Context: The Palomar Planet-Crossing Asteroid Survey (PCAS) was an astronomical survey, initiated by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S Palomar Observatory, California, in 1973. The program is responsible for the discovery of 95 near-Earth Objects including 17 comets, while the Minor Planet Center directly credits PCAS with the discovery of 20 numbered minor planets during 19931994. PCAS ran for nearly 25 years until June 1995. It had an international extension, INAS, and was the immediate predecessor of the outstandingly successful NEAT program. , A comet is an icy small Solar System body that, when passing close to the Sun, warms and begins to evolve gasses, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred metres to tens of kilometres across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times the Earth's diameter, while the tail may stretch one astronomical unit. If sufficiently bright, a comet may be seen from the Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures., An astronomical survey is a general map or image of a region of the sky which lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of many images or spectra of objects which share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth. Surveys have generally been performed as part of the
production of an astronomical catalog., La Cañada Flintridge is a city in Los Angeles County, California, with a population of 20,246 in 2010. It is located in the Crescenta Valley and far western end of the San Gabriel Valley, to the northwest of Pasadena. It is the home of the Jet Propulsion Laboratory of NASA., The National Aeronautics and Space Administration (NASA ) is an independent agency of the executive branch of the United States federal government responsible for the civilian space program as well as aeronautics and aerospace research., Palomar Observatory is an astronomical observatory located in San Diego County, California, United States, southeast of Los Angeles, California, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech) located in Pasadena, California. Research time is granted to Caltech and its research partners, which include the Jet Propulsion Laboratory (JPL) and Cornell University., A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By definition, a solar system body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical unit (AU). NEOs include more than fourteen thousand near-Earth asteroids (NEAs), more than one hundred near-Earth comets (NECs), and a number of solar-orbiting spacecraft and meteoroids, large enough to be tracked in space before striking the Earth. It is now widely accepted that collisions in the past have had a significant role in shaping the geological and biological history of the Earth. NEOs have become of increased interest since the 1980s because of increased awareness of the potential danger some of the asteroids or comets pose, and mitigations are being researched. In January 2016, NASA announced the Planetary Defense Coordination Office to track NEOs larger than 30 to 50 meters in diameter and coordinate an effective threat response and mitigation effort., The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in La Cañada Flintridge, California and Pasadena, California, United States., 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, and other trans-Neptunian 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 )., Near - Earth Asteroid Tracking ( NEAT ) was a program run by NASA and the Jet Propulsion Laboratory to discover near - Earth objects . The NEAT project began in December 1995 and ran until April 2007 . NEAT was the successor of the Palomar Planet - Crossing Asteroid Survey ( PCAS ) ., Aerospace is the human effort in science, engineering and business to fly in the atmosphere of Earth (aeronautics) and surrounding space (astronautics). Aerospace organisations research, design, manufacture, operate, or maintain aircraft and/or spacecraft. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications., The Minor Planet Center (MPC) is the official worldwide organization in charge of collecting observational data for minor planets (such as asteroids) and comets, calculating their orbits and publishing this information via the "Minor Planet Circulars". Under the auspices of the International Astronomical Union, it operates at the Smithsonian Astrophysical Observatory, which is part of the Center for Astrophysics along with the Harvard College Observatory., Aeronautics (from the ancient Greek words  "r", which means "air", and  "nautik" which means "navigation", i.e. "navigation into the air") is the science or art involved with the study, design, and manufacturing of air flight capable machines, and the techniques of operating aircraft and rockets within the atmosphere. The British Royal Aeronautical Society identifies the aspects of "aeronautical Art, Science and Engineering" and "the profession of Aeronautics (which expression includes Astronautics)." , Pasadena is a city in Los Angeles County, California, United States. As of 2013, the estimated population of Pasadena was 139,731, making it the 183rd-largest city in the United States. Pasadena is the ninth-largest city in Los Angeles County. Pasadena was incorporated on June 19, 1886, becoming only the second city to be incorporated in what is now Los Angeles County, after Los Angeles (April 4, 1850). It is one of the primary cultural centers of the San Gabriel Valley., Subject: near-earth asteroid tracking, Relation: instance_of, Options: (A) acting (B) administration (C) agency (D) aircraft (E) april (F) art (G) asteroid (H) astronomical catalog (I) astronomical object (J) astronomical observatory (K) astronomical survey (L) atmosphere (M) catalog (N) charge (O) city (P) college (Q) comet (R) data (S) dwarf (T) engineering (U) feature (V) federally funded research and development center (W) government (X) history (Y) home (Z) human ([) hundred (\) information (]) institute of technology (^) instrumental (_) june (`) laboratory (a) manufacturing (b) map (c) military (d) minor planet (e) mountain (f) mountain range (g) navigation (h) nucleus (i) number (j) object (k) observatory (l) orbit (m) organization (n) planet (o) role (p) science (q) sky (r) small solar system body (s) society (t) space (u) spacecraft (v) study (w) time (x) track (y) valley (z) wind
Output: organization