Please answer the following question: Information:  - The Science Mission Directorate (SMD) of the National Aeronautics and Space Administration (NASA) engages the United States science community, sponsors scientific research, and develops and deploys satellites and probes in collaboration with NASAs partners around the world to answer fundamental questions requiring the view from and into space.  - Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed "Curiosity", a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigating Mars' habitability, studying its climate and geology, and collecting data for a manned mission to Mars. The rover carries a variety of scientific instruments designed by an international team.  - Arizona State University (commonly referred to as ASU or Arizona State) is a public metropolitan research university on five campuses across the Phoenix, Arizona, metropolitan area, and four regional learning centers throughout Arizona. The 2016 university ratings by "U.S. News & World Report" rank ASU No. 1 among the Most Innovative Schools in America for the second year in a row.  - Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets; while the phenomena include supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. More generally, all astronomical phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe as a whole.  - Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed us to understand those physical laws. Physical cosmology, as it is now understood, began with the development in 1915 of Albert Einstein's general theory of relativity, followed by major observational discoveries in the 1920s: first, Edwin Hubble discovered that the universe contains a huge number of external galaxies beyond our own Milky Way; then, work by Vesto Slipher and others showed that the universe is expanding. These advances made it possible to speculate about the origin of the universe, and allowed the establishment of the Big Bang Theory, by Georges Lemaitre, as the leading cosmological model. A few researchers still advocate a handful of alternative cosmologies; however, most cosmologists agree that the Big Bang theory explains the observations better.  - Louis Dill Friedman (born July 7, 1941) is an American astronautics engineer and space spokesperson. He was born in New York and raised in the Bronx. Dr. Friedman was a co-founder of The Planetary Society with Carl Sagan and Bruce C. Murray.  - Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, after Mercury. Named after the Roman god of war, it is often referred to as the "Red Planet" because the iron oxide prevalent on its surface gives it a reddish appearance. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the valleys, deserts, and polar ice caps of Earth.  - Lockheed Martin is an American global aerospace, defense, security and advanced technologies company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington, DC, area. Lockheed Martin employs 126,000 people worldwide. Marillyn Hewson is the current President and Chief Executive Officer.  - James ( Jim ) F. Bell III ( born 1965 ) is a Professor of Astronomy at Arizona State University , specializing in the study of planetary geology , geochemistry and mineralogy using data obtained from telescopes and from various spacecraft missions . Dr. Bell 's active research has involved the NASA Mars Pathfinder , Near Earth Asteroid Rendezvous ( NEAR ) , Comet Nucleus Tour ( CONTOUR ) , 2001 Mars Odyssey , Mars Reconnaissance Orbiter , Lunar Reconnaissance Orbiter , and the Mars Science Laboratory missions . His book Postcards from Mars includes many images taken by the Mars rovers . Dr. Bell is currently an editor of the space science journal Icarus and president of The Planetary Society . He has served as the lead scientist in charge of the Panoramic camera ( Pancam ) color imaging system on Mars rovers Spirit and Opportunity .  - A planet is an astronomical body orbiting a star or stellar remnant that The term "planet" is ancient, with ties to history, astrology, science, mythology, and religion. Several planets in the Solar System can be seen with the naked eye. These were regarded by many early cultures as divine, or as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, incorporating a number of disparate objects. In 2006, the International Astronomical Union (IAU) officially adopted a resolution defining planets within the Solar System. This definition is controversial because it excludes many objects of planetary mass based on where or what they orbit. Although eight of the planetary bodies discovered before 1950 remain "planets" under the modern definition, some celestial bodies, such as Ceres, Pallas, Juno and Vesta (each an object in the solar asteroid belt), and Pluto (the first trans-Neptunian object discovered), that were once considered planets by the scientific community, are no longer viewed as such.  - 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.  - Physics (from , from "phúsis" "nature") is the natural science that involves the study of matter and its motion and behavior through space and time, along with related concepts such as energy and force. One of the most fundamental scientific disciplines, the main goal of physics is to understand how the universe behaves.  - The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process.<ref name="doi10.1146/annurev-astro-081913-040012"></ref> It is by far the most important source of energy for life on Earth. Its diameter is about 109 times that of Earth, and its mass is about 330,000 times that of Earth, accounting for about 99.86% of the total mass of the Solar System. About three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.  - Mars Pathfinder (MESUR Pathfinder) is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight (10.6 kg/23 lb) wheeled robotic Mars rover named "Sojourner", which became the first rover to operate outside  the Earth-Moon system.  - Arizona (O'odham: "Al onak" [ai onak]) is a state in the southwestern region of the United States. It is also part of the Western United States and the Mountain West states. It is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is one of the Four Corners states. It has borders with New Mexico, Utah, Nevada, California, and Mexico, and one point in common with the southwestern corner of Colorado. Arizona's border with Mexico is 389 miles (626 km) long, on the northern border of the Mexican states of Sonora and Baja California.  - 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.  - A robot is a machineespecially one programmable by a computercapable of carrying out a complex series of actions automatically. Robots can be guided by an external control device or the control may be embedded within. Robots may be constructed to take on human form but most robots are machines designed to perform a task with no regard to how they look.  - 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.  - Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter. Chemistry includes topics such as the properties of individual atoms, how atoms form chemical bonds to create chemical compounds, the interactions of substances through intermolecular forces that give matter its general properties, and the interactions between substances through chemical reactions to form different substances.  - 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)."   - 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 Planetary Society is an American internationally active non-governmental, nonprofit foundation. It is involved in research, public outreach, and political advocacy for engineering projects related to astronomy, planetary science, and space exploration. It was founded in 1980 by Carl Sagan, Bruce Murray, and Louis Friedman, and has over 40,000 members from more than one hundred countries around the world.  - Carl Edward Sagan (November 9, 1934  December 20, 1996) was an American astronomer, cosmologist, astrophysicist, astrobiologist, author, science popularizer, and science communicator in astronomy and other natural sciences. He is best known for his work as a science popularizer and communicator. His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation. Sagan assembled the first physical messages sent into space: the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the now accepted hypothesis that the high surface temperatures of Venus can be attributed to and calculated using the greenhouse effect.  - In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet about a star or a natural satellite around a planet. Normally, orbit refers to a regularly repeating path around a body, although it may occasionally be used for a non recurring trajectory or a path around a point in space. To a close approximation, planets and satellites follow elliptical orbits, with the central mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion.  - Sir Arthur Charles Clarke, CBE, FRAS (16 December 1917  19 March 2008) was a British science fiction writer, science writer and futurist, inventor, undersea explorer, and television series host.  - A research university is a university that expects all its tenured and tenure-track faculty to continuously engage in research, as opposed to merely requiring it as a condition of an initial appointment or tenure. Such universities can be recognized by their strong focus on innovative research and the prestige of their brand names. On the one hand, research universities strive to recruit faculty who are the most brilliant minds in their disciplines in the world, and their students enjoy the opportunity to learn from such experts. On the other hand, new students are often disappointed to realize their undergraduate courses at research universities are overly academic and fail to provide vocational training with immediate "real world" applications; but many employers value degrees from research universities because they know that such coursework develops fundamental skills like critical thinking.   - Mars Reconnaissance Orbiter (MRO) is a multipurpose spacecraft designed to conduct reconnaissance and exploration of Mars from orbit. The spacecraft was built by Lockheed Martin under the supervision of the Jet Propulsion Laboratory (JPL). The mission is managed by the California Institute of Technology, at the JPL, in La Cañada Flintridge, California, for the NASA Science Mission Directorate, Washington, D.C. It was launched August 12, 2005, and attained Martian orbit on March 10, 2006. In November 2006, after five months of aerobraking, it entered its final science orbit and began its primary science phase. As MRO entered orbit, it joined five other active spacecraft that were either in orbit or on the planet's surface: "Mars Global Surveyor", "Mars Express", "2001 Mars Odyssey", and the two Mars Exploration Rovers ("Spirit" and "Opportunity"); at the time, this set a record for the most operational spacecraft in the immediate vicinity of Mars. "Mars Global Surveyor" and the "Spirit" rover have since ceased to function; the remainder remain operational as of September 2016.  - A robotic spacecraft is an uncrewed spacecraft, usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn, Uranus, and Neptune are too distant to reach with current crewed spaceflight technology, so telerobotic probes are the only way to explore them.  - Natural science is a branch of science concerned with the description, prediction, and understanding of natural phenomena, based on observational and empirical evidence. Mechanisms such as peer review and repeatability of findings are used to try to ensure the validity of scientific advances.  - In physics, a wave is an oscillation accompanied by a transfer of energy that travels through a medium (space or mass). Frequency refers to the addition of time. "Wave motion" transfers energy from one point to another, which displace particles of the transmission mediumthat is, with little or no associated mass transport. Waves consist, instead, of oscillations or vibrations (of a physical quantity), around almost fixed locations.  - 2001 Mars Odyssey is a robotic spacecraft orbiting the planet Mars. The project was developed by NASA, and contracted out to Lockheed Martin, with an expected cost for the entire mission of US$297 million. Its mission is to use spectrometers and a thermal imager to detect evidence of past or present water and ice, as well as study the planet's geology and radiation environment. It is hoped that the data Odyssey obtains will help answer the question of whether life has ever existed on Mars and create a risk-assessment of the radiation future astronauts on Mars might experience. It also acts as a relay for communications between the Mars Exploration Rovers, Mars Science Laboratory, and previously the Phoenix lander to Earth. The mission was named as a tribute to Arthur C. Clarke, evoking the name of "".    Given the information above, choose from the list below the object entity that exhibits the relation 'occupation' with the subject 'james f. bell'.  Choices: - academic  - accounting  - acting  - advocacy  - astronomer  - author  - chief executive officer  - communicator  - computer  - engineer  - executive officer  - explorer  - faculty  - founder  - model  - mountain  - peer  - physics  - pioneer  - president  - president and chief executive officer  - research  - science  - science communicator  - science fiction writer  - spokesperson  - television  - writer
Answer:
astronomer