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694 Ekard
694 Ekard is a minor planet orbiting the Sun that was discovered by American astronomer Joel Hastings Metcalf on November 7, 1909. The asteroid's name comes from the reverse spelling of Drake University in Des Moines, Iowa, where Seth Barnes Nicholson and his wife calculated its orbit. Photometric observations of this asteroid gave a light curve with a period of 5.925 hours and a brightness variation of 0.50 in magnitude. Measurements of the thermal inertia of 694 Ekard give a value of around 100–140 J m−2 K−1 s−1/2, compared to 50 for lunar regolith and 400 for coarse sand in an atmosphere. 13-cm radar observations of this asteroid from the Arecibo Observatory The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science F ... between 1980 and 1985 were used to produce a diameter estima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joel Hastings Metcalf
Joel Hastings Metcalf (January 4, 1866 – February 23, 1925) was an American astronomer, humanitarian and Minister (Christianity), minister. Reverend Metcalf graduated from Harvard Divinity School in 1892. He served as a Unitarianism, Unitarian minister in Burlington, Vermont and in Taunton, Massachusetts, Winchester, Massachusetts and Portland, Maine. He discovered or co-discovered several comets, including 23P/Brorsen-Metcalf and 97P/Metcalf-Brewington, and also 41 asteroids during 1905–1914, as credited by the Minor Planet Center. Two of his discoveries, the main-belt asteroids 726 Joëlla and 792 Metcalfia, were named in his honor. Bibliography See also References External links Joel Hastings Metcalf – Minister, Humanitarian, AstronomerMetcalf, Joel Hastings (1866-1925) {{DEFAULTSORT:Metcalf, Joel Hastings 1866 births 1925 deaths American astronomers Discoverers of asteroids Discoverers of comets Harvard Divinity School alumni People from Bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Curve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequency interval or band. Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it. Variable stars Graphs of the apparent magnitude of a variable star over time are commonly used to visualise and analyse their behaviour. Although the categorisation of variable star types is increasingly done from their s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Named Minor Planets
Named may refer to something that has been given a name. Named may also refer to: * named (computing), a widely used DNS server * Naming (parliamentary procedure) * The Named (band), an American industrial metal group In literature: * ''The Named'', a fantasy novel by Marianne Curley * The Named, a fictional race of prehistoric big cats, depicted in ''The Books of the Named'' series by Clare Bell See also * Name (other) * Names (other) Names are words or terms used for identification. Names may also refer to: * ''Names'' (EP), by Johnny Foreigner * ''Names'' (journal), an academic journal of onomastics * The Names (band), a Belgian post-punk band * ''The Names'' (novel), by ... * Naming (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discoveries By Joel Hastings Metcalf
Discoveries may refer to: Music * ''Discoveries'' (Cannonball Adderley album), 1955 * ''Discoveries'' (Josh Nelson album), 2011 * ''Discoveries'' (Northlane album), 2011 Other uses * ''Discoveries'' (film), a 1939 British film * Discoveries (horse), a racehorse * ''Discoveries'' (Robertson Davies), a 2002 book by Robertson Davies * ''Discoveries'' (TV series), a Canadian youth science television series which aired on CBC Television in 1957 * ''Abrams Discoveries'', a series of illustrated non-fiction books published by Harry N. Abrams * ''Discoveries'', a work by William Butler Yeats, written in 1907 * ''Discoveries'', a magazine published by Cedars-Sinai Medical Center See also * Age of Discoveries * Discovery (other) Discovery may refer to: * Discovery (observation), observing or finding something unknown * Discovery (fiction), a character's learning something unknown * Discovery (law), a process in courts of law relating to evidence Discovery, The Discov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Background Asteroids
Background may refer to: Performing arts and stagecraft * Background actor * Background artist * Background light * Background music * Background story * Background vocals * ''Background'' (play), a 1950 play by Warren Chetham-Strode Recorded works * ''Background'' (1953 film), a British drama * ''Background'' (1973 film), a documentary * ''Background'' (TV series), a Canadian journalistic television series * ''Background'' (Lifetime album), 1992 * ''Background'' (Bassi Maestro album), 2002 Science and engineering * Background extinction rate * Background independence, a condition in theoretical physics * Background noise * Background radiation, the natural radiation that is always present in a location ** Background (astronomy), small amounts of light coming from otherwise dark parts of the sky ** Cosmic background (other) ** Gravitational wave background ** X-ray background * Background process, software that is running but not being displayed * String b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA and managed by the nearby California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network. Among the laboratory's major active projects are the Mars 2020 mission, which includes the ''Perseverance'' rover and the '' Ingenuity'' Mars helicopter; the Mars Science Laboratory mission, including the ''Curiosity'' rover; the InSight lander (''Interior Exploration using Seismic Investigations, Geodesy and Heat Transport''); the ''Mars Reconnaissance Orbiter''; the ''Juno'' spacecraft orbiting Jupiter; the ''SMAP'' satellite for earth surface s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecibo Observatory
The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science Foundation (NSF). The observatory's main instrument was the Arecibo Telescope, a spherical reflector dish built into a natural sinkhole, with a cable-mount steerable receiver and several radar transmitters for emitting signals mounted above the dish. Completed in 1963, it was the world's largest single-aperture telescope for 53 years, surpassed in July 2016 by the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. Following two breaks in cables supporting the receiver platform in mid-2020, the NSF decommissioned the telescope. A partial collapse of the telescope occurred on December 1, 2020, before controlled demolition could be conducted. In 2022, the NSF announced the telescope will not be rebuilt, with an educational fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Regolith
Lunar soil is the fine fraction of the regolith found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil. The physical properties of lunar soil are primarily the result of mechanical disintegration of basaltic and anorthositic rock, caused by continual meteoric impacts and bombardment by solar and interstellar charged atomic particles over billions of years. The process is largely one of mechanical weathering in which the particles are ground to progressively finer size over time. This situation contrasts fundamentally to terrestrial dirt formation, mediated by the presence of molecular oxygen (O2), humidity, atmospheric wind, and a robust array of contributing biological processes. ''Lunar soil'' typically refers to only the finer fraction of lunar regolith, which is composed of grains 1 cm in diameter or less, but is often used interchangeably. Lunar dust generally connotes even finer materials than ''lunar soil''. There is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Inertia
In thermodynamics, a material's thermal effusivity, thermal inertia or thermal responsivity is a measure of its ability to exchange thermal energy with its surroundings. It is defined as the square root of the product of the material's thermal conductivity (\lambda) and its volumetric heat capacity (\rho c_p). :e = \sqrt The SI units for thermal effusivity are \sqrt / (), or, equivalently, / ( \sqrt). Thermal effusivity is a parameter that emerges upon applying solutions of the heat equation to heat flow through a thin surface-like region. It becomes particularly useful when the region is selected adjacent to a material's actual surface. Knowing the effusivity and equilibrium temperature of each of two material bodies then enables an estimate of their interface temperature T_m when placed into thermal contact. :T_m = \frac Specialty sensors have also been developed based on this relationship to measure effusivity. Thermal effusivity and thermal diffusivity are related quan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnitude (astronomy)
In astronomy, magnitude is a unitless measure of the brightness Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light. In other words, brightness is the perception elicited by the luminance of a visual target. The perception is not linear to luminance, ... of an astronomical object, object in a defined passband, often in the visible spectrum, visible or infrared spectrum, but sometimes across all wavelengths. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. The scale is Logarithmic scale, logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is \sqrt[5] \approx 2.512 times brighter than the magnitude 1 higher. The brighter an object appears, the lower the value of its magnitude, with the brightest objects reaching negative values. Astronomers use two different defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometry (astronomy)
Photometry, from Greek '' photo-'' ("light") and '' -metry'' ("measure"), is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is measured through a telescope using a photometer, often made using electronic devices such as a CCD photometer or a photoelectric photometer that converts light into an electric current by the photoelectric effect. When calibrated against standard stars (or other light sources) of known intensity and colour, photometers can measure the brightness or apparent magnitude of celestial objects. The methods used to perform photometry depend on the wavelength region under study. At its most basic, photometry is conducted by gathering light and passing it through specialized photometric optical bandpass filters, and then capturing and recording the light energy with a photosensitive instrument. Standard sets of passbands (called a photometric system) are defined to allow a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taunton, Massachusetts
Taunton is a city in Bristol County, Massachusetts, Bristol County, Massachusetts, United States. It is the county seat, seat of Bristol County. Taunton is situated on the Taunton River which winds its way through the city on its way to Mount Hope Bay, to the south. At the 2020 United States Census, 2020 census, the city had a population of 59,408. Shaunna O'Connell is the List of mayors of Taunton, Massachusetts, mayor of Taunton. Founded in 1637 by members of the Plymouth Colony, Taunton is one of the oldest towns in the United States. The Native Americans called the region ''Cohannet'', ''Tetiquet'' and ''Titicut'' before the arrival of the Europeans. Taunton is also known as the "Silver City", as it was a historic center of the silver industry beginning in the 19th century when companies such as Reed & Barton, F. B. Rogers Silver Co., F. B. Rogers, Poole Silver, and others produced fine-quality silver goods in the city. Since December 1914, the city of Taunton has provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
