Lunar Mountains Research Articles

Automatic mountain detection in lunar images using texture of DTM data

This paper presents the development and implementation of a novel approach for automatic detection of the lunar mountains using Digital Terrain Model (DTM). The approach consists preprocessing the data, denoising, extracting texture information of the DTM, choosing an appropriate threshold using the Rényi Entropy threshold selection method, then the post-processing to extract the boundary of the mountain. The approach is applied to eight test sites, which were chosen in a manner so that the mountains are isolated. The detected mountains are assessed by their morphometric properties. The accuracy of the approach was assessed by determining its accuracy in detecting manually defined mountains and by comparing diameter estimates with separately determined values. The results are in agreement with the manually detected mountains, with the average detection performance of 0.91 and average precision of 0.97. The proposed approach extracts the mountain boundaries slightly more precisely than K-Means clustering which had an average detection performance of 0.89.

Galileo's visions: piercing the spheres of the heavens by eye and mind

Introduction Bibliographic abbreviations 1. Approaching Galileo's science through a fable 2. Subtleties of vision and of the scientific revolution 3. Casting light on Galileo's contrasts 4. The Lunar candour and the Litheosphorus 5. Sensory surprises 6. Seeing mountains on the moon 7. Visible and invisible luminous peaks of lunar mountains 8. Visual limits and the visibility of infinitesimals 9. Heavens sensed 10. Galileo's sensory philosophy 11. The problem of Galileo's predecessors 12. A moon circle: celestial reflections and illusions with Sarpi, Galileo and Castelli 13. Alternative visions 14. Galileo's visions

Essay Review: Sidereus Nuncius Debated, Galileo's O., Galileo's Sidereus Nuncius: A Comparison of the Proof Copy (New York) with other Paradigmatic Copies, Galileo Makes a Book: The First Edition of the Sidereus Nuncius, Venice 1610

SIDEREUS NUNCIUS DEBATED Galileo 's O. Edited by Horst Bredekamp. Vol. i: Galileo 's Sidereus Nuncius: A Comparison of the Proof Copy (New York) with Other Paradigmatic Copies. Edited by Irene Briickle and Oliver Hahn. Vol. ii: Galileo Makes a Book: The First Edition of the Sidereus Nuncius, Venice 1610. Paul Needham (Akademie Verlag, Berlin, 2011). Pp. 188 + 249. euro128. ISBN 978-3-05-005095-9.The discovery in 2005 of a copy of Galileo's Sidereus nuncius (1610) containing wash drawings instead of the usual etchings has garnered attention out of proportion to its historical significance. That is owing partly to commercial interest and partly to scholarly compulsion. The elaborate books under review contain the latest contributions to the printing history of Galileo's masterpiece and the provenance of the odd copy.In Galileo 's Sidereus nuncius, Horst Bredekamp and a team of experts support his earlier findings that the odd copy (labelled after the initials of its owners) is a bound proof documenting a stage in the printing and that its washes guided the etcher. Bredekamp's further judgements, based on his expertise in Galileo's style of drawing, that the author himself did the washes and, perhaps, also the etchings, while not confirmed, remain alive.The ML illustrations are in general closer to the etchings than to either of the other two sets of drawings previously considered as the etchings' antecedents. These are the figures in a letter to an unknown correspondent dated 7 1610 (JL for January letter) and on the familiar bifolium preserved among Galileo's papers in (FB for Florence bifolium). FB has no date; JL is known from two seventeenth-century copies, one now lost, of a lost original. JL's date and illustrations, which include depictions of the progressive illumination of a huge crater that appears combined with other views on the etchings, suggest the chronological sequence JL, ML, etchings. That leaves the bistre washes of FB, whose single crater stands apart in a miniature all to itself, disconnected from the printing history of Sidereus nuncius. This conclusion, which Bredekamp reached in his Galilei der Kunstler (2007), is reinforced by Paul Needham's Galileo makes a book.Needham gives a masterful account of the composition, make-up, ingrethents, and printing of Sidereus nuncius (SN). His apt diagrams guide the reader through details about signatures, additions, subtractions, watermarks, layouts, papers, presses, and printing. One learns why and when Galileo decided to impose his out-of-scale crater on a terminator where he probably had not seen it. It was to save space. The original design of SN had called for seven depictions of the Moon's surface for which only five spaces could be found after Galileo added sections concerning the Moon's silhouette and the height of lunar mountains, perhaps in order to pre-empt objections that had occurred to him when reviewing his draft.1Needham was able to put together so intricate an account because the original draft of SN, with its corrections and expansions, has survived. So have a fair copy of about half of it and a good many of the 550 standard copies of the book originally printed. Add to these the dated letters Galileo wrote while seeing it through the press and inferences from watermarks, and the relevant documentation dwarfs that available for all of Shakespeare's plays. Needham remarks that no other early printed book except Gutenberg's bible lends itself to, or has received, the elaborate analysis he has given Sidereus nuncius.Several astronomers previously sought to identify the dates and even hours when Galileo made the observations apparently recorded on FB. The rapidly changing inventory of features visible near the terminator makes this exercise practicable and its results probable. If, however, FB does not belong in the pre-printing sequence but, as Bredekamp suggests, to preparations for the second edition of Sidereus nuncius that Galileo advertised but did not issue, the identifications rest on a false assumption. …

MOONSTRUCK: HOW REALISTIC IS THE MOON DEPICTED IN CLASSIC SCIENCE FICTION FILMS?

Classical science fiction films have been depicting space voyages, aliens, trips to the moon, the sun, Mars, and other planets, known and unknown. While it is difficult to critique the depiction of fantastic places, or planets about which little was known at the time, the situation is different for the moon, about which a lot of facts were known from astronomical observations even at the turn of the century. Here we discuss the grade of realism with which the lunar surface has been depicted in a number of movies, beginning with George Melies' 1902 classic Le Voyage dans la lune and ending, just before the first manned landing on the moon, with Stanley Kubrick's 2001: A Space Odyssey. Many of the movies present thoughtful details regarding the actual space travel (rockets), but none of the movies discussed here is entirely realistic in its portrayal of the lunar surface. The blunders range from obvious mistakes, such as the presence of a breathable atmosphere, or spiders and other lunar creatures, to the persistent vertical exaggeration of the height and roughness of lunar mountains. This is surprising, as the lunar topography was already well understood even early in the 20th century.

Origin of Lunar Mountains and Maria Inferred from the Age Data of Their Rocks

Origin of Lunar Mountains and Maria Inferred from the Age Data of Their Rocks

57．Origin of the lunar mountains and maria inferred from age-dating of their rocks (2)

57．Origin of the lunar mountains and maria inferred from age-dating of their rocks (2)

Ubvri photometry of some lunar topographies

Examples of ‘pure’ lunar mountains, dark and light maria, and cratered terrae have been observed with the UBVRI stellar photometry system. Johnson's (1965) absolute calibration was used to compute brightnesses. These brightnesses were reduced using Hapke's photometric model to a standard geometry (angle of incidence 60°, emergence 40°, phase 90°), and relative albedos were then computed. The mountains, as distinct from the other regions, appear to require a wavelength dependent phase function. The albedos for the four topographic types are approximately linear functions of wavelength. The terrae are redder than the maria. Very low contrast between the topographies is predicted for full-moon at wavelengths shorter than 0.30μ. On the basis of laboratory studies, the lunar particles are comparable to basalt grains having sizes less than 50μm. Larger particle sizes are associated with the dark maria and smaller ones with the cratered highlands.

Comparison of the Ocean Floor with the Lunar Surface

Many attempts have been made to compare the smaller features of the moon with earthly features. Thus such familiar structural items as lava flows, faults, domes, and pressure ridges have been delineated. The larger lunar features—the maria, the mountains, the clefts, and the larger craters—have not heretofore been thought to have earthly counterparts. There are two principal theories of origin of the lunar features—volcanic and meteoritic. Both theories lead to the conclusion that the agent which produced the structures was more active in the past and may have been essentially dormant since the Archeozoic era. The most likely place on earth to search for similar features is in areas that have remained little changed since that time. In many ways the floor of the Atlantic Ocean resembles the moon9s surface. The Madeira Abyssal Plain is similar in size and shape to Mare Crisium; the Sohm Abyssal Plain is very like Oceanus Procellarum or Mare Frigoris; the Mid-ocean ridge is reminiscent of the lunar uplands; mid-ocean canyons recall the clefts of the moon; and the sea-mounts are like the isolated peaks and mountains of the Mare Imbrium district. East of Bermuda is a range of low hills (abyssal hills) arranged in a fan-shape very similar to the lunar Haemus Mountains. Two gashes across the Mid-Atlantic ridge, one at Lat. 30°N. and one at the equator, are very like the Alpine Valley of the moon. Steep slopes are characteristic of both the lunar mountains and the submarine slopes of the Atlantic. Both the Atlantic floor and the topographically low areas of the moon are thought to be blanketed with dust-sized material.

Occultations and lunar mountains

view Abstract Citations (14) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Occultations and lunar mountains Evans, David S. Abstract A bstract. Possibilities for stellar and selenographic research using photoelectric observations of occultations are sug- gested. The geometrical and selenographic problems of the distortion of occultation curves of stars of large angular diameter by mountain formations on the lunar limb are discussed. Tables for the rapid calculation of occultation curves are given. A method is discussed for the statistical study of slopes on the lunar limb of an extent too small to be visible, and some observational results are given. The accuracy of measurement of diffraction patterns observed at occultations of stars of negligible angular diameter is discussed. A statistical correction to observed angular diameters of large stars for mountain formations on the limb is suggested. Publication: The Astronomical Journal Pub Date: December 1955 DOI: 10.1086/107253 Bibcode: 1955AJ.....60..432E full text sources ADS |

Our Astronomical Column

THE PARTIAL SOLAR ECLIPSE OF MARCH 28.—This eclipse is a successor, after twelve lunations, of the large eclipse of last April. On this occasion the central line has moved southwards, crossing Brazil and the Sahara. The whole of the British Isles enjoy a partial eclipse, the magnitude of which diminishes from 0.20 at Greenwich to zero at the Shetlands. At Greenwich the eclipse begins at 1.19 P.M. at the lowest point of the disc, attains its greatest phase at 2.15, and ends at 3.8. The only observations of importance that can be made are the timing of the contacts and the watch for lunar mountains at the edge of the moon.

Our Astronomical Column

SCHMIDT'S CHARTE DER GEBIRGE PES MONDES.—In the Introduction to the Erläuterungsband, accompanying Prof. Schmidt's lunar charts, he has given an interesting account of the progress of his great work, of the difficulties he encountered, and the assistance afforded him in a variety of ways, until the honourable and flattering conclusion. It was in the autumn of 1839, at his native place, Eutih in Holstein, that his attention, at first given to botany and zoology, was directed to the moon, by the circumstance of a copy of Schröter's work having come into his hands through a sale by auction. The engravings of the numerous craters and mountain-shadows made so strong and lasting an impression upon his mind that he appears to have resolved to make the study of the surface of our satellite the principal aim of his life. At fourteen years of age the possession of a small draw-telescope, constructed by his father, enabled him to commence his observations of the lunar features, and his first sketch was one of the well-known streaks of Tycho, made with this instrument, which was supported against a street lamp-post! A stand being subsequently provided, he began to draw whole phases, in which Mayer's charts were found of service. Thus he observed in 1840, his school studies, as he tells us, suffering thereby not a little. As so often happens in similar cases, young Schmidt's peculiar bent attracted the attention of one who had the disposition and the means to aid him, and. State-Councillor Hellwag, a highly-educated man, with advanced knowledge of astronomy, provided him with a very perfect telescope by Dollond, and with it he observed at Hellwag's house. In July, 1841, he saw the moon for the first time in a large telescope, Peterseri, assistant' to Schumacher at Altona, having shown him the crater Gassendi and Bullialdus. He then learned first, as he says, the richness of the lunar formations, the more that he became acquainted at this time with the large chart of Madler. In 1842 Schmidt went to Hamburg, and obtained access to the observatory under Rümker's charge; here, through the good-will of the director, he made use of various telescopes; in fufvt therance of his lunar work during the fears 1842-45. In Tune, 1842, he was also assisted by Herr Bartels of Hohenfelde, near Hamburg, who allowed him the use of his telescope, and it was at this time that he made the earliest drawings which proved available in the construction of his great chart. In 1845 he went to Bilk, near Dusseldorf, the site of Benzenberg's observatory, but his progress was slow here, the principal instruments originally in the building not being then serviceable, During his residence at Bonn in connection with, the observatory presided over by Argelander, this continued to some extent, the regular work of the establishment claiming attention; nevertheless in the period 1845-1853 he obtained sketches which proved of value, with written descriptions of many of the features of the moon's surface. On several occasions during this interval, by the encouragement of Profs. Galle and Bruhns, he had opportunities of making drawings with the aid of the Berlin 9-inch refractor. From 1853 to 1858, Schmidt had charge of the observatory of Herr v. Unkrechtsberg, an ecclesiastic at Olmiitz, and here he undertook micrometncal measures for determining the heights of the lunar mountains, &c. In March, 1855, visiting Rome, he made sketches with the large refractor of the Observatory of the Collegio Romano, and in the following month delineated many of the lunar landscapes with the telescopes at the Observatory of Naples. In December, 1858, he entered upon his present position as director of the Observatory of Athens, but from the state of the institution and the instruments, observations were not practicable for nearly a twelvemonth, so that it was only in November, 1859, that he was able to use, for his work on the moon, the 6-feet Plössl refractor, with which so much of the remainder of his long-continued labours has been completed.

The Lake Regions of Central Equatorial Africa, with Notices of the Lunar Mountains and the Sources of the White Nile; Being the Results of an Expedition Undertaken under the Patronage of Her Majesty's Government and the Royal Geographical Society of London, in the Years 1857-1859

The Lake Regions of Central Equatorial Africa, with Notices of the Lunar Mountains and the Sources of the White Nile; Being the Results of an Expedition Undertaken under the Patronage of Her Majesty's Government and the Royal Geographical Society of London, in the Years 1857-1859

III. Notes on the drawing of 'Copernicus,' presented to the Royal Society by P. A. Secchi

Of the few attempts which have been made of late years to prepare drawings, on a large scale, of selected lunar mountains, this contribution from the Roman Observatory appears to be one of the most successful. It is on a scale of magnitude (about 10 geographical miles to one inch) such as only the larger modern telescopes can command, and characterized by such firmness of definition as to do honour alike to the maker of the instrument and to the artist engaged in the delineation. It may assist those who have not attempted, with their own hands, any drawings of this kind, and desire to form a right judgement of the value of this work of P. Secchi, if I send for comparison a drawing of Gassendi, executed from my object-glass of 6¼ inches (Cook), with a focal length of 11 feet. The drawing is on a scale of 20 geographical miles to an inch, and Gassendi thus appears of half the linear dimension of Copernicus, being really almost of the same diameter.