Photograph courtesy NASA/JHUAPL
to connect.
irregularly shaped planetary body, ranging from 6 meters (20 feet) to 933 kilometers (580 miles) in diameter, orbiting the sun between Mars and Jupiter.
area of the solar system between the orbits of Mars and Jupiter filled with asteroids.
person who takes part in space flights.
to stay away from something.
unusually large, bright meteor.
very bad.
natural object in space, such as a planet or star. Also called an astronomical object.
crash.
celestial object made up of ice, gas, and dust that orbits the sun and leaves a tail of debris.
harm that reduces usefulness or value.
remains of something broken or destroyed; waste, or garbage.
having parts or molecules that are packed closely together.
very large, extinct reptile chiefly from the Mesozoic Era, 251 million to 65 million years ago.
to fall apart and disappear.
microscopic particles of rocks or minerals drifting in space. Also called cosmic dust or space dust.
to put at risk.
person who plans the building of things, such as structures (construction engineer) or substances (chemical engineer).
to prepare or provide the right equipment.
delicate or easily broken.
state of matter with no fixed shape that will fill any container uniformly. Gas molecules are in constant, random motion.
one of the four enormous outermost planets in the solar system (Jupiter, Saturn, Neptune, Uranus), composed mostly of gases instead of rock. Also called a Jovian planet.
environment where an organism lives throughout the year or for shorter periods of time.
collision or crash.
one of the four rocky planets closes to the sun: Mercury, Venus, Earth, or Mars. Also called a terrestrial planet.
tool.
chemical element with the symbol Fe.
region in the outer solar system containing thousands of tiny, icy bodies and thought to be the source of short-period comets (comets that take less than 200 years to to orbit the sun).
having to do with Earth's moon or the moons of other planets.
a skillful movement.
very large or heavy.
process or assembly that performs a function.
category of elements that are usually solid and shiny at room temperature.
rocky debris from space that enters Earth's atmosphere. Also called a shooting star or falling star.
large amount of rocky debris falling into Earth's atmosphere, usually when Earth passes through the orbit of a comet.
instrument used to view very small objects by making them appear larger.
inorganic material that has a characteristic chemical composition and specific crystal structure.
to observe and record behavior or data.
Earth's only natural satellite.
(National Aeronautics and Space Administration) the U.S. space agency, whose mission statement is "To reach for new heights and reveal the unknown so that what we do and learn will benefit all humankind."
event in the physical environment that is destructive to human activity.
head of a comet, mostly composed of frozen gases and solid particles of ice.
region on the edge of the solar system filled with millions of tiny comets, some of which are drawn into the inner solar system by passing stars.
path of one object around a more massive object.
any one of the four gas giants that orbit the sun beyond the asteroid belt: Jupiter, Saturn, Neptune, or Uranus.
small piece of material.
possible.
to adjust and maintain the atmospheric pressure in a contained area.
continuous action, operation, or series of changes taking place in a defined manner.
to take action to prevent injury or attack.
any area on Earth with one or more common characteristics. Regions are the basic units of geography.
the act of opposing something.
natural substance composed of solid mineral matter.
to release or cast off.
protective material or device.
moving, measurable change in pressure and density of a material.
most common group of minerals, all of which include the elements silicon (Si) and oxygen (O).
the sun and the planets, asteroids, comets, and other bodies that orbit around it.
vehicle designed for travel outside Earth's atmosphere.
occasional and happening in isolated instances.
star at the center of our solar system.
stream of gas or dust debris behind a comet.
having to do with heat or temperature.
movement from one place to another.
worth a considerable amount of money or esteem.
device used for transportation.
capable of being hurt.
to stand up to or endure.
