A Tour of the Planets
Alaina Oscroft
10/16/2010
CIS 1020
Word Final Project
Alaina Oscroft
The Solar System
A Tour of the Planets
It is difficult to imagine what lies beyond the atmosphere of our own beautiful planet.
The mysteries of the Universe may never be explained, but much has been learned about the
heavenly bodies that lie within our solar system. Let’s take a tour and see what is out there!
THE SUN-THE CENTER OF OUR SOLAR SYSTEM
The Sun is by far the largest and brightest object in our solar
system. The Sun may appear to have a solid surface, but, in fact, it is a
massive sea of extremely hot gases. There are cooler spots of the sun
which are typically referred to as sunspots. The Sun’s gravity governs the orbits of the planets,
making it the most influential object in our sky. It is the source of virtually all of the visible light
in our solar system, and its heat is the primary influence on the temperatures of planetary
surfaces. (Bennet)
MERCURY
Mercury is the innermost planet of our solar system and is the
smallest of the eight official planets. It is a desolate world with no rain,
wind, or life. If you were to stand on Mercury with your back to the sun, you would see stars
even in the day time due to the lack of air to scatter sunlight. The rotation and orbit of Mercury
give it days and nights that last about three Earth months each. Due to its proximity to the Sun,
Mercury is very difficult to see through telescopes, making it the least studied planet in the
inner solar system.
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CIS 1020
Word Final Project
Alaina Oscroft
VENUS
Venus is the second planet from the sun. Its surface is completely
hidden from view by dense clouds so little was known about it until a few
decades ago. Because so little was known about Venus, it was speculated that it was a lush,
tropical paradise, somewhat like Earth. In actuality, Venus’s atmosphere contains no oxygen to
breathe, and there is no liquid water. The surface is baked to an incredible 880 degrees
Fahrenheit. There is no relief from this heat even in the night time. The geology of Venus
features mountains, valleys, and craters, along with many signs of past and present volcanic
activity.
DID YOU KNOW?
Venus is the only planet in the Solar System that rotates on
its axis clockwise. All of the other planets rotate in a counterclockwise direction. (www.universetoday.com)
EARTH
Our home planet, Earth, is the only known oasis of life in our solar
system. It is the only planet with oxygen to breathe and its ozone protects us
from deadly solar radiation. Earth’s atmosphere contains just enough carbon dioxide and water
vapor to create pleasant temperatures. Blue oceans cover nearly three-fourths of Earth’s
surface, making its beauty striking. The polar caps are white with snow and white clouds scatter
above the surface. Earth is the first planet in our tour with a moon.
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CIS 1020
Word Final Project
Alaina Oscroft
MARS
The last of the four inner planets in the solar system is Mars. Mars is
larger than Mercury, but smaller than Earth. Mars has two tiny moons that
look like asteroids. Mars has many ancient volcanoes that dwarf the largest mountains on Earth.
Mars is frozen today, but there are signs of dried-up riverbeds, rock-strewn floodplains, and
minerals that form in water. This tells us that Mars had some warm and wet periods in the
distant past, offering the possibility that Mars may have once been hospitable to life.
JUPITER
Far beyond Mars, through an asteroid belt, we come to Jupiter, the
largest planet in the solar system. Jupiter’s mass is more than 300 times that
of Earth. Jupiter’s most famous feature, known as the Great Red Spot, is
actually a huge, long-lived storm. This storm is large enough to swallow two or three Earth’s.
Jupiter is made primarily of hydrogen and helium gas, and has no solid surface. Jupiter reigns
over dozens of moons and a thin set of rings.
SATURN
Saturn is famous for its spectacular rings. Of the four planets in the outer solar system,
Saturn’s rings are the most easily seen through a telescope. These rings
are made of countless tiny particles of rock and ice. Like Jupiter, Saturn is
orbited by many moons, most of which are small in size. Saturn’s most
fascinating moon is Titan, which is blanketed by a thick atmosphere. From probes and radar
mapping, it has been discovered that Titan with lakes of liquid methane and an erosion-carved
landscape.
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Word Final Project
Alaina Oscroft
URANUS
Uranus is much smaller than Jupiter or Saturn, but is much larger than Earth. It has more
than two dozen moons and a set of rings that are similar to Saturn’s, but much darker and
difficult to see. The most interesting feature of Uranus is that the
entire system of planet, rings, and moons, is tipped on its side. This
sideways axis tilt makes seasonal patterns more extreme on Uranus than any other planet in the
solar system.
NEPTUNE
The furthest planet from the Sun is Neptune. Neptune is almost identical to Uranus,
although it is more strikingly blue. Neptune has rings and numerous moons. It has an icy surface
that has features resembling geysers. These geysers spew nitrogen gas, rather than water, into
the air. Neptune has been visited by the Voyager 2 space craft, but no
further missions are currently planned.
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Alaina Oscroft
MOONS
The four outer planets of our Solar system are orbited by several moons of various sizes.
Each moon has a different surface and atmosphere. A few of the largest moons are:
Ganymede-This moon orbits Jupiter and is the largest in the Solar System
Callisto-This moon also orbits Jupiter and has a surface of water.
Titan-This moon orbits Saturn and is the second largest in the Solar System
Io-This moon orbits Jupiter and is the most volcanically active body in the Solar
System. (Booth)
Do all of the planets have moons orbiting them? The answer is, no. Only six of the planets have
moons orbiting them. Those six include:
1. Earth
2. Mars
3. Jupiter
4. Saturn
5. Uranus
6. Neptune
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Word Final Project
Alaina Oscroft
Sun
Mercury
696,000 km
2440 km
Venus
6051 km
Earth
6378 km
Mars
3397 km
Jupiter
71,492 km
Saturn
60,268 km
Uranus
25,559 km
Neptune
24,764 km
COMPOSITION AND CHARACTERISTICS
The planets are divided into two categories. The four planets in the inner Solar System are
referred to as Terrestrial Planets. The four planets in the outer Solar System are referred to as
Jovian Planets. Let’s see how these two types of planets, and the sun, differ:
Jovian Planets
Larger size and mass
Lower Density
Hydrogen and Helium material
No solid surface
Rings and many moons
Farther from the sun
Sun
Middle of the solar system
Largest object in the sky
Hydrogen and Helium material
Brightest object in the sky
Governs orbits of the planets
Contains 99.9% of the Solar Systems mass
Terrestrial Planets
Smaller size and mass
Higher Density
Rock and metal material
Solid surface
Few moons and no rings
Closer to the sun
(www.qrg.northwestern.edu)
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CIS 1020
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Alaina Oscroft
Bibliography
Bennet, Donahue, Schneider, Voit. The Essential Cosmic Perspective. Glenview: James Smith,
2007.
Booth, Robert L. The New Universe, Here, Now, and Beyond. New Yord: Book Publishing Group,
2010.
www.qrg.northwestern.edu. <http://www.qrg.northwestern.edu/projects/vss/docs/spaceenvironment/2-what-are-planets-made-of.html>.
www.universetoday.com. <http://www.universetoday.com/36687/rotation-of-venus/>.
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