Creation Factsheet No. 20: Our Unique Planet
Factsheet No. 20
OUR UNIQUE PLANET
Do we take Planet Earth for granted? Or do we ever stop to consider just how wonderfully unique our planet is? We hear a good deal about 'extra-terrestrial life' these days, and science fiction stories have tended to increase speculation about the possibility that organic life exists elsewhere in the universe. However, all such speculation ignores one very important fact: very special conditions make life on earth possible, conditions which are not known to exist anywhere else in the entire universe! Although extra-solar planets have been observed, astronomers have not discovered another planetary system like our own, nor any earth-like planets. Our planet earth certainly seems to be quite unique, and some of its unique features are detailed below.
THE EARTH'S SIZE
The diameter of the earth is 8,000 miles. Did you know that this size is crucial for the existence of life? If the earth's size varied 10% either way, life would be impossible. If its diameter were only 7,200 miles, most of the atmosphere would escape, due to the lower gravity, and almost the whole earth would be reduced to a waste of snow and ice. A diameter of 8,800 miles, on the other hand, would double the weight of the atmosphere, increasing the total amount of water, so that the whole planet would probably be inundated.
ORBIT AND ROTATION
The earth orbits the sun every 365 1/4 days, and the axial tilt of 23 1/2 gives us our four seasons. The length of one year gives time for crops to be planted and harvested, but is not so long that we cannot exist until the next harvest. Imagine what it would be like if the earth took 84 years to orbit the sun, like the planet Uranus!
If the earth were 10% smaller, most of the atmosphere would escape, reducing the planet to an icy waste.
Or if it were only 88 days, as is the case with Mercury? The earth's rotation every 24 hours is very convenient; a longer interval would mean that the earth's surface would heat tremendously during the day, whilst temperatures would plunge to life-destroying levels during the prolonged hours of darkness. Most of the other planets in our solar system have much longer or shorter periods of rotation, ranging from 10 hours for Saturn to 243 days for Venus.
DISTANCE FROM SUN
The earth's distance from sun average 93 million miles seems to me just right to ensure temperatures suited for organic life. The earth's average temperature is 15° C.. Venus, at 67 million miles from the sun, has an average temperature of 470° C., whilst Mars, at 141 million miles, averages -50° C. A well-known (evolutionist) magazine commented: 'Earth thrives in such a narrow niche between unlivable extremes.'1
If the earth's average temperature rose only two or three degrees many large cities would be underwater, due to the melting of the polar ice-caps. This would also inundate hundreds of thousands of square miles of low-lying land.
In contrast to the other planets in the solar system, where only traces of oxygen exist, and whose atmospheres are made up largely of poisonous gases, the earth's atmosphere has 21% oxygen. This appears to be an ideal percentage. A greater amount of oxygen say 50% would make our planet highly inflammable. A single lightning striking would cause a whole forest to explode into flame. However, if the oxygen content of the air were only 10% fire would not burn at all.
Oxygen also helps maintain vital ozone layer 40 miles above the earth, which acts as a 'buffer' to deflect deadly ultraviolet rays from the sun. If the ozone layer only about one eighth of an inch thick if compressed should suddenly disperse, all life on earth would perish within minutes. Compare earth's atmosphere with that of Venus, which consists of carbon dioxide and methane gas! A well-known astronomer wrote, 'The earth is unique because it is the only world in our solar system upon which we could survive.'2 Is this uniqueness the result of coincidence and accident? The evolutionist must believe so, but that surely takes a lot of faith. As we contrast the other barren, lifeless bodies in space with our own planet, teaming with life, does it not make sense to believe that the earth is like it is because it was designed that way by a loving Creator? That 'God, who formed the earth and made it... formed it to be inhabitanted.'!3
Venus has a surface temperature of 470°C., and an atmosphere of carbon dioxide and methane gas
- National Geographic, Vol. 167: 1, January 1985.
- Patrick Moore, A Guide to the Planets.
- Isaiah 45:18.
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