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3581 Alvarez
3581 Alvarez, provisional designation ', is a carbonaceous asteroid and a very large Mars-crosser on an eccentric orbit from the asteroid belt, approximately in diameter. It was discovered on 23 April 1985, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California. The likely spherical B-type asteroid has a rotation period of 33.4 hours. It was named for scientists Luis Alvarez and his son Walter Alvarez. Orbit and classification ''Alvarez'' is a Mars-crossing asteroid, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU. However, due to the high inclination of its orbit, it never actually passes through the orbit of Mars since at perihelion it is well away from Mars' orbital plane. It orbits the Sun at a distance of 1.7–3.9 AU once every 4 years and 7 months (1,689 days; semi-major axis of 2.78 AU). Its orbit has an eccentricity of 0.41 and an in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carolyn Shoemaker
Carolyn Jean Spellmann Shoemaker (June 24, 1929 – August 13, 2021) was an American astronomer and a co-discoverer of Comet Shoemaker–Levy 9, Comet Shoemaker–Levy 9. She discovered 32 comets (then a record for the most by an individual) and more than 500 asteroids. Having earned degrees in history, political science, and English literature, she had little interest in planetary science until she met and married geologist Eugene Merle Shoemaker. Her career in astronomy began when she demonstrated good stereopsis, stereoscopic vision, a particularly valuable quality for looking for objects in near-Earth space. Despite the fact that her degrees were not in science, having that visual ability motivated the California Institute of Technology (Caltech) to hire her as a research assistant on a team led by her husband. She went on to making record-setting discoveries in the field of astronomy, as well as being awarded honorary degrees and many professional awards. Personal l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Belt
The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids or minor planets. The identified objects are of many sizes, but much smaller than planets, and, on average, are about one million kilometers (or six hundred thousand miles) apart. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System. The asteroid belt is the smallest and innermost circumstellar disc in the Solar System. Classes of small Solar System bodies in other regions are the near-Earth objects, the centaurs, the Kuiper belt objects, the scattered disc objects, the sednoids, and the Oort cloud objects. About 60% of the main belt mass is contained in the four largest asteroids: Ceres, Vesta, Pallas, and Hygiea. The total mass of the asteroid be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alvarez Hypothesis
The Alvarez hypothesis posits that the Extinction event, mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the Impact event, impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and colleagues (2013) gave an updated value of 66 million years. Evidence indicates that the asteroid fell in the Yucatán Peninsula, at Chicxulub, Mexico. The hypothesis is named after the father-and-son team of scientists Luis Walter Alvarez, Luis and Walter Alvarez, who first suggested it in 1980. Shortly afterwards, and independently, the same was suggested by Dutch paleontologist Jan Smit (paleontologist), Jan Smit. In March 2010, an international panel of scientists endorsed the asteroid hypothesis, specifically the Chicxulub crater, Chicxulub impact, as being the cause of the extinction. A team of 41 scientists reviewed 20 years of sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Impact
An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and Biosphere, biospheric consequences, as the impacting body is usually traveling at several kilometres per second (km/s), with a minimum impact speed of 11.2 km/s (7.0 mi/s) for bodies striking Earth. Atmosphere, While planetary atmospheres can mitigate some of these impacts through the effects of atmospheric entry, many large bodies retain sufficient energy to reach the surface and cause substantial damage. This results in the formation of Impact crater, impact craters and Impact structure, structures, shaping the dominant landforms found across various types of solid objects found in the Solar System. Their prevalence and ubiquity pres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Boundary
The Cretaceous–Paleogene (K–Pg) boundary, formerly known as the Cretaceous–Tertiary (K–T) boundary, is a geological signature, usually a thin band of rock containing much more iridium than other bands. The K–Pg boundary marks the end of the Cretaceous Period, the last period of the Mesozoic Era, and marks the beginning of the Paleogene Period, the first period of the Cenozoic Era. Its age is usually estimated at 66 million years, with radiometric dating yielding a more precise age of 66.043 ± 0.043 Ma. The K–Pg boundary is associated with the Cretaceous–Paleogene extinction event, a mass extinction which destroyed a majority of the world's Mesozoic species, including all dinosaurs except for some birds. Strong evidence exists that the extinction coincided with a large meteorite impact at the Chicxulub crater and the generally accepted scientific theory is that this impact triggered the extinction event. The word "Cretaceous" is derived from the Latin "creta" ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkeley, it is the state's first land-grant university and is the founding campus of the University of California system. Berkeley has an enrollment of more than 45,000 students. The university is organized around fifteen schools of study on the same campus, including the UC Berkeley College of Chemistry, College of Chemistry, the UC Berkeley College of Engineering, College of Engineering, UC Berkeley College of Letters and Science, College of Letters and Science, and the Haas School of Business. It is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". Lawrence Berkeley National Laboratory was originally founded as par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minor Planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor planet'', but that year's meeting IAU definition of planet, reclassified minor planets and comets into dwarf planets and Small Solar System body, small Solar System bodies (SSSBs).Press release, IAU 2006 General Assembly: Result of the IAU Resolution votes International Astronomical Union, August 24, 2006. Accessed May 5, 2008. In contrast to the eight official planets of the Solar System, all minor planets fail to clearing the neighborhood, clear their orbital neighborhood. Minor planets include asteroids (near- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goethe Link Observatory
The Goethe Link Observatory, observatory code 760, is an astronomical observatory near Brooklyn, Indiana, United States. It is owned by Indiana University and operated by the Indiana Astronomical Society https://iasindy.org/about.html, which efforts are dedicated to the pursuit of amateur astronomy. Observatory Address: 8403 Observatory Ln, Martinsville, IN 46151. Hours: During and after General Meetings of the Indiana Astronomical Society (IAS). See https://iasindy.org/events.html, for dates and times. It is named in honor of amateur astronomer Dr. Goethe Link, an Indianapolis surgeon, who built it with his private funds. Construction of the observatory started in 1937, and the telescope was first operated in 1939. In 1948, he donated the observatory to Indiana University. From 1949 until 1966, the Indiana Asteroid Program was conducted at Goethe Link, using a 10-inch Cooke triplet astrograph (''f/''6.5). The program resulted in the discovery of 119 asteroids, which were cr ... [...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] |
