|
LARES (satellite)
LARES (Laser Relativity Satellite) is a passive satellite system of the Italian Space Agency. Mission Launch LARES was launched into orbit on 13 February 2012 at 10:00:00 UTC. It was launched on the first Vega rocket from the ESA Centre Spatial Guyanais in Kourou, French Guiana. Composition The satellite is made of THA-18N, a tungsten alloy, and houses 92 cube-corner retroreflectors, which are used to track the satellite via laser from stations on Earth. LARES's body has a diameter of about and a mass of about . LARES was inserted in a nearly circular orbit near and an inclination of 69.49 degrees. The satellite is tracked by the International Laser Ranging Service stations. The LARES satellite is the densest object known orbiting the Earth. The high density helps reduce disturbances from environmental factors such as solar radiation pressure. Scientific goals The main scientific target of the LARES mission is the measurement of the Lense–Thirring effect with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Laser Ranging
In satellite laser ranging (SLR) a global network of observation stations measures the round trip time of flight of ultrashort pulses of light to satellites equipped with retroreflectors. This provides instantaneous range measurements of millimeter level precision which can be accumulated to provide accurate measurement of orbits and a host of important scientific data. The laser pulse can also be reflected by the surface of a satellite without a retroreflector, which is used for tracking space debris. Satellite laser ranging is a proven geodetic technique with significant potential for important contributions to scientific studies of the earth/atmosphere/ocean system. It is the most accurate technique currently available to determine the geocentric position of an Earth satellite, allowing for the precise calibration of radar altimeters and separation of long-term instrumentation drift from secular changes in ocean topography. Its ability to measure the variations over time in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lense–Thirring Precession
In general relativity, Lense–Thirring precession or the Lense–Thirring effect (; named after Josef Lense and Hans Thirring) is a Theory of relativity, relativistic correction to the precession of a gyroscope near a large rotating mass such as the Earth. It is a gravitomagnetism, gravitomagnetic frame-dragging effect. It is a prediction of general relativity consisting of secular variation, secular precessions of the longitude of the ascending node and the argument of pericenter of a test particle freely orbiting a central spinning mass endowed with angular momentum S. The difference between de Sitter precession and the Lense–Thirring effect is that the de Sitter effect is due simply to the presence of a central mass, whereas the Lense–Thirring effect is due to the rotation of the central mass. The total precession is calculated by combining the de Sitter precession with the Lense–Thirring precession. According to a 2007 historical analysis by Herbert Pfister, the effect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vega-C
Vega ( it, Vettore Europeo di Generazione Avanzata, or french: Vecteur européen de génération avancée, or en, European Vector of Advanced Generation, meaning "Advanced generation European carrier rocket") is an expendable launch system in use by Arianespace jointly developed by the Italian Space Agency (ASI) and the European Space Agency (ESA). Development began in 1998 and the first launch took place from the Guiana Space Centre, Centre Spatial Guyanais on 13 February 2012. It is designed to launch small payloads – 300 to 2500 kg satellites for scientific and Earth observation satellite, Earth observation missions to Polar orbit, polar and Low Earth orbit, low Earth orbits. The reference Vega mission is a polar orbit bringing a spacecraft of 1500 kg to an altitude of 700 km. The rocket, named after Vega, the List of brightest stars, brightest star in the constellation Lyra, is a single-body launcher (no strap-on boosters) with three Solid-propellant rocke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Geodesy
Satellite geodesy is geodesy by means of artificial satellites—the measurement of the form and dimensions of Earth, the location of objects on its surface and the figure of the Earth's gravity field by means of artificial satellite techniques. It belongs to the broader field of space geodesy. Traditional astronomical geodesy is ''not'' commonly considered a part of satellite geodesy, although there is considerable overlap between the techniques. The main goals of satellite geodesy are: # Determination of the figure of the Earth, positioning, and navigation (geometric satellite geodesy) # Determination of geoid, Earth's gravity field and its temporal variations (dynamical satellite geodesy or satellite physical geodesy) # Measurement of geodynamical phenomena, such as crustal dynamics and polar motion Satellite geodetic data and methods can be applied to diverse fields such as navigation, hydrography, oceanography and geophysics. Satellite geodesy relies heavily on orbital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geodynamics
Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting. It also attempts to probe the internal activity by measuring magnetic fields, gravity, and seismic waves, as well as the mineralogy of rocks and their isotopic composition. Methods of geodynamics are also applied to exploration of other planets. Overview Geodynamics is generally concerned with processes that move materials throughout the Earth. In the Earth's interior, movement happens when rocks melt or deform and flow in response to a stress field.Turcotte, D. L. and G. Schubert (2014). "Geodynamics." This deformation may be brittle, elastic, or plastic, depending on the magnitude of the stress and the material's physical properties, especially the stress relaxation time scale. Roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the ' is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations. Newton's law of universal gravitation, which describes classical gravity, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass distributions. Some predictions of general relativity, however, are beyond Newton's law of universal gravitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Astronautica
''Acta Astronautica'' is a monthly peer-reviewed scientific journal covering all fields of physical, engineering, life, and social sciences related to the peaceful scientific exploration of space. The journal is widely known as one of the top aerospace engineering journals. The journal was established in 1955 under the name ''Astronautica Acta'', obtaining its current title in 1974, with volume-numbering simultaneously restarting at 1. The journal is published by Elsevier, sponsored by the International Academy of Astronautics. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 2.413. References External links * Space scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Astronomy (journal)
''New Astronomy'' is a peer-reviewed scientific journal covering topics in astronomy and astrophysics. The journal was established in 1996 and is currently published by Elsevier. Abstracting and indexing The journal is abstracted and indexed in the following databases: *Current Contents/Physics, Chemical, & Earth Sciences * INSPEC *SCISEARCH *Science Citation Index *Scopus According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.325. References External links * Astronomy journals Elsevier academic journals English-language journals Publications established in 1996 {{astronomy-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Journal Of Physics
The ''Canadian Journal of Physics'' is a monthly peer-reviewed scientific journal covering research in physics. It was established in 1929 as the '' Canadian Journal of Research, Section A: Physical Sciences'', obtaining its current title in 1951. The journal is published monthly by the NRC Research Press and edited by Robert Mann (University of Waterloo) and Marco Merkli (Memorial University of Newfoundland). The journal is affiliated with the Canadian Association of Physicists. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.358. References External links *{{Official, http://www.nrcresearchpress.com/journal/cjp Publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrophysics And Space Science
''Astrophysics and Space Science'' is a bimonthly peer-reviewed scientific journal covering astronomy, astrophysics, and space science and astrophysical aspects of astrobiology. It was established in 1968 and is published by Springer Science+Business Media. From 2016 to 2020 the editors-in-chief were both Prof. Elias Brinks and Prof. Jeremy Mould. Since 2020 the sole editor-in-chief is Prof. Elias Brinks. Other editors-in-chief in the past have been Zdeněk Kopal (Univ. of Manchester) (1968-1993) and Michael A. Dopita (Australian National University) (1994-2015). Abstracting and indexing The journal is abstracted and indexed in the following databases: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Physica Polonica B
Acta or ACTA may refer to: Institutions * Anti-Counterfeiting Trade Agreement, an intellectual property trade agreement * Administrative Council for Terminal Attachments, a standards organization for terminal equipment such as registered jacks * Alameda Corridor Transportation Authority, in southern California * American Council of Trustees and Alumni, an education organization * Atlantic County Transportation Authority, a transportation agency in Atlantic County, New Jersey * Australian Community Television Alliance, an industry association representing community television licensees in Australia Science and technology * Acta, the transactions (proceedings) of an academic field, a learned society, or an academic conference * Acta (software), early outliner software * Activin A, mammalian protein * ACTA1, actin alpha 1 (skeletal muscle), human protein * ACTA2, actin alpha 2 (smooth muscle), human protein * Actin assembly-inducing protein, motility protein in the bacterium ''Listeri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity And Gravitation
A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, and marines or naval infantry. In some usages the term "general officer" refers to a rank above colonel."general, adj. and n.". OED Online. March 2021. Oxford University Press. https://www.oed.com/view/Entry/77489?rskey=dCKrg4&result=1 (accessed May 11, 2021) The term ''general'' is used in two ways: as the generic title for all grades of general officer and as a specific rank. It originates in the 16th century, as a shortening of ''captain general'', which rank was taken from Middle French ''capitaine général''. The adjective ''general'' had been affixed to officer designations since the late medieval period to indicate relative superiority or an extended jurisdiction. Today, the title of ''general'' is known in some countries as a four-star rank. However, different countries use different systems of stars or other insignia for senior ranks. It has a NATO rank scal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
