The Sun is a star—the closest one to Earth. It is a large ball of very hot gas. The air we
breathe and the Helium in a balloon are both gases. It is over 5,500 °C at the surface, and
much hotter at the centre, about 15 million °C. The Sun is made of mostly hydrogen (70%)
and helium (28%). It turns much hydrogen into helium every second, thus creating heat
and light.

The Sun makes light and heat that warms the surface of the
Earth and allows plants to
grow. We can get food from plants, and we can burn wood and other parts of plants to
cook, warm our houses, and make cars go. Without the Sun there would be no life on

Sun Facts
  • Never look directly at the Sun
  • If you looked at the Sun in a telescope, you could go blind.
  • The Sun is 150,000,000 km (93 million miles) away from Earth.
  • The Sun's light takes 8 minutes to reach us on Earth. That means that if the Sun
    blew up, we wouldn't see it blow up until 8 minutes later!
  • The temperature of the Sun's light decreases as it travels farther.
  • Every second, the Sun turns over 4 million metric tons of gas into energy. That's
    881,849,000,000 pounds!
  • The Sun is as wide as 109 Earths.
  • The Sun is so hot that a piece of it the size of a pinhead could kill someone 160
    km (100 miles) away.

Did You Know?
  • Some people from long ago thought of the Sun as a god. They did not want the
    god to be angry with them. To keep the Sun happy, they offered it gifts such as gold
    and food.
  • Heat from the centre of the Sun takes a million years to reach the Sun's surface.
    Once the heat leaves the Sun's surface, though, it only takes it 8.5 minutes to
    reach Earth!

In a Nutshell:
The Sun is our closest star. It is a member of the Milky Way galaxy. The Sun is a yellow
dwarf star, which means it is a medium size star. It is believed to be over 4 billion years
old. The Sun spins slowly on its axis as it revolves around the galaxy.

The centre, or core, of the Sun is very hot. A process called "nuclear fusion" takes place
there. Nuclear fusion produces a lot of energy. Some of this energy travels out into space
as heat and light. Some of it arrives at Earth! Streams of gas particles known as the solar
wind also flow out from the Sun.

On the Sun's surface, we can see storms. We call these storms "sunspots" because they
look like dark spots on the Sun's surface. The Sun also produces big explosions of
energy called solar flares. These flares shoot fast moving particles off the Sun's surface.
These particles can hit the Earth's atmosphere and cause a glow called an aurora.

How big is the Sun?
The Sun is very big - much, MUCH bigger than the Earth! It is more than a million km (109
Earths) across and contains more than 99.9% of the Solar System's mass. If you could
stand on the surface of the Sun, you would weigh 28 times as much as you do on Earth
because the Sun has more mass and therefore more gravitational pull than earth.

More than a million Earths could fit beneath the surface of the Sun. It doesn't look that big
from Earth, though. That's because the Sun is so far away. Compared to other stars, the
Sun is about average-sized. There are much bigger stars, and much smaller stars.

A very thin solar wind of gases blows from the Sun all the way to the edge of the
System. When it gets there, the gases mix with those coming from other stars.

What is the surface like?
There is really no actual surface on the Sun, but the whole sun is made out of gases, fire,
and plasma. The gas becomes thinner as you go farther from the centre of the Sun, but
there is no obvious edge. The part we see when we look at the Sun is called the
photosphere, which means "ball of light". We call it the surface of the sun because that's
where most of the light we see comes from. There is actually a lot of material from the
Sun above the photosphere, and some of the gas is even blasted away to great distances.

How does the sun make light and heat?
The Sun is the main source of energy for the
Earth. This energy is made deep inside the
Sun in a process called nuclear fusion. Four hydrogen atoms are fused together to make
one helium atom. Some of the leftover matter turns into energy. This is the same way
energy is released in a hydrogen bomb.

Core: The centre of the Sun is very dense. It's about 12 times as dense as lead. That
means that a gallon of the gas from the core of the Sun would weigh half a ton. It's also
very hot - about 15,000,000 °C. This region is where most of the nuclear reactions are
taking place.

Radiative zone: In this zone the light and heat produced in the core fight their way out
towards the surface. The gases that make up the zone are very dense and keep
absorbing and emitting the rays. Have you ever tried to run through water? That's what it's
like for light waves in this region of the Sun. Light can't go very far at all before it runs into
something. Then it bounces off in a different direction. The light doesn't get very far this
way. It can take a single ray of light a million years to get out of this zone.

Convection zone: Have you ever seen the air shimmer above a fire? Perhaps you've been
told it's because heat rises? Actually, it is the hot air that is rising. Hot gases get lighter
and rise. Cold gases get heavier and sink. In this zone, the gases are less dense. They
behave like air in a fireplace. Gas at the bottom of the zone gets heated up from below. It
rises to the surface, gives off its heat to space, and sinks again. The gas in the convection
zone forms currents like those in Earth’s oceans and atmosphere. The currents are
called convection cells.

Download Sun Printable eBook
Get Acrobat Reader Now
Join the Mailing List
Enter your name and email address below:
Subscribe  Unsubscribe 
Home   eBooks       Audio Books   Lit Arts    Language      Pre-K      Free ESL Resources     Online Games    Book of the Day       Game of the Day
AddThis Social Bookmark Button
Our Solar System
The Sun
Our Solar System
This comprehensive book
contains information on
all major planets, major
star constellations, space
exploration and our solar
system. Included are fact
sheets, fast facts,
wordsearches, crossword
puzzles, Q's & A's,
Student Activity Sheets,
Teacher/parent resources
and tips, lesson plans and
crafts and activities.  
Preview entire book 208
The Chinese lunar calendar
dates back to the second
millennium BC. The Chinese
calendar is cyclical. Each
cycle is made up of 12 years;
after the 12th year, the cycle
is repeated.  
This book
contains comprehensive
teacher/parent resources,
lesson plans and activities
relating both to the Chinese
Zodiac and to the Chinese
New Year. A Fun interactive
learning experience for Gr
K-5  with a particular focus
on adjectives,  
characteristics and traits.  
Preview the entire book here