zero - The temperature limit at which no further cooling of
a substance can occur, and at which the motion of the molecules
is at a minimum (or, more accurately, at the minimum allowed
by Quantum Mechanics). The energy associated with this minimum motion
is called "zero point energy" by physicists.
lines - Dark lines in a spectrum, produced when light or other
electromagnetic radiation coming from a distant source passes through
a gas or similar object closer to the observer.
spectrum - A graph or display relating how a substance absorbs
electromagnetic radiation as a function of wavelength.
- A machine for speeding subatomic particles to a high velocity,
then colliding them with a stationary target or with another beam
of particles moving in the opposite direction, producing exotic
- The process in which small rocks, dust particles or gases accumulate
under the influence of gravity.
- Something shaped in a way in which air can easily move around
it. Noun: A branch of dynamics that deals with the motion of air
or other gases in motion.
metals - A group of soft, very reactive elements including lithium,
sodium and potassium.
- Non-acidic; basic, having a pH greater than 7.
earth metals - A group of metallic elements including calcium,
strontium and barium.
- A solid solution of two or more metals.
- An acronym for atomic mass unit.
Andromeda galaxy - A major spiral galaxy, 2.2 million light-years
from the Earth, which is gravitationally bound to the Milky Way
- The boundary where the pressure of the solar wind equals the pressure
of a planet's upper atmosphere; also known as ionopause.
- A unit of distance measure that equals 10-10 meters.
- A negatively charged chemical substance.
- A departure from the expected; an abnormality.
- Material composed of antiparticles, which are just like ordinary
protons, electrons, and neutrons except they have opposite electrical
charges and magnetic moments. When antimatter and matter collide,
both are annihilated with the production of other elementary particles,
such as photons.
- Particles that have the same mass as ordinary quarks but have
- The farthest point from the sun in an orbit.
- A group of individual pieces arranged in a repeating order to
form a complete unit.
- A small solar system body ranging in size from a few hundred kilometers
to less than one kilometer in size.
belt - The region between the orbits of Mars and Jupiter where
most of the Solar System asteroids are found.
- Scientists that study the natural world beyond the Earth.
unit (AU) - The average distance between the Earth and the sun,
1.5 x 10ØØ meters.
- The science that studies the natural world beyond the Earth.
- The smallest unit of an element.
mass unit - A unit of mass equal to 1/12 the mass of an atom
of the carbon isotope with mass number 12; approximately 1.66 x
number - The number of protons in an atoms nucleus, used
to identify the element.
radius - A measure of the size of an atom, assuming the atom
has the shape of a sphere.
spectroscopy - The study of the absorption and emission of light
- (see mean)
atomic mass - A value for an element's atomic mass based on
the relative abundances of different isotopic masses.
- The development
and production of electrical or electronic devices for use in aviation,
missiles, or astronautics.
- A theoretical elementary particle with a mass less than one millionth
or an electron that has never been detected. If axions exist, dark
matter could consist of large collections of axions.
- The straight line, through the poles about which a body rotates.
- The angular position along the horizon, measured clockwise from
radiation - (see cosmic background radiation)
matter - (see MACHOs and baryons)
- Elementary particles with a large mass that are influenced by
the strong nuclear force and are held together by a combination
of three quarks. Protons and neutrons are baryons. Baryons have
Bang - A theory of cosmology that the universe originated billions
of years ago as a violent eruption of a single point.
binary compounds - Chemical compounds made of only two elements.
- Material emitted in streams from opposites sides of an object.
hole - The highly compressed remains of a star which has mass
but takes up no space.
- A body that absorbs and reemits all radiation falling on it.
spectrum - The spectrum of energy level against wavelength for
electromagnetic radiation emitted by an object capable of absorbing
all the energy that strikes it.
model - A view of the atom as consisting of a central nucleus
with electrons orbiting around the nucleus.
- Force-carrying particles including photons, the quanta of electromagnetic
force and gluons, quanta that carry the strong nuclear force.
shock - (see shock wave)
- (see luminous matter)
dwarf stars - Low-mass stellar objects too small and too cool
for hydrogen fusion to occur.
- (see voids)
or combustor - Part of a propulsion system where high-pressure
air is mixed with a highly flammable fuel and ignited.
- The source of matter being created in order to maintain a steady
state universe. See also steady state.
- The unit of heat defined as the amount of heat required to cause
a one degree temperature centigrade increase in one gram of water.
- A positively charged chemical substance.
The (imaginary) single point at which the mass of an object may
be considered to be concentrated; used for calculations.
Cepheid variables - A group of variable stars with exceptionally
regular periods of pulsation.
- The Center for European Nuclear Research, Geneva, Switzerland.
devices (CCDs) - Technological instruments that contain light-sensitive
silicon chips with an arrangement of light-sensitive spots called
- Groups of elements sharing similar physical and chemical characteristics.
- An incandescent, transparent
layer of gas lying above and surrounding the photosphere of a star,
but clearly separated from the corona; the outermost layer of the
universe - A universe that will continue to expand slowly enough
that the gravitational attraction between the different galaxies
will cause the expansion to slow down until the universe collapses;
one in which the ratio of actual density to the critical density
is less than 1.
- (see star clusters or galactic clusters)
- A property of quarks that expresses their behavior in the presence
of the strong nuclear force; analogous to electrical charge, but
there are three color charges-red, green, and blue.
- The compressor is part of a propulsion system used to squeeze
the air, or to increase the pressure of the air flow.
temperature - The temperature at
which a gaseous substance becomes a liquid.
conduction - The transfer of heat (or electricity) through
a substance, resulting from a difference in temperature (or electrical
potential) between parts.
- An event
that may possibly occur, but its occurrence is uncertain.
spectrum - An electromagnetic spectrum containing all wavelengths
of the visible region.
convection - Heat transfer in a gas or liquid by the circulation
of currents from one region to another.
zone or layer - A
layer of the sun's structure that exists external to the radiative
zone and below the photosphere. Convection currents circulate the
sun's energy within the convection zone.
corona - A
faintly colored luminous ring that appears to surround celestial
coronal streamer - Large
scale magnetic structure observed in the sun's corona.
background radiation -
Microwave radio emission coming from all directions and corresponding
to a blackbody curve.
microwave background radiation -
(see cosmic background radiation)
cosmic rays - A
stream of ionizing radiation of extraterrestrial origin.
Large structures such as stars, planets, galaxies, and clusters
of galaxies formed late in the present epoch.
- Scientists concerned with the origin of the universe.
- The study
of the origin of the universe.
constant - A term used to express a force of "cosmic repulsion,"
the force that counteracts gravity.
- Scientists who study the structure and changes in the present
universe in order to predict the future of the universe.
cosmology - An
astrophysical study of the structure and dynamics of the universe.
- A depression
on the surface of a planet (or a moon) usually caused by the impact
of a meteoroid.
density - The
cosmic density of matter required to "close" the universe and eventually
halt cosmic expansion.
Careful storage of samples in unadulterated form for later scientific
- An atomic mass unit. A unit of mass that equals 1/12 the mass
of the most abundant isotope of carbon (12C),
which is assigned a mass of 12.
dark line - The absence of a given wavelength or set of wavelengths
in a continuum spectrum.
matter - Material that is believed to make up more than 90%
of the mass of the universe, but is not readily visible because
it neither emits nor reflects electromagnetic radiation, such as
light or radio signals. Its composition is unknown.
parameter - The quantity that defines the rate at which the
expansion of the universe is slowing down; the braking effect of
the galactical gravitational force; a function of cosmic matter
density - The ratio of an object's mass to its volume.
derived data - Values calculated from collected data.
deuterium - The isotope of hydrogen whose nucleus is one
neutron and one proton.
- The nucleus of a deuterium atom, consisting of a proton and a
neutron. It is regarded as a subatomic particle with a unit positive
- Differences or unlikeness.
Doppler effect - An apparent change in the frequency of waves
(such as sound or light) that occurs when the source and observer
are in motion relative to each other. The frequency increases when
the source and observer approach each other, while the frequency
decreases when they move apart.
shifts - Usually regards spectral lines. (see Doppler
quarks - One of six flavors of quarks that has a charge of -1/3
in units of elementary electric charge.
galaxies - Galaxies having only 1 million to 10 million stars.
They have low mass and low escape velocities.
dwarf stars - Stars with masses less than 5 times the mass
of the sun. (The sun is a dwarf star.)
- Pertaining to change or process over time resulting from physical
forces of energy.
- The ratio of the distance of a focus from the center of an ellipse
to its semi-major axis. The flatness of an ellipse.
binary star - A pair of stars in which the dimmer one regularly
passes in front of and then behind the brighter one, decreasing
and increasing the visible light from the pair in a sequential pattern.
- The apparent annual path of the sun on the celestial sphere.
plane - The
plane of the Earths orbit around the sun.
- Material expelled from the impact site during a crater formation.
- Carries energy through a medium, including empty space, where
it travels at the speed of light in the form of a wave of tiny packets
of energy (see photons).
spectrum - The entire range of electromagnetic radiation.
- A subatomic (elementary) particle carrying a unit negative charge.
- A measure of the tendency to attract electrons in order to form
a chemical bond.
- Matter composed of atoms with identical numbers of protons in
- A closed curve drawn so that the sum of the distances from a point
on the curve to two fixed points is always constant. A symmetrical
galaxies - One of the three major classifications of galaxies.
They are spherical or cigar-shaped and contain no disks or spiral
lines - Bright spectral lines produced in a spectrum by a luminous
emission nebula - A cloud of interstellar gas lit by nearby
spectrum - The spectrum of bright lines, bands, or continuous
radiation that is provided by a specific emitting substance as it
loses energy and returns to its ground state.
development unit (EDU) - A model that serves as a mechanical
prototype for proof of concept; matches form, fit, and function
of the final product.
- A measure of the amount of disorder in a system.
diameter - The diameter of a planet measured at its equator,
which is greater than the pole to pole diameter if the planets is
velocity - The speed needed by an object to escape from the
gravitational field of a body.
geometry - Geometry is the mathematics of lines drawn through
space. In Euclidean geometry, space is postulated to be "flat,"
similar to a three-dimensional analog of a plane.
nozzle - Part of the propulsion system where exhaust gases are
elements - Elements not existing in nature; manmade elements.
- Inferring or estimating a value by projecting or extending known
- Anything that originates, is located, or occurs outside Earth
or its atmosphere.
- structure whose primary function is to produce a smooth outline
and to reduce drag. For Genesis the fairing contains the spacecraft.
- A prominence that appears dark against the bright solar disk.
- Having definable limits; circumscribed or restricted, measurable.
first ionization potential (fip) - A measure of the energy required
to remove the outermost electron from an atom.
Law of Thermodynamics - Heat is a form of energy. When this
is taken into account, energy for a closed system (one that
doesn't ineract in any way with anything else) is always conserved.
- The splitting of a large nucleus into smaller pieces.
universe - A universe that will continue to expand very slowly,
just fast enough to avoid recollapse; one in which the ratio of
actual density to the critical density is 1.
- Designation of one of six quark types-up, down, strange, charm,
top and bottom-that determines how they are influenced by the weak
- The total number of particles delivered to an area; time-integrated
flux; similar to a dosage.
- Two points on an ellipse in which the sum of the distances to
the foci from any point on the ellipse is a constant.
- Singular for foci.
frequency - The number of wave crests that pass a stationary
observer in one second.
forces - Agents that cause a change in a system. There are four
known fundamental forces-strong nuclear force, weak nuclear force,
gravity, and electromagnetic.
particles - Particles that cannot be divided into smaller particles.
- (see nuclear fusion)
fusion reaction - (see nuclear fusion)
clusters - Cosmic structures in which many galaxies are found
in close proximity to each other.
disk - The plate-shaped component of a spiral galaxy that constitutes
the plane of the galaxy.
dynamics - The orbital motion or rotation of stars and galaxies
under the influence of gravitational force.
halo - A spherical aggregation of stars, globular star clusters
and thin gas clouds centered on the nucleus of a galaxy and extending
beyond the known extremities of the galactic disk.
- A large aggregation of stars, bound together by gravity. There
are three major classifications of galaxies-spiral, elliptical,
rays - Highly energetic electromagnetic radiation emitted by
- A movable structure with platforms at different levels used for
erecting and servicing rockets before launching.
planets - (see Jovian planets)
- Unit of intensity of a magnetic field equal to a field of one
line of force per cm2.
relativity - (see relativity)
Earth Orbit (GEO) - An orbit whose period is the same as the
rotational rate of the Earth, so that the position of a satellite
seems to stay in the same spot over the Earth.
planets - (see Jovian planets)
giant stars - Stars with masses from 5 to 100 solar masses.
globular cluster - A roughly spherical group of stars, smaller
than a galaxy. A cluster of 105 stars, mostly very old,
red, low mass stars.
Epoxy Strap-On Motors (GEM) - solid rocket motors used on the
Delta rocket's first stage.
constant - A constant, G, in the mathematical formula of Newton's
definition of gravitational force, F=GmØm2/rœ. When the
mass of objects is expressed in kilograms and r is in meters, then
G = 6.6 x 10-ØØ N mœ/kgœ and the force unit, F, is Newtons.
energy - The capacity to do work by objects moving under the
influence of the attraction between their masses.
lensing - A technique that takes advantage of the fact that
matter distorts the space surrounding it, warping the light from
background stars and galaxies, used to detect the presence of dark
bound - Pertaining to galaxies being held together by gravity
and not drawn apart by the expansion of the universe.
- The quanta thought to convey gravitational force, analogous
to photons, gluons, and bosons.
- In Newtonian physics, the universal, mutual attraction of
all massive objects for one another. Its force is directly proportional
to the mass of each object, and decreases by the square of the distance
separating the objects. In Einstein's general relativity, gravity
is viewed as a consequence of the curvature of space induced by
the presence of a massive object.
greenhouse effect - The warming effect caused by the Earth's
atmosphere allowing easy entry of visible light, but difficult escape
of infrared radiation (heat).
- The levels of cosmic structures having densities and orbital velocities
between galaxies and clusters. Most galaxies belong to small groups.
- Elementary particles with large mass that are influenced by the
strong nuclear force. There are two types of hadrons-mesons, which
have zero spin, and baryons, which have half-integral spins.
- Binary compounds that contain halogen atomsfluorine,
chlorine, bromine, and iodine.
- (see galactic halo)
halogens - A group of five nonmetallic elements, including fluorine,
chlorine, bromine, iodine, and astatine.
heat - Energy that can move or transfer from one object to another
because of a difference in temperature, resulting in a gain or loss
of internal energy of particle motion.
helioseismology - The study of oscillations of the sun's
photosphere that result from seismic events within the interior.
- a bubble in space produced by the solar wind.
helium nucleus - Two bare bound protons, with one or two
- A unit of frequency equal to one cycle (or wave) per second.
- Consisting of dissimilar constituents (mixed).
histogram - A "bar graph."
- The quality of consisting of similar parts or elements.
constant - The rate at which the universe expands, equal to
20 kilometers per second per 106 light years of distance.
law - The law that correlates the velocities at which distant
galaxies are receding from one another to the distances between
bubbles - (see voids)
hydrogen nucleus - A bare proton.
- The solid state of substances (such as ammonia, carbon dioxide,
and methane) that are found in the gaseous state at standard atmospheric
- Violent compression; opposite of explode.
- The tendency of matter to remain at rest if at rest or to
remain in motion in a straight line if in motion. (see Newton's
- Being without limits of any kind; without end or indefinitely
(IR) - Invisible radiation, sensed as heat, which has wavelengths
longer than red visible light and shorter than microwaves.
radiation - Electromagnetic radiation having a wavelength longer
than the longest visible wavelength but shorter than those in the
microwave and radio ranges.
- Not homogenous. (see homogenous)
or air intake - Helps determine the amount of air flow into
insulator - A material that is a poor conductor of heat, therefore
delaying the transfer of heat (also can be used to describe electrical
- Determining or estimating a value between known values.
interstellar - Between the stars.
interstellar dust grains - Clumps of atoms and molecules
in the interstellar medium.
interstellar gases - Molecules of gas in the interstellar
interstellar medium - Material occupying the space between
- An atom or molecule that has a net electrical charge from gaining
or losing electrons.
ionization potential - A measure of the energy required to
remove an electron from an atom or ion.
- Turn into an ion or charged particle.
- Electromagnetic radiation that has sufficient energy to cause
the loss of one or more electrons from atoms or molecules, thereby
- (see anemopause)
- A layer of the Earth's atmosphere ranging from about 100 to 700
km above the surface in which oxygen and nitrogen are ionized by
sunlight, producing free electrons.
- One of two or more atoms having the same atomic number but differing
in atomic weight and mass number.
- The state of having the same properties in all directions.
propulsion - Propulsion of an airplane by jet engines by the
forwardly directed forces of the reaction resulting from the rearward
discharge of a jet of fluid.
planets - The four larger planets (Jupiter, Saturn, Uranus and
Neptune) which, if they have solid surfaces, are covered by a deep
- A unit of absolute temperature.
First Law of Planetary Motion - Law of Ellipses- The orbit of
each planet is an ellipse, with the sun at one focus.
Second Law of Planetary Motion - Law of Equal Areas- A line
drawn from a planet to the sun sweeps out equal areas in equal times.
Third Law of Planetary Motion - Harmonic Law- The square of
the orbital period of a planet is directly proportional to the cube
of its average distance from the sun.
- Lagrangian point; the point of stability between two celestial
bodies; for Genesis, the L1 point is on the sun side of the Earth.
period - How many days a rocket can be launched into the proper
window - The dates or times (or set of times during a given
day) that a rocket can launch, meet mission objectives, stay within
safety guidelines, and be safely sent into its trajectory.
- Elementary particles that have very small or no measurable mass
and are not influenced by the strong nuclear force. Electrons and
neutrinos are leptons.
- An oscillation in the apparent aspect of a secondary body (such
as a satellite) as seen from the primary object around which it
year - The distance that light travels in one year, 5.8 x 1012
miles or 9.3 x 1015 meters.
line spectrum - A spectrum that appears as distinct lines
of particular wavelengths that are characteristic for the various
Earth Orbit (LEO) - An orbit from about144 to 960 kilometers
above the Earth commonly used by the Space Shuttle.
luminosity - The radiant energy output from an object.
matter - Matter that emits or reflects electromagnetic radiation.
Also called bright matter, it is made primarily of baryonic material.
1 - The speed of sound.
- Dark matter jargon for Massive Compact Halo Objects referring
to objects in galactic halos made of protons and neutrons; also
called baryonic matter.
field - The region of space near a magnetized body, in which
magnetic forces are exerted.
- The outer boundary of a planet's magnetosphere where the magnetosphere
encounters the solar wind.
- The turbulent region between the bow shock and the magnetosphere
of a planet.
magnetosphere - The region surrounding a planet where the
behavior of electrically charged particles is determined by the
planet's magnetic field.
magnetotail - An elongated "wake" of plasma found on the
side of a planet opposite the sun.
axis - The long axis on an ellipse.
variable - In an experiment the factor that is intentionally
changed by the investigator. Also known as the independent variable.
- A measure of an object's resistance to acceleration; different
from but proportional to the object's weight.
mass number - The total number of neutrons and protons in the
nucleus of an atom.
mass spectrometry - The experimental determination of the mass
of an atom or molecule by observing its behavior as it is accelerated
in a magnetic field.
mass spectrum - A graph obtained from a mass spectrophotometer
that shows the atomic or molecular mass of the sample vs. the number
of atoms or molecules having that mass.
mean - A number that typifies a set of numbers of which it is
a function. The value obtained by dividing the sum of a set of quantities
by the number of quantities in the set.
parsec - One million parsecs.
metals - A group of solid lustrous elements, often ductile and
malleable, that form compounds easily with nonmetals and form alloys
with other metals.
metalloids - A group of elements that either have a mixture
of metallic and nonmetallic characteristics (like arsenic) or are
generally nonmetallic but can form alloys with metals (like carbon).
meteorite - That portion of a meteoroid that survives passage
through the atmosphere.
meteoroid - A meteoritic body in space.
- (see gravitational lensing)
- A unit of length equal to 1/1000 of a millimeter.
- Electromagnetic radiation with wavelengths of about 10-4
to 1 m.
Way galaxy - The spiral galaxy of which our sun is a part.
instructions per second
(MIPS) - A measure of computer information processing speed.
axis - The short axis on an ellipse.
molecular cloud - A collection of chemical molecules in the
interstellar medium mutually attracted by gravity.
momentum - The quantity of motion in a body. For linear momentum,
it is the mass of the body multiplied by its velocity.
- A unit of distance measurement that equals 10-9
neutrino - Mysterious and poorly understood sub-atomic particles
that have no charge and little, if any, mass.
neutron - An uncharged, subatomic particle of approximately
the same mass as the proton.
First Law Of Motion - Objects at rest tend to stay at rest unless
acted on by an unbalanced force. Objects in motion tend to stay
in motion in a straight line unless acted on by an unbalanced force.
Second Law Of Motion - As force is increased, acceleration increases.
As mass is increased, acceleration decreases. Therefore, force equals
mass times acceleration. (force = mass x acceleration)
Third Law Of Motion - For every action or force there is an
equal, opposite and simultaneous reaction or force.
noble gases - A group of elements that, except for helium,
combine to form compounds only under extreme conditions. Helium
does not form compounds, even under these conditions.
nonmetals - A group of elements that gain or share electrons
to form compounds with metals or other nonmetals. They are poor
conductors of heat and electricity, even in the solid state.
nova - Literally a "new" star; an exploding star which suddenly
becomes visible from Earth.
nuclear fusion - The process of two atomic nuclei fusing
to produce a new nucleus, the mass of which is less than the sum
of the masses of the two fusing atoms.
reaction - A chemical reaction which, unlike most, occurs between
the nuclei of atoms rather than between their exterior electrons.
nuclei - Plural of nucleus.
nucleon - Protons and neutrons, those particles that
make up the nucleus of an atom.
nucleus - The protons and neutrons, found at the center of
an atom, that contribute most of the atom's mass.
nuclide - An atomic nucleus specified by its atomic number
and atomic mass.
- An index of matter density of the universe, defined as the ratio
of actual density to the critical density.
universe - A universe that will continue to expand forever;
one in which the ratio of actual density to the critical density
is greater than 1.
definitions - In an experiment, a description of how the investigator
has decided to measure a variable.
- A unit of length in astronomy; 3.258 light years.
- Fundamental units of matter and energy.
perihelion - The closest point to the sun in an orbit.
- Having a repeating pattern.
- Tiny, discrete packets (or units) of electromagnetic energy
photosphere - The visible surface of the sun; the zone that
occurs at the top of the convection zone, where atoms no longer
block radiative flow. As the hot atoms cool, they release their
excess energy as photons of radiant energy, some of which fall into
the visible light portion of the spectrum.
- That property of sound which is determined by the frequency of
vibration of sound waves which strike the ear.
- A cosmic object that is more massive than an asteroid but less
massive than a star and shines by reflected light.
- Accretions of solar nebula material having a mass of 10
g, which combine to form more massive bodies.
plasma - An electrically neutral yet highly ionized gas comprised
of ions, electrons, and neutral particles; often considered to be
the fourth state of matter.
universe - A theory of the universe that asserts that parts
of the universe expand while others contract.
positron - A positively charged electron.
potential energy - The energy of a particle or system of
particles derived from position, or condition, rather than from
preconception - A concept formed in advance of further instruction;
if inaccurate, may make learning difficult.
nebula - (see solar nebula)
prism - An object, usually a triangular-based polyhedron
of glass, that causes a mixture of wavelengths of light to be separated
or dispersed. Isaac Newton produced a spectrum with a prism in 1672.
- Branch of mathematics that deals with the predicted outcomes of
random chance events.
probability cloud - Description of the most likely region
where an electron may be found.
prominence - A structure in the corona consisting of cool plasma
supported by magnetic fields.
- To drive forward or onward by or as if by means of a force
that imparts motion.
protium - The isotope of hydrogen whose nucleus is one proton
proton - A subatomic particle having a single positive charge
and constituting the nucleus of the ordinary hydrogen atom.
fusion - A nuclear fusion process in which both reacting atoms
are ionized hydrogen atoms that lack electrons.
- Young stars.
- Fundamental units of energy.
- Fundamental particles of which protons and neutrons are made;
held together by strong nuclear force. Quarks have color, flavor,
and fractional electric charges.
- A quasi-stellar object; objects far from Earth, moving extremely
swiftly away from Earth, and emitting visible light and radio frequency
energy - (see electromagnetic radiation)
radiation - The emission or transmission of energy in the form
of waves through space or another medium.
zone or layer - About 70% of the sun; the section where energy
travels outward by radiation.
emissions - Radiation in the radiowave portion of the electromagnetic
radiation emanating from an object.
- Sensitive radio antennae used to detect radio energy emitted by
nebulae, galaxies, and pulsars.
earth metals -
Elements with atomic numbers from 57 through 71.
- A comparison
of two quantities, expressed as a fraction.
- A system of bright, elongated streaks, sometimes associated with
centimeter - The quotient of
unity divided by a measurement in centimeters, or 1/cm.
giant stars - Later evolutionary stages of low-mass stars, which
collapse then expand.
red shift - An apparent increase in wavelength (becoming
more red) of the radiation from an object moving away from the observer.
in an identical copy of a functional component to serve as backup
in case of failure of the primary component.
relative abundance (of isotopes) - The proportion in a sample
of the masses of all naturally occurring isotopes of an element
to the mass of the most abundant isotope of that element.
- Einstein's general theory of relativity was his theory of gravitational
force. His special theory of relativity was his theory of the electrodynamics
of moving systems.
variable - In an experiment, the factors that are affected by
the manipulated variable. Also known as the dependent variable.
- A part of the Boeing company created to build rocket engines in
support of national defense and U.S. involvement in space.
period - The time necessary for a body to make one turn about
Rydberg equation - An equation that predicts the positions
of the lines in an emission spectrum of the hydrogen atom.
- A chemical compound formed by combining the anion of an acid with
the cation of a base.
Law of Thermodynamics - Some forms of transformations of one
kind of energy to another are not observed to occur in natural processes.
The observed transformations in a closed system are always characterized
by a nondecreasing entropy. In open systems where the entropy may
be kept constant, the allowed transformations are always characterized
by a decrease in the amount of (free) energy available to do useful
axis - Half of the major axis.
wave - A region of abrupt change in pressure and density caused
by supersonic flow around a body.
A nonmetallic chemical element, number 14, which is a major
component of many types of rocks and minerals on Earth; used to
make glass, concrete, and semiconductors.
solar core - The central region of the sun's structure that
consists of protons, neutrons, nuclei, and free electrons and is
the site of proton-proton fusion reactions.
solar nebula - A diffuse mass of interstellar dust and/or
gas that is thought to be the remnants of the material out of which
the sun formed.
wind - The components of the sun that are spewed into the void
of outer space.
- The four-dimensional description of events as depicted in the
theory of relativity.
impulse - The thrust produced per unit rate of consumption of
the propellant that is usually expressed in pounds of thrust per
pound of propellant used per second and that is a measure of the
efficiency of a rocket engine.
spectra - Plural of spectrum.
spectrograph - A device used to spread-out radiation into
its component wavelengths.
- A tool which produces, observes, and records the spectra
- The study of spectra.
- The distribution of energy from a radiant source, arranged in
order of wavelengths.
spin - Angular momentum.
galaxy - One of the three major classifications of galaxies;
their characteristics include a plate-shaped disk containing spiral
point - The point at which the solar wind plasma comes closest
to the center of a planet.
- A cosmic structure that generates energy by means of nuclear fusion
at its core.
37 FM - The motor that propels the third stage of the Delta
II rocket containing the Genesis spacecraft.
clusters - Aggregations of stars that are gravitationally bound,
but are smaller and less massive than galaxies.
- Pertaining to bodies at rest, without motion, at equilibrium;
not being acted upon by physical forces of energy.
steady state - A condition that exists when the value of
some parameter remains constant over time because the rate of accumulation
of this parameter equals the rate of its loss.
stellar wind - A flow of charged particles out of a star.
process - A process or event that involves the occurrence of
random chance events.
nuclear force - Fundamental force of nature that binds quarks
together; holds protons and neutrons together to form the nucleus
of an atom. A gluon is a quanta of strong nuclear force.
- (see cosmic structure)
sunspot - A temporary, disturbed area of the solar photosphere
that appears dark because it is cooler than the surrounding areas;
concentration of strong magnetic flux on the sun's surface.
- A cluster of tens of thousands of galaxies, typically about one
hundred million light-years in diameter.
supergiant stars - Stars with masses over 100 solar masses.
- A system for taking measurements in the spacecraft or satellites
and transmitting them to ground stations.
- Belonging to the Earth.
planets - Those planets - Mercury, Venus, Earth, Mars (and Pluto?)
- having a hard, rocky surface.
equilibrium - A condition that exists between two objects when
they have reached the same temperature and heat energy no longer
flows between them.
- The study of heat and its transformation into mechanical energy.
- A practical device used to open and close an electrical circuit
through the bending of a bimetallic strip, due to a difference in
the rate of contraction and expansion of the different types of
metal on each side of the strip.
Law of Thermodynamics - There is an absolute zero to temperature
(0 Kelvin) where all forms of matter become perfectly ordered (usually
to perfect crystals).
experiment - An experiment that cannot be or is not carried
out in practice; it is reasoned through by thought and intuition.
tidal force - A gravitational force that causes a changing
effect on the shape of an object.
light - A theory of the universe that maintains that light,
as it travels vast distances, loses energy, creating a redshift
distance relationship that is not due to cosmic expansion.
- A path, usually curved, of an object moving through space.
- The isotope of hydrogen whose nucleus is one proton and two neutrons.
radiation - Radiation of wavelengths between that of violet
visible light and x-rays.
quarks - One of six flavors of quarks that has a charge of +2/3
in units of elementary electric charge.
electron - An outer electron which can participate in forming
- Factors that is subject to change in an experiment.
- A quantity that is expresses direction and magnitude.
spectrum - Electromagnetic radiation with wavelengths from about
400 nm to around 750 nm.
- Spaces between superclusters that are relatively free of luminous
matter. Also called bubbles.
- The space occupied by an object.
- The distance between adjacent wave crests of electromagnetic radiation.
- Propagation of energy by means of coherent vibration.
nuclear force - Fundamental force of nature that governs the
process of nuclear radioactive decay.
- A mean or average that is adjusted to reflect value or proportion.
- Dark matter jargon for Weakly Interacting Massive Particles; includes
electrons, which have very little mass, and neutrinos, which may
have zero mass. Also called nonbaryonic matter.
holes - Tunnels through space-time linking one black hole to
particles - Theoretical particles that may have decayed into
quarks and antiquarks as the temperature significantly decreased
after the Big Bang.
emissions - Radiation in the x-ray portion of the electromagnetic
radiation emanating from an object.
- A relatively high-energy photon with wavelengths in the range
of 0.01 to 10 nanometers.