The sun is really
a star. It looks large and bright because it is closer to Earth than
any other star. It is 150 million kilometers away from Earth.
The sun is larger than the Earth. More than 1 million Earths could
fit inside the sun!
The sun is made of hot gases.
The gases give off light and heat energy. The light travels through
space to Earth. When the light from the sun hits the Earth, it turns
to heat. This heat warms the air around the Earth.
The sun is the center of our solar
system. All of the planets orbit (make a loop) around the sun.
Depending on where the planet is in relationship to the sun determines
the length of the year.
The moon is the
closest object to the Earth. The moon has no life on it. It
has no air or water like Earth. The surface is covered with rocks
and dust. Like the Earth it has tall mountains and flat plains.
There are also many craters on the moon.
The moon revolves around the Earth.
It takes one month to revolve around the Earth. The moon also rotates
(spins around like a top) as it revolves around the Earth. It also
takes one month to rotate. Since the moon rotates and revolves around
the Earth at the same speed, the same side of the moon always faces the
Earth. There is usually only 1 full moon per month.
The moon is the only planet that man
has visited and landed on. On July 20th, 1969 Neil Armstrong and
Edwin "Buzz" Aldrin landed on the moon. Michael Collins was
in the orbiter (the spacecraft that stayed in space above the moon).
Mercury is the closest planet to the
sun. It is a small planet made mostly of rock. Mercury is about
the size of the Earth's moon. It is covered with many "bowl shaped"
holes. These holes are called craters.
These were caused by volcanoes. Mercury is 59 million kilometers
from the sun and has no moons or rings.
Mercury's daytime last as long as
59 Earth days. The temperature during the day is as hot as an oven
(like cooking cookies!). During the night, which last 59 Earth days
as well, the temperature gets as cold as a freezer (storing ice-cream!).
The second planet from the sun is
Venus. Venus is about the same size as Earth. Venus is made
mostly of rock. It is covered with thick clouds. These thick
clouds trap a lot of heat. This makes Venus the hottest planet in
the solar system! Venus is 108 million kilometers from the sun and
has no moons or rings. Venus is the second brightest object in our
If you were to land on Venus you would
die from either the poisonous gas, be baked because of the heat or be crushed
because of the pressure.
Earth is the
third planet from the sun. Like the other planets closest to the
sun it is mostly made up of rocks. Even though Earth is mainly rock,
water covers most of the surface. Earth is the only planet with air
and water. Scientist believe Earth is the only planet with organisms
(living things) on it.
Earth has one moon and no rings.
It is 150 million kilometers from the sun. Earth rotates one time
in 24 hours. That is our day/night. The Earth revolves
around the sun in 356 days, that is our year. The tilt of the earth
and revolution around the sun determines our seasons; fall, winter, spring
The fourth planet
is Mars. Mars is known as the "Red Planet". It has a red rocky
landscape that is about half the size of the Earth. Mars is covered
with craters, canyons, mountains and the largest volcano in the solar system.
The volcano is three times higher than Earth's highest mountain.
The north and south poles of Mars
are covered by ice. Mars is 228 million kilometers from the sun and
has no rings and 2 moons. Each day on Mars is 24 hours, like Earth's
day. The year on Mars is 687 days, it takes this long for Mars to
revolve around the sun.
Scientist have recently received information
from space exploration vehicles that Mars may have some elements similar
Jupiter is the 5th planet.
Jupiter is also the largest planet in the solar system. Unlike the
first four planets, Jupiter is made mostly of frozen gases. These
gases make the surface "slushy". A spaceship would sink if it landed
on Jupiter. Jupiter has a large red spot on the surface. The
spot is really a wind storm that has been going on for over 300 years.
There is a thin ring of dust around
Jupiter. It has 16 moons and is 778 million kilometers from the sun.
It takes 10 Earth hours for Jupiter to rotate on its axis (this would be
1 Jupiter day). One Jupiter year takes almost 12 Earth years.
The sixth planet
is Saturn. It is the second largest planet. Saturn is also
made mostly of frozen gases. Saturn is known for its seven wide rings
that surround it. The rings are made of ice and dust. The ice
particles are as small as a fingernail or as big as a car!
Saturn has 18 known moons but scientist
think there are more. Saturn is over 1 billion (1,000,000,000) kilometers
from the sun! The "day" (rotation) on Saturn is 10 Earth hours.
A year (a revolution around the sun) on Saturn is about 29 Earth years.
Saturn was discovered in the early 1600's.
The seventh planet
is Uranus. It is much bigger than Earth. Like Saturn and Jupiter
it is mostly made of frozen gases. Uranus also is surrounded by rings
and has over 20 moons. Uranus rotates on its side. Scientist
think the reason could be because another large object crashed into it.
Uranus is 3 billion kilometers form
the sun. A day on Uranus last 18 Earth hours. The year on Uranus
is 84 Earth years. Therefore, Uranus will only go around the sun
1 time in a person's life. Uranus was discovered in 1781.
The eighth planet
is Neptune. Neptune is also made up of frozen gases and similar in
size to Uranus. There are strong winds and storms blowing around
the planet. It does have rings but they are very thin and hard to
see. Neptune has 8 moons. Neptune is 5 billion kilometers from
The Neptune day last 19 Earth hours
and the Neptune year last 165 Earth years. Neptune was discovered
The last planet
is Pluto. Pluto is also the smallest planet in the solar system.
It is smaller than the Earth's moon. We know very little of Pluto
because it is so far away. We can only get fuzzy pictures of its
surface. It is 6 billion kilometers away from the sun. Scientist
think it is made of ice and rock. Pluto is the only planet
that has not been visited by any type of spacecraft.
A Pluto day (1 rotation) is 6 Earth
days and a Pluto year (1 revolution around the sun) is 248 Earth years.
It was discovered in 1930.
Man has always
wanted to explore the unknown. The ocean and space are the
last 2 "frontiers" that need to be explored. Before any human went
into space animals were used to see how safe it would be. The first
animal was a dog. The country of Russia put a dog in space
during the year of 1957. The spacecraft lasted 4 days. Several
small monkeys were used as well. Some survived some did not.
Since the first rockets were sent
into space, man has walked on the moon, created a reusable spaceship (the
Shuttle) and sent probes to Mars. Man has been exploring space
since the late 1950's. Man first landed on the moon in 1969.
Neil Armstrong was the first man to walk on the moon and his famous quote
"One small step for man, one giant leap for mankind" has been a saying
for anyone doing something one would have thought impossible.
One of the tragic events in the space
exploration history happened on January 28th, 1986. The space shuttle
Challenger exploded only 73 seconds after take-off. All seven astronaunts,
including a teacher Sharon McAuliffe,
died. Even with such a tragedy, space flight and
exploration continues today.