Lunar Eclipse Research Articles

Solar Motion and Lunar Eclipses in Philolaus’ Cosmological System

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.

SHOWCASING SEVENTEENTH-CENTURY JESUIT ASTRONOMY IN ASIA: THE LEAD UP TO THE FIRST SCIENTIFIC OBSERVATIONS OF A SOLAR ECLIPSE MADE IN SIAM

The first great ruler to encourage the adoption of Western culture and technology throughout Siam was King Narai, who also had a passion for astronomy. He showed this by encouraging French and other Jesuit missionaries, some with astronomical interests and training, to settle in Siam from the early 1660s. One of these was Father Antoine Thomas, and he was the first European known to have carried out scientific astronomical observations from Siam, in 1681 and 1682. Later, the lunar eclipse of 11 December 1685 assumed an important place in the history of Thai astronomy when a contingent of French missionary-astronomers joined King Narai and his court astrologers and observed it from the King's country retreat near Lop Buri. This event so impressed the King that he approved the erection of a large modern well-equipped astronomical observatory at Lop Buri. Construction of Wat San Paulo Observatory—as it was known—began in 1686 and was completed in 1687. A second contingent of French Jesuit astronomers settled in Lop Buri at about this time, and were involved in various astronomical observations. Arguably, the last of these of any importance was of the partial solar eclipse of 30 April 1688, just one week before the sudden demise of scientific astronomy in Siam. In this paper we examine King Narai's enlightened attitude towards Western science and technology and his growing interest in Western astronomy, before discussing the observations that he and/or the Jesuit missionaryastronomers made leading up to and including the partial solar eclipse of 30 April 1688. We then explore the growing disquiet among some members of the Royal Family that triggered a coup on 5 June 1688 when King Narai was overthrown and most of the Western missionary-astronomers were expelled from Siam.

AYYĀM AL-BĪḌ SYAR'I AND ASTRONOMY PERSPECTIVE (BETWEEN FASTING MOMENTUM AND SCIENTIFIC CALCULATION)

Ayyām al-Bīdis a group of days in the hijri calendar system. Ayy termām al-Bīdobtained from the hadith of the Prophet which contains the command to fast for three days in each hijri month, which is sunnah. Ayy understandingām al-Bīdfrom the hadith of the Prophet is the date / day of the 13th, 14th, and 15th of the Hijri month. However, at a practical level, scholars differed when they mentioned the implementation of Ayy's fastām al-Bīd. There are 9 versions of this opinion. Here the writer wants to examine more deeply ayyām al-BīdThis is seen from a shar'i and astronomical perspective. The writer studies it with the research library method using the scientific-cum-doctriner approach. The data collected came from the books of hadith and fiqh, then analyzed with an astronomical approach. From this research, it was found that the meaning of the term Ayyām al-BīdIn the view of syar'i, it is the best time to observe the sunnah fast for three days every month. Matan hadith of the Prophet SAW regarding Ayyām al-Bīd which stipulates on the 13th, 14th and 15th of the Hijri month because that is the time when the full moon and lunar eclipses occur. From the review of astronomy Ayyām al-Bīdis the time when at night the Moon shines brighter than the other nights. Astronomically this can occur 4-5 days in the middle of the Hijri month.

COMPARATIVE ANALYSIS OF SKY QUALITY AND METEOROLOGICAL VARIABLES DURING THE TOTAL LUNAR ECLIPSE ON 14-15 APRIL 2014 AND THEIR EFFECT ON QUALITATIVE MEASUREMENTS OF THE BORTLE SCALE

A total lunar eclipse plausibly has an influence on the variation of some environmental physical parameters, specifically on the conditions of the sky brightness, humidity and temperature. During the eclipse on 14th - 15th April 2014, these parameters were measured with a photometer and a weather station. The obtained results allow the comparison, practically, of the optimal conditions for observational astronomy work in the Tatacoa desert and, therefore, to certify it as suitable place to develop night sky astronomical observations. This investigation determined, to some extent, the suitability of this place to carry out astronomical work and research within the optical range. Thus, the changes recorded during the astronomical phenomenon allowed the classification of the sky based on the Bortle Scale.

Giant Impact: The Leading Scenario of the Origin of the Moon

Moon, an astronomical body hanging in the sky, has been recorded and studied by mankind for thousands of years, even before the invention of the word “moon”. There are numerous varying theories about its origin. The aim of this article is to compare and further analyze the common theories of the origin of Moon. First, we provide basic information about the moon, the moon’s soil, and the basic elements of the moon and offer an introduction to solar and lunar eclipses and why they exist, as well as human efforts to explore the moon, including the Apollo program and the Chang’E program. Finally, we analyze and compare the four most common theories about the origin of the Moon: the split theory, homologation theory, capture theory and impact theory. Among all, the more accepted theory is the big collision theory though there is still no scientific basis for it. This article introduces the origins of the Moon by analyzing the pros and cons and describing possible future directions.

The Understanding and Awareness of First-Year Undergraduate Physics Students in Astronomical Phenomena: A Response of Penumbral Lunar Eclipses on June 5th, 2020

A penumbral lunar eclipse phenomenon occurs when Earth’s outer shadow falls on the Moon’s face. This astronomical phenomenon is easy to miss because sunlight still illuminates most of the Moon. In this research, we want to describe the first-year undergraduate physics students’ understanding and awareness of Penumbral Lunar Eclipses, especially on June 5th, 2020. The study using qualitative research with a questionnaire and an interview. The subject of the course is 100 participants from first-year undergraduate physics students. Physics students’ answers are categorized into four levels, namely Dissatisfaction, Intelligible, Plausibility, and Fruitfulness. From the results, it can be concluded that physics students know with the Dissatisfaction category related to the phenomenon of the penumbra lunar eclipse. Otherwise, for knowledge about the strawberry full moon eclipse, students learn the intelligible and dissatisfaction types. It recommended that physics students increase their understanding of the occurrence of a lunar eclipse by understanding scientific processing skills to reinforce their opinion.

Decrement of secondary gamma radiation flux during lunar eclipse June 16, 2011

The lunar eclipse at Udaipur (27◦ 43’ 12.00” N, 75◦ 28’ 48.01” E), India was experimentally observed on June16, 2011 using ground based NaI (Tl) Scintillation detector. We interpret such decrement of secondary gamma radiation flux (SGRF) on the basis of obstruction effect produced by Earth and Moon during lunar eclipse on radiation. Objective: To observe secondary gamma radiation flux during lunar eclipse day on comparison to pre and post eclipse days. Methods: For this experimental study we used ground based NaI (Tl) Scintillation detector. The data files were stored in computer for thirty minutes duration from 1.00 AM to 2.00 AM (Indian Time) on pre-eclipse normal days June 14 and 15, 2011 as well as on post eclipse normal day June 17 and also on eclipse day June 16, 2011. Finding: The analyzed data reveal significant decrement of secondary gamma radiation flux (SGRF) on lunar eclipse day about 6% on comparison to pre and post lunar eclipse days. Novelty: In this experimental study first time we reported about 6% decrement of secondary gamma radiation flux on lunar eclipse day on comparison to pre and post lunar eclipse days. Keywords: Lunar eclipse; cosmic radiation; reflected solar radiation; secondary gamma radiation; obstruction effect by Earth and Moon

Assessment of awareness and barriers to clubfoot treatment in the Indian scenario.

Background:We undertook this study to evaluate the awareness of the Primary Caregivers of children with clubfoot aka Congenital Talipes Equino Varus (CTEV) and their familiarity with the disease, their beliefs, knowledge and compliance to treatment, and barriers encountered during the treatment process.Settings and design:Cross-sectional, analytical study.Materials and methods:A standard questionnaire in the local vernacular language was prepared, on which 108 respondents were interviewed. Data were analyzed by using Statistical Package for the Social Sciences (SPSS) software program, version 21.0. Chi-square test was applied wherever suitable as a parametric test.Results:Approximately 57.40% of participants had no prior knowledge of clubfoot at all, till they had a child born of the deformity in the family. Superstitions like lunar eclipse (37.96%), punishment from God (37.03%), solar eclipse (34.26%) and black magic (26.85%) were widely prevalent as the perceived cause of the deformity. Only 25% of the participants believed that any kind of treatment should be started immediately after birth and 20.37% of the study population felt the first line of treatment should be a visit to a spiritual healer or to a shrine of a saint. Approximately 68.52% of the study participants were satisfied with the explanation of the disease process and treatment plan offered by the treating doctor. Approximately 52.77% perceived social stigma as an obstacle to treatment, whereas 58.33% had difficulties adjusting to change of home or workplace routines.Conclusion:The awareness level regarding clubfoot in the primary caregivers in the Indian scenario is low and has an implication on successful treatment and compliance.

Lunar Eclipses and Allais Effect

Two anomalies observed during lunar eclipses, the enlargement of the Earth’s shadow and the excessive clarity of the penumbra, possibly attributed to insufficient causes if not doubtful, would refute the assertion of certain experimenters according to which the lunar Allais eclipse effect would be almost impossible to detect. The Earth’s umbra seems to be 2% larger than what is expected from geometrical considerations and it is believed that the Earth’s atmosphere is responsible for the extent of the enlargement, but it is realized that the atmospheric absorption cannot explain light absorption at a height as high as 90 km above the Earth, as required by this hypothesis. It was also argued that the irradiation of the Moon in the Earth’s shadow during the eclipse is caused by the refraction of sunlight in the upper regions of the Earth’s atmosphere. However, the shade toward the center is too bright to be accounted for by refraction of visible sunlight. Although these assumptions are not trifling, we attribute the majority of these abnormalities to the Allais eclipse effect. This effect would cause a slight decrease of gravity during the eclipse: the geodesics would be displaced a small amount outwards; the ray of light coming from the Sun, passing close by the Moon would be less attracted, which would expand the shadow cone of the Moon. On the other hand, the rays emanating from the Moon would have a shorter wavelength and therefore the luminescence would increase by anti-Stoke Raman effect: the scattered photon has more energy than the absorbed photon.

Influence of lunar eclipse of 15 April 2014 on the intrinsic background current noises in fission chamber

The sun-grazing comet C/2011 W3 (Lovejoy) showed a distorted, unconventional tail morphology near its perihelion (1.2Rs). Based on the “Solar Corona and Inner Heliosphere” modeling result of the magnetic field and plasma dynamics in the solar corona, we use the Runge-Kutta method to simulate the moving trajectory of charged dust and ion particles released at different positions from the C/2011 W3 orbit. We find that the dust particles near the sun, which are subject to a strong magnetic Lorentz force, travel differently from their counterparts distant from the sun, where the latter are mainly affected by the solar gravitational force and radiation pressure. According to the simulation results, we propose that the magnetic mirror effect can rebound the charged dust particles back away from the sun and be regarded as one crucial cause of the dust-free zone formation. We find that ions mainly move along magnetic field lines at an acute angle to the comet's direction of motion. The cometary ions' movement direction was determined by the comet's velocity and the coronal magnetic field, which are responsible for the C/2011 W3’s unique comet tail shape near perihelion. Additionally, the ion particles also experience perpendicular drift motion, mainly dominated by the electric field drift, which is similar to and can be used to approximate the solar wind's transverse velocity at its source region.

On the Development of a Simple and Portable Ground-Based Infrared Imaging System for Lunar and Atmospheric Studies

A small, portable, infrared (wavelength of 7 - 14 μm) system has been designed and developed to study the thermal behavior of the lunar surface and for thermal remote sensing applications. The principal operation of the system depends on collecting large amounts of infrared light, using a modified Newtonian telescope. The light from the object is reflected by the primary mirror and the secondary mirror. This collected light is then focused into a thermal camera by using an intermediate germanium lens as a field lens to provide a real optical image on the camera sensor. Several observations have been obtained out using the developed system, and eliciting some interesting results. These include lunar observations during different phases and during partial lunar eclipse. The thermal behavior of the lunar surface was identified, proving the system’s functionality and performance. The developed system is, also, particularly suitable tool for outreach programs and students projects which can possibly offer useful learning and exploration opportunities for students in different applications. In this paper, a brief description about the developed system is provided. Some of the obtained results are illustrated. The future applications and improvements to the designed system are also summarized.

Some Qur'anic Verses in Hodja Sadeddin Efendi's Tâj al-Tawârîh

Hoca Sadeddin Efendi 16. yüzyılın en önemli tarihçilerinden biridir. Telif ettiği Tâcu’t-Tevârîh adlı eserinde, Osmanlı Devleti’nin kuruluşundan başlayarak Yavuz Sultan Selim’in vefatına (1520) kadar gerçekleşmiş olayları ele almıştır.Tâcu’t-Tevârîh, Osmanlı tarihini başlangıcından 16. yüzyılın sonlarına kadar anlatan güvenilir ve çok okunan bir kaynak eser olmuştur.Tâcu’t-Tevârîh 16. yüzyıl Osmanlı ilim dilinin en parlak örneklerindendir. Tarih ilmi açısından Türk tarihçileri ve dünya tarihçileri arasında önemli bir yere sahiptir. Bu nedenle de eserin bazı zeyilleri yazılmıştır. Tâcu’t-Tevârîh Avrupa’da büyük rağbet görmüş ve 17. yüzyıldan itibaren, Fransızca, Almanca ve İtalyanca’ya tamamen, Rusça, İngilizce ve Macarca’ya da kısmen tercüme edilmiştir.Hoca Sadeddin Efendi’nin Tâcu’t-Tevârîh’inde verdiği bilgiler, Osmanlı Tarihi’ne ışık tutmuş ve daha sonra telif edilen Osmanlı tarihlerine kaynaklık etmiştir. O, eserini telif ederken konunun önemine göre âyet, hadis, atasözleri kullanarak anlattığı olayları dini kaynaklarla desteklemiştir. Bu durum Hoca Sadeddin Efendi’nin dinî ve tarihî bilgiler konusuna çok hâkim olduğunu göstermektedir.Hoca Sadeddin Efendi, Yavuz Sultan Selim ve Kanuni Sultan Süleyman dönemi olaylarını yazma işinin kendisine kaldığını ifade eder ve eserinde övme ve yermede aşırı gitmeksizin “uslûb-ı itidâl” üzere bütün teferruatıyla yazdığını belirterek nasıl bir metot uygulayacağını ortaya koyar. Ancak eserinde kaleme aldığı ilk dönem konuları hakkında, belki aradan uzun zaman geçmesinden ve olayları nakledenlerin bilgileri karıştırmasından dolayı dikkatli olunması gerektiğini ve sağlıklı bilgiler veremeyeceğini belirtir.Hoca Sadeddin Efendi, ilk dönem olaylarının nakledilmesinde uzun yılların geçmesiyle, ravilerin bazı sözleri karıştırdığı, hatta kendi görüşünü de katmasıyla birtakım sapmaların olabileceğini ifade eder. Hoca Sadeddin Efendi, eserinde yakın dönem olaylarının doğru olduğunu ve ifadelerinde yalan haber bulunmadığını söyler. Hoca Sadeddin Efendi, bazı olayları özet olarak anlatma yoluna giderek, sadece isimleri zikretmekle yetinmiştir. Bunun nedeni ise ya olaylarla ilgili bilgi veya kaynak bulamamış ya da yararlandığı kaynakta ancak bu kadar bilgi bulmuş olmasından kaynaklanmaktadır.Hoca Sadeddin Efendi, olayları ele alırken, okuyucunun eseri bıkmadan okumasını sağlamak için bir kısım olayları “Latîfe ve Hikâyet” başlıkları altında anlatmıştır. Sadeddin Efendi bu metoduyla, eseri savaş sahneleri ile dolu bir eser olmaktan uzaklaştırmıştır. O, “Latîfe ve Hikâyet” başlığı altında anlatılan konularla; olayların daha iyi anlaşılmasını ve zihinlerde derin izler bırakmasını sağlamak, insanları iyiliğe teşvik etmek için onları daha cazip bir üslupla zihinlere yerleştirmek istemiştir. Hoca Sadeddin Efendi de modern tarih yazarları gibi, olayların temelindeki sosyal, ekonomik, siyasî ve dinî sebepleri aramaya ve araştırmaya çalışmıştır. Olayların sebeplerini belirtmiş ve gerekli yerlerde de eleştirilerini yapmıştır. Olayları ve kaynakları karşılaştırmıştır. Bu hareketiyle tarih bilgisini felsefî bir çehreye büründürmüştür. Hoca Sadeddin Efendi, dönemin sosyal olaylarından olan; kıtlık, deprem, yangın, ay ve güneş tutulması, törenler, salgın hastalıklar ve ölümler hakkında da bilgiler verir. Osmanlı tarihi yazarlarının, devletin ilk kuruluş ve takip eden yıllarla ilgili verdikleri bilgiler; genelde şifahi halk destanlarına dayanmaktadır. Bunlar ise bir milletin o dönemdeki kültürü, sosyal hayatı ve inancı ile ilgili değerli bilgilerdir. Hoca Sadeddin Efendi, Tâcu’t-Tevârîh’in mukaddimesinde; tarihin tanımı, konusu, amaçları ve bir tarihçide bulunması gereken özellikler, tarihçinin eserinde takip etmesi gereken metotlar hakkında bilgi verir. Ona göre tarih; millet ve din yolunda hizmet edenlerin hizmetlerini, güzel huy ve hayat hikâyelerini, yaptığı mücadelelerini kısaca, bunların durumlarını yazarak gelecek nesillere aktarmaktır.Hoca Sadeddin Efendi eserinde, Osmanlı Devleti tarihi alanındaki en önemli kaynaklardan biri olan ve Osmanlı Devleti’nin kuruluşundan Yavuz Sultan Selim dönemi sonuna kadar meydana gelen olayları aktarır. Tâcu’t-Tevârîh, dokuz bölümden oluşur ve her bölümde bir padişah döneminde meydana gelen olayları anlatır.

The Projection of Societal Evil in the Poetry of Hamid Khan

The concept of evil is foregrounded in most of the poems of Khan. This paper focuses on the theme of evil in its variant shapes that are foregrounded in Khan’s poetry. For this purpose, both the collections of Khan, “Velvet of Loss” and “Pale Leaf (Three Voices)” are used for the data under study. Only those poems are selected that bear the foregrounded theme of evil. The poems that foreground the evil are Octopus, I Won’t Talk, The Dawn, The City, In a Café, Labyrinth, Nostalgia, Nemesis, Eclipsed Moon, Space-Scape, and Inertia. The presence of evil that negatively shapes the human condition is indirectly projected for making the reader taking interest which, in turn, compels them to become conscious of their plight in the present and terrifying dangers in the future. This consciousness, ultimately, leads to the reformation of society. In this regard, Khan can be taken as a great reformer of the society who carries a sense of sympathy and empathy through his terse and stenographic style. Lastly, this paper will guide local researchers for furthering research in the area of Pakistani Literature in English. In this regard, local voices will be analyzed for local issues and problems.

WACANA ASTRONOMIS DALAM TAFSIR BAHASA MADURA

This article examines the scientific interpretations in the book Tapsèr Sorat Yaa-siin (Bhāsa Madhurā) by Muhammad Ershad. The presence of this Madurese interpretation has complemented a series of Nusantara’s Qur’anic exegesis which has a tendency towards scientific nuances. Therefore, it is important to study the Qur’anic exegesis of cultural observers as a form of safeguarding one of the treasures of Qur’anic exegesis works in Indonesia, especially those with local languages. This study will only focus on scientific interpretations that are astronomical. This study find out, the astronomical interpretations of the Tapsèr Sorat Yaa-siin (Bhāsa Madhurā) has four broad themes; the solar system, the sun's dimming process, the creation of the universe, and the solar and lunar eclipses. During the interpretation process, Muhammad Ershad adopted a lot of information contained in the scientific discipline of astronomy. Apart from that, he also displayed his own drawings to make the reader easier in understanding the explanation he provided. Keywords: Muhammad Ershad, astronomical interpretation, Tapsèr Sorat Yaa-siin (Bhāsa Madhurā)

The Miracle of Sciences: Between Authenticity and Constraint | الإعجاز العلمي بين التأصيل والتكلف

Scientific Miracles is a type of Qur’anic Miracles that perhaps might be considered the most common one in this day and age. Scholars have different opinions regarding Scientific Miracles, while it is braced by the majority of scholars as a way to spread Islam, others oppose it fearing that it could lead to a misunderstanding to the meanings of the Qur’anic verses. This paper analyzes the views of the two parties and discusses some examples of Scientific Miracles in the Qur’an, (splitting of the moon, blotting the sign of the night, Saying the name of Allah while slaughtering). The study relies upon fudamantal resouses in the field such as the books authored by Dr. Zaghloul al Najjar along with trusted websites. The paper then concludes with several key points which includes that the splitting of the moon is not an actual physical split, but rather some sort of moon eclipse. As for blotting the sign of night, it was settled that Allah has created the night dark as it is without the bright light in contrast to the day. Lastly, saying the name of Allah while slaughtering is only a way of worshiping the almighty creator. Thus, we have to be careful not to include Scientific Miracles as Qur’anic Miracles if it cannot be proven scientifically.

A (NOT SO) BRIEF HISTORY OF LUNAR DISTANCES: LUNAR LONGITUDE DETERMINATION AT SEA BEFORE THE CHRONOMETER

Longitude determination at sea gained increasing commercial importance in the late Middle Ages, spawned by a commensurate increase in long-distance merchant shipping activity. Prior to the successful development of an accurate marine timepiece in the late-eighteenth century, marine navigators relied predominantly on the Moon for their time and longitude determinations. Lunar eclipses had been used for relative position determinations since Antiquity, but their rare occurrences precludes their routine use as reliable way markers. Measuring lunar distances, using the projected positions on the sky of the Moon and bright reference objects—the Sun or one or more bright stars—became the method of choice. It gained in profile and importance through the British Board of Longitude's endorsement in 1765 of the establishment of a <italic>Nautical Almanac</italic>. Numerous 'projectors' jumped onto the bandwagon, leading to a proliferation of lunar ephemeris tables. Chronometers became both more affordable and more commonplace by the mid-nineteenth century, signaling the beginning of the end for the lunar distance method as a means to determine one's longitude at sea.

Alexander the Great’s Route to Gaugamela and Arbela

SummaryThe aim of this paper is to analyse the chronology and itinerary of the march of the Macedonian army during the last days (September 18–October 1) of the Gaugamela campaign in 331 BC in the light of literary sources, cuneiform data, topographic and archaeological data, and GIS capabilities. The overall aim of this analysis is to contribute to the topographical enigma of the identification of Gaugamela as either (in the vicinity of) Tell Gomel or Karamleis/Qaraqosh. The cuneiform data allows us to establish the most important dates of the final course of the Gaugamela campaign: the Tigris crossing on September 18, a lunar eclipse on the evening of September 20, and the battle on October 1. Furthermore, a critical analysis of Arrian and Curtius suggests that the Macedonians spent only six days on the march and four days in the camp. Given the estimated average rate of the march of the Macedonian army, it is possible to reject certain routes between the Tigris crossing and Gaugamela and consider others as more or less likely. It is concluded that the Macedonians crossed the Tigris in the vicinity of modern Basorin and not Abu Dhahir or Abu Wajnam, as is widely assumed. Furthermore, it is also demonstrated that the difference between Tell Gomel and Karamleis/Qaraqosh, regarding their distance from Arbela, is much less striking than is frequently assumed, and as such does not speak against any of the widely held identifications of Gaugamela.

Estimating the Moon-to-Earth Radius Ratio with a Smartphone, a Telescope, and an Eclipse

From ancient times, the different features of planets and moons have created a huge interest. Aristarchus was one of the first to study the relative relations among Earth, Moon, and Sun. This interest has remained until today, and therefore it is always relevant to make this knowledge more appealing to the younger generations. Nowadays, smartphone technology has become an important tool to teach physics, and this gives us a huge opportunity to bring science closer to students in a simpler manner. In this work, we show how simple photographs of a partial lunar eclipse are sufficiently good to estimate the ratio between the Moon and Earth radii. After taking the photographs, the procedure for the calculation is straightforward and it can be reproduced easily in a one–hour class.

Effect of total Lunar Eclipse of 27th July 2018 on the D-region Ionosphere by using VLF observations

Effect of total Lunar Eclipse of 27th July 2018 on the D-region Ionosphere by using VLF observations

The Hubble Space Telescope's Near-UV and Optical Transmission Spectrum of Earth as an Exoplanet

Abstract We observed the 2019 January total lunar eclipse with the Hubble Space Telescope’s STIS spectrograph to obtain the first near-UV (1700–3200 Å) observation of Earth as a transiting exoplanet. The observatories and instruments that will be able to perform transmission spectroscopy of exo-Earths are beginning to be planned, and characterizing the transmission spectrum of Earth is vital to ensuring that key spectral features (e.g., ozone, or O3) are appropriately captured in mission concept studies. O3 is photochemically produced from O2, a product of the dominant metabolism on Earth today, and it will be sought in future observations as critical evidence for life on exoplanets. Ground-based observations of lunar eclipses have provided the Earth’s transmission spectrum at optical and near-IR wavelengths, but the strongest O3 signatures are in the near-UV. We describe the observations and methods used to extract a transmission spectrum from Hubble lunar eclipse spectra, and identify spectral features of O3 and Rayleigh scattering in the 3000–5500 Å region in Earth’s transmission spectrum by comparing to Earth models that include refraction effects in the terrestrial atmosphere during a lunar eclipse. Our near-UV spectra are featureless, a consequence of missing the narrow time span during the eclipse when near-UV sunlight is not completely attenuated through Earth’s atmosphere due to extremely strong O3 absorption and when sunlight is transmitted to the lunar surface at altitudes where it passes through the O3 layer rather than above it.