Mare Orientale / ɔːr i ɛ n ˈ t eɪ l iː / (Latin orientāle , the "eastern sea") is a lunar mare . It is located on the western border of the near side and far side of the Moon , and is difficult to see from an Earthbound perspective. Images from spacecraft have revealed it to be one of the most striking large scale lunar features, resembling a target ring bullseye .
31-530: During the 1960s, rectified images of Mare Orientale by Gerard Kuiper at the Lunar and Planetary Laboratory gave rise to the notion of it being an impact crater . The structure, with the flat plain of the mare in the center, is about 900 kilometres (560 mi) across and was formed by the impact of an asteroid-sized object, possibly 64 km (40 mi) in diameter and travelling at 15 km/s (9.3 mi/s). Compared with most other lunar basins, Mare Orientale
62-542: A Convair 990 aircraft in the 1960s. In the 1950s Kuiper's interdisciplinary collaboration with the geochemist and Nobel Laureate Harold C. Urey to understand the Moon's thermal evolution descended into acrimony, as the two engaged in what became known as the "Hot Moon, Cold Moon" controversy. Their falling out, in part a scientific dispute, also reflected the challenge of maintaining professional relationships across overlapping but distinct scientific disciplines. In 1951, in
93-438: A few weeks per year. Analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers' time. Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes. Most universities also have outreach programs, including public telescope time and sometimes planetariums , as a public service to encourage interest in
124-802: A heart attack on 23 December 1973 in Mexico City , while on vacation with his wife. Besides the minor planet 1776 Kuiper , three craters ( Mercurian , lunar , and Martian ), Kuiper Scarp in Antarctica, and the now-decommissioned Kuiper Airborne Observatory were also named after him. Astronomers refer to a region of minor planets beyond Neptune as the " Kuiper belt ", since Kuiper had suggested that such small planets or comets may have formed there. However Kuiper himself believed that such objects would have been swept clear by planetary gravitational perturbations, so that none or few would exist there today. The Kuiper Prize , named in his honor,
155-561: A paper in Astrophysics: A Topical Symposium , Kuiper speculated that a large disc of small astronomical bodies formed early in the Solar System's evolution. He suggested that the disc consisted of "remnants of original clusterings which have lost many members that became stray asteroids, much as has occurred with open galactic clusters dissolving into stars." In another paper, based upon a lecture Kuiper gave in 1950, also called On
186-691: A position at Yerkes Observatory of the University of Chicago and received American citizenship in 1937. From 1947 to 1949, Kuiper served as the director of the McDonald Observatory in west Texas. In 1949, Kuiper initiated the Yerkes–McDonald asteroid survey (1950–1952). From 1950-1960 he was professor at the University of Chicago , directing the Yerkes Observatory . He was doctoral advisor to Carl Sagan . In 1958,
217-738: A system of stars or a galaxy to complete a life cycle, astronomers must observe snapshots of different systems at unique points in their evolution to determine how they form, evolve, and die. They use this data to create models or simulations to theorize how different celestial objects work. Further subcategories under these two main branches of astronomy include planetary astronomy , astrobiology , stellar astronomy , astrometry , galactic astronomy , extragalactic astronomy , or physical cosmology . Astronomers can also specialize in certain specialties of observational astronomy, such as infrared astronomy , neutrino astronomy , x-ray astronomy , and gravitational-wave astronomy . Historically , astronomy
248-439: Is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth . Astronomers observe astronomical objects , such as stars , planets , moons , comets and galaxies – in either observational (by analyzing the data) or theoretical astronomy . Examples of topics or fields astronomers study include planetary science , solar astronomy , the origin or evolution of stars , or
279-553: Is less flooded by mare basalts , so that much of the basin structure is visible. The basalt in the central portion of the Orientale basin is probably less than 1 km (0.62 mi) in thickness which is much less than mare basins on the Earth-facing side of the Moon. The collision caused ripples in the lunar crust, resulting in the three concentric circular features. The innermost rings of this vast, multi-ringed crater are
310-668: Is the Moon's most recent impact basin, probably younger than the Imbrium Basin , which is about 3.85 billion years old, with an estimated age of around 3.7-3.8 billion years. The surrounding basin material is of the Lower Imbrian epoch with the mare material being of the Upper Imbrian epoch. Global seismic shaking following the impact that created the basin has been credited with the levelling of almost all slopes steeper than 35° in layers of Imbrian age and older on
341-693: Is the most distinguished award given by the American Astronomical Society 's Division for Planetary Sciences , an international society of professional planetary scientists. One of the three buildings at Arizona that makes up the Lunar and Planetary Laboratory is named in his honor. Episode 6 ("The Man of a Trillion Worlds") of the TV series Cosmos: Possible Worlds featured the Kuiper–Urey conflict. Astronomer An astronomer
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#1732794201898372-663: The Oort cloud or out of the Solar System; there would not be a Kuiper belt today if this were correct. The name "Kuiper belt" was given to the region in the 1980s; it was first used in print by Scott Tremaine in 1988. In the 1960s, Kuiper helped identify landing sites on the Moon for the Apollo program . Kuiper discovered several binary stars which received "Kuiper numbers" to identify them, such as KUI 79. He married Sarah Parker Fuller on 20 June 1936. Kuiper died age 68 of
403-557: The University of Arizona , serving as the laboratory's director for the rest of his life, until his death in 1973. Kuiper discovered two natural satellites of planets in the Solar System , namely Uranus 's satellite Miranda and Neptune 's satellite Nereid . In addition, he discovered carbon dioxide in the atmosphere of Mars , and the existence of a methane -laced atmosphere above Saturn 's satellite Titan in 1944. Kuiper also pioneered airborne infrared observing using
434-527: The formation of galaxies . A related but distinct subject is physical cosmology , which studies the Universe as a whole. Astronomers usually fall under either of two main types: observational and theoretical . Observational astronomers make direct observations of celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate models of things that cannot be observed. Because it takes millions to billions of years for
465-435: The Moon. Located at the antipode of Mare Orientale is Mare Marginis . A mass concentration (mascon), or gravitational high, was identified in the center of Mare Orientale from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The mascon was confirmed and mapped at higher resolution with later orbiters such as Lunar Prospector and GRAIL . Mare Orientale is difficult to observe from Earth, as it lies at
496-685: The Netherlands on his thesis on binary stars with Hertzsprung in 1933. He traveled to California to become a fellow under Robert Grant Aitken at the Lick Observatory . In 1935 he left to work at the Harvard College Observatory , where he met Sarah Parker Fuller (1913-2000), whom he married on 20 June 1936. Although he had planned to move to Java to work at the Bosscha Observatory , he took
527-488: The Origin of the Solar System , Kuiper wrote about the "outermost region of the solar nebula, from 38 to 50 astr. units (i.e., just outside proto-Neptune)" where "condensation products (ices of H 2 0, NH 3 , CH 4 , etc.) must have formed, and the flakes must have slowly collected and formed larger aggregates, estimated to range up to 1 km or more in size." He continued to write that "these condensations appear to account for
558-545: The PhD level and beyond (as of 2024). Contrary to the classical image of an old astronomer peering through a telescope through the dark hours of the night, it is far more common to use a charge-coupled device (CCD) camera to record a long, deep exposure, allowing a more sensitive image to be created because the light is added over time. Before CCDs, photographic plates were a common method of observation. Modern astronomers spend relatively little time at telescopes, usually just
589-766: The astronautic convention for East and West on the Moon and this limb became the western edge. The first detailed study of the Mare Orientale was by Hugh Percy Wilkins , who called it "Lunar Mare X". Franz's discoveries were not well known, and in the 1976 edition of his book Guide to the Moon , Patrick Moore claims that he and Wilkins discovered and named Mare Orientale in 1946. However, Moore credits Franz as discoverer in his 2009 Yearbook of Astronomy (p. 133–135). Gerard Kuiper Gerard Peter Kuiper ( / ˈ k aɪ p ər / KY -pər ; born Gerrit Pieter Kuiper , Dutch: [ˈɣɛrɪt ˈpitər ˈkœypər] ; 7 December 1905 – 23 December 1973)
620-411: The comets, in size, number and composition." According to Kuiper "the planet Pluto, which sweeps through the whole zone from 30 to 50 astr. units , is held responsible for having started the scattering of the comets throughout the solar system." It is said that Kuiper was operating on the assumption, common in his time, that Pluto was the size of Earth and had therefore scattered these bodies out toward
651-421: The core sciences, a competency examination, experience with teaching undergraduates and participating in outreach programs, work on research projects under the student's supervising professor, completion of a PhD thesis , and passing a final oral exam . Throughout the PhD training, a successful student is financially supported with a stipend . While there is a relatively low number of professional astronomers,
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#1732794201898682-578: The extreme western edge of the near side. All that can be seen are the rough mountain ranges—the Montes Rook and the Montes Cordillera—and some glimpses of the dark mare material beyond them. However, the Moon's libration means that on rare occasions Mare Orientale is turned slightly more toward the Earth, and becomes a little more discernible. Although various astronomers had observed hints of
713-474: The field is popular among amateurs . Most cities have amateur astronomy clubs that meet on a regular basis and often host star parties . The Astronomical Society of the Pacific is the largest general astronomical society in the world, comprising both professional and amateur astronomers as well as educators from 70 different nations. As with any hobby , most people who practice amateur astronomy may devote
744-489: The field. Those who become astronomers usually have a broad background in physics, mathematics , sciences, and computing in high school. Taking courses that teach how to research, write, and present papers are part of the higher education of an astronomer, while most astronomers attain both a Master's degree and eventually a PhD degree in astronomy, physics or astrophysics . PhD training typically involves 5-6 years of study, including completion of upper-level courses in
775-490: The inner and outer Montes Rook , and the outermost ring are the Montes Cordillera , 930 km (580 mi) in diameter. Outward from here, ejecta extend some 500 km (310 mi) from the foot of the mountains and form a rough surface with hummocks and with features radially aligned towards the center. The Apollo program did not sample rocks from Mare Orientale so its precise age is not known. However, it
806-694: The majority of their time working on research, although they quite often have other duties such as teaching, building instruments, or aiding in the operation of an observatory. The American Astronomical Society , which is the major organization of professional astronomers in North America , has approximately 8,200 members (as of 2024). This number includes scientists from other fields such as physics, geology , and engineering , whose research interests are closely related to astronomy. The International Astronomical Union comprises about 12,700 members from 92 countries who are involved in astronomical research at
837-579: The mare, it was first fully described by the German astronomer Julius Franz in his 1906 book Der Mond ("The Moon"). Franz also gave the mare its name, the "Eastern Sea", as it was located on what the convention at the time considered was the eastern side of the Moon as viewed from Earth , though it is the western side as viewed by an astronaut walking on the Moon. In 1961, however, the International Astronomical Union adopted
868-494: The time a very large number of astronomers had congregated. He befriended fellow students Bart Bok and Pieter Oosterhoff , and was taught by Ejnar Hertzsprung , Antonie Pannekoek , Willem de Sitter , Jan Woltjer , Jan Oort , and the physicist Paul Ehrenfest . He received his candidate degree in Astronomy in 1927 and continued straight on with his graduate studies. Kuiper received his PhD degree from Leiden University in
899-577: The two worked on the classified military Project A119 , a secret Air Force plan to detonate a nuclear warhead on the moon. In 1959, he sent Jürgen Stock to Chile, to search for suitable sites of an observatory for the Southern skies, who eventually would identify the spot for the Cerro Tololo Inter-American Observatory . In 1960 Kuiper moved to Tucson , Arizona , to found the Lunar and Planetary Laboratory at
930-615: Was a Dutch-American astronomer , planetary scientist , selenographer , author and professor. The Kuiper belt is named after him. Kuiper is considered by many to be the father of modern planetary science . Kuiper, the son of a tailor in the village of Tuitjenhorn in North Holland , had an early interest in astronomy. He had extraordinarily sharp eyesight, allowing him to see with the naked eye magnitude 7.5 stars, about four times fainter than those visible to normal eyes. He studied at Leiden University in 1924, where at
961-498: Was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using physical laws . Today, that distinction has mostly disappeared and the terms "astronomer" and "astrophysicist" are interchangeable. Professional astronomers are highly educated individuals who typically have a PhD in physics or astronomy and are employed by research institutions or universities. They spend