I got a real thrill out of down-loading pictures from Mars. They had travelled 100 million miles from the little Mars Rover to NASA and then half way around the Earth to my computer.
And yet, what is revealed is a deep-frozen rocky wilderness. But some of the most beautiful pictures of all time must be those taken of the Earth from space. In contrast with the other planets the Earth is amazingly fine-tuned to support life.
The other planets are barren, inhospitable places. Mercury is barren cratered rock and varies in temperature from -170 to +430 degrees C (five times the boiling point of water!). The mountainous, volcanic terrain of Venus is covered by clouds of sulphuric acid and has a temperature of 450 degrees C. Mars has a carbon dioxide atmosphere. Sometimes colossal dust storms engulf the entire planet.
Jupiter, Saturn, Uranus and Neptune are giant balls of gas, mainly hydrogen and helium, with small rocky cores.
However the Earth is just the right distance from the Sun. Nearer and we would fry. Further away and we would freeze. It is important therefore that our orbit around the Sun is almost circular, otherwise Earth would be an oven in the summer and a deep freeze in the winter.
Earth is also just the right size. Much smaller, like Mars, and it would not have enough gravity to keep an atmosphere. Much bigger and gravity would make us so heavy we’d collapse under our own weight.
Earth also rotates at the right speed: once every 24 hours. A day on Venus lasts 243 Earth-days. Much longer days would cause the oven-freezer temperature variation between day and night. If Earth rotated much faster like Jupiter and Saturn (roughly 10-hour days) the likely result would be devastating winds which would make life impossible.
Our home planet is also unique in possessing oceans of liquid water which is essential to life – living creatures being 90% water. Water seems very scarce elsewhere. But it covers 80% of the Earth. The oceans provide rain by evaporation and they help regulate the temperature by absorbing heat in the summer and releasing it in winter.
Earth also is rich in other essentials to life: oxygen, carbon and nitrogen which also appear scarce elsewhere. They are present in just the right proportions in our atmosphere. Animals and humans breathe out carbon dioxide which is essential to plants. The plants give off oxygen which is essential to animals and humans.
90% of our Oxygen is said to come from seaweed and microscopic sea creatures, underlining another importance of water.
However you think it all came about (evolution, special creation) it is simply the method God used. The fine-tuning of the earth to support life is an amazing evidence of God’s handiwork. Almost more amazing is the fact that many people think it’s all coincidence!
© Tony Higton: see conditions for reproduction