Transcript Galaxies - TeacherWeb

Galaxies
By: Anthony Lambright
Introduction
• Galaxies are large space systems that
are made up of dust, gas, and several
stars. There is no limit to the number of
galaxies in the universe. At minimum,
the universe may contain 100 billion
galaxies.
Types of Galaxies
• There are four main types of galaxies, spiral, elliptical,
lenticular and irregular.
• Spiral galaxies consist of a bulge, disk, and a halo. The
disk includes new stars, planets, dust, and gas that all
rotate around the center which is called the Galactic
Center. The bulge consist of millions of old stars which
are burning out at this very second.
• Elliptical galaxies consist of a bulge and a halo, but they
lack a disk. Because they lack a disk elliptical galaxies
have more old stars than new stars. The elliptical galaxy
can be mistaken for the bulge of a spiral galaxy.
Types of Galaxies Continued
• Lenticular galaxies consist of only a disk, they have used
up most of their matter and power. As a result they have
very little stars and if there is a star it is an aged or old
star.
• Irregular galaxies consist of a disk and a halo. An
irregular galaxy has an irregular shape because it
doesn’t have enough gravitational force to pull itself into
a regular shape.
Lenticular galaxy
Irregular galaxy
Our galaxy
• The galaxy that we reside in is the Milky
Way. The Milky way is a spiral galaxy and
has around 400 billion stars. The Milky
Way is the second largest galaxy that has
been discovered, the largest galaxy is the
Andromeda Galaxy. The Milky Way is
large because it consist of one cluster of
30 other galaxies.
Inside a Galaxy
• Inside a galaxy are planets, stars, and
other smaller bodies in space. The planets
make up solar systems in the galaxies.
Solar systems have different numbers of
planets, suns, stars, moons, and other
matter formations. Other objects in space
can include comets, meteors, meteoroids,
asteroids, quasars (star like formations),
and nebulas.
Dark Matter
• 12 to 14 billion years ago the big bang
theory happened to make all the galaxies
and matter in the universe. Today galaxies
are still being formed. Particles that are
not made up of protons or neutrons that
were unable to create galaxies, planets, or
stars became what we call dark matter.
This is what scientist claim to be dark
matter, but they’re not really sure what it’s
purpose is.
Intergalactic Collisions
• Many collisions happen in the universe to
form many things. For example, thirty
different galaxies collided to make the
Milky Way. Also a planetisimal crashed
into the Earth to make the moon. In three
billion years our galaxy, the Milky Way, will
collide with the galaxy Andromeda.
Center of the Universe
• There is no actual center of the universe.
When the big bang happened all matter
didn’t expand out from the center of the
universe. Everything is still expanding, but
the Universe doesn’t expand from the
middle outward it expands equally
everywhere. Space never ends therefore
there was never a middle or end and there
never will be.
Bibliography
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<http://www.crecalde.com/Charlie/charlies_cosmos__milky_w
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Acten. ACT360° Media Ltd. , 1 Nov. 2009. Web. 1 Nov.
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<http://www3.actden.com/sky_den/formation.htm>.
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math.ucr.edu. Phillip Gibbs, 2009. Web. 1 Nov. 2009.
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The End