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Street (crater)
Street is a lunar impact crater located just to the south of the prominent ray crater Tycho. Street lies within the skirt of high-albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ... ejecta from Tycho, and it is more heavily worn than its younger and larger neighbor. There are several smaller craters joined to the western rim, as well as two craters along the eastern rim. The floor is relatively smooth and flat, except for a small craterlet in the western half. The crater is in diameter and in depth. It may be from the Pre-Imbrian period, which lasted from 4.55 to 3.85 billion years ago. It is named for the 17th-century English astronomer Thomas Street.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006. Satellite craters By convention these features are ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Orbiter 4
Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Apollo mapping and site selection. It was given a more general objective, to "perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions". It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. Mission Summary The spacecraft was placed in a cislunar trajectory and injected into an elliptical near polar high lunar orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Street (astronomer)
Thomas Street (also spelled Streete) (1621–1689) was an English astronomer, known for his writings on celestial motions. He has sometimes been confused with Thomas Street the judge, who lived from 1626 to 1696. The crater Street on the Moon is named after him. Life According to ''Brief Lives'' by Street's contemporary John Aubrey, Street was born at Castle Lyons in Ireland on 5 March 1621, and died "in Chanon-row (vulgarly Channel-rowe) at Westminster, the 17th August, 1689, and is buried in the church yard of the new chapell there". Astronomy On 3 May 1661 Streete observed a transit of Mercury from Long Acre in London with Nicholas Mercator and Christiaan Huygens. Streete subsequently disputed Hevelius observation of this event. The same year also saw Streete publishing ''Astronomia Carolina, a new theorie of Coelestial Motions''. An ''Appendix to Astronomia Carolina'' (including tables) followed in 1664. ''Astronomia Carolina'' was widely read, and used by students who late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Craters
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The word ''crater'' was adopted from the Greek word for "vessel" (, a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Johann Hieronymus Schröter (1791), extending its previous use with volcanoes. Robert Hooke in '' Micrographia'' (1665) proposed two hypotheses for lunar crater formation: one, that the craters were caused by projectile bombardment from space, the other, that they were the products of subterranean lunar volcanism. Scientific opinion as to the ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tycho (crater)
Tycho () is a prominent lunar impact crater located in the southern lunar highlands, named after the Danish astronomer Tycho Brahe (1546–1601)., accessed 19 February 2019 It is estimated to be 108 million years old. To the south of Tycho is the crater Street, to the east is Pictet, and to the north-northeast is Sasserides. The surface around Tycho is replete with craters of various sizes, many overlapping still older craters. Some of the smaller craters are secondary craters formed from larger chunks of ejecta from Tycho. It is one of the Moon's brightest craters, with a diameter of and a depth of . Age and description Tycho is a relatively young crater, with an estimated age of 108 million years ( Ma), based on analysis of samples of the crater ray recovered during the Apollo 17 mission. This age initially suggested that the impactor may have been a member of the Baptistina family of asteroids, but as the composition of the impactor is unknown this remained conjecture. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albedo
Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation. Surface albedo is defined as the ratio of radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as obtained from flux measurements) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kalmbach Books
Kalmbach Media (formerly Kalmbach Publishing Co.) is an American publisher of books and magazines, many of them railroad-related, located in Waukesha, Wisconsin. History The company's first publication was ''The Model Railroader'', which began publication in the summer of 1933 with a cover date of January 1934. A press release announcing the magazine appeared in August 1933, but did not receive much interest. In 1940, business was good enough for Kalmbach to launch another magazine about railroads in general with the simple title of '' Trains Magazine''. From its first issue dated November 1940, it grew quickly from an initial circulation of just over 5,000. Kalmbach became exclusively a publisher when it discontinued its printing operations in 1973, opting to contract production from other printers. In 1985, Kalmbach purchased AstroMedia Corporation, adding its four magazines: ''Astronomy'', ''Deep Sky'', the children's science magazine ''Odyssey'' and ''Telescope Making' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Geologic Timescale
The lunar geological timescale (or selenological timescale) divides the history of Earth's Moon into five generally recognized periods: the Copernican, Eratosthenian, Imbrian (Late and Early epochs), Nectarian, and Pre-Nectarian. The boundaries of this time scale are related to large impact events that have modified the lunar surface, changes in crater formation through time, and the size-frequency distribution of craters superposed on geological units. The absolute ages for these periods have been constrained by radiometric dating of samples obtained from the lunar surface. However, there is still much debate concerning the ages of certain key events, because correlating lunar regolith samples with geological units on the Moon is difficult, and most lunar radiometric ages have been highly affected by an intense history of bombardment. Lunar stratigraphy The primary geological processes that have modified the lunar surface are impact cratering and volcanism, and by using standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
