absolute magnitude noun - The brightness of a star if they were viewed from assistance of 10 parsecs, or 32.6 light years.

acceleration noun- The rate of change of velocity with respect to time. Increasing speed over time.

Alnilam - A star in the Belt of Orion.

Alnitak - A star in the Belt of Orion

asteroid (as·ter·oid) noun - Rocky or metallic objects, most of which orbit the Sun in the asteroid belt between Mars and Jupiter. A few asteroids approach the Sun more closely. None of the asteroids have atmospheres.

asterism (as·ter·ism) noun - a group of stars within a constellation

astrology (as·trol·o·gy) noun - the study of the influence of heavenly bodies to the lives of humans

astronomy (as·tron·o·my) noun - the study of objects and matter outside the Earth's atmosphere and of their physical and chemical properties

astronomical (as·tro·nom·i·cal) adjective - of or relating to astronomy

atmosphere (at·mo·sphere) noun - the gaseous envelope of a celestial body (as a planet)

atmospheric pressure (at·mo·spher·ic pres·sure) - one atmosphere is 14.7 pounds per square inch (105 Newtons per square meter); the average atmospheric pressure at sea level on Earth. Atmosphere is also a layer of gases surrounding a planet, moon, or star. The Earth's atmosphere is 120 miles thick and is composed mainly of nitrogen, oxygen, carbon dioxide, and a few other trace gases

axis (ax·is) noun - straight line about which a body or a geometric figure rotates or may be supposed to rotate

Babylonia (Bab·y·lo·nia) noun - ancient country in valley of the lower Euphrates & the Tigris in northern Africa

binocular (bin·oc·u·lar) noun - a handheld optical instrument composed of two telescopes and a focusing device and usually having prisms to increase magnifying ability usually used in plural

Bode’s Law - a sequence of numbers that represent approximately the mean distances of the planets from the Sun

body (body) noun - a mass of matter distinct from other masses

bombardment (bom·bard·ment) noun - to subject to the impact of rapidly moving particles

Brahe, Tycho (1546-1601) was a Danish astronomer who made extensive and seminal calculations of the orbits of the planets. His work (done without a telescope) was the basis upon which Kepler made his revolutionary orbital formulas.

carbon dioxide (car·bon di·ox·ide)noun - a heavy colorless gas CO2 that does not support combustion, dissolves in water to form carbonic acid, is formed especially in animal respiration and in the decay or combustion of animal and vegetable matter, is absorbed from the air by plants in photosynthesis, and is used in the carbonation of beverages

carbon monoxide noun - a colorless odorless very toxic gas CO that burns to carbon dioxide with a blue flame and is formed as a product of the incomplete combustion of carbon

celestial equator - the great circle on the celestial sphere 90º from each of the two celestial poles

celestial prime meridian - the great circle through the celestial poles and the point overhead

centaur (cen·taur) noun - a half-man, half-horse creature

Ceres (Cer·es) noun - The first minor planet (asteroid) to be discovered

Charon (Char·on) noun - the only moon of Pluto

Christianity (Chris·tian·i·ty) noun - the religion derived from Jesus Christ, based on the Bible as sacred scripture, and professed by Eastern, Roman Catholic, and Protestant bodies

civilization (civ·i·li·za·tion) noun - the culture characteristic of a particular time or place

clockwise (clock·wise) adverb - in the direction in which the hands of a clock rotate as viewed from in front or as if standing on a clock face

collide (col·lide) transitive verb - to come together with solid or direct impact

collision (col·li·sion) noun - an encounter between particles (as atoms or molecules) resulting in exchange or transformation of energy

comet (com·et) noun- a astronomical body in orbit around the Sun, usually in an elongated orbit

concave (con·cave) noun - a lense that is hollowed or rounded inward like the inside of a bowl; it is thicker at the edges than at the center

constant velocity (con·stant ve·loc·i·ty) - steady quickness of motion

constellation (con·stel·la·tion) noun - an apparent grouping of stars named for a mythical figure, animal, or inanimate object; there are 88 constellations

Copernicus, Nicholas biographic name -1473_1543 Polish astronomer; developed view that Earth rotates on an axis and revolves around a stationary Sun

conclusion (con·clu·sion) noun - a reasoned judgment the last part of something

counterclockwise - in the direction opposite to the rotation of the hands of a clock

declination noun -celestial latitude ((astronomy) the angular distance to a point on a celestial object measured north or south from the celestial equator; expressed in degrees; used with right ascension to specify positions on the celestial sphere)

density (denqsiqty) noun - Density is a measure of how massive an object is per unit volume. For example, iron is more dense than wood; one cubic meter of iron weighs more than one cubic meter of wood.

diffuse cluster - A group of stars that form no pattern, but are in close proximity

disintegrate (disqinqteqgrate) - break into parts or components; decay, decompose

distortion (disqtorqtion) noun - the act of distorting; the quality or state of being distorted; a lack of proportionality in an image resulting from defects in the optical system; falsified reproduction of an audio or video signal caused by change in the wave form of the original signal

double or multiple stars - Stars seem to be solitary but in fact the majority of stars have one or more companion stars. There are two types of double stars. Those that are in an apparent close arrangement to our eyes from Earth (so really not close) and those stars that are linked by gravity causing a genuine binary system. They sometimes occur in groups more than two and are called multiple.

dust tail noun - a tail behind a comet that is composed of dust

eccentric (ec·cen·tric) adjective - deviating from a circular path

ecliptic (eclip·tic) noun - the great circle of the celestial sphere that is the apparent path of the sun among the stars or of the earth as seen from the Sun; the plane of the Earth's orbit extended to meet the celestial sphere

Egyptian (Egyp·tian) adjective - relating to, or characteristic of Egypt or the Egyptians

Einstein, Albert (Ein·stein) 1879-1955 American (German-born) physicist; explained the theory of relativity; discovered equivalence of mass and energy (E=mc2), etc.; awarded 1921 Nobel prize for physics for contributing to physics and the understanding of Universe

electromagnetic waves - the family of radiation that includes light, radio waves, infrared, ultraviolet light, X-ray, and gamma rays

elliptical galaxy - a galaxy without arms, ellipsoidal in shape

epicycle (epi·cy·cle) noun - a circle in which a planet moves and which has a center that is itself carried around at the same time on the circumference of a larger circle

evolution (evo·lu·tion) noun - change through time; theoretical explanation of the changes in the Universe from its beginning

extraterrestrial (exqtraqterqresqtriqal) noun - originating, existing, or occurring outside the earth or its atmosphere.

featureless adjective - lacking distinguishing characteristics or features.

fertility (ferqtilqiqty) noun - the property of producing abundantly and sustaining growth

flat plane - a surface of such nature that a straight line joining two of its points lies wholly in the surface; a flat or level surface

fleet-footed (fleet-footqed) adjective - able to run fast

galaxy (gaqlaxy) - a large collection of stars, dust, and gas in space; a system of millions or billions of stars held together by gravitation

Galileo Galilei (biographical name) Italian astronomer and mathematician; demonstrated that different weights descend at the same rate; perfected the refracting telescope that enabled him to make many discoveries (1564-1642)

Galilean moons - moons of Jupiter that was discovered by Galileo

gamma rays noun - a quantity of high energy radiation emitted from the nucleus of a radioactive atom

gaseous planet - planets whose surface is composed of thick gas; a gas giant

gas giants - The gas giants are the large outer planets of our Solar System: Jupiter, Saturn, Uranus, and Neptune

gas tail - tail of a comet that is composed of gas

gaseous - (gas·eous) adjective - existing as or having characteristics of a gas

generation (genqer·a·tion) noun - all the people living at the same time or of approximately the same age

globular cluster - A globular star cluster is a spherical group of up to a million stars held together by gravity. These remote objects lie mostly around the central bulge of spiral galaxies. The brightest globular cluster is Omega Centauri (in the constellation Centaurus); it is easily seen by the naked eye and is magnitude 4.

gravity (gravqiqty) noun - Gravity is a physical force that pulls objects together. Every bit of mass produces a gravitational force; this force attracts all other masses. The more massive an object, the stronger the gravitational force. Newton formulated the laws of gravity.

Greek noun - of or relating to or characteristic of Greece or the Greeks

Greek alphabet - The Greek alphabet has 24 letters, alpha, beta, gamma, delta, epsilon, zeta, eta, theta, iota, kappa, lambda, mu, nu, xi, omicron, pi, rho, sigma, tau, upsilon, phi, chi, psi, and omega. The Bayer system in astronomy uses Greek letters to denote stars by their relative brightness in each constellation (in order of decreasing brightness). The brightest star in a constellation is alpha, the second-brightest is beta, the third is gamma, etc.

Greek mythology noun - study of myths; myths collectively; the body of stories associated with a culture or institution or person of ancient Greek

greenhouse effect noun - warming that results when solar radiation is trapped by the atmosphere; caused by atmospheric gases that allow sunshine to pass through but absorb heat that is radiated back from the warmed surface of the earth.

guidance system noun - a system that helps to guide a rocket or other projectiles direction or orbit

gyroscopes (gy·ro·scope) noun - a wheel or disk mounted to spin rapidly about an axis and also free to rotate about one or both of two axes perpendicular to each other and to the axis of spin so that a rotation of one of the two mutually perpendicular axes results from application of torque to the other when the wheel is spinning and so that the entire apparatus offers considerable opposition depending on the angular momentum to any torque that would change the direction of the axis of spin

Hale, Allen - astronomer who the Hale-Bopp comet is named for

Heliocentric theory (heqlioqcenqtric) adjective - referred to or measured from the sun's center or appearing as if seen from it

helium (heqliqum) noun - Helium is an element with the atomic number 2. It has two protons and two neutrons in its nucleus which is orbited by two electrons. It is the second most abundant element in the universe. It is created from hydrogen atoms in the process of nuclear fusion that occurs within stars. The Sun is about 25% Helium. Helium was named after the Sun (called "Helios" in Greek) because it was first discovered on the Sun by Jules Janssen in 1868. Helium is plentiful on the Sun and rare on Earth

hemisphere (hemi·sphere) noun - a half of the celestial sphere divided into two halves by the horizon, the celestial equator, or the ecliptic; half of a spherical or roughly spherical body (as a planet); specifically : the northern or southern half of the earth divided by the equator or the eastern or western half divided by a meridian

Herschel, William (1738-1822) was a British astronomer and organist who built an improved reflecting telescope and used it to discover the planet Uranus (March 13, 1781) and moons of Uranus and of Saturn. Herschel cataloged over 2500 discoveries, mostly deep sky objects. Herschel's sister Caroline Lucretia Herschel (1750-1848) helped him in his discoveries and discovered many clusters and nebulae (and 8 comets) herself.

Holland noun - a country in northern Europe, also called the Netherlands

horizon noun- the line at which the sky and Earth appear to meet

hue noun - gradation of color; the attribute of colors that permits them to be classed as red, yellow, green, blue, or an intermediate between any contiguous pair of these colors

hydrogen (hyqdroqgen) noun - It is the lightest element and the most abundant in the universe. Its nucleus is a single proton which is orbited by one electron. It fuels nuclear fusion that occurs within stars, converting hydrogen into helium. The sun is 75% hydrogen

impacts (im·pact) verb - a collision between two planetary bodies. In the case when one is much smaller than the other (like a meteoroid colliding with the Earth), a crater may be produced on the larger body.

incline (in·cline) verb - to deviate from a line, direction, or course; specifically : to deviate from the vertical or horizontal

inertia (in·er·tia) noun - a property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some external force

infrared (in·fra·red) adjective - situated outside the visible spectrum at its red end; used of radiation having a wavelength between about 700 nanometers and 1 millimeter

ionized chemicals - pertaining to chemicals that convert wholly or partly into ions which is an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons

ionized gas - pertaining to gases that become ions which is an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons

inorganic (in·or·gan·ic) adjective - being or composed of matter other than plant or animal; relating or belonging to the class of compounds not having a carbon basis

interplanetary (in·ter·plan·e·tary) adjective - between or among planets

Italian noun - a person or item that has its origin from Italy, a country in southern Europe

ansky, Karl - (1905-1949) was an American radio engineer who pioneered and developed radio astronomy. In 1932, he detected the first radio waves from a cosmic source - in the central region of the Milky Way Galaxy.
Kelvin - William Thompson (1824 - 1907) designed the Kelvin temperature scale in which 0 degrees Kelvin is defined as absolute zero and the size of one degree is the same as the size of one degree Celsius. Water freezes at 273.16 degrees Kelvin; water boils at 373.16 degrees Kelvin.

Kepler, Johannes (1571-1630) was a German mathematician who realized that the planets go around the sun in elliptical orbits. He formulated what we now call "Kepler's Three Laws" of planetary motion that mathematically describe the elliptical orbits of celestial objects.

Kuiper Belt - distant objects than circle the Sun, past the orbit of Pluto named for a Dutch_American astronomer Gerard P. Kuiper, who, in 1951, championed the idea that the solar system contains this distant family

land configuration - how the land is shaped

landscape - an expanse of scenery that can be seen in a single view

latitude (lat·i·tude) noun -Latitude is the angular distance north or south of the equator of a celestial object.

light year - A light-year is the distance that light can travel in one year in a vacuum, which is about 5,880,000,000,000 miles

longitude (lon·gi·tude) noun - Longitude is the angular distance east or west of the prime meridian of a celestial object.

lunar terrain - the appearance of the Moon’s surface

magnetic field - A magnetic field is a region near a magnet where other magnets are affected. The Earth’s magnetic field is probably caused by its molten iron-nickel core. This field is aligned with the north and south poles, and has reversed many times during geologic history. William Gilbert hypothesized that the Earth was a giant magnet in 1600.

magnification (mag·ni·fi·ca·tion) noun - the apparent enlargement of an object by an optical instrument.

Mariner 10 - NASA's series of Mariner missions were designed to gather information from the planets Venus, Mercury, and Mars. They were sent to map these planets and take atmospheric measurements (like temperature, composition, pressure, and density).

mass (mass) noun - bulk, object, volume

Mesopotamia - the land between the Tigris and Euphrates; site of several ancient civilizations; a demarcated area of the Earth

Meteorite - an object, usually a chunk or metal or rock, that survives entry through the atmosphere to reach the Earth's surface. Meteors become meteorites if they reach the ground

methane - Methane (CH4) is an odorless, colorless, flammable gas

methane ice cloud - a cloud of small ice particles composed of frozen methane gas

microgravity (mi·cro·grav·i·ty) noun - virtual absence of gravity; a condition of weightlessness

microwaves -Microwave radiation is a type of electromagnetic radiation that has a wavelength between 1 mm and 30 cm.

microworld (mi·cro·world ) noun- a small universe; specifically : the natural universe observed at the microscopic or submicroscopic level

Mintaka - a star in the belt of Orion

mirror (mir·ror) noun a polished or smooth surface (as of glass) that forms images by reflection

molten (mol·ten) adjective - fused or liquefied by heat

monuments (mon·u·ment) noun - a lasting evidence, reminder, or example of someone or something notable or great

Newton, Sir Isaac (1642 - 1727) was an English mathematician and physicist who invented calculus (simultaneously, but independently of Leibniz), formulated the laws of gravitation and mechanics, investigated the nature of light (he discovered that sunlight is made of light of different colors).

North Star - The north star is a star that is located almost due north and is useful for navigation. Polaris is currently the pole star of the Northern Hemisphere.

North Celestial Pole - the area near the North Star, the North Pole of the Celestial Globe

nucleus (of a comet) - the center of the head of a comet

observational (ob·ser·va·tion) noun - an act of recognizing and noting a fact or occurrence often involving measurement with instruments; a record or description so obtained

omens (omen) noun - a sign of something about to happen

Oort, Jan (1900-1992) was a Dutch astronomer who calculated the distance to the middle of the Milky Way galaxy, mapped our galaxy, proved that the areas around the center of a galaxy revolves, and proposed the existence of the Oort Cloud in the 1950's.

Oort Cloud - The Oort Cloud is a cloud of rocks and dust that may surround our solar system. This cloud may be where long-period comets originate. It has been hypothesized that the Oort Cloud is responsible for the periodic mass extinctions on Earth.

open cluster - An open cluster is a loose collection of up to about 1,000 relatively young stars that formed around the same time. An open cluster is about 10 parsecs across. Examples include the Pleiades and Hyades.

optical (op·ti·cal) adjective - of, relating to, or being objects that emit light in the visible range of frequencies

optics (op·tics) noun - a science that deals with the genesis and propagation of light, the changes that it undergoes and produces, and other phenomena closely associated with it

orbit (or·bit) noun - An orbit is a closed path that an object takes as it revolves around another body. Orbits are generally elliptical, but may be perturbed by the presence of yet other bodies and may even form unusual figures.

Orion - also known as "The Hunter," is a constellation in the zodiac. The brightest stars in Orion are Rigel. Betelgeuse, and Bellatrix.

outgassed (out·gas) - to remove gases from usually by heating; broadly; to remove gases from

parallel (par·al·lel) adjective - extending in the same direction, everywhere equidistant, and not meeting; of or relating to the simultaneous performance of multiple operations

philosophical (phil·o·soph·i·cal) adjective - characterized by the attitude of a philosopher; meeting trouble with level-headed detachment

photomosaic (pho·to·mo·sa·ic) noun - a photographic mosaic; especially; one composed of aerial or orbital photographs

plague - a disastrous evil or affliction

planet (plan·et) noun - A planet is a large celestial body that orbits a star and does not shine on its own. There are nine planets orbiting the sun in our solar system.

planetary bodies - large bodies (planet size) that orbit the Sun

planetary motion - movement of planetary bodies around the Sun, revolution of planets

planetary nebulae - A planetary nebula is a nebula formed from by a shell of gas which was ejected from a certain kind of extremely hot star. As the giant star explodes, the core of the star is exposed. Planetary nebulae have nothing to do with planets. The Hourglass Nebula is a planetary nebula.

primitive microbial fossils - small organisms, that are primitive in their structure, and found in rocks; could be skeleton that is found or more likely, a shape (mold) of the organisms

probe - A probe is an unmanned spacecraft that is sent to collect data from space. Some probes return to Earth, others are not meant to.

proportional (pro·por·tion·al) noun - properly related in size or degree or other measurable characteristics

Ptolemaic System - The Ptolemaic System is an outdated view of the solar system written about by Ptolemy (about 87-150) in his major work, Almagest (Mathematical Syntaxis). Ptolemy believed that all the planets and the sun orbited around the Earth in the order: Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. He also devised a system of circular orbits within orbits (called epicycles) to explain the way the planets orbited around the Earth. It was not until the 1500's when the Copernicus System (with a heliocentric solar system) was accepted.

Ptolemy (Claudius Ptolemaeus) (about 87-150) was a Greek astronomer and mathematician who wrote about his belief that all celestial bodies revolved around the Earth. His writings influenced people's ideas about the universe for over a thousand years, until the Copernican System (with a heliocentric solar system) was accepted.

Quasar (short for quasi- stellar radio source) is a point source, no more than one light year in diameter that emits tremendous amounts of energy, as much as hundreds of galaxies. Current hypotheses suggest that quasars are powered by super massive black holes.
radiate (ra·di·ate) verb - give out or emit

radio telescope - A radio telescope is a metal dish that gathers radio waves from space.

rainbow effect - giving the colors of the rainbow, due to refraction of light through a substance that changes the direction of the light

reaction (reac·tion) noun - a process in which one or more substances are changed into others

reflecting (re·flect) verb - to give back or exhibit as an image, likeness, or outline

reflecting telescope - A reflecting (or Newtonian) telescope uses two mirrors which magnify what is viewed. The first reflecting telescope was first described by James Gregory in 1663

refracting (re·fract) verb - deflection from a straight path undergone by a light ray or energy wave in passing obliquely from one medium (as air) into another (as glass) in which its velocity is different; the change in the apparent position of a celestial body due to bending of the light rays emanating from it as they pass through the atmosphere

refracting telescope - A refracting telescope uses two lenses which magnify what is viewed; the large primary lens does most of the magnification. The first refracting telescope was invented by Hans Lippershey in 1608.

relative magnitude - brightness of a star or celestial object as seen to humans eyes on Earth; does not reflect the true brightness of the star only its apparent brightness

resolution (res·o·lu·tion) noun - the act or process of reducing to simpler form: as; the act of analyzing a complex notion into simpler ones

revolve (re·volve) verb - move in an orbit, as of celestial bodies

revolution (rev·o·lu·tion) noun - the action by a celestial body of going round in an orbit or elliptical course; apparent movement of such a body round the earth; the time taken by a celestial body to make a complete round in its orbit

right ascension Right ascension is a celestial coordinate that is used to measure the degrees of longitude on the on the celestial sphere. Zero degrees of right ascension is the position of the Sun during the vernal (spring) equinox (March 21).

ringlet (ring·let) noun - Many planets are orbited by rings of rock, ice and/or dust. Saturn, Jupiter, Uranus, and Neptune have rings

Roman (ro·man) noun - referring to the people of ancient Rome; an empire established by Augustus in 27 BC and divided in AD 395 into the Western Roman Empire and the eastern or Byzantine Empire; at its peak lands in Europe and Africa and Asia were ruled by ancient Rome

rotation (ro·ta·tion) noun - When an object rotates, it turns around a central point or axis. One planetary day is defined as the time it takes the a planet to rotate around its axis.

satellites - Satellites are objects that orbit a planet or a moon. Many man-made satellites and one natural satellite (the Moon) orbit the Earth

Sagittarius - Sagittarius is the ninth constellation of the zodiac. To the ancients, it represented a centaur (half-man, half-horse) archer who was aiming at the Scorpion (the next constellation) which bit Orion. Its central section (the archer's chest) also resembles a teapot.

scatter (scatter) verb - to cause to separate or break up

scientific (sci·en·tif·ic) adjective - of, relating to, or exhibiting the methods or principles of science

scintillation (scin·til·la·tion) noun - rapid changes in the brightness of a celestial body

scorched (scorch) verb- damaged or discolored by superficial burning

sea level noun - the level of the surface of the sea especially at its mean position midway between mean high and low water

sextant (sex·tant) noun - an instrument for measuring angular distances used especially in navigation to observe altitudes of celestial bodies (as in ascertaining latitude and longitude)

Shapley, Harlow (1885-1972) was an American astronomer who was the first person to accurately estimate the size of the Milky Way Galaxy and our position in it.

shooting stars - A shooting star is not a star; it is a meteor (made of rock and/or iron) which is burning up in the Earth's atmosphere.

sister planet – Venus is sometimes regarded as Earth’s sister planet. In some ways they are very similar: Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass. Both have few craters indicating relatively young surfaces. Their densities and chemical compositions are similar. Because of these similarities, it was thought that below its dense clouds Venus might be very Earth-like and might even have life. But, unfortunately, more detailed study of Venus reveals that in many important ways it is radically different from Earth.

space telescope - The Hubble Space Telescope is a powerful telescope in orbit around the Earth. HST transmits pictures and spectra of objects in space without the interference of the atmosphere (which makes telescopic images from the ground have less detail). It was launched into space in April 1990 and was repaired in December, 1993.

speed - Speed is a measure of how fast something is moving.

Solar System - A solar system is a group of planets, moons, asteroids, and comets that orbit around a sun. In our solar system, nine planets, over 61 moons, and many other objects orbit around our Sun

solar power panels - the ability to create energy from the Sun; these panels can capture light and convert to electrical energy

spectral type Spectral classes are groups of stars that have similar characteristic emission lines in their spectra (indicating that they have similar compositions).

spectrum - The spectrum is the band of colors that composes white light, in the order: red, orange, yellow, green, blue, indigo, violet (from long to short wavelength). Newton first discovered that sunlight could be divided into the visible spectrum.

spiral (spi·ral) adjective - which one of or relating to the advancement to higher levels through a series of cyclical movements; Spiral galaxies are galaxies with a central, dense area and spiraling arms. There are two types of spiral galaxies, "S" (normal spiral) and "SB" (barred spiral, with an elongated center). The Milky Way and Andromeda Galaxy are two of a multitude of known spiral galaxies.

star - A star is a ball of hot gas held together by its own gravity. Gravity also causes stars to undergo nuclear fusion within their interiors. The energy release associated with this fusion causes the star to shine.

Stonehenge - was built in several stages from 2800 - 1800 BC. It seems to have been designed to allow for observation of astronomical phenomena - summer and winter solstices, eclipses, and more.

streaming tails - pertaining to a long, lighted area that starts from the head of a comet and then trails behind, caused by encounter with Sun’s rays

sulfuric acid droplet - drops of water mixed with a strong acid

superheated (su·per·heat) transitive verb - to heat (a vapor not in contact with its own liquid) so as to cause to remain free from suspended liquid droplets; to heat (a liquid) above the boiling point without converting into vapor

supernova - A supernova is a huge explosion that occurs at the end of a mid- to heavy-weight star's life. A supernova releases a tremendous amount of energy, expelling the outer layers of the star and becoming extremely bright. What remains is a neutron star (from a supergiant star) or a black hole (from a middle-weight star).

telescope - an instrument used to collect large amounts of light from far away objects and increase their visibility to the naked eye. Telescopes can also enlarge objects that are relatively close to the Earth

terrestrial planets – a name given to a planet composed mainly of rock and iron, similar to that of Earth.

The Galaxy - a special term referring to our Milky Way Galaxy

three-dimensional (three-dimensional) adjective - giving the illusion of depth or varying distances; used of an image or a pictorial representation especially when this illusion is enhanced by stereoscopic means

trident (tri·dent) noun - having three teeth, processes, or points used by Neptune the God

turbulent (tur·bu·lent) adjective - given to insubordination and disorder

unbalanced - throw out of balance or equilibrium

Universe - The universe is everything, all matter and energy that is in existence.

ultraviolet - Ultraviolet rays are a type of electromagnetic radiation with very short wavelengths (below those of the color blue). Ultraviolet rays are invisible to us. The ozone layer traps much of the Sun’s ultraviolet energy coming through Earth’s atmosphere.

variable stars - Stars with varying brightness. In some cases energy output varies through time in other cases one star might eclipse another star that appears to us on Earth as changing.

velocity (ve·loc·i·ty) noun - the rate of change of position along a straight line with respect to time : the derivative of position with respect to time

Vikings Lander - NASA's Viking Mission to Mars was composed of two spacecraft, Viking 1 and Viking 2, each consisting of an orbiter and a lander. The primary mission objectives were to obtain high resolution images of the Martian surface, characterize the structure and composition of the atmosphere and surface, and search for evidence of life. The Lander refers to the vehicle that landed on Mars to collect samples.

Voyager 2 - NASA launched the two Voyager missions in 1977 to explore the solar system. They transmitted images of the outer planets and their moons back to Earth

wall quadrant an instrument for measuring altitudes consisting commonly of a graduated arc of 90 degrees with an index; usually having a plumb line for fixing the vertical or horizontal direction

Wright, Thomas (1711-1786) was a British cosmologist. Wright was one of the first people (along with Johann Lambert (1728-77) and Immanuel Kant (1724-1804) who in 1750 speculated about the structure and origin of our solar system and galaxy. Using religious and philosophical arguments, Wright hypothesized that the Milky Way was a thin flat system of stars with our solar system near the center and that there were other similar but distant star systems (which he called nebulae)
x-ray - X-rays are a type of electromagnetic radiation (between ultraviolet light and gamma rays in wavelength, frequency, and energy) - basically, it's light that is way past the blue-violet end of the visible spectrum - we cannot see it. They have short wavelength (and high frequency) as compared to visible light. Each photon of X-ray radiation has a lot of energy. X-rays can go through most solid objects. X-ray images of celestial objects are one way of learning about their high-energy properties