Transcript digital book, stars and planets

Stars and
Planets
By: Janet Borg
Stars and Planets
Stars and Planets
The sky is everywhere.
It begins at your feet, touches
the water in the sea, passes
over the grass in the fields,
surrounds the roofs of houses
and buildings, and then goes
higher….
Beyond the clouds…..
When you look up at the
sky, you see some amazing
things. In this book you will
explore some of the most
interesting objects beyond
the sky: the Sun, the Moon,
the planets, and the stars.
The Sun: The Source of Life
When you go outside
during the day, you
encounter the one
star in the whole
universe that is the
closest to us: the Sun.
Can you believe that
the sun is like the
stars in the night sky?
If the Sun were as far away as the rest of the stars, it
would only be a twinkling dot in the sky. And that
wouldn’t be much help to us here on Earth because the
sun provides us with light and warmth. Without it, there
would be no clouds, no rain, no plants or trees- no
possibility of life on earth.
Our planet, Earth, circles
around the Sun. Earth’s path
around the Sun is called
its orbit.
Earth
The Sun is an enormous ball
of burning and bubbling
gases. It was born about five
billion years ago. Now, its
life is just about half over.
But don’t worry. It will take
more than four billion years
for the Sun to burn out.
Earth receives just the right
amount of warmth and light
from the Sun. If we were
closer to the Sun,
everything would burst into
flame. If we were farther
away, Earth would be too
cold to live on.
The Sun’s Path
Before there were
clocks, people used
sundials to tell time.
A sundial is a pointer
attached to a flat
surface marked with
the hours of the day.
The sun casts the
shadow of the
pointer on the
current time. As
time passes, the sun
appears to move
through the sky (it’s
actually Earth
moving), and the
shadow on the
sundial moves, too.
East
In the morning, the
Sun comes up.
The Sun climbs.
It’s noon.
Have you noticed
In that the
sun appears in about the
same place every
morning? It always rises in
the east.
Throughout the
morning, the Sun
moves higher in the
sky. Watch the
shadows of the trees
get smaller.
The Sun is at its
highest point. This
is the time when
shadows are the
shortest.
West
Afternoon begins.
The Sun starts to sink.
As the Sun goes down,
shadows grow long again.
The shadows stretch in the
opposite direction from the
way they fell in the morning.
Now you know that
the Sun rises in the
east and sets in the
west. So, you can
easily find two of the
four points on the
compass. You can
use them to find the
other directions.
If you face the place
where the Sun rises
in the morning, you
The Sun sets!
are looking east. This
means that west is
At the end of the day, the behind you. South is
Sun sets in the western sky on your right. North
ablaze as it sinks lower and
is one your left.
lower in the sky.
The Earth spins on its axis like a top. It takes 24 hours –one entire
day for it to turn all the way around.
At the same time, Earth is also orbiting the Sun.
This voyage takes one year to complete.
Day and
Night
Since Earth is
spinning, the Sun only
shines on one side at
a time. On the side of
Earth facing the Sun, it
is day. It is night on
the side that is turned
away from the Sun.
When you get up in
the morning, children
far away are getting
ready to go home
after a long day at
school. And
somewhere else,
other children are still
sound asleep.
The End of the Day…
Little by little, the Sun disappears
in the west and night falls.
The first thing you may see in the
night sky is a twinkling light near the
setting Sun. It’s Venus, the planet
sometimes called the Evening Star.
Venus shines because the
clouds that surround it reflect
the sunlight like a mirror.
…the Beginning of Night
Then, as the sky grows ever
darker, the real stars appear.
At first, you see dozens of stars. And
then, hundreds and thousands.
A galaxy is a collection of
stars. The galaxy that we
live in is called the Milky
Way. Its billions of stars
stretch across the sky in
a twirling spiral. Billions
of galaxies make up the
universe.
Soon, the sky is filled with a
multitude of stars. Try counting
them some evening.
Queen of the Night
The Moon
Some nights, you look at
the dark sky and
discover a thin sliver of
light peeking out from
behind a tree or
between two buildings.
Or, you may look up and
see a huge, round, disk
lighting up the sky. It’s
the Moon!
The Moon is the Earth’s satellite. It makes a complete circle around our
planet every 28 days. As the Moon orbits the Earth, it also makes the
yearly journey around the Sun with us.
The Moon doesn’t create its own light like a star does. It merely
reflects the Sun’s light. Its different “shapes” are called phases.
The phases happen because even though the Sun always shines on one
half of the Moon, we see different parts of the lit up half each evening.
Think of it as a game of hide-and-seek between the Sun, the Moon and Earth.
Mercury
The Solar System
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto
Planets orbit around stars.
The nine planets in our
solar system circle our
star, the Sun.
Our calendars and clocks are based on the movement of the Earth and Moon.
One year is measured by the time it takes Earth to travel completely around
the Sun. One month is about equal to the time it takes the Moon to orbit
Earth. One day is the length of time it takes for Earth to rotate once around
on its axis.
…To look at the stars always makes me dream.
-Vincent van Gogh