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Romulus (moon)
Romulus, formal designation 87 Sylvia I, is the outer and larger moon of the main-belt asteroid 87 Sylvia. It follows an almost-circular and close-to-equatorial orbit around the asteroid. In this respect it is similar to the other Sylvian moon Remus. Discovery and naming Romulus was discovered in February 2001 from the Keck II telescope by Michael E. Brown and Jean-Luc Margot. Its formal designation is (87) Sylvia I; before receiving its name, it was known as S/2001 (87) 1. The moon is named after Romulus, the mythological founder of Rome, one of the twins of Rhea Silvia raised by a wolf. Characteristics 87 Sylvia has a low density, which indicates that it is probably a rubble pile formed when debris from a collision between its parent body and another asteroid re-accreted gravitationally. Therefore, it is likely that both Romulus and Remus, the second of Sylvia's moons, are smaller rubble piles which accreted in orbit around the main body from debris of the same collisi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remus (moon)
Remus, formal designation 87 Sylvia II, is the inner and smaller moon of the main-belt asteroid 87 Sylvia. It follows an almost-circular and close-to-equatorial orbit around the parent asteroid. In this respect it is similar to the other Sylvian moon Romulus (moon), Romulus. Discovery and naming Remus was discovered several years after Romulus on images taken starting on August 9, 2004, and announced on August 10, 2005. It was discovered by Franck Marchis of UC Berkeley, and Pascal Descamps, Daniel Hestroffer, and Jérôme Berthier of the Observatoire de Paris, France, using the Yepun telescope of the European Southern Observatory (ESO) in Chile. Marchis, the project leader, was waiting for the completion of the image acquisition programme before starting to process the data. Just as he was set to go on vacation in March 2005, Descamps sent him a brief note entitled "87 Sylvia est triple ?" pointing out that he could see two moonlets on several images of Sylvia. The entire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romulus And Remus
In Roman mythology, Romulus and (, ) are twins in mythology, twin brothers whose story tells of the events that led to the Founding of Rome, founding of the History of Rome, city of Rome and the Roman Kingdom by Romulus, following his fratricide of Remus. The image of a She-wolf (Roman mythology), she-wolf suckling the twins in their infancy has been a symbol of the city of Rome and the Ancient Rome, ancient Romans since at least the 3rd century BC. Although the tale takes place before the founding of Rome around 750 BC, the earliest known written account of the myth is from the late 3rd century BC. Possible historical bases for the story, and interpretations of its local variants, are subjects of ongoing debate. Overview Romulus and Remus were born in Alba Longa, one of the many ancient Latin cities near the seven hills of Rome. Their mother Rhea Silvia, also known as Ilia, was a Vestal Virgin and the daughter of former king Numitor, who had been displaced by his brother A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Satellites
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the inner Solar System or is co-orbital with Jupiter ( Trojan asteroids). Asteroids are rocky, metallic, or icy bodies with no atmosphere, and are broadly classified into C-type (carbonaceous), M-type (metallic), or S-type (silicaceous). The size and shape of asteroids vary significantly, ranging from small rubble piles under a kilometer across to Ceres, a dwarf planet almost 1000 km in diameter. A body is classified as a comet, not an asteroid, if it shows a coma (tail) when warmed by solar radiation, although recent observations suggest a continuum between these types of bodies. Of the roughly one million known asteroids, the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in a region known as the main asteroid belt. The total mass of all the asteroids combined is only 3% tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar day) that is synchronized to its orbital period (Lunar month#Synodic month, lunar month) of 29.5 Earth days. This is the product of Earth's gravitation having tidal forces, tidally pulled on the Moon until one part of it stopped rotating away from the near side of the Moon, near side, making always the same lunar surface face Earth. Conversley, the gravitational pull of the Moon, on Earth, is the main driver of Earth's tides. In geophysical definition of planet, geophysical terms, the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is , roughly one-quarter of Earth's (about as wide as the contiguous United States). Within the Solar System, it is the List of Solar System objects by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Orbit
A synchronous orbit is an orbit in which an orbiting body (usually a satellite) has a period equal to the average rotational period of the body being orbited (usually a planet), and in the same direction of rotation as that body. Simplified meaning A synchronous orbit is an orbit in which the orbiting object (for example, an artificial satellite or a moon) takes the same amount of time to complete an orbit as it takes the object it is orbiting to rotate once. Properties A satellite in a synchronous orbit that is both equatorial and circular will appear to be suspended motionless above a point on the orbited planet's equator. For synchronous satellites orbiting Earth, this is also known as a geostationary orbit. However, a synchronous orbit need not be equatorial; nor circular. A body in a non-equatorial synchronous orbit will appear to oscillate north and south above a point on the planet's equator, whereas a body in an elliptical orbit will appear to oscillate eastward and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hill Radius
A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent as mountains. Hills fall under the category of slope landforms. Terminology The distinction between a hill and a mountain is unclear and largely subjective, but a hill is universally considered to be not as tall, or as steep as a mountain. Geographers historically regarded mountains as hills greater than above sea level. In contrast, hillwalkers have tended to regard mountains as peaks above sea level. The ''Oxford English Dictionary'' also suggests a limit of and Whittow states "Some authorities regard eminences above as mountains, those below being referred to as hills." Today, a mountain is usually defined in the UK and Ireland as any summit at least high, while the UK government's Countryside and Rights of Way Act 2000 defined mountainous areas (for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hill Sphere
The Hill sphere is a common model for the calculation of a Sphere of influence (astrodynamics), gravitational sphere of influence. It is the most commonly used model to calculate the spatial extent of gravitational influence of an astronomical body (''m'') in which it dominates over the gravitational influence of other bodies, particularly a Primary (astronomy), primary (''M''). It is sometimes confused with other models of gravitational influence, such as the Laplace sphere or being named the Roche sphere, the latter causing confusion with the Roche limit. It was defined by the United States, American astronomer George William Hill, based on the work of the France, French astronomer Édouard Roche. To be retained by a more gravitationally attracting astrophysical object—a planet by a more massive star, a natural satellite, moon by a more massive planet—the less massive body must have an orbit that lies within the gravitational potential represented by the more massive body ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubble Pile
In astronomy, a rubble pile is a celestial body that consists of numerous pieces of debris that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the various chunks that make them up. The asteroids Bennu and Ryugu have a measured bulk density which suggests that their internal structure is a rubble pile. Many comets and most smaller minor planets (<10 km in diameter) are thought to be composed of coalesced rubble. Minor planets 
Most smaller s are thought to be rubble piles.
Rubble piles form when an aste ...
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Rhea Silvia
Rhea (or Rea) Silvia (), also known as Ilia, (as well as other names) was the mythical mother of the twins Romulus and Remus, who founded the city of Rome.Livy I.4.2 This event was portrayed numerous times in Roman art. Her story is told in the first book of '' Ab Urbe Condita Libri'' of Livy and in Cassius Dio's ''Roman History''. The Legend of Rhea Silvia recounts how she was raped by Mars while she was a Vestal Virgin, resulting in the twins, as mentioned in the ''Aeneid'' and the works of Ovid. Legend According to Livy's account of the legend, she was the daughter of Numitor, king of Alba Longa, and descended from Aeneas. Numitor's younger brother Amulius seized the throne and killed Numitor's son, then forced Rhea Silvia to become a Vestal Virgin, a priestess of the goddess Vesta. As Vestal Virgins were sworn to celibacy, this would ensure the line of Numitor had no heirs. Rhea, however, became pregnant with the twins Romulus and Remus by the god Mars.Livy I.4.2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rome
Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2,746,984 residents in , Rome is the list of cities in the European Union by population within city limits, third most populous city in the European Union by population within city limits. The Metropolitan City of Rome Capital, with a population of 4,223,885 residents, is the most populous metropolitan cities of Italy, metropolitan city in Italy. Rome metropolitan area, Its metropolitan area is the third-most populous within Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber Valley. Vatican City (the smallest country in the world and headquarters of the worldwide Catholic Church under the governance of the Holy See) is an independent country inside the city boun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keck Telescope
The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and, when completed in 1993 (Keck I) and 1996 (Keck II), they were the largest optical reflecting telescopes in the world. They have been the third and fourth largest since 2006. Overview With a concept first proposed in 1977, telescope designers Terry Mast, of the University of California, Berkeley, and Jerry Nelson of Lawrence Berkeley Laboratory had been developing the technology necessary to build a large, ground-based telescope. In 1985, Howard B. Keck of the W. M. Keck Foundation gave $70 million to fund the construction of the Keck I telescope, which began in September 1985. First light occurred on November 24, 1990, using 9 of the eventual 36 segments. When construction of the first telescope was well advanced, further donations all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael E
SS ''Michael E'' was a cargo ship that was built in 1941. She was the first British catapult aircraft merchant ship (CAM ship): a merchant ship fitted with a rocket catapult to launch a single Hawker Hurricane fighter aircraft to defend a convoy against long-range German bombers. She was sunk on her maiden voyage by a German submarine. Description ''Michael E'' was built by William Hamilton & Co Ltd, Port Glasgow. Launched in 1941, she was completed in May of that year. She was the United Kingdom's first CAM ship, armed with an aircraft catapult on her bow to launch a Hawker Sea Hurricane. The ship was long between perpendiculars ( overall), with a beam of . She had a depth of and a draught of . She was measured at and . She had six corrugated furnaces feeding two single-ended boilers with a combined heating surface of . The boilers fed a 443 nominal horsepower triple-expansion steam engine that had cylinders of , and diameter by stroke. The engine was buil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
