Astronomy Glossary of Key Terms "I don't think the human race
will survive the next thousand years unless we spread into space."
Stephen Hawking
Slide 2
Scientific Vocabulary This refers to the words used by
scientists to accurately describe matter, organisms, processes and
systems. These words have an exact meaning or definition, and
application. Sometimes these words are used incorrectly or
imprecisely when applied in everyday use. Because Science is
dynamic -characterized by constant change, activity, or progress,
you may find that sometimes the definitions for science vocabulary
will change and develop as scientists continue to understand the
universe by incorporating new ideas, thinking and experimental
evidence. Its important to have the correct most up to date
definitions of science vocabulary. Its been exactly one whole year
since I saw you last, 12 Months! I know! Scientifically speaking,
the Earth has only made one revolution around the sun, the moon has
orbited the earth about 12 times since I saw you last! And the
Earth has rotated on its axis 365 and times! How have you been? We
dont normally speak scientifically! A glossary of key terms will
help you to develop your Science Vocab to enable you to develop
your Science Knowledge and understanding mostly just so you know
what we are talking about.
Slide 3
Astronomy The branch of science that deals with celestial
objects, space, and the physical universe as a whole. Astronomy was
greatly furthered by the invention of the telescope. From the Greek
word astronomos meaning star-arranging. Milky Way Galaxy (northern
band) many bright stars, dark dust lanes, red emission nebulae,
blue reflection nebulae and star clusters can be seen. Astronomy
Picture of the Day, John P. Gleeson July 10, 2011.
http://apod.nasa.gov/apod/archivepix.html
Slide 4
Celestial Positioned in or relating to the sky, or outer space
as observed in astronomy: a celestial body.
Slide 5
Astrology The study of the movements and relative positions of
celestial bodies interpreted as having an influence on human
affairs and the natural world. Ancient observers of the heavens
developed elaborate systems of explanation based on the movements
of the sun, moon, and planets through the constellations of the
zodiac, for predicting events and for casting horoscopes. By 1700
astrology had lost intellectual credibility in the West, but
continued to have popular appeal. Modern astrology is based on that
of the Greeks.
Slide 6
Constellation a group of stars forming a recognizable pattern
that is traditionally named after its apparent form or identified
with a mythological figure. Modern astronomers divide the sky into
eighty-eight constellations with defined boundaries
Slide 7
Zodiac a belt or ring of constellations that lines the ecliptic
(the apparent path of the sun, the path of the moon and planets
roughly lie within the ecliptic also) It is divided into twelve
equal signs (Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra,
Scorpio, Sagittarius, Capricorn, Aquarius, Pisces).
Slide 8
Horoscope forecast of a person's future, typically including a
delineation of character and circumstances, based on the relative
positions of the stars and planets at the time of that person's
birth. a short forecast for people born under a particular sign,
esp. as published in a newspaper or magazine.
Slide 9
Astronomer An expert in or a student of astronomy.
Slide 10
Gravity The force that attracts a body toward the center of the
earth, or toward any other physical body having mass.
Slide 11
Mass The quantity of matter that a body contains. Mass and
weight are not the same. In science these words have special
meanings. Mass is a measure of the amount of matter (material) in
an object and is commonly measured in grams (g) or kilograms
(kg).
Slide 12
Weight The force acting on the mass of a body by a
gravitational field. Weight and mass are not the same. Weight is a
measure of the force of gravity pulling on a mass and is measured
in newtons (N). Under ordinary conditions the mass of an object can
be said to be constant (the objects mass will be the same at
different locations in the Universe). The weight of an object is
not constant, since the force of gravity varies from place to
place
Slide 13
Day A single rotation of a planet
Slide 14
Year The time taken by a planet to make one revolution around
the sun.
Slide 15
Lunar Month A month measured between successive new moons
(roughly 29 1 / 2 days). The earths moon orbits the earth in a
period of 29.5 days. There are different phases of the moon
illuminated during its orbit..
Slide 16
Phases of the moon Lunar phase is the appearance of the
illuminated (lighted) portion of the Moon as seen by an observer,
usually on Earth. Moon The lunar phases changes as the Moon orbits
the Earth, according to the positions of the Earth, Moon, and Sun.
orbitsEarthMoonSun One half of the lunar surface is always
illuminated by the Sun (except during lunar eclipses), and is
bright, butlunar eclipses the portion that is visible to an
observer can vary from 100% (full moon) to 0% (new moon).full
moonnew moon
Slide 17
Eclipse An obscuring of the light from one celestial body by
the passage of another between it and the observer or between it
and its source of illumination. E.g. Lunar eclipse: an eclipse in
which the moon appears darkened as it passes into the earth's
shadow. E.g. Solar eclipse: an eclipse in which the sun is obscured
by the moon. Lunar Eclipse time lapse video (39sec)
http://www.youtube.com/watch?v=Xuej7_orvfM&feature=related
Total solar eclipse (2min)
http://www.youtube.com/watch?v=XMyqPxFh5Zw
Slide 18
Moon The natural satellite of the earth, visible (chiefly at
night) by reflected light from the sun. A natural satellite of any
planet. The earth's moon orbits the earth in a period of 29.5 days,
going through a series of phases from new moon to full moon. A
natural satellite or moon is a celestial body that orbits a planet
or smaller body, which is called its primary.celestial
bodyorbitsplanet
Slide 19
Artificial Satellites An artificial body placed in orbit around
the earth or moon or another planet in order to collect information
or for communication.
Slide 20
Planet The definition of planet set in 2006 by the
International Astronomical Union (IAU) states that in the Solar
System a planet is a celestial body that: is in orbit around the
Sun,International Astronomical UnionSolar Systemplanetcelestial
bodyorbitSun has sufficient mass to assume hydrostatic equilibrium
(a nearly round shape), and has "cleared the neighbourhood" around
its orbit.hydrostatic equilibriumcleared the neighbourhood
Slide 21
Sun The star around which the earth orbits. The sun is the
central body of the solar system. It provides the light and energy
that sustains life on earth, and its position relative to the
earth's axis determines the terrestrial seasons.
Slide 22
Solar System The collection of eight planets and their moons in
orbit around the sun, together with smaller bodies in the form of 5
dwarf planets, small solar system bodies (SSSB), asteroids,
meteoroids, and comets.
Slide 23
Galaxy A system of millions or billions of stars, and stellar
remnants, an interstellar medium (between stars) of gas and dust
and an important but poorly understood component tentatively dubbed
dark matter, held together by gravitational attraction. The Milky
way is the galaxy of which the solar system is a part; is located
is a disk-shaped spiral galaxy with approximately 100,000 million
stars.
Slide 24
Universe All existing matter and space considered as a whole;
the cosmos. The universe is believed to be at least 10 billion
light years in diameter and contains a vast number of galaxies; it
has been expanding since its creation in the big bang about 13
billion years ago.
Slide 25
Telescope An instrument designed to make distant objects appear
nearer, containing an arrangement of lenses, or of curved mirrors
and lenses, by which rays of light (electromagnetic radiation) are
collected and focused and the resulting image magnified.
Slide 26
Space Probe An unmanned exploratory spacecraft designed to
transmit information about its environment.
Slide 27
Asteroid A small rocky body (SSSB) orbiting the sun. Large
numbers of these, ranging in size from nearly 1,000 km across to
dust particles, are found esp. between the orbits of Mars and
Jupiter and a few pass close to the earth or enter the atmosphere
as meteors. 253 Mathilde The 253 rd asteroid to be discovered,
measuring about 50km across. Photo taken 1997 by NEAR Shoemaker
probe.
Slide 28
Comet A celestial object consisting of a nucleus of ice and
dust and, when near the sun, a tail of gas and dust particles
pointing away from the sun. Comet-Hale-Bopp-29-03- 1997
Slide 29
Meteor A small body of matter from outer space that enters the
earth's atmosphere, becoming incandescent -emitting light as a
result of being heated as a result of friction and appearing as a
streak of light.
Slide 30
Black Hole A region of space having a gravitational field so
intense that no matter or radiation can escape. Probably formed
when a massive star exhausts its nuclear fuel and collapses under
its own gravity.
