amateur: One who engages in a pursuit as a pastime, not as a profession.
astronomer: A scientist who works in the field of research that deals with celestial objects, space and the physical universe.
average: (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.
brown dwarf: A would-be star that never became massive enough to sustain nuclear fusion.
citizen science: Scientific research in which the public — people of all ages and abilities — participate. The data that these citizen “scientists” collect helps to advance research. Letting the public participate means that scientists can get data from many more people and places than would be available if they were working alone.
data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.
debris: Scattered fragments, typically of trash or of something that has been destroyed. Space debris, for instance, includes the wreckage of defunct satellites and spacecraft.
dwarf planet: One of the solar system’s small celestial objects. Like a true planet, it orbits the sun. However, dwarf planets are too small to qualify as true planets. Prime examples of these objects: Pluto and Ceres.
engineer: A person who uses science to solve problems. As a verb, to engineer means to design a device, material or process that will solve some problem or unmet need. (v.) To perform these tasks, or the name for a person who performs such tasks.
glacier: A slow-moving river of ice hundreds or thousands of meters deep. Glaciers are found in mountain valleys and also form parts of ice sheets.
Grand Canyon: A natural canyon in northwest Arizona that formed as the Colorado River cut through the rock here over the past 5 million to 6 million years. This is one of many canyons on the river, which drains water from seven states. The Grand Canyon is 446 kilometers (277 miles) long. Its depth varies. At its deepest point, the river is 1,829 vertical meters (6,000 feet) below the upper rim. From rim to rim, the canyon’s width also varies — from about 16 kilometers (10 miles) to 29 kilometers. Of this impressive national land formation, more than a million acres (4,931 square kilometers, to be exact) was turned into a U.S. national park in 1919.
gravity: The force that attracts anything with mass, or bulk, toward any other thing with mass. The more mass that something has, the greater its gravity.
hover: To above the ground, maintaining an intentional position.
infrared: A type of electromagnetic radiation invisible to the human eye. The name incorporates a Latin term and means “below red.” Infrared light has wavelengths longer than those visible to humans. Other invisible wavelengths include X-rays, radio waves and microwaves. Infrared light tends to record the heat signature of an object or environment.
Jupiter: (in astronomy) The solar system’s largest planet, it has the shortest day length (9 hours, 55 minutes). A gas giant, its low density indicates that this planet is composed mostly of the light elements hydrogen and helium. This planet also releases more heat than it receives from the sun as gravity compresses its mass (and slowly shrinks the planet).
Kuiper belt: An area of the solar system beyond the orbit of Neptune. It is a vast area containing leftovers from the formation of the solar system that continue to orbit the sun. Many objects in the Kuiper belt are made of ice, rock, frozen methane and ammonia. The best known of the larger Kuiper Belt objects is the dwarf planet Pluto. The belt extends out from the sun at a distance of 30 to 55 astronomical units. (An astronomical unit is equal to Earth’s from the sun.)
Mars: The fourth planet from the sun, just one planet out from Earth. Like Earth, it has seasons and moisture. But its diameter is only about half as big as Earth’s.
methane: A hydrocarbon with the chemical formula CH4 (meaning there are four hydrogen atoms bound to one carbon atom). It’s a natural constituent of what’s known as natural gas. It’s also emitted by decomposing plant material in wetlands and is belched out by cows and other ruminant livestock. From a climate perspective, methane is 20 times more potent than carbon dioxide is in trapping heat in Earth’s atmosphere, making it a very important greenhouse gas.
moon: The natural satellite of any planet.
orb: Something having a spherical shape.
orbit: The curved path of a celestial object or spacecraft around a galaxy, star, planet or moon. One complete circuit around a celestial body.
plane: (in mathematics) A flat 2-dimensional surface, meaning it has length and width but no depth. A plane also extends infinitely in all directions.
planet: A large celestial object that orbits a star but unlike a star does not generate any visible light.
Pluto: A distant world that is located in the Kuiper Belt, just beyond Neptune. Pluto is the ninth largest object orbiting the sun.
robot: A machine that can sense its environment, process information and respond with specific actions. Some robots can act without any human input, while others are guided by a human.
solar: Having to do with the sun or the radiation it emits. It comes from sol, Latin for sun.
solar system: The eight major planets and their moons in orbit around our sun, together with smaller bodies in the form of dwarf planets, asteroids, meteoroids and comets.
star: The basic building block from which galaxies are made. Stars develop when gravity compacts clouds of gas. When they become hot enough, stars will emit light and sometimes other forms of electromagnetic radiation. The sun is our closest star.
sun: The star at the center of Earth’s solar system. It is about 27,000 light-years from the center of the Milky Way galaxy. Also a term for any sunlike star.
survey: To view, examine, measure or evaluate something, often land or broad aspects of a landscape.
system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.
topography: (adj. topographic) The mapped shape and size of features of some landscape, typically the surface of Earth or a moon — but even, potentially, the nanoscale highs and lows of structures atop some computer chip.
