Transcript Constellations

Constellations
By: Caitlin, Emily, and Jerrell
Background of Constellations
• Our modern constellation system comes
from the ancient Greeks.
• Constellations originated with the
Sumerians and Babylonians
• Knowledge of constellations then came to
Egypt where Greek scholars heard about
them and wrote about them.
• No one is sure exactly where, when, or by
whom they were invented.
• Only little detective work reveals a possible
origin for constellations.
• The Greeks recognized and named fortyeight constellations.
• Many constellations were also recognized by
the Arabs, Egyptians, and the Babylonians.
Zodiac Mythology
• The Zodiac constellations
should not be confused with
the signs of the zodiac
• Examples of the zodiac signs
are Cancer; the crab,
Sagittarius; the archer, and
Taurus; the bull.
• People believe that these
signs can tell them their
future through horoscopes
like in the newspaper
everyday.
• No one really knows who
exactly invented these
myths, but ancient Chinese
civilizations could have
something to do with it.
Constellations
• Constellations are groups of stars that
form patterns of imaginary things in
the sky and are defined by exact
boundaries.
• Animals, mythical gods and
goddesses, and heroes are examples of
these imaginary things created in
constellations.
• The term "constellation" can also be
referred to as the more noticeable
stars that seem to form a pattern in a
specific area.
Where are they
located?
• 29 of the constellations are
between the ecliptic and the
North Celestial Pole.
• 47 of the constellations lie
between the ecliptic zone and
the South Celestial Pole.
• 12 of the constellations lie on
the ecliptic, known as the
“Zodiacs.”
What are they composed of?
• Constellations are composed of groups of
stars.
How many are there?
• 88 constellations cover the entire sky in
both the Northern and Southern
Hemispheres.
• The area known as
the Zodiac is a band
about 18 degrees
wide centered on the
Ecliptic.
• They are no different
than other
constellations except
that they are patterns
in that 18 degree
band in the sky.
• The changing
positions of the Sun,
Moon and planets,
make other stars look
like they roam
aimlessly about the
Zodiac band, but
stars only move over
millions of years.
Band of
Zodiac
Constellations
Relationship with the Months
of the Year
• Much of astrology today is based on the
relationship constellations have with the
seasons.
Visibility of Constellations
• Annually, 55 of the 88 constellations come into view in
the night sky from our latitude.
• Constellations like Ursa Major and Cassiopeia can be
seen 8 out of the 12 months of the year.
• Zodiac constellations like Sagittarius and Scorpius can
only be seen 3 months during the year.
• Although, these constellations and a few others are
relatively bright and the easiest to learn.
• We actually are in pretty good location for seeing
constellations.
• In a very dark sky, there can be so many stars visible that
it is hard to pick out each of the patterns.
• Since Earth’s right side faces in different directions
throughout the year, it makes it possible to different
constellations at night.
Birth and Death of Stars
• The birth of a star starts when it first becomes dense cloud of gas.
• Hydrogen atoms then fall with increasing speed and energy (which
heats the gas) toward the center of the cloud under the force of the
star's gravity.
• Over for some millions of years, the temperature reaches amazing
temperatures and then hydrogen within the star ignites and burns in
a continuing series of nuclear reactions, marking the birth of a star.
• Stars expand as they grow old. their core runs out of hydrogen and
then helium, the outer layers expand, it cools, and become less
bright. It will then eventually collapse and explode.
• A star's life span and eventual fate are determined by the original
mass of the star.
Movement
• Constellations seem to move
across the sky because the
Earth is rotating on its axis.
• The Earth moves in a way
that makes it look as if the
constellations are moving,
creating an optical illusion.
• The constellations appear to
move from East to West
• We could say that Earth
rotates so we can see different
constellations.
• As the Earth continues to
rotate the constellations then
“apparently” move across the
sky.
In Conclusion…
• Constellations are groups of stars that
make patterns in the sky which create
imaginary things for the human eye to
see.
• We chose constellations, because of the
interesting patterns they create and the
myths of the Zodiacs.
• Constellations are important, because
they allow human imagination to go
beyond reality.
Works Cited
•
Free Online Psychic Chat N.p., n.d. Web. 25 Oct. 2009
<www.freepsychicsight.com/2009/08/who-invented-chinese-zodiac.htm
•
AbsoluteAstronomy.com N.p., n.d. Web. 25 Oct. 2009
<www.absoluteastronomy.com/topics/Sagittarius_(constellation)>.
•
Tools for Science N.p., n.d. Web. 14 Oct. 2009
<http://www.physics.csbsju.edu/astro/asp/constellation.faq.html#who>
•
Clackamas Community College N.p., n.d. Web. 30 Oct. 2009
<http://depts.clackamas.cc.or.us/haggart/whats
up/constellationvisibility.htm>.
Words Cited Cont.
•
Windows to the Universe N.p., 2008. Web. 14 Oct. 2009
<http://www.windows.ucar.edu/tour/link=/the_universe/conste
llations/constellations4.html>.
•
Science Encyclopedia N.p., 2009. Web. 14 Oct. 2009
<http://science.jrank.org/pages/1732/Constellation.html>.
•
Tour Egypt! N.p., 2005. Web. 14 Oct. 2009
<http://www.touregypt.net/astro/>.
•
University of Wisconsin-Madison N.p., 2009. Web. 25 Oct. 2009
<http://www.astro.wisc.edu>.
•
"Constellation." Wikipedia MediaWiki, 2009. Web. 30 Oct. 2009
<http://en.wikipedia.org/wiki/constellation>.