Asteroid Belt - the area of space in our solar system between Mars
and Jupiter where the majority of the asteroids are found. It is believed
that a planet would have formed here if not for Jupiter's strong gravitational
affects disrupting the planets formation
Astronomical Unit (AU) - a unit of measurement for distances in the
solar system. One AU is the average distance from the Earth to the sun and
is equal to approximately 149,600,000 kilometers (92,956,000 miles)
Astronomy - branch of science dealing with stars, solar systems, galaxies,
or any celestial body in the universe
Atmosphere - a collection of gases trapped by a celestial body's gravitational
field. The gases surrounding the planet cause pressure (the weight of the
gas as felt by some location on the surface) and can also filter out (or keep
in) energy sent by the sun
Aurora - a magnificent light show seen in the atmosphere of a planet
when charged particles from sunspots get trapped in the magnetic field of
the planet. They released their energy and cause reaction in the atmosphere
causes the sky to light up in ribbons of various colors. Auroral affects are
most often visible closer to the poles of a planet
Axis of Rotation - an imaginary line around which a celestial body
spins. Most of the planets tend to have their axis perpendicular to the ecliptic,
bot not all of them
Big Bang Theory - states that all the matter in the universe existed
in a single point in space. This point exploded and the resulting temperature
caused the subatomic particles to join together to form the first atoms of
hydrogen and helium
Black Hole - caused by the death of an extremely large star, black
holes have gravitational fields strong enough to trap light. Black holes consist
of a singularity, the center where all the
mass resides, and an event horizon, a
black disk encircling the singularity and
the point at which light can no longer escape the gravitational forces of
the black hole
Celestial - anything pertaining to the sky, heavens, space, etc.
Comet - comets are similar to asteroids
but contain much more ice in them. When they pass the orbit of Jupiter and
approach the sun, the ice sublimates and creates
a ball of gas around the comet. The solar wind then blows the gas away from
the comet, creating the part of a comet most known by people, its tail
Constellation - a collection of stars that form the shape of another
object. There are 88 named constellations. The stars that make up a constellation
are not necessarily close to each other in space, rather they simply appear
in the same area of the sky when viewed from Earth
Convection Zone - the outer third layer of the sun. The energy created
in the core of the sun is transported through the
convection zone similar to boiling water. The gases of the convection zone
seem to "bubble" to the top and release the energy
Core - innermost part of a star where nuclear reactions take place
Coronal Mass Ejection - when a large amount of the corona (the outer
layer of the sun) is ejected into space. This happens in small amount with
the solar wind. Larger amounts of the corona,
as seen in a coronal mass ejection, can cause havoc with electrical equipment
here on Earth
Cosmology - study of the universe, including its structure, origin,
evolution, and future
Density - the ratio of the mass of a body to its volume
Dwarf, Black - the remnant of a white dwarf;
a white dwarf that has ceased to shine
Dwarf, Brown - a forming star that did not have enough mass to reach
the temperature necessary to start nuclear fusion
Dwarf, White - the remnant of a low-mass star. White dwarfs are the
core of the star in the process of converting helium to carbon and oxygen.
They are very small, but very hot
E=MC^2 - equation giving the amount of energy in any given amount of
mass. By multiplying the mass by the speed of
light, squared, the energy can be determined
Eccentric - not circular; elliptical. See also ellipse
Eclipse - the blocking of one celestial object by another, specifically
an object casting its shadow on another object
Ecliptic - plane of space where roughly all of the planets lie
Einstein - physicist who came up with the Theory
of Relativity and E=MC^2
Ellipse - an oval; an ellipse has two focus points.
Event Horizon - black disk encircling a black
hole. The event horizon is the point at which light can no longer
escape the gravitational forces of the black hole.
The radius of the event horizon can be calculated by the equation Rs=2GM/C^2
Food Chain - link between food sources. A simple food chain may start
with plants, then herbivores, and then carnivores. If any part of the food
chain is damaged, the entire chain would collapse
Galaxy - A collection of stars orbiting around a common center. Galaxies
also contain star clusters, hydrogen gas, and cosmic rays
Global Warming - warming of a planet due to the greenhouse
effect
Gravity - the property of mutual attraction of two objects having mass.
The force of gravity is equal to the mass of the first object, times the mass
of the second object, times the gravitational constant (6.7e-11), divided
by the distance between the two objects or: Fg=GM1M2/R^2
Great Dark Spot - a large storm raging on the planet Neptune
Great Red Spot - a large storm raging on the planet Jupiter
Greenhouse effect - the result of greenhouse
gases trapping the suns infrared radiation on a planet. Without the
presence of greenhouse gases, infrared
radiation would reflect off the surface of the planet and back into space.
With greenhouse gases, however, the
infrared radiation is trapped in the atmosphere and results in global
warming
Greenhouse gases - gases associated with the greenhouse
effect including carbon dioxide, methane, nitrous oxide, and chlorofluorocarbons
(CFCs)
Heat - the result of the collision between atoms in a substance
Heliocentric - the belief that the sun, not the Earth, was the center
of the universe. Copernicus is credited for garnering wide-spread support
for this belief
Hemisphere, Northern - the northern half of the Earth; all parts of
the Earth north of the equator
Hemisphere, Southern - the southern half of the Earth, all parts of
the Earth south of the equator
Hertzprung-Russel Diagram - a diagram plotting a star's luminosity
vs. surface temperature. Using a HR Diagram stars fall into four different
areas. These areas can then be used to determine which stage in life a star
has reached
Industrial Revolution - the movement of different countries from a
society based largely on agriculture to one based more upon the mechanized
production of manufactured goods
Kepler's Three Laws of Planetary Motion - Kepler's three laws describing
the motion of the planets around the sun
Light Pollution - man-made light drowning out the light of the stars.
This is most notable near a large city
Little Ice Age - the period of time between 1645 and 1715 where most
of Europe experienced extremely cold temperatures. Although not as severe
as the Ice Ages that occur every 150 million years or so
Luminosity - the measure of the absolute brightness of a star. Luminosity
has much to do with the amount of power put out by the star as well as the
size of the star
Lutheran - a Christian denomination; as called Protestants or Evangelists
Magnetic Field - the area around an object that will react with another
magnetic object. Planets have magnetic fields about them. These fields interact
with the charged particles streaming from the sun. Evidence of this can easily
be seen by watching the aurora
Main Sequence - the section of the HR Diagram that runs from the upper-left
hand corner to the lower-right hand corner and characterizes stars in the
main stage of their life; the stage at which they fuse hydrogen and helium
in their core
Meteor Shower - when Earth passes through the debris left by a comet,
the small particles of dust and rocks enter the Earth's atmosphere. There
they are heated by friction and begin to glow. These are called "shooting
stars" or "falling stars"
Moon - a natural satellite orbiting a planet
Nebula - a cloud of interstellar gas and dust made up mostly of hydrogen
and helium. Nebulas come in different forms; planetary nebulas, supernova
remnants, and diffuse nebulas. When stars form, they form as a result of a
nebula condensing
Neutron Star - the remnant of a high-mass star. The gravity of these
stars is strong enough to knock the electrons out of their orbit and into
the nucleus of the atoms. There, they form with protons to form neutrons.
The structure of the nucleus is strong enough to resist any further gravitational
collapse
Newton's Third Law of Motion - states that for every action, there
is an equal, and opposite, reaction. E.g. when you jump into the air, there
is a force equal and opposite to the one that moved you upward. The reason
the Earth doesn't seem to move away from you is that it is large enough that
your pushing it had almost no affect
Nuclear Fusion - the process of combining two lighter elements to form
a heavier element. Nuclear fusion is the source of energy in stars. The most
common nuclear fusion is that of hydrogen to helium. The most difficult thing
to accomplish with nuclear fusion is to heat the elements to the necessary
temperature for the reaction to occur. It takes around ten million degrees
Kelvin before hydrogen will fuse into helium
Orbit - the path of an object through space. This path is usually affected
gravitationally by another object, causing it to be curved. Kepler's
First Law of Planetary Motion describes such a curve in the orbit
of the planets
Outer Layers - When referring to the outer layers of the sun we are
usually referring to the convection zone and, within that, the chromosphere,
photosphere, and corona
Period - the amount of time it takes a body to perform one rotation
or revolution. In the case of Kepler's Third Law of Planetary
Motion it is the time it takes for a planet to complete one revolution,
or one orbit about the sun
Photosynthesis - the process by which plants produce energy. By combining
carbon dioxide, water, and sunlight, plants are able to produce sugar for
energy
Planet - any larger bodies that orbit around the sun and are illuminated
by the sun and not by an internal light source
Planetary Nebula - see nebula
Polar Cap - the polar region of a planet. Typically it is colder than
the rest of the planet so elements that exist as either a liquid or a gas
on other parts of the planet are more likely to be solids here
Pole - the point at which a planets axis
of rotation crosses the planet
Protostar - the result of the contraction of a nebula.
A protostar is the point between a nebula and
a main sequence star
Quark - general name given to any of six hypothetical particles believed
to make up protons and neutrons
Radiation, Electromagnetic - energy waves resulting by the acceleration
of an electric charge. They range from low frequency, low wavelength to high
frequency, short wavelength. In order of increasing wavelength, the electromagnetic
spectrum consists of radio waves, microwaves, infrared radiation, visible
light, ultraviolet radiation, X rays, and gamma rays
Radiation Zone - the are of the sun between the core
and the convection zone. Energy radiates
through this zone from the core to the convection
zone
Radius - the distance between the perimeter of a circle and the center
of a circle. Sometimes, simply the distance between two points
Radius, Average - since ellipses have varying radii, the average of
all the radii are used to perform calculations of Kepler's
Third Law of Planetary Motion
Red Giant - a star in its dying phases. As the core
of the star shrinks and heats up, the outer layers
must expand and cool according to Newton's Third Law
of Motion. These stars are very luminous but very cool
Rotation - the spin of a planet about its axis
of rotation
Rs=2GM/C^2 - formula used to calculate the radius of the event
horizon. The radius is equal to 2 times the gravitational constant
(6.7e-11) times the mass of the black hole
divided by the speed of light squared
Satellite - See moon
Season - the change in temperature of a parts of a planet due to the
variation of the location where the suns rays are most direct
Singularity - a single point in space-time with an infinite density
of matter. A singularity is believed to be at the center of black
holes
Solar Flare - an explosion of cooler gases from a small area on the
suns surface. Also associated with an intense outburst of radiation
Solar Mass (M) - the mass of our sun, approximately 1.99e30 kilograms
Solar System - the combination of a star, its surrounding planets,
asteroids, comets, dust, etc.
Solar Wind - a stream of particles leaving the suns surface and traveling
through space
Speed of Light - believed to be the speed limit in the universe. Nothing
is supposed to be able to exceed the speed of light. It is also constant at
3e8 meters per second
Stable Equilibrium - when the nuclear reactions in a stars core are
strong enough to withstand the crushing force of gravity
Star - a large celestial body, composed of highly condensed, hot gases.
Energy in stars is produced by nuclear fusion
it the stars core and is released in the form of
electromagnetic radiation
Sublimate - the process in which a solid moves directly to the gaseous
state, skipping over the form of a liquid
Sunspot - a dark, cooler area of the suns surface appearing as the
result of changes in the suns magnetic field at that location
Supernova - the explosion of a high-mass star in its final stages before
death
Synchronous Rotation - where the orbital period of a satellite is equal
to its rotational period, resulting in the same "face" of the satellite pointing
towards the planet
Theology - the study of religion and faith
Theory of Relativity - helped to show the unity between matter and
energy, space and time, and gravity and acceleration.
Umbra - the conic-shaped shadow cast behind an object by the sun
Universe - all existing things, including the earth, the solar system,
the galaxy, and everything therein regarded as a whole
Zodiac Sign - the 12 zodiacal constellations. Every person has a zodiac
sign and it equated to the constellation that was in the direction of the
sun at the time of your birth
Zodiacal - see ecliptic