oxford, England, it came out that the effective thickness of the ozone at N.T.P. above Little America was about 0.28 cm on November 13, 1929, and January 25, 1930.The ultraviolet limit of lunar spectra taken at Little America on April 24, 1929, two days after the Antarctic winter night set in, and on July 18, 1929, thirty-five days before the night ended, was at about $305\ensuremath{\mu}\ensuremath{\mu}$.

ENERGY CURVE OF THE LUNAR SPECTRUM IN THE VISUAL REGION

ENERGY CURVE OF THE LUNAR SPECTRUM IN THE VISUAL REGION

Our Astronomical Column

THE SPECTRUM OF MARS.—In connection with the recent discussion as to the presence or absence of the bands of water vapour in the spectrum of Mars, Dr. Janssen has published further particulars of the observations made by him in 1867 (Comptesrendus, July 29). He points out that even with the quantity of vapour in our own atmosphere, the bands would be all but invisible to an observer on Mars if the solar light were reflected normally from the earth's surface, and since the general conditions of the planet point to its atmosphere being less important than our own, it is easy to understand that the detection of the bands is a very delicate observation. To reduce the absorptive effect of the terrestrial atmosphere, observations, should be made at a high altitude, and the use of the lunar spectrum as a term of comparison is also important. As to the apparatus required, Dr. Janssen does not consider large telescopes indispensable, as even with them the telluric bands can only be observed in their totality. Previous to observing the spectrum of Mars, Dr. Janssen had been engaged in an extensive study of the spectrum of water, vapour as exhibited by a tube 37 metres in length. The observations of Mars were made on May 12-15, 1867, from a station on Mount Etna at an altitude of nearly 3000 metres; at meridian passage the altitude of the planet was 72°, and at sunset, when the observations were commenced, it was still more than 60° above the horizon, while the moon was a little lower. The cold was excessive during the nights of observation, and the quantity of vapour contained in the atmosphere overlying the place of observation would not be able to give indications of the telluric groups near C and D, according to the experiments with the long tube. Under these highly favourable conditions, Dr. Janssen found feeble but certain indications of the groups at C and D, and he is confident that future researches will justify the conclusion at which he arrived.

Our Astronomical Column

OBSERVATIONS OF THE SPECTRUM OF NOVA AURIGÆ.—Dr. Henry Crew, in Astronomy and Astro-Physics for March, gives a general description of the visible spectrum of Nova Aurigæ on February 10 and 11, observed by him with a spectroscope attached to the 36-inch of the Lick Observatory. The positions of the following lines were determined by direct comparison with the lunar spectrum and the spark spectra of hydrogen and magnesium:—

Scientific Serials

American Journal of Science, December.—The invisible solar and lunar spectrum, by S. P. Langley. This paper, which is an abstract of a memoir about to appear in the publications of the United States Academy of Sciences, summarizes the result of investigations carried on at the Allegheny Observatory in continuation of the author's previous researches on the infra-red of the solar spectrum to the extent of about three microns. By means of the improved apparatus here described, the extreme infra-red solar spectrum has now been searched from three to over eighteen microns; and it is shown that in this region the ratios between solar and lunar heat are completely changed from what they are in the visible spectrum. While the solar light in the latter is about 500,000 times that of moonlight, the solar heat received in the invisible part of the spectrum is probably less than 500 times the lunar. These studies also promise important results for meteorology, by opening to observation the hitherto unknown region of the spectrum, in which are to be found the nocturnal and diurnal radiations, not only from the moon towards the earth, but from the soil of the earth towards space.—A brief history of Taconic ideas, by James D. Dana. The Taconic question is here treated in chronological order from 1818 till the present year, in which the controversy may be regarded as practically closed. The conclusion is now firmly established that this system is not pre-Silurian, but merely another name for the older term “Lower Silurian.”—Certain generic electrical relations of alloys of platinum, by C. Barus. In this paper are given the chief results of the investigations on the measurement of high temperatures already described in vol. xxxv. p. 407, of the Journal. The results generally point to a limit below which, in the case of solid metals and at ordinary temperatures, neither electrical conductivity nor temperature-coefficient can be reduced. It thus appears that a lower limit of both conductivity and temperature-coefficient is among the conditions of metallic conduction, not to say of the metallic state absolutely.—On the Puget group of Washington Territory, by Charles A. White. A careful study of some fossil Mollusca from the coal-bearing formation in the Puget Sound basin, shows that they belong to a hitherto unknown brackish-water fauna, characterizing a deposit of unusual interest. A section of this formation measured at the town of Wilkeson gives a minimum thickness of no less than 13,200 feet, with a probable maximum of 14,500 feet. The surprise caused by the discovery of such an extraordinary thickness in an estuary deposit is increased by the fact that its Molluscan fauna appears to range vertically throughout the whole formation. The fauna itself seems to be of the same age, but distinct from, the Laramie, which flourished, not in an estuary, but in a land-locked basin. The area of the Puget group includes the Cascade Range, but is not otherwise yet clearly denned eastwards from the Pacific seaboard.—Papers are contributed by L. G. Eakins, on some sulphantimonites from Colorado; by A. E. Kenneliy, on the voltametric measurement of alternating Currents; by Dr. C. Hart Merriman, on the fauna of the Great Smoky Mountains, with description of a new species of red-backed mouse; by W. E. Hidden and J. B. Mackintosh, on anerlite, a new thorium mineral; and by O. C. Marsh, on a new family of horned Dinosaurians (Ceratops montanus) recently discovered in situ in the Laramie deposits of the Cretaceous period, in Montana, This reptile was a very formidable animal, armed not only with horns of great strength, but with a thick dermal hide, and varying in length from 25 to 30 feet.

II. On the spectra of some of the fixed stars

After a few introductory remarks, the authors describe the apparatu which they employ, and their general method of observing the spectra the fixed stars and planets. The spectroscope contrived for these inqu ries was attached to the eye end of a refracting telescope of 10 feet foe length, with an 8-incli achromatic object-glass, the whole mounted equa torially and carried by a clock-movement. In the construction of th spectroscope, a plano-convex cylindrical lens, of 14 inches focal length, wa employed to convert the image of the star into a narrow line of light which was made to fall upon a very fine slit, behind which was placed an achromatic collimating lens. The dispersing portion of the arrangement consisted of two dense flint-glass prisms; and the spectrum was viewe through a small achromatic telescope with a magnifying power of between 5 and 6 diameters. Angular measures of the different parts of the spectrum were obtained by means of a micrometric screw, by which the position of the small telescope was regulated. A reflecting prism was placed over one half of the slit of the spectroscope, and by means of a mirror, suitably adjusted, the spectra of comparison were viewed simultaneously with the stellar spectra. This light was usually obtained from the in­duction spark taken between electrodes of different metals. The dispersive power of the apparatus was sufficient to enable the observer to see the line Ni of Kirchhoff between the two solar lines D ; and the three constituents of the magnesium group at b are divided still more evidently*. Minute details of the methods adopted for testing the exact coincidence of the corresponding metallic lines with those of the solar and lunar spectrum, are given, and the authors then proceed to give the results of their obser­vations.

VIII. On the Magnetic Influence of the Lunar Spectrum, in relation to a new theory of terrestrial magnetism

VIII. <i>On the Magnetic Influence of the Lunar Spectrum, in relation to a new theory of terrestrial magnetism</i>