This material was developed for the Live From Mars project by Passport to Knowledge. Live From Mars was a precursor to Mars Team Online.
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action-reaction The law that when one body exerts a force on another, the second body exerts an force equal in magnitude, but in the opposite direction.
aerobraking The method of using the force of friction between a spacecraft and the atmosphere to slow and lower its orbit.
altimeter An instrument for measuring altitude (height) with respect to a fixed level, such as sea level.
anemometer A device for measuring the speed of wind.
angle The space between two straight lines meeting in a point or two surfaces meeting along a line, measured in degrees.
atmosphere A layer of gas surrounding a planet or celestial body.
autonomous Independent; ruling or managing itself.
avalanche A large mass of snow, ice, rocks, mud, etc. sliding swiftly down a mountain.
axis An imaginary line that passes through the poles of a body, such as the Earth, about which it rotates.
balanced The state of equality; to make two things or parts equal in weight or value.
barometer An instrument that measures the pressure of the atmosphere used for forecasting changes in the weather and finding the height above sea level.
center of mass That point of a material body or system of bodies which moves as though the systemÕs total mass existed at the point and all external forces were applied at the point. Also known as the center of inertia. Also, center of balance.
climate The average weather conditions of a place over a period of years.
climatology The branch of meteorology concerned with the atmosphere together with the variations in both space and time reflected in weather behavior over a period of many years.
cone Anything shaped like a solid object having a flat, round base that narrows to a point at the top. "The cone of a volcano."
constellation A grouping of stars in the sky, which has usually been given a mythological name (like Leo or Orion). Stars in a constellation are not usually at the same distance from Earth but spread throughout space.
crater A hollow bowl-shape such as that created by a volcano or impact from a meteorite hitting a planet's surface.
data Facts or experimental evidence or measurements which can be studied in order to make conclusions or judgments.
datum surface A permanently established horizontal plane or level to which soundings, ground elevations, water surface elevations, and tidal data are referred; reference level or reference plane.
delta A triangle-shaped piece of land formed when sand and soil are deposited at the mouth of a river.
density The mass of a given substance per unit of volume.
deploy To spread out or extend.
depression A hollow of any size on a plain surface having no natural outlet for surface drainage.
descent The act of descending or moving down to a lower place.
diameter A straight line passing through the center of a circle or sphere, from one side to the other.
ejecta Material which is discharged by a volcano or collision.
electromagnetic spectrum The total range of wavelengths or frequencies of
electromagnetic radiation, extending from the longest radio waves to the shortest known cosmic rays.
elevation Vertical distance to a point or object from sea level or some other datum.
ellipse A closed, elongated shape which describes the orbits of planets.
emission Any radiation of energy by means of electromagnetic waves, as from a radio transmitter.
erosion The loosening and transportation of rock debris. The wearing away of the land, chiefly by rain and running water.
extinct No longer active or living; having died out.
flow patterns Erosion on the surface of an object due to the flow of water or other liquids.
force The influence on a body which causes it to accelerate.
friction The rubbing of a surface against something which slows it down, creating heat
geologist A person who specializes in the study of the earth.
geology The study of the science of the earth, its history, and its life as recorded in the rocks.
gravity The force of attraction that is felt between two or more bodies, such as the pull between the Earth and the Moon.
hydrosphere The water portion of the earth as distinguished from the solid part (lithosphere) and from the gaseous outer envelope (atmosphere).
hypothesis An unproved idea that may explain certain facts or can be used as the basis for reasoning, study, and the design of experiments.
image Any reproduction of an object produced by means of focusing light, sound, electron radiation or other emanations coming from the object or reflected by another object.
imaging The formation of images of objects.
impact The action of one object hitting another with force.
infrared (IR) Heat radiation. Its wavelength is between light and radio waves, in the range from about 0.75 micrometers to 1000 micrometers.
kilometer A unit of measure equal to 1,000 meters or about 5/8 mile.
landerSpacecraft deployed to the surface of a planet equipped with scientific instrumentation for data collection.
landform All the physical, recognizable, naturally formed features of land, having a characteristic shape.
laser A device that sends out light waves in a very narrow and strong beam of a specific, coordinated wavelength. (Light Amplification through Stimulated Emission of Radiation.)
latitude The angular distance north or south of the Equator of a spherical body (such as the Earth). Latitude is measured in degrees, minutes and seconds of arc.
longitude The angular distance east or west of an imaginary line (the meridian) on a spherical body, such as the Earth. Longitude is measured in degrees, minutes and seconds of arc.
meandering Winding back and forth; the snakelike appearance of streams or rivers.
microns A unit of wavelength equal to one millionth of a meter.
observation The act or power of seeing or noticing and writing down some fact.
opposition The situation of two celestial bodies having celestial longitudes or sidereal hour angles differing by 180 degrees.
orbit The path followed by a planet, a satellite, or a star around a more massive body in its gravity induced motion.
outflow channels Large channels on Mars created by releases of vast amounts of water. Surface feature on Mars, evidence that liquid water once existed there in great quantity.
pahoehoe A Hawaiian name for a volcanic lava flow whose surface is glassy, smooth, and undulating; the lava is basaltic and also known as ropy lava.
payload That which an aircraft, rocket, or the like carries over and above what is necessary for the operation of the vehicle.
petri dish A shallow glass or plastic dish with a loosely fitting overlapping cover used for bacterial plate cultures and plant and animal tissue cultures.
plate tectonics Geologic theory based on a model of the earth characterized by a small number of semi-rigid plates which float on some viscous underlayer in the mantle. Movement and collision of plates results in volcanism and seismic activity.
precipitation Any or all forms of water particles, whether liquid or solid, that fall from the atmosphere and reach the ground.
pressure A force which is exerted uniformly in all directions; its measure is the force exerted per unit area.
probe A spacecraft with instruments in it for exploring the upper atmosphere of a planet.
pulse A brief burst of energy.
radar A system using beamed and reflected radio-frequency energy for detecting and locating objects, measuring distance or altitude, navigating, homing and other purposes.
radiation The energy or rays sent out from atoms and molecules because of changes inside them. Light, heat, radio waves and X-rays are kinds of radiation.
ratio The relation of one thing to another in size, amount, proportion.
retro-rocket Small rocket on a spacecraft that produces thrust in a direction opposite to the direction in which the spacecraft is moving, in order to reduce speed, especially for landing.
retrograde motion The apparent backward motion of a planet in the sky, which occurs because the Earth overtakes the planet.
robotics The science or technology of producing and using robots (a completely self-controlled electronic, electric, or mechanical device).
rover A mobile robotic device remotely controlled equipped with instrumentation for data collection.
Scientific Method The systematic collection and classification of data and usually the formulation and testing of hypotheses based on the data. A way to gather facts and explain them.
simulate To mimic some or all of the behavior of a system.
simulation Something that is designed to look or act like or seem to be something else.
slope The inclined surface of any part of the earth or a planetÕs surface.
sonar Device that sends sound waves through water and picks them up after they strike some object and bounce back. Used to determine the depths of oceans, location of submarines, etc.
spectrometer A spectroscope that is provided with a calibrated scale for measuring wavelength. (A spectroscope is an optical instrument which produces a spectrum for visual observation.)
spectrum (pluralÊspectra) The spreading out of radiation given off by an object according to color or wavelength. For example, the rainbow of colors that make up so-called white light, where each color corresponds to a different wavelength of radiation in the spectrum.
stream table A device used to simulate (replicate) the flow of water in a stream or river.
thermal Having to do with heat.
thermometer A device for measuring temperature. Usually measured in degrees Celsius or Fahrenheit.
topographic map A map showing relief and elevation.
trajectory The curve described by an object moving through space, as of a planet around the sun, a projectile fired from a gun, or a rocket in flight.
velocity The speed and direction of a moving object.
volcano A fissure or vent in the crust through which molten rock rises to the surface to form a mountain.
weather The conditions outside at any particular time and place with regard to temperature, sunshine, rainfall, etc.