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Patroclus–Menoetius
617 Patroclus ( ) is a large binary Jupiter trojan asteroid. It is a dark D-type asteroid and a slow rotator, due to the 103-hour orbital period of its two components. It is one of five Jupiter trojan asteroids targeted by the ''Lucy'' space probe, and is scheduled for a flyby in 2033. Patroclus was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany, and was named after Patroclus in Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek figure, as the convention of naming one 'camp' after Greek figures of the Trojan War and the other after Trojan figures had not yet been established. Patroclus was long thought to be one of the largest Jupiter trojans, with a diameter on the order of 150 km. However, in 2001 it was discovered to be a binary asteroid of two similarly sized objects. The name ''Patroclus'' is now assigned to the larger component, some 110–115&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lucy (spacecraft)
''Lucy'' is a NASA space probe on a twelve-year journey to eight different asteroids. It is slated to visit two Asteroid belt, main belt asteroids as well as six Jupiter trojans – asteroids that share Jupiter's orbit around the Sun, orbiting either ahead of or behind the planet. All target encounters will be Flyby (spaceflight), flyby encounters. The ''Lucy'' spacecraft is the centerpiece of a US$981 million mission. On 4 January 2017, ''Lucy'' was chosen, along with the Psyche (spacecraft), ''Psyche'' mission, as NASA's Discovery Program missions 13 and 14 respectively. It was launched on 16 October 2021. In November 2023 and in April 2025 it flew by and photographed asteroids 152830 Dinkinesh, Dinkinesh and Donaldjohanson, respectively. Lucy will reach its first main target, the Jupiter Trojan asteroid 3548_Eurybates, Eurybates, in August 2027. The mission is named after the Lucy (Australopithecus), Lucy hominin fossils, because study of the trojans could reveal the "foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
617 Patroclus
617 Patroclus ( ) is a large binary Jupiter trojan asteroid. It is a dark D-type asteroid and a List of slow rotators (minor planets), slow rotator, due to the 103-hour orbital period of its two components. It is one of five Jupiter trojan asteroids targeted by the ''Lucy (spacecraft), Lucy'' space probe, and is scheduled for a flyby (spaceflight), flyby in 2033. Patroclus was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany, and was named after Patroclus in Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek figure, as the convention of naming one 'camp' after Greek figures of the Trojan War and the other after Trojan figures had not yet been established. Patroclus was long thought to be one of the 617 Patroclus#Diameter and albedo, largest Jupiter trojans, with a diameter on the order of 150 km. However, in 2001 it was discovered to be a binary asteroid of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyby (spaceflight)
A flyby () is a spaceflight operation in which a spacecraft passes in proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist (also called ''swing-by'') to impel it towards another target. Spacecraft which are specifically designed for this purpose are known as flyby spacecraft, although the term has also been used in regard to asteroid flybys of Earth for example. Important parameters are the time and distance of closest approach. Spacecraft flyby Flyby maneuvers can be conducted with a planet, a natural satellite or a non-planetary object such as a small Solar System body. Planetary flybys have occurred with Mars or Earth for example: * List of Earth flybys * Mars flyby An example of a comet flyby is when International Cometary Explorer (formerly ISEE-3) passed about from the nucleus of Comet Giacobini-Zinner in September 1985. Another application of the flyby is of Earth's Moon, usually called a lunar flyby. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menoetius
Menoetius or Menoetes (; ''Menoitios''), meaning ''doomed might'', is a name that refers to three distinct persons from Greek mythology: * Menoetius, a second generation Titan, son of Iapetus and Clymene or Asia, and a brother of Atlas, Prometheus and Epimetheus. Menoetius was killed by Zeus with a flash of lightning in the Titanomachy, and banished to Tartarus. His name means "doomed might", deriving from the Ancient Greek words ''menos'' ("might, power") and ''oitos'' ("doom, pain"). Hesiod described Menoetius as hubristic, meaning exceedingly prideful and impetuous to the very end. From what his name suggests, along with Hesiod's own account, Menoetius was perhaps the Titan god of violent anger and rash action. * Menoetes, guard of the cattle of Hades. During Heracles twelfth labor, which required him to steal the hound Cerberus from the Underworld, he slays one of Hades' cattle. A certain Menoetes, son of Keuthonymos, challenges Heracles to a wrestling match, during wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observation Arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly used in the discovery and tracking of asteroids and comets. Arc length has the greatest influence on the accuracy of an orbital estimate. The number, spacing of intermediate observations, and timestamps have a lesser effect. Short arcs A very short arc leaves a high uncertainty parameter. The object might be in one of many different orbits, at many distances from Earth. In some cases, the initial arc was too short to determine if the object was in orbit around the Earth, or orbiting out in the asteroid belt. With a 1-day observation arc, was thought to be a trans-Neptunian dwarf planet, but is now known to be a 1 km main-belt asteroid. With an observation arc of 3 days, was thought to be a Mars-crossing asteroid that could be a thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecliptic
The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the fixed stars, background of stars – specifically the Zodiac constellations. The planets of the Solar System can also be seen along the ecliptic, because their orbital planes are very close to Earth's. The Moon's orbital plane is also similar to Earth's; the ecliptic is so named because the ancients noted that eclipses only occur when the Moon is crossing it. The ecliptic is an important Plane of reference, reference plane and is the basis of the ecliptic coordinate system. Ancient scientists were able to calculate Earth's axial tilt by comparing the ecliptic plane to that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * Circular orbit: * Elliptic orbit: * Parabolic trajectory: * Hyperbolic trajectory: The eccentricity is given by e = \sqrt where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trojan War
The Trojan War was a legendary conflict in Greek mythology that took place around the twelfth or thirteenth century BC. The war was waged by the Achaeans (Homer), Achaeans (Ancient Greece, Greeks) against the city of Troy after Paris (mythology), Paris of Troy took Helen of Troy, Helen from her husband Menelaus, king of Sparta. The war is one of the most important events in Greek mythology, and it has been Epic Cycle, narrated through many works of ancient Greek literature, Greek literature, most notably Homer's ''Iliad''. The core of the ''Iliad'' (Books II – XXIII) describes a period of four days and two nights in the tenth year of the decade-long siege of Troy; the ''Odyssey'' describes the journey home of Odysseus, one of the war's heroes. Other parts of the war are described in a Epic Cycle, cycle of epic poems, which have survived through fragments. Episodes from the war provided material for Greek tragedy and other works of Greek literature, and for Latin literature, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
