ASTEROID
A rocky space object which can be from a few hundred feet to several
hundred km wide. Most asteroids in our solar system orbit the Sun in a belt
between Mars and Jupiter.
ASTRONOMER
An expert in the study of the Sun, Moon, stars, planets, and
other space bodies.
ASTRONOMICAL UNIT
The approximate distance from the Sun to the Earth which is
equal to 150,000,000 kilometers.
ASTROPHYSICS
The branch of astronomy that deals with the physics of stellar phenomena.
ATMOSPHERE
The layers of gases which surround a star, like our Sun, or a
planet, like our Earth.
AXIS
An imaginary straight line around which an object rotates.
BASALT
A dark, fine-grained volcanic rock.
BIG BANG THEORY
A theory which states that the Universe began to expand
after a super powerful explosion of concentrated matter and energy.
BLACK HOLE
The leftover core of a super massive star after a supernova.
Black holes exert a tremendous gravitational pull.
CENTIGRADE
See CELSIUS.
CHARGED PARTICLES
electrons, protons, ions.
COMA
A hazy cloud which surrounds the nucleus of a comet.
COMET
Frozen masses of gas and dust which have a definite orbit through
the solar system.
CORONA
The very hot outermost layer of a star's atmosphere. Our Sun's corona can
only be seen during a total solar eclipse.
COSMONAUT
An astronaut from the former Soviet Union or the current
republic of Russia.
COSMOLOGICAL
Having to do with the study of the history, structure, and changes in the
Universe.
DENSITY
The mass per unit of volume of a substance.
DOPPLER SHIFT
A shift in an object's spectrum due to a change in the
wavelength of light that occurs when an object is moving toward or away from
Earth.
ELECTROMAGNETIC WAVE
A wave of electric and magnetic energy that is generated
when an electric charge is accelerated.
ELLIPTICAL
Shaped like an elongated closed curve.
ENERGY
Usable heat or power; in physics, it is the capacity of a physical
system to perform work.
FUSION
A nuclear reaction in which an element with small atoms fuses to form
an element with larger atoms, releasing large amounts of energy.
GAMMA-RAYS
Penetrating short wave electromagnetic radiation of very high frequency.
GEOSYNCHRONOUS
An orbit in which a satellite's rate of revolution matches the
Earth's rate of rotation. This allows the satellite to stay over the same
site on the Earth's surface at all times.
GRAVITATIONAL FIELD
The volume over which an object exerts a gravitational pull.
GRAVITATIONAL FORCE
See Gravity
GRAVITATIONAL PULL
See Gravity
GRAVITY
The force of attraction between two objects which is influenced by
the mass of the two objects and the distance between the two objects.
GYROSCOPE
A heavy wheel or disk mounted so that its axis can turn freely in
one or more directions. A spinning gyroscope tends to resist change in the
direction of its axis.
HELIOCENTRIC
Having the Sun as a center, such as a heliocentric solar system.
INFRARED WAVES
Electromagnetic radiation with long wavelengths which is
found in the invisible part of the spectrum. Human beings experience
infrared waves as heat.
ION
An electrically charged particle. Ions may be negatively or positively
charged.
KILOGRAM
1000grams. A kilogram equals 2.2 pounds.
KILOMETER
1000 meters. A kilometer equals 0.6214 miles.
KILOPARSEC
1000 parsecs. A parsec equals 3.26 light years.
MANTLE
The middle layer of a planet located between the crust, or surface,
and the core.
MASS
The measure of the amount of matter in an object.
MATTER
Anything which has mass and occupies space.
METEOR
Meteoroids which burn up in the atmosphere of a space body, such as the
Earth, prior to impacting on the surface.
METEORITE
Fragments of material that fall from space and impact on other larger space
bodies.
METEOROID
Fragments of material which vaporize when they have a close encounter with
a space body which has an atmosphere.
METRIC TON
1000 kilograms. A metric ton equals 2,204 pounds.
MICROMETEOROID
Very small pieces of matter which are encountered in space.
MICROWAVE
Electromagnetic radiation which has a long wavelength (between
1 mm and 30 cm). Microwaves can be used to study the Universe, communicate
with satellites in orbit around Earth, and cook popcorn.
MYLAR
A tough polyester material used as an insulator.
NEBULA
A low density cloud of gas and dust in which a star is born.
ORBIT
A specific path followed by a planet, satellite, etc.
PAYLOAD BAY
The main body of the Space Shuttle where the payload, or cargo,
is stored.
PHOTOSYNTHESIS
The process by which plants use carbon dioxide, nutrients, and sunlight
to produce food.
PHYSICIST
A person who studies physics.
PHYSICS
The science of matter and energy, and of interactions between the two.
A person who studies physics is called a physicist.
PLAINS
Vast, flat areas with low elevation.
PROBES
Unmanned spacecraft which are launched into space in order to
collect data about the solar system and beyond. Space probes are not
necessarily designed to return to Earth.
QUASAR
A distant energy source which gives off vast amounts of radiation,
including radio waves and X-rays.
RETROGRADE
Having a direction which is opposite that of similar bodies.
REVOLUTION
The circling of a smaller object around a larger object.
ROTATION
The spinning of an object on its axis.
SILICON
A non-metallic chemical element.
SOLAR ECLIPSE
A shadow which falls on an area of Earth when the Moon moves
between the Sun and Earth.
SOLAR FLARES
A magnetic storm on the Sun's surface which shows up as a sudden
increase in brightness.
SOLAR PROMINENCES
Gases trapped at the edge of the Sun which appear to shoot
outward from the Sun's surface.
SOLAR SYSTEM
The Sun and all of the planets, comets, etc. which revolve
around it.
SOLAR WIND
A continuous stream of charged particles which are released from the Sun
and hurled outward into space at speeds up to 800 kilometers per second.
Solar winds are very prominent after solar flare activity.
SOLAR WINGS
A panel of solar cells which converts sunlight into electrical
energy.
SPECTROGRAPH
The image of the electromagnetic spectrum produced by a spectroscope.
SPECTROSCOPE
An instrument which separates visible light into its various
wavelengths. Each wavelength corresponds to a specific color in the spectrum.
SPECTRUM
A band of colors which forms when visible light passes through a
prism. The band ranges in color from violet (shorter wavelength) to red
(longer wavelength).
SUNSPOT
A magnetic storm on the the Sun's surface which appears as a dark area. A
sunspot is approximately 1500 degrees Celsius cooler than it's surrounding
material. The number of sunspots we see on the Sun at any given time appears
to cycle every 11 years.
TELESCOPE
Any of various devices, sometimes made with an arrangement of lenses,
mirrors, or both, used to detect and observe distant objects by their
emission, transmission, reflection, or other interaction with
invisible radiation.
THERMOMETER
An instrument for measuring temperature.
UNIVERSE
The vast expanse of space which contains all of the matter and
energy in existence.
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