An Astronomical Tour
Objects in the Universe
Objects in our Solar System
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A solar system is a collection of
objects that are gravitationally
associated with a star
Objects in our solar system include
star, planets, moons, asteroids,
comets, meteors
Active Sun
viewed in
X-rays ->
<- Coronal loops
Planets
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Objects that orbits (revolve around) a star
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
(Pluto is a minor planet)
My very excellent mother just served us
nachos
Mercury
Venus
(UV)
Earth
Earth’s
Moon
Earth
and its
Moon
Earth and
its Moon
Mars
Jupiter
and the
four
Galilean
Moons
Saturn and Its Larger Moons
Uranus (true and false
color)
Neptune
Pluto and Charon (from HST
faint object camera)
Our
Solar
System
The Planets (in size
perspective)
Asteroids (Phobos, Deimos,
Gaspra)
Asteroid Belt
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Between the orbits of Mars and
Jupiter is a large “belt” of asteroids
There are also groups of asteroids
that orbit the Sun and cross the
orbit of the Earth from time to time.
Comets and the Oort Cloud
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Comets are “dirty snowballs”
composed of frozen water and dust.
As they approach the Sun they melt
and leave a stream of water vapor and
dust that is a “tail”
Scientists believe that these
originate from a large region filled
with comet cores called the Oort
cloud.
Comet Halley (March 1986)
Moving Out…
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Our solar system is a small part of a
large collection of stars, gas, and
dust called a galaxy.
Our galaxy is called the Milky Way
galaxy and is a spiral galaxy.
Galaxies
HST
Deep
Field
Photo of
Galaxies
Star Deaths
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When stars finish their life cycle
they may explode or throw out shells
of gas. Such an object is referred to
as a nebula (pl. nebulae)
Nebulae are common objects in a
galaxy.
Eskimo
Nebula
Orion
Nebula
Carina Nebula
Cat’s Eye Nebula
Sting Ray Nebula
(young)
Bug Nebula
Section of
the Eagle
Nebula
Other Objects…
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There are special classes of stars
called variable stars, neutron stars,
pulsars and black holes. These may
be stars in the process of evolving or
the result of a star explosion.