The Protected Roof

In the Qur'an, God calls our attention to a very important attribute of the sky:

We made the sky a preserved and protected roof yet still they turn away from Our Signs. (Qur'an, 21:32 )

This attribute of the sky has been proved by scientific research carried out in the 20th century: The atmosphere surrounding the Earth serves crucial functions for the continuity of life. While destroying many meteors - big and small - as they approach the Earth, it prevents them from falling to Earth and harming living things.

In addition, the atmosphere filters the light rays coming from space that are harmful to living things. The most striking feature of the atmosphere is that it lets only harmless and useful rays - visible light, near ultraviolet light and radio waves pass through. All of this radiation is vital for life. Near ultraviolet rays, which are only partially let in by the atmosphere, are very important for the photosynthesis of plants and for the survival of all living beings. The majority of the intense ultraviolet rays emitted from the Sun are filtered out by the ozone layer of the atmosphere. Only a limited and essential part of the ultraviolet spectrum reaches the Earth.

The protective function of the atmosphere does not end here. The atmosphere also protects the earth from the freezing cold of the space, which is approximately -454 F.

It is not only the atmosphere that protects the Earth from harmful effects. In addition to the atmosphere, the Van Allen Belt - the layer caused by the magnetic field of the Earth - also serves as a shield against the harmful radiation that threatens our planet. This radiation, which is constantly emitted by the Sun and other stars, is deadly to living things. If the Van Allen belt did not exist, the massive outbursts of energy called solar flares that frequently occur in the Sun would destroy all life on Earth.

On the importance of the Van Allen Belt, Dr. Hugh Ross says:

In fact, the Earth has the highest density of any of the planets in our Solar System. This large nickel-iron core is responsible for our large magnetic field. This magnetic field produces the Van-Allen radiation shield, which protects the Earth from radiation bombardment. If this shield were not present, life would not be possible on the Earth. The only other rocky planet to have any magnetic field is Mercury—but its field strength is 100 times less than the Earth's. Even Venus, our sister planet, has no magnetic field. The Van-Allen radiation shield is a design unique to the Earth.

The energy transmitted in just one of these bursts detected in recent years was calculated to be equivalent to 100 billion atomic bombs, each akin to one dropped on Hiroshima at the end of World War II. Fifty-eight hours after the burst, it was observed that the magnetic needles of compasses displayed unusual movement and 155 miles above the Earth's atmosphere, the temperature suddenly increased to 4532 F.

In short, a perfect system is at work high above the Earth. It surrounds our world and protects it against external threats. Centuries ago, God informed us in the Qur'an of the world's atmosphere functioning as a protective shield.

The Right Star, the Right Planet, and the Right Distance

In "The Blue Planet" we compared our world with the other planets of the solar system and found that the range of temperatures necessary for life exists only on Earth. The biggest reason for this is that the Earth is just the right distance from the Sun: the outer planets like Mars, Jupiter, or Pluto are too cold while the inner planets Venus and Mercury are too hot.

Those who refuse to admit that there is intentional design in the distance between Earth and Sun suggest something like the following:

"The universe is full of stars, some of them much bigger than the sun and some of them much smaller. These could very well have planetary systems of their own. If a star is bigger than the sun, then the ideal planet for life would be located at a much greater distance than the earth is from the sun. For example, a planet in an orbit around a red giant at the distance of Pluto could have a temperate climate like our world has. Such a planet would be just as fit for life as our earth is."

The claim is invalid in one very important respect for it ignores the fact that stars of different masses radiate different types of energy.

The factors that determine the wavelengths of the energy that a star radiates are its mass and its surface temperature (the latter of which is directly related to mass). For example, the sun radiates near ultraviolet, visible, and near infrared light because its surface temperature is around 6,000°C. If the sun's mass were a bit bigger, its surface temperature would be higher; but in that case, the energy levels of the sun's radiation would also be higher and the sun would be radiating much more destructive ultraviolet rays than it does.

This tells us that any star that is to radiate light that will support life absolutely must have a mass close to that of our sun. But if there are to be life-supporting planets orbiting around such stars, those planets must be located at distances not substantially different from that between the earth and the sun.

In other words, no planet revolving around a red giant, a blue giant, or any other star whose mass was substantially different from the sun's could harbor life. The only source of energy capable of supporting life is a star like our sun. The only planetary distance that is suitable for life is the distance between the earth and the sun.

There is another way of expressing this truth: The sun and the earth were each created to be just as they needed to be. And indeed, in the Qur'an it is revealed that God created everything according to precise calculation:

It is He Who splits the sky at dawn, and appoints the night as a time of stillness and the Sun and Moon as a means of reckoning. That is what the Almighty, the All-Knowing has ordained. (Qur'an, 6:96)