INTRODUCTION

Have you ever thought about the vastness of the universe in which we live? Perhaps you have not given much thought to this subject until now. Even if you have, one can still hardly imagine the huge size of the universe. Let us try to explain how big it really is with an example. What is the biggest width you can think of? The distance from one side of the city you live in to the other may seem pretty big to you. Alternatively, it may well be that you have travelled all the way from the east to the west of your country and couldn't help but be amazed by how big it was. Some of you might have travelled to distant countries. Nevertheless, always keep in mind one important fact! Even if you travelled all around the whole world, that would still be too tiny to help you imagine the enormous size of the universe. That is because the size the Earth occupies in the entire universe barely compares to the size of a speck of dust.
This might surprise you, but it is the truth; the planet Earth is only a speck of dust in comparison to the whole universe.

Little cars placed on a ball topple over on to the floor. Have you every wondered how we stand on our Earth?

Dear children! Now think about our Earth, a tiny speck in this enormous universe. Every day you wake up in your homes on this round ball. The roads that take you to school are also built on it.
Now consider this for a moment! If you put toy cars on top of a ball in your hand, would they be able to stay on it? Certainly not. And yet you spend all your day on this round planet, playing and enjoying yourself with your friends without falling off!
Now, think about the Sun. How could you warm yourselves, and where would your light come from without this yellow ball of fire? Would you be able to go swimming and have a dip? Would you be able to go on picnics with your family or classmates? Absolutely not! You wouldn't be able to do any of these things, because without the Sun, there would be no living things on Earth. Not only the plants, trees, birds, insects and the pets that you love so much, but also your mother, father, friends, brothers or sisters and even you yourself would not be around.
These two examples about the Earth and Sun reveal the importance of the heavenly bodies and their features for our lives. We are going to give you plenty of similar interesting examples in this book. It is very exciting to learn about the universe through these examples. You must also share what you learn with your mother, father, family and friends. They will also enjoy learning about these thought-provoking topics.
As you read this book, you will see that Allah our Creator created our universe and all the creatures in it. You will also see that Allah has created the Sun, Moon and Earth and everything in the universe, so that we could lead our lives most enjoyably and comfortably, and to test us and try us.
Now, let's start our wondrous journey through the universe.

ARE YOU READY!!!!

CHAPTER 1: CREATION OF THE UNIVERSE

Have you ever wondered how the endless universe we live in came into existence? How did the enormous Earth, Sun, Moon and stars come into being? Did you know that the universe is full of many interesting things as well as the Earth, Moon and the Sun? Did you know that a very delicate balance exists in the universe that provide exactly the right conditions for life?
Now let's start learning the answers to these questions, and how Allah created the universe.

Once Upon a Time There Was No Universe!

In ancient times, man's knowledge of space was quite limited. The equipment needed to explore the sky was not as advanced as it is today. Therefore, people sometimes had strange ideas about how the universe originated. The idea that the universe had always existed was the funniest. That is to say, before man had telescopes and instruments to examine the heavens with, some ignorant people suggested that the universe did not have a beginning but had existed for ever and would continue to exist for ever.

The fact hat there is a sculptor who designed and made this statue reminds us that there must also be a designer who made us, and that nothing can occur spontaneously.

However, that was illogical! Your house and school building were built on particular dates. Even the lines you are reading were written at a certain time. Similarly, you, your mother and father have birthdays. That means everything, whether living or non-living, comes into existence at a certain time. Saying, "The universe has no date of origin, because it has always existed" is ridiculous. No one believes that now.
Let us give you an example: on your morning journey to school, imagine that you took a different route and found a statue. What would you think? You would certainly think, "A sculptor made this statue and placed it here," wouldn't you? Well, what would you say if one of your friends said, "No, this statue has always been here; nobody carved it"? You would probably tell him, "Don't be ridiculous! Every work of art has a maker!" Wouldn't you?
Those who claim that the universe has always existed have a more ridiculous way of thinking than your friend who argues that the statue has always been there. A statue is only a piece of sculpted rock, but the universe consists of many heavenly bodies and systems much more delicate and intricate than a piece of rock.
Thanks to astronomical discoveries, the mistaken nature of this assertion that the universe has always existed became obvious. These studies revealed that, like everything else, the universe also had a beginning.
The first man who proved that the universe had a beginning was the astronomer Edwin Hubble. (Let us remind you that an astronomer is a person who studies space, the stars and galaxies.) Hubble worked with a giant telescope. One day in 1929, he realised that the stars were moving.
These are not ordinary random movements. Stars are continually moving away from us. Furthermore, they are also moving away from each another. A universe in which everything moves away from everything else means a universe that is constantly growing larger.
Not until a hundred years ago did people understand this. Today, all scientists agree that stars are moving away from each other as well as away from Earth.
This movement of the stars is a very important piece of information about the creation of the universe. The fact that the stars are steadily moving away from each other indicates that they were at one time closer together. Scientists computed that 15 billion years ago all the matter in the universe was gathered together in a single point as small as the tip of a needle. Our universe came into being when that tiny point exploded.
Now let us note down one by one what we have seen so far:
- Stars move continually;
-. Stars are moving away from us;
-. If time could be turned back, we would see stars coming closer together.
This would continue until the entire universe was gathered together at one point.
If we went a little further, this point would also disappear. This means that the universe came into existence from nothing: Allah created it.
You might get a better idea of what "nothing" means by answering these three simple questions:
1. How old were you one year ago?
You might answer "A year younger."
2. If you counted your age back year by year, what age would be the last one you would get to?
Your answer would be "one". A year after your birth, you were one year old. At birth, however, you were not old enough to have an age. This could be expressed as "zero age".
3. Think about the year before your first birthday! How old were you then? Where were you?

If we could travel back in time, these pictures of you would continue in the opposite direction until the time you did not exist yet.

You should have answered that by saying, "I wasn't around then."
You didn't exist at all before your mother became pregnant.
If we also turned time back for your body, you would see that your body would also disappear at the end of this operation. For every year we went back, your body would become smaller and smaller, until finally you would become a baby in your mother's womb. If this operation were carried still further, you would reach the time when your mother was not yet pregnant.
There was no universe before Allah created it. When we rewind time, the universe also becomes younger. It gets smaller until it becomes an insignificant point and finally disappears. All these indicate that the universe has been "created".
Meanwhile, let's remind ourselves that we use the word "creation" when we want to explain that something is brought into being from nothing. Only Allah can cause something to exist from nothing. In other words, only Allah can "create" something. People can also make things that did not exist before. For instance, they can paint pictures. They can build ships. However, the truth is that people can cause something to exist using the materials available in this world and by imitating things already existing in this world. Therefore, we cannot call this "creation". Creation is bringing something into being from nothing without prior examples. Allah has created everything in the universe, including Earth, from nothing.

Can you draw something you have never seen before? This is unlikely because only Allah can create something without a prior example. Even the things artists make up out of their heads are made up of things they have already seen.

Man imitates what Allah has already created, even if painting a picture. If we asked you to draw a picture of a landscape on a sheet of paper, what would you draw? Most possibly you would paint the Sun, a mountain, a few green trees, a rainbow and the sea. However, have you ever thought that it would be impossible for you to draw a tree if you had never seen one? Think of a person who is blind from birth. He can only know that the Sun is round and bright, if somebody describes it to him. He can only have an idea about something if he sees it.
Dear Children! As these examples show, only Allah has the power to create something without a prior example. The Qur'an, the Book Allah sent to all humanity as a guide, informs us:

He is the Originator of the heavens and the earth.... (Surat al-An'am: 101)

Now, it is time to learn how Allah created the universe. You should be curious to hear how such a great event took place. 

THE BIG BANG AND
THE EXPANSION OF THE UNIVERSE 

You know that billions of years ago the universe was only a tiny speck. It is now time to learn how all of a sudden this tiny speck started expanding.
You probably watch cartoon films on TV. Generally, an enemy chases the hero in these films and the hero does anything he can to escape. One of the things he frequently does is to use dynamite. For example, Bugs Bunny's enemies place dynamite in his home, or Road Runner's enemies lay dynamite in his path. In each case, these heroes manage to escape the dynamite with great skill.
Now, try and visualise one of these explosions. For instance, the hunter chasing Bugs Bunny puts explosives in his underground home. What happens when they explode? The soil is scattered around and the pieces move away from one another, right? Before the explosion, the pieces of soil remain together. However, after the explosion, the tiny pieces of soil scatter around and move away from one another.
Billions of years ago, the universe came into being after an explosion. Many pieces came into existence with this explosion. These pieces moved away and scattered around, just like the bits of soil scattering around. Then they started to form the universe and the planets etc.
This explosion, which was the beginning of the creation of the universe by Allah, has come to be called the Big Bang. The moment this great explosion took place, the universe started constantly growing and expanding, and is still expanding today.
Before continuing with the next section, let's recap a few points we made earlier:
1. A long time ago, there was no universe;
2. The universe came into being with the explosion of one tiny speck;
3. After the explosion, incredible numbers of particles came into existence which came to make up our universe, and these particles started moving away from one another;
4. The universe expands as the objects in it move away from each other.
These are all evidence of Allah's infinite might. Even if all the people in the world came together, they could never make even a bad imitation of the universe. Even if all the materials available on earth were gathered together, man would still fail to imitate an explosion as big as the Big Bang. All power belongs to Allah, the One Who creates everything. Reading the next passage, you will better understand the infinite nature of Allah's power and wisdom.

ORDER EMERGES OUT OF AN EXPLOSION

A bomb explosion devastates everything close to it. After an explosion, no orderly structure comes into existence by accident.

Dear children, as you can also imagine, no explosion brings about an orderly structure. On the contrary, an explosion destroys existing order. It damages everything around it. A high-explosive bomb can reduce huge buildings to nothing. The most powerful bomb in the world is the atom bomb. When dropped, this bomb devastates everything in its target, in some cases entire cities.
The Big Bang created a more powerful explosion than billions of atom bombs. The big bang, however, mysteriously produced the opposite effect and established a perfectly orderly world. The world we know, carefully designed to suit our needs, came into existence after this explosion.
How do you think the Big Bang produced such perfect order?

The sandcastle in the picture could not have formed by accident after an explosion. Similarly, after the Big Bang, our planet Earth with all the living things on it could not have come into existence by itself, without Allah's intervention.

Allah created the universe from nothing by means of that big explosion. Obviously, our Lord also makes the perfect order in the universe.
Any answer other than the one above is wrong. For instance, saying that this order came into existence by chance after the explosion is irrational. Let's make an analogy to better explain why:
What would happen to the sand if a bomb were dropped on the beach? The sand particles would be scattered randomly this way and that, wouldn't they? What would you think if someone said that a castle came into existence because of an explosion on the beach? You would probably think him insane or think that he was telling a lie. Similarly, a person who claims that the order in the universe came into being by itself is mad. There are countless details, examples of balance and perfect order in this giant universe, which are incomparably more complex than a sandcastle.
In conclusion, the perfect order in the universe proves that the universe did not come into being by itself. Every order and balance existing in the universe is a sign of Allah's infinite wisdom.

INFORMATION THE QUR'AN PROVIDES ABOUT THE UNIVERSE

The Qur'an is the Noble Book Allah sent to people. It provides the most accurate information on every issue. That is because every line of the Qur'an is the Speech of Allah, the Exalted in Power. However, during the period the Qur'an was revealed, science and technology were not as advanced as in our day. Therefore, until recently, no one could conduct research on the information the Qur'an provided. Today, however, there has been great progress in science and technology. Almost all developments in science are in agreement with the information the Qur'an gives. For instance, the Qur'an informs us that the heavens and the earth - i.e. the universe - were initially sewn together, but then Allah unstitched them. In the Qur'an, this scientific fact is described as follows:

Do those who are disbelievers not see that the heavens and the earth were sewn together and then We unstitched them… (Surat al-Anbiya': 30)

Let's examine the verse together:
- The word "heavens" stands for all the "skies" i.e. outer space.
- The statement "The heavens and the earth were sewn together," describes everything in the universe being initially all together.
Finally, the statement "We unstitched them" makes clear that the universe broke into pieces with the explosion.
This example proves two important facts:
- The Qur'an is a revealed Book definitely sent by Allah,
- The information provided by the Qur'an is always the most accurate information. Since Allah, the Creator of the entire universe, sent the Qur'an, surely He is the One Who knows what He has created.
In this chapter, we saw that Allah created the entire universe from nothing. Now let's set out on a journey through the universe, which is the demonstration of Allah's infinite power and knowledge.

CHAPTER 2: THE UNIVERSE

In this chapter, we will dwell on the planets and other bodies in the universe. The Sun, Moon and Earth are among the ones we are most familiar with. There are, however, other celestial bodies in the universe you are not able to see.
Think about cartoon films or movies about space! The space above the clouds is full of stars, planets and meteorites that you have seen in these films. Each one of these is called a celestial body. Billions of these celestial bodies come together to form the giant collection of star systems we call galaxies. All celestial objects are enormous. For instance, our planet Earth is really quite small in comparison with the other celestial bodies. Despite this, it is big enough to hold human beings, animals, mountains, oceans and everything else you can think of.
Now let us proceed to the giant collection of star systems, the galaxies where billions of stars exist together. 

GALAXIES

Galaxies are composed of billions of stars. (Stars are big celestial bodies such as the Sun. Neither the Earth nor the Moon is a star.) There are about three trillion stars in the biggest galaxy. In a galaxy of an average size, there are about 200 to 300 billion stars, while there are about 100 billion stars in a small galaxy.
Now let's stop and think for a moment: What does the number one billion mean to you? For example, if you put two zeros next to the number one, it becomes 100. If you add one more zero to this number, it becomes 1,000. Add another zero and now you have the number 10,000 (ten thousand). Can you count up to 10,000? Maybe you can, but this will probably take a long time. Meanwhile, we still have not reached a billion. Then let us add two more zeros to 10,000. Now we have 1,000,000 (one million). We are still short of the number of stars in galaxies. However, if you put three more zeros next to 1,000,000, you reach the number 1,000,000,000 (one billion). Can you count up to 1,000,000,000? Let's answer this outright: Counting up to one billion would take a few decades, a decade being a period of ten years.
Now we have almost reached the number of stars in galaxies. If you put two more zeros next to the number 1,000,000,000, it becomes 100,000,000,000 (one hundred billion). This is the number of stars in the smallest galaxies.
Now do you have some idea of the size of the universe? If you spent all your life doing nothing but counting numbers, you would still fail to count all the stars in space. Allah, the Creator of the universe, has created this vast space that you are unable to imagine from nothing, and He encompasses every point of this immense universe every moment. Allah knows and sees every being in our giant universe, and everything that happens. The infinite power of our Lord is related in the Qur'an as follows:

... He knows what is in the heavens and what is on earth. Allah has power over all things. (Surah Al 'Imran: 29)

Now let's return to our topic and try to learn more about the galaxies.
In galaxies of average or large size, there exists a galactic centre. Around the galactic centre are arms rotating at immense speed. These arms are made up of stars, gas and dust clouds.
With their arms and centres, galaxies are the biggest celestial bodies in space. These giant celestial bodies also form clusters of celestial bodies. There are thousands of galaxies in some galactic clusters. Moreover, these galactic clusters form other clusters of celestial bodies. This regular clustering goes on and on, getting bigger and bigger.
Now let's go over what we have seen so far:
- Galaxies are composed of billions, even trillions of stars.
- The big and average galaxies have galactic centres.
- The galaxy has arms made up of stars, gas and dust clouds. These arms spin around the galactic centre at great speed.
- The galaxies come together to form galactic clusters. Sometimes, there may be thousands of galaxies inside a galactic cluster. The galactic clusters also come together in clusters of clusters.
Keep in mind that a galaxy composed of 100 billion stars is a small galaxy, not to mention that every star is at least as big as the Sun. In addition, there are both large and small planets such as our Earth that spin around many of these stars.
Now, consider the following: Could billions of stars gather together by chance in an orderly manner? Could the stars spontaneously establish an order in which they can move without colliding with other celestial bodies (for instance our Earth and other planets)?
These are all unlikely. This means that the stars' spinning and moving at great speed without colliding with other celestial bodies since the first day of their existence is a sign of the existence of a Creator, a Planner and an Organiser, Allah, the Ruler of the universe. Allah has created countless paths for the planets, stars and comets in space. All these celestial bodies follow their own paths without colliding with one another.
Now let's continue our journey with our galaxy.

The Milky Way 

The Milky Way is the name of the galaxy in which our Earth is located. The Milky Way galaxy is enormous. As is the case with all big galaxies, the Milky Way also has a galactic centre. You will probably remember what a galactic centre is since we discussed it in the previous section. The stars inside these centres are older stars; they are red or yellow in colour. The stars in the arms of the galaxies are mostly young and hot stars of blue colour. These aside, gas and dust clouds exist in these arms.

SaThe arrow shows the location of our Earth in the Milky Way.

The Milky Way has the shape of a spiral; in fact, the shape of the galaxy is identical to a "pinwheel". That is, it has arms at the centre extending towards the outer parts. There are four arms. One of these is the "Hunter Arm". The group of planets called the "Solar System" is located in this arm, and our Earth is one of the planets within this group.
Our Solar System is located a little more than one half of the way out from the centre of this spiral-shaped galaxy. The Sun (and our solar system) is revolving around the centre of the galaxy, and makes a complete revolution every 220 million years or so.
The giant Milky Way has maintained this form and movement for billions of years. Although the stars in it revolve at great speed, they preserve their own paths.
However, it is not possible for stars to form such patterns on their own. It is also impossible for them to reach agreement; that is to line up in the most appropriate way and to move in an organised manner. Nor is it possible for the laws that govern these stars to have formed by themselves. Think about the stones in your garden! Could these stones take a decision and say, "Let some of us form the centre and the rest take up positions on the arms, and then perpetually spin in the garden"? Would you believe someone who says he had heard the stones talking to each other in this way? No doubt, you would not. By the same token, saying that the Milky Way came into existence by coincidence and the stars started to move of their own accord would be as funny as the example of stones in the garden. Keep in mind that celestial bodies are non-living, unconscious beings just like the stones in the garden.
No power other than Allah is capable of creating billions of giant stars in an orderly universe. Allah created them and the laws to which they are subject. They all testify to His power and control over the entire universe. For that reason, each piece of information we learn about the universe reminds us of Allah's existence and His creation of it. This way, Allah also shows us His infinite wisdom and knowledge.
Now, let us proceed to the stars.

STARS

Stars and planets come into existence through the compression of the masses of gases and dust in space called "nebulae". For this reason, nebulae, the sources of celestial bodies, have a major role in the universe. Nebulae do not have any light of their own as is in the case of stars. Therefore, it is hard to see them. They become visible only when their inner gas gives off light or if they reflect the light coming from stars. We can also see them when they pass by a source of light.

Looking from a distance, we see stars as pentagons or hexagons. Actually, stars are round, just like our Sun.

Stars give off heat, light and energy. Apart from tiny stars, there are also very large stars. Surprisingly the Sun is not a major star as we believe to be; There are many stars much bigger than it.
Well, did you know that stars also have life spans? Stars are not living beings, but just like them, they are born, lead a life and die.
As we have shown, stars come into existence in the nebulae. A huge star's life often ends in an immense explosion, the material that makes it up being scattered in every direction. From these scattered pieces, there emerge the elements that contribute to the construction of relatively smaller stars and planets. The Sun and planets within the Solar System and our Earth have come into being following the explosion of a huge star in the past.
Now, let's take a tour in our Solar System and see how it looks! 

THE SOLAR SYSTEM

In our Solar System, there are nine major planets with 61 satellites and countless asteroids, all revolving around a single star called the "Sun". The Sun is located at the heart of the Solar System.
These nine planets, which are a part of our Solar System, revolve around themselves as well as the Sun in an orderly pattern. Let us review the names of the planets starting from the one closest to the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. As you can see, our Earth is the third planet from the Sun.
Every planet within the Solar System has different features. The temperatures on some of these planets are high enough to cause lead to melt. Others, on the other hand, are totally covered with ice. Some of the planets are entirely composed of gases. Moreover, some planets are as tiny as the Moon.
There is a very harmonious relationship between the satellites and their primaries. (In astronomy, a primary is something that another body revolves about. Earth's primary is the Sun; the Moon's primary is Earth.) Planets attract their satellites. However, satellites balance this attraction. Without such a balance, satellites would become stuck to the planets or break loose into space.
For instance, if the Moon rotated slower, it would plunge into Earth at an immense speed. This would mean the end of Earth. If it rotated faster, it would gradually move away from Earth and would no longer be our satellite.
Now let's look at the Sun, the heart of our Solar System.
The Sun

The Sun is the greatest celestial body in the Solar System. It consists of very hot, glowing gases. Every second, explosions occur all over its surface, for the Sun itself is an enormous nuclear bomb. These surface explosions are equivalent to the energy given off by millions of atom bombs. They shoot off flares 40-50 times larger than our Earth.
The Sun looks like a ball of fire and gives off enormous heat and light from its surface. If the Sun did not exist, it would always be night for us, and our whole world would be covered with ice. Most importantly, there would be no life on Earth.

The surface temperature on the Sun is 6,000°C (11,000°F), while its internal temperature is 12,000,000°C (21,600,000°F).

Space (you will also remember the films about the space) is a very dark, huge, empty place. Our Earth is a celestial body in this dark expanse, and no other celestial body is near enough to illuminate and heat our Earth.
The light from the Sun is very bright. You have probably tried looking at the Sun on a clear day. After looking for a few seconds, your eyes were dazzled, weren't they? Because its light is very bright, looking straight at the Sun is very dangerous for our eyes. As well as that, being exposed to sunlight for a long time in summer is dangerous. Severe sun-burns may occur on our skin, and they only heal up after medical treatment. Especially in summer, the heat radiating from the Sun is very high. However, the Sun is millions of kilometres away from Earth, and only one part in two-thousand of the heat it radiates reaches Earth.
If the temperature of Earth is so high despite the distance between Earth and the Sun, can you imagine how hot the Sun is?
Scientists provide approximate values for this. However, we cannot have any idea of this temperature by trying to compare it with the temperature of anything we are familiar with in this world. Consider that on the surface of the Sun, the temperature is 6,000°C (11,000°F). Inside, it rises as high as 12,000,000°C (21,600,000°F). There is nothing as hot on Earth with which you could compare this temperature! Your hands can hardly touch water around 50°C (120°F). Even on hot summer days, the temperature remains at about 40-50°C (105-120°F). This example shows that Allah tuned the distance between Earth and the Sun most delicately. If the Sun were a little closer to us, everything on the world would be withered and dried by the heat and turn into ashes. However, if it were a little more distant, everything would freeze. Of course, life would not be possible in either case.

If our Sun were closer to Earth, our planet would become overheated. All of these delicate balances are under Allah's control.

Polar regions, where heat from the Sun is received less, are always covered with ice. The equator, on the other hand, the region where many more solar rays are received, is always hot. Allah has created these regions as examples for us. Other regions are more suitable to support life for human beings. This shows the mercy Allah pours down on us. That is because, if Allah had not tuned the distance between the Sun and Earth so delicately, life on Earth would be much harder for us. There might even be no life at all.
As we have explained earlier, Allah created the Sun and the Moon exactly the way it has to be for human life to exist on our planet. In the Qur'an, Allah informs us that the Sun and the Moon move by the command of Allah:

Allah is He Who raised up the heavens without any support-you can see that-and then established Himself firmly on the Throne. He made the sun and moon subservient, each running for a specified term. He directs the whole affair. He makes the Signs clear so that hopefully you will be certain about the meeting with your Lord. (Surat ar-Ra'd: 2)

The Gravitational Attraction of the Sun

Countless celestial bodies move in an orderly manner without colliding with one another because Allah placed them in finely-adjusted orbits. An orbit is the path a planet or comet follows as it revolves around the Sun. No planet stops following its orbit to fly off into the depths of outer space. That is because planets remain under the gravitational attraction of the Sun. As you read these lines, our Earth is moving at the enormous speed of 108,000 kilometres (70,000 miles) per hour in its orbit around the Sun. An analogy may help you to grasp the enormity of this speed: the maximum speed a car can travel is around 200 kilometres (125 miles) per hour. This means the speed of Earth's rotation around the Sun is 540 times the speed of a car. Another example is the following: a bullet moves at a speed of 1,800 kilometres (1,100 miles) per hour. The speed of Earth's rotation around the Sun is 60 times the speed of a bullet.

The delicate balances created by Allah, and His Control over everything, allow us to walk and run on this planet without difficulty.

Because of this high speed the Earth moves at, the gravitational pull of the Sun is very important. If the Sun started to exert less gravitational force, we would fly off into space together with the Earth. This would certainly be the end of Earth…
On the other hand, if the Sun started to exert an even greater gravitational force, then our Earth would plunge into the Sun and melt. In this case, we would also vanish. Furthermore, the gravitational pull of the Sun also prevents the planets in their respective orbits from colliding with each other. However, have you ever thought how the Sun attracts these planets?
The answer is obvious. It is our Creator Allah, Exalted in Power, Who creates and continually preserves these balances.
Besides, not only the Sun has a gravitational pull. The planets within the Solar System also have their own gravitational forces. For instance, the gravitational force of Earth attracts the Moon towards it. Because of this gravitation, the Moon is almost suspended at a certain distance. In this way, Earth does not collide with the Moon. Without doubt, the infinite might of Allah prevents the Moon from falling onto Earth.
There is another gravitational pull similar to that of the sun, which is specially designed for mankind to live. That is the gravitational pull of the earth that gives us our weight. The gravitational force, which we experience as weight, holds us on Earth and provides us with the ability to walk and run with ease without floating off into space.
Assume that there is a ball in your hand. What happens when you withdraw your hand? The ball drops, doesn't it? That is because gravity attracts it to the ground. However, if you left this ball far out in remote outer space, the ball would not fall down since there is less gravitation there. Therefore, the existence of the higher force of gravity on Earth is essential for us.
There is another very important detail about gravitation: Gravitation should be neither more nor less than its current force. If it were less, you would be walking up in the air and not be able to touch the floor with your feet. You would not be able to move as you wish; you would constantly drift from one place to another, bounce when you take a step and hit the ceiling. Similarly, if the gravitational force of Earth were greater, you would not be able to walk because you would be drawn down towards the ground. You would only be able to crawl along the ground, if that.
Yet, none of these happen to us; Allah has created exactly the right strength of gravitation for us.
You can attain a better understanding of this by help of an example: The Moon, like Earth, also has a gravitational force. However, this gravitational pull is less than the one on Earth. Therefore, it is not possible for you to survive on the Moon. On television, you have probably seen how astronauts walk on the Moon. Could we spend our entire life this way? Definitely not.
Now let us continue our journey by visiting the planets within the gravitational pull of the sun. 

PLANETS

We mentioned earlier that planets are the celestial bodies that rotate around the stars. In this section, we are going to examine the planets in the solar system our Earth is located in. If we assume the Solar System to be a circle, the Sun is right at the centre of it.
Pluto is the planet on the outermost circle. Pluto is the smallest and farthest planet from the sun. Observation of this planet is hard, and even the Hubble telescope can only show some rough details of its surface. This planet is quite a cold place. The temperature is around -238°C (-396°F). In winter, when the temperature on Earth dips below-2or-3°C (-28 or -26°F), it becomes freezing. -238°C (-396°F) is a temperature 100 times colder than a temperature we on Earth can hardly resist in wintertime. This kind of cold would end our lives. From the outside, Pluto looks like a ball covered in ice.
Advancing closer towards the sun, we meet Neptune. This planet is also quite "cold"; its surface temperature is about -218°C (-360°F). Its atmosphere consists of gases poisonous to human beings. This aside, dreadful storms reaching up to 2,000 kilometres (1,250 miles) per hour blow over its surface.
Moving a little further towards the sun, in the middle of the circle, we meet Uranus. Uranus is the third largest planet in the Solar System. The temperature of its atmosphere is about -214°C (-353°F), which means this planet is cold enough to freeze us in only a second. Its atmosphere consists of poisonous gases that definitely would not support life.
If we continue our journey towards the sun, we next encounter Saturn. This, the second largest planet of the Solar System, is particularly notable for the system of rings around it. These rings are made up of gases, rocks and ice. The temperature on this planet is again unsuitable for human life: -178°C (-288°F).
When we come even closer to the sun, we encounter Jupiter, the largest planet of the Solar System. Jupiter is a planet 11 times bigger than Earth. Conditions on this planet are again not suitable for life, and it is a very cold place.
After Jupiter comes Mars. Mars is a dead planet that does not even compare to Earth. Mars has no life on it. There are reasons for this: First, the atmosphere of Mars is a poisonous mixture containing concentrated carbon dioxide. Second, there is no water on the planet. Third, the temperature on Mars is about -53°C (-63°F). Finally, there are very strong winds and sandstorms on Mars that last for months.
The blue planet that appears before us after Mars is our Earth. We will focus our attention on our planet Earth in the last chapter. Meanwhile, let's remind you of one point: Our Earth is the only planet that allows organisms to live.
Heading towards the sun, our search brings us to a planet called Venus. Venus is the brightest celestial body after the Sun and Moon. Therefore, people have known it since ancient times. Although all the planets as far out as Saturn have also been quite familiar to people throughout the ages, Venus is incomparably bright and clear in both the morning and evening skies. In contrast to the other planets, Venus is very hot. The temperature on the surface is 450°C (840°F), which is enough to cause even lead to melt. Another feature of Venus is its heavy atmosphere composed of a concentrated layer of carbon dioxide. Besides that, the atmosphere of Venus contains layers of acid several kilometres deep. No organism could survive in such a place for a second.
Speeding away from Venus, we reach Mercury, the planet closest to the sun. Its rotation has been so slowed down by its proximity to the Sun that the planet makes only three full turns in the time it takes to revolve twice around the sun. That is why one side of Mercury is extremely hot while the other is extremely cold. The difference between the day and night sides of Mercury is as much as 1,000°C (1,800°F). Of course such an environment cannot support life.
Our search so far reveals that except for Earth, none of the planets in the Solar System offers anything that might serve as a haven for life. Each of them is a lifeless and silent body. Our world, however, is a planet that provides everything necessary for life. With its green forests and blue oceans, it looks beautiful from space. The first astronauts on the Moon were astonished by the colourful and bright view they had of Earth.

OTHER CELESTIAL BODIES

A comet

Some other celestial bodies in the Solar System are comets, asteroids and meteorites. These are the celestial bodies remaining from the nebula in which the Solar System originated four to six billion years ago.
- Comets are made up of condensed gases and dust. Sometimes, their orbits bring them closer to the sun. As the comet approaches the sun, its surface starts evaporating because of the heat. This evaporation causes a bright light. A huge ball of gas and dust appears around the nucleus. This ball of gas and dust is called a "coma". Also, there is a tail of gas and dust related to this coma.

Meteorites are meteors that reach the Earth's surface.

- Meteors are rocky objects in space. Usually, they are observed in between the orbits of Mars and Jupiter. In some cases, the diameter of meteors may be as much as 1,000 kilometres (620 miles).
- Meteorites are solid bodies which fall to Earth from outer space. Pieces of rock, or mixtures of rock and iron detach themselves from meteors and comets. Sometimes when Earth passes through the dust cloud remaining from a comet, for example, the objects within this dust cloud burn in the atmosphere. They heat up when they enter Earth's atmosphere and leave a fine line of light in the sky. This is called a meteor. Sometimes, when they do not burn completely, meteors strike the Earth. These meteors that reach Earth are called aerolites or meteorites.
Consider one important point here: Meteors that reach the atmosphere occasionally fall on the Earth. When they fall, the destruction they cause varies according to their size. Our Earth is vulnerable to such a threat at every moment, but our Lord has created these celestial bodies in such a way that they are usually burned and destroyed in the atmosphere and thus are no danger to us. This shows Allah's mercy and compassion for us as well as the protection He provides us.
You must now have grasped that Allah has control over all celestial bodies, whether huge or small, and governs them all at every moment in a planned and orderly manner.