A minor planet is an astronomical object in direct orbit around the Sun that is neither a planet nor exclusively classified as a comet. Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, as of 2016, the orbits of 709,706 minor planets were archived at the Minor Planet Center,469,275 of which had received permanent numbers. The first minor planet to be discovered was Ceres in 1801, the term minor planet has been used since the 19th century to describe these objects. The term planetoid has also used, especially for larger objects such as those the International Astronomical Union has called dwarf planets since 2006. Historically, the asteroid, minor planet, and planetoid have been more or less synonymous. This terminology has become complicated by the discovery of numerous minor planets beyond the orbit of Jupiter. A Minor planet seen releasing gas may be classified as a comet. Before 2006, the IAU had officially used the term minor planet, during its 2006 meeting, the IAU reclassified minor planets and comets into dwarf planets and small Solar System bodies. Objects are called dwarf planets if their self-gravity is sufficient to achieve hydrostatic equilibrium, all other minor planets and comets are called small Solar System bodies. The IAU stated that the minor planet may still be used. However, for purposes of numbering and naming, the distinction between minor planet and comet is still used. Hundreds of thousands of planets have been discovered within the Solar System. The Minor Planet Center has documented over 167 million observations and 729,626 minor planets, of these,20,570 have official names. As of March 2017, the lowest-numbered unnamed minor planet is 1974 FV1, as of March 2017, the highest-numbered named minor planet is 458063 Gustavomuler. There are various broad minor-planet populations, Asteroids, traditionally, most have been bodies in the inner Solar System. Near-Earth asteroids, those whose orbits take them inside the orbit of Mars. Further subclassification of these, based on distance, is used, Apohele asteroids orbit inside of Earths perihelion distance. Aten asteroids, those that have semi-major axes of less than Earths, Apollo asteroids are those asteroids with a semimajor axis greater than Earths, while having a perihelion distance of 1.017 AU or less. Like Aten asteroids, Apollo asteroids are Earth-crossers, amor asteroids are those near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
An astronomer is a scientist in the field of astronomy who concentrates their studies on a specific question or field outside of the scope of Earth. They look at stars, planets, moons, comets and galaxies, as well as other celestial objects — either in observational astronomy. Examples of topics or fields astronomers work on include, planetary science, solar astronomy, there are also related but distinct subjects like physical cosmology which studies the Universe as a whole. Astronomers usually fit into two types, Observational astronomers make direct observations of planets, stars and galaxies, and analyze the data, theoretical astronomers create and investigate models of things that cannot be observed. They use this data to create models or simulations to theorize how different celestial bodies work, there are further subcategories inside these two main branches of astronomy such as planetary astronomy, galactic astronomy or physical cosmology. Today, that distinction has disappeared and the terms astronomer. Professional astronomers are highly educated individuals who typically have a Ph. D. in physics or astronomy and are employed by research institutions or universities. They spend the majority of their time working on research, although quite often have other duties such as teaching, building instruments. The number of astronomers in the United States is actually quite small. The American Astronomical Society, which is the organization of professional astronomers in North America, has approximately 7,000 members. This number includes scientists from other such as physics, geology. The International Astronomical Union comprises almost 10,145 members from 70 different countries who are involved in research at the Ph. D. level. Before CCDs, photographic plates were a method of observation. Modern astronomers spend relatively little time at telescopes usually just a few weeks per year, analysis of observed phenomena, along with making predictions as to the causes of what they observe, takes the majority of observational astronomers time. Astronomers who serve as faculty spend much of their time teaching undergraduate and graduate classes, most universities also have outreach programs including public telescope time and sometimes planetariums as a public service to encourage interest in the field. Those who become astronomers usually have a background in maths, sciences. Taking courses that teach how to research, write and present papers are also invaluable, in college/university most astronomers get a Ph. D. in astronomy or physics. Keeping in mind how few there are it is understood that graduate schools in this field are very competitive
Lowell Observatory is an astronomical observatory in Flagstaff, Arizona, United States. Lowell Observatory was established in 1894, placing it among the oldest observatories in the United States, in 2011, the Observatory was named one of The Worlds 100 Most Important Places by TIME. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh, the Observatorys original 61-centimeter Alvan Clark & Sons Telescope is still in use today for public education. It was founded by astronomer Percival Lowell of Bostons well-known Lowell family and is overseen by a sole trustee, the first trustee was Lowells third cousin Guy Lowell. Percivals nephew Roger Putnam served from 1927–1967, followed by Rogers son Michael, Michaels brother William Lowell Putnam III, the observatory operates several telescopes at three locations in the Flagstaff area. The telescope, built in 1896 for $20,000, was assembled in Boston by Alvan Clark & Sons, also located on the Mars Hill campus is the 33-centimeter Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the dwarf planet Pluto. Lowell is a partner with the United States Naval Observatory and Naval Research Laboratory in the Navy Precision Optical Interferometer also located at that site, the Observatory also operates smaller research telescopes at its historic site on Mars Hill and in Australia and Chile. Past Anderson Mesa, on the peak of Happy Jack, Lowell Observatory has also built and is commissioning the 4. 28-meter Discovery Channel Telescope in partnership with Discovery Communications, Inc. Aside from the array of research and discoveries listed below. When Harold L. Johnson took over as the director in 1952, in 1953, the current 53 cm telescope was erected. Beginning in 1954, this telescope began monitoring the brightness of two planets, and comparing these measurements with a reference set of sunlike stars. Lowell Observatory is building a major new reflecting telescope in partnership with Discovery Communications, located near Happy Jack, the primary mirror of the Discovery Channel Telescope will be 4.28 m in diameter. It will be notable for its uncommon meniscus design for such a large mirror. This mirror was ground and polished into its parabolic shape at the Optical Fabrication, Lowell Observatorys astronomers conduct research on a wide range of solar system and astrophysical topics using ground-based, airborne, and space-based telescopes. In addition, the Observatory staff designs and builds custom instrumentation for use on Lowells telescopes, for example, Lowell staff built a sophisticated high-speed camera for use on the Stratospheric Observatory for Infrared Astronomy. SOFIA is a joint project of the United States and German space agencies, Lowell, Percival, Pickering, W. H. and the founding of the Lowell Observatory. National Historic Landmarks Program, Lowell Observatory+ Historic American Buildings Survey No, aZ-206, Lowell Observatory,1400 West Mars Hill Road, Flagstaff, Coconino County, AZ HABS No. AZ-206-A, Lowell Observatory, Slipher Building HABS No, aZ-206-B, Lowell Observatory, Clark Dome HABS No
A blink comparator was a viewing apparatus used by astronomers to find differences between two photographs of the night sky. It permitted rapidly switching from viewing one photograph to viewing the other, blinking back and this allowed the user to more easily spot objects in the night sky that changed position. It was also known as a blink microscope. It was invented by physicist Carl Pulfrich at Carl Zeiss AG, then constituted as Carl-Zeiss-Stiftung, photographs taken at longer intervals could be used to detect stars with large proper motion, or variable stars, or to distinguish binary stars from optical doubles. The most notable body to be using this technique was Pluto. The Projection Blink Comparator, invented by amateur astronomer Ben Mayer, was a low-cost version of the professional tool and it consisted of two slide projectors with a rotating occluding disk that alternatingly blocked the images from the projectors. This tool allowed amateur astronomers to contribute to some phases of serious research, in modern times, CCDs have largely replaced photographic plates and astronomical images are stored digitally on computer. The blinking technique can easily be performed on a screen rather than with a physical blink comparator apparatus as before. The blinking technique is used today because image differencing algorithms detect moving objects more effectively than human eyes can. This is particularly effective in cases where the object is very faint
Robert Burnham Jr.
Robert Burnham Jr. was an American astronomer, best known for writing the classic three-volume Burnhams Celestial Handbook. He is the discoverer of numerous asteroids including the asteroid/minor planet 3397 Leyla, Burnhams late years were tragic, he died destitute and alone. However, he is remembered by a generation of deep sky observers for his contribution to astronomy. The main-belt asteroid 3467 Bernheim was named in his honor, Burnham was born in Chicago, Illinois, in 1931, the son of Robert Sr. and Lydia. His family moved to Prescott, Arizona, in 1940, and that was the culmination of his formal education. Always a shy person, he had few friends, never married, in the fall of 1957 he received considerable local publicity when he discovered his first comet. This led to his being hired by Lowell Observatory in Flagstaff, Arizona, while Burnham was working at Lowell, he and his co-worker, Norman G. Thomas, discovered five more comets, and in excess of 1500 asteroids. In addition to his duties at the observatory, Burnham spent almost all of his free time working on the Celestial Handbook. His writing and his book were never supported by Lowell Observatory. Subtitled An Observers Guide to the Universe Beyond the Solar System, thousands of stars and deep sky objects visible in small telescopes are covered in meticulous detail. It is still in-print and is considered to be a classic in the literature of amateur astronomy, ortega then described the book series as. a sort of real-life hitchhikers guide to the galaxy, a compendium with something to say about nearly every cosmic destination worth visiting. Part travel guide, part history text, part encyclopedia, its like a natural history museum of the universe. And for decades its held a grip on the imaginations of most people who ply the night skies with telescopes, people who yearn to travel in space and know that they can, any dark and clear night. And all of it is meant as an incentive for the reader to recover those treasures by merely looking upward and it is rarely compared to other books because there simply is none other like it. No other popular work approaches its utility and completeness, few other scientific texts contain its sense of wonder, despite months of warning, he failed to make other arrangements and, after twenty-one years at Lowell, his job ended in December of that year. Unwilling to take the position that was offered to him. Burnham was never able to personally, professionally, or financially after he lost the job at Lowell. Over the next few years, while sales of the Celestial Handbook were rapidly growing and his shyness increased and he shunned all publicity, becoming even more reclusive
The Apollo asteroids are a group of near-Earth asteroids named after 1862 Apollo, discovered by German astronomer Karl Reinmuth in the 1930s. They are Earth crossing asteroids that have an orbital semi-major axis greater than that of the Earth, as of November 2016, the steadily growing number of known Apollo asteroids has reached a total of 8,180 members. It is by far the largest group of objects, compared to the Aten, Amor. Currently, there are 1,133 numbered Apollos, asteroids are not numbered until they have been observed at two or more oppositions. There are also 1,472 Apollo asteroids that are enough. The closer their semi-major axis is to Earths, the eccentricity is needed for the orbits to cross. The largest known Apollo asteroid is 1866 Sisyphus, with a diameter of about 8.5 km, examples of known Apollo asteroids include, Apollo asteroids Apollo asteroid records List of Apollo minor planets