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OBJECTS IN SPACE
By,
Jacob Emery
Introduction
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We live in a solar system in the vast Milky
Way Galaxy. The Sun is our central star,
orbited by nine planets, and containing
more than 100 moons, millions of rocky
asteroids, and billions of icy comets and
stars.
Galaxies
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Scientists believe that the number of
galaxies in the universe could be as few as
10 billion or as many as 100 billion.
Astronomers categorize galaxies primarily
by their shapes -- elliptical, spiral, and
irregular.
NGC 4242
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NGC 4242 is a very low
surface brightness
spiral galaxy in the
constellation of Canes
Venatici.
It is estimated to be 27
million light years away!
NGC 5792
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NGC 5792 is a spiral
galaxy, the most
common type.
Images of this galaxy
were taken at the
Lowell Observatory.
NGC 6946
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NGC 6946 is more than
15 million light-years
away.
NGC 6946 is a big spiral
galaxy that looks a lot
like our own galaxy, the
Milky Way.
Over the last century,
astronomers have
recorded six supernovae
in the galaxy.
NGC 3516
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NGC 3516 is one of
Astronomers favorites. They
keep turning their
telescopes toward it
because it is interesting and
easy to study.
NGC 3516 is near the Big
Dipper.
It's a spiral galaxy
containing hundreds of
billions of stars.
It's about a hundred million
light-years away -- close as
galaxies go.
NGC 4731
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This very dim galaxy
appears a bit bent out of
shape due to the
gravitational effect of its
neighbor.
NGC 4731 is an
estimated distance of 65
million light years away.
The background is
mottled with galaxies
perhaps hundreds of
times more distant.
Planets
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There are nine planets including Earth that orbit
the Sun.
Is our Solar System alone? Astronomers have
discovered planets orbiting several other stars,
but we have not found any Earth-like planets.
The inner planets are made up of mostly rock
and metal and the outer planets are mostly
made of ice and gas.
Saturn
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Saturn is the second
largest planet.
Saturn's rings are
made of ice and rock.
It spins so fast that it
bulges at the equator,
and stretches its clouds
into bands that encircle
the globe.
Saturn has more than
three dozen moons,
and it's encircled by
bright rings.
This view was taken by
the Hubble Telescope.
Mercury
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Mercury is the planet closest
to the Sun.
It is slightly larger than
Earth's Moon, and looks very
much like the Moon, with
craters scarring its rocky
surface.
Mercury flies along in its
orbit at an average speed of
29 miles per second – faster
than any other planet!
Venus
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Venus is the second planet
from the Sun.
It is the hottest world in
the solar system.
It has a thick atmosphere
that heats its surface to
almost 900 degrees
Fahrenheit (480 C).
Jupiter
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Jupiter is the largest planet
in the solar system.
In fact, it is more massive
than all the other planets
and moons in our solar
system combined.
Its core may be as hot as
54,000 degrees Fahrenheit
(30,000 C).
Mars
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Mars is the fourth planet.
Although Mars is smaller
and colder than Earth, it is
still quite similar to our
planet.
It has a thin atmosphere
and polar ice caps, and dry
riverbeds across its
surface.
Frozen or even liquid
water may exist beneath
the red Martian soil -perhaps providing a home
for living organisms.
This was taken by the
Hubble Space Telescope.
Stars and Nebulas
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On a really dark night, you can see about
1000 to 1500 stars.
Stars form deep inside vast clouds of
interstellar gas and dust called nebulae.
The nearest star to Earth is the one we
see every day – the Sun. It is 93 million
miles away.
Red Rectangle Nebula
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A dying star lights up
clouds of dust around it in
this nebula.
This old star began
blowing its outer layers
into space, one by one,
about 14,000 years ago.
Dust grains reflect light
from the star, creating the
nebula's layered look.
Eventually, the star will
lose all of its outer layers,
exposing its hot core,
which will cause vast
clouds of gas around the
star to glow like a neon
bulb.
Image from the Hubble
Space Telescope.
Fomalhaut
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This infrared image
from the Spitzer Space
Telescope hints that
one or more planets
may orbit Fomalhaut, a
nearby bright star
One side of the disk (at
the bottom of the
picture) is brighter than
the other. This could
indicate that a planet is
hidden inside this
portion of the disk, and
its gravity is causing
more of the dust grains
to congregate around
it.
Supernova 1987A
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Supernova 1987A is a
massive star in a nearby
galaxy that blasted itself to
bits.
The ring around the
exploded star spans about
one light-year. It formed
when the star expelled a
shell of gas about 20,000
years before it exploded.
Image from Hubble Space
Telescope.
M17 Nebula
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Clouds of hydrogen gas
mix with small amounts of
oxygen, sulfur, and other
elements of a region of
M17, a nebula that is
giving birth to new stars.
The nebula is about 5,500
light-years away.
The energy of hot, young
stars in the nebula causes
the gas to glow.
The different colors
represent different
elements.
Image from Hubble Space
Telescope.
M22 Star Cluster
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The globular cluster M22
is just one of several
bright star clusters
visible in the
constellation Sagittarius.
M22 contains several
hundred thousand stars
packed into a region of
space just a few dozen
light-years in diameter.
Its stars are some of the
oldest in the galaxy, at
more than 10 billion
years.
Comets
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Comets are a ball of frozen water and gases mixed with
solid chunks of rock.
There is a vast shell of comets that surrounds the solar
system.
Something disturbs the comet's orbit -- like the gravity of
a passing star -- starting it on a long fall toward the Sun.
As a comet approaches the Sun, some of its ice
vaporizes, freeing particles of rock as well. This material
forms a bright cloud around the comet. And some of the
material is pushed into a long, glowing tail.
Comet C/2001 Q4
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Comet C/2001 Q4 (NEAT)
streaks around the Sun in
this recent image.
The comet passed closest
to Earth in early May.
Image from the WIYN
telescope at Kitt Peak
National Observatory in
Arizona.
Comet Wild 2
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Comet Wild 2 appears to
glow in this image from the
Stardust spacecraft, which
flew past the comet in
January.
The dark part of the picture
shows craters, pits, and
bright spots on the surface.
The bright rays around the
comet show where gas and
dust is blowing into space
from "jets" on the comet's
surface.
It has a tail several million
miles long.
Comet Ikaya-Zhang
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Comet Ikeya-Zhang, was
in its peak brightness this
past February.
This false-color image
shows the comet's nucleus
in white and blue, and a
tail of electrically charged
water molecules in red.
Comet Borrelly
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Comet Borrelly slowly
tumbles through space in
this image.
The comet's nucleus, which
is a chunk of ice mixed with
rock, measures about five
miles long.
Ice is vaporizing from the
bright patch near the
center of the nucleus,
spraying a "jet" of gas and
dust into space.
Image from Deep Space 1.
Comet Encke
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Since its discovery in
1786, Comet Encke has
circled the Sun more than
60 times!
Encke orbits the Sun once
every 3.3 years -- more
often than any other
comet yet discovered.
Moons
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Most of the planets in our solar system
have moons — planet-like bodies that
orbit a bigger body.
Earth has only one moon, but some
planets have many: Jupiter, for example,
has 63 known moons.
A planet and its moons actually revolve
about each other.
Titan Moon
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Titan is the largest
moon of Saturn.
Astronomers cannot see
Titan's surface directly
because a cold, hazy
atmosphere envelopes
the big moon.
Image by the European
Southern Observatory's
Very Large Telescope in
Chile.
S/2001 U1
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S/2001 U1 is the 21st
known moon of the planet
Uranus.
It is a small chunk of rock
that follows an irregular
orbit around the giant
planet.
Europa
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Warm ice bubbling to
the surface creates
reddish patches on the
icy surface of Jupiter's
moon Europa.
A deep ocean of liquid
water may exist beneath
Europa's ice crust,
perhaps providing a
home for living
organisms.
NASA released the
image, which combines
two pictures from the
Galileo spacecraft.
Phobos
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American astronomer
Asaph Hall discovered
the moons of Mars 125
years ago.
Phobos, shown in this
image from Mars
Global Surveyor, is the
larger moon.
Its surface is covered
with impact craters.
The largest crater, at
top left, is about six
miles across and is
named Stickney.
Earth’s Moon
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The Moon probably formed
very early in the history of
the solar system when a
large object -- perhaps
several times the mass of
Mars -- slammed into
Earth.
Unlike Earth, the Moon has
no atmosphere, and no
water.
The lunar surface is
covered with craters, the
scars from countless
boulders -- some much
bigger than mountains -that struck it over billions
of years ago.
Asteroids
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The name "asteroid" comes from a Greek
word that means "starlike." When seen
through a telescope, an asteroid looks like
a faint star.
Asteroids are made up mostly of rock,
often rich in iron and other metals, and
perhaps some ice.
Mathilde
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A close picture of
Mathilde revealed the
asteroid’s heavily crater
surface.
One of only 4 asteroids
photographed up close.
First scanned in 1997.
Gaspra
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The surface of Gaspra,
shown in a Galileo
image, has been pitted
by asteroid collisions.
Grooves in its surface
may have been caused
by an impact that split
Gaspra from a larger
asteroid.
Galileo found that
Gaspra is about 22 by
14 by 12 miles.
It's covered with
impact craters, which
means it's taken a
pounding as smaller
asteroids slammed into
it.
433 Eros
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Images show the asteroid
433 Eros to have a 21mile-long solid body and a
face pockmarked with
craters.
Observations show that
Eros is left over from the
formation of our solar
system four and a half
billion years ago.
It hasn't been heated very
much, so it's still the
same jumbled up mixture
of rock and metal as
when it formed.
Ceres
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Ceres was the first
asteroid discovered back in
1801.
Ceres is only about a
quarter of the size of our
own Moon.
The surface of Ceres
consists of dark, carbonrich rock mixed with a fair
amount of water.
The picture at right is a
circular scar -- known as
the Manicouagan crater –
left when an asteroid
rammed into present-day
Quebec about 200 million
years ago.
Pallas
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As first, Astrnomers thought
Pallas was a planet, when it
was discovered on March
28th, 1802.
At right, This microscopic
sample of zircon is one bit of
evidence that a giant asteroid
slammed into Earth about 3.5
billion years ago, triggering
massive changes in the
environment.
Although there is no remaining
impact crater, a team has
found microscopic remains of
the collision in Australia and
Africa.
Conclusion
The more scientists
discover, the more
complicated our world
seems. Earth is a
warm, wet planet with
an oxygen-rich
atmosphere – the
perfect place for life, but
who knows what is yet
to be discovered?
Bibliography
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http://stardate.org/
http://www.svetn.org/Angel/section/default.asp?
id=2%2DBRE%2DSCIENC%2DCURR%2D1
http://www.astro.umontreal.ca/~opiomm/image
s/ngc6946/ngc6946.jpg
http://imagine.gsfc.nasa.gov/Images/news/ngc3
516_big.jpg
http://www.noao.edu/outreach/aop/observers/n
4731.html