If the weather plays along once a month our moon shines in all its glory. This natural street lighting is quite obvious when at night sunlight is reflected down onto Earth. However even without a serious accident our planet could become pitch dark outside at night.
4 million years ago, as scientists today believe, a boulder the size of Mars collided with our home planet. It created a violent explosion, which would have wiped out every living thing, but however did not have a tragic ending because the Earth at that time was still an uninhabited firebrand - a glowing molten planet, which coped with losing a large piece of the Earth’s crust. It was probably not even 1000 years before the Earth had once again reformed into a similar sphere through its own gravitational force.
A second large body formed with time out of the shards of debris. This second boulder is the moon we see today. But what is so special about it? After all, our neighbouring planet Mars is made of two parts. Jupiter possesses 4 large and a cluster of small moons, and 31 have so far been counted around Saturn, whose largest, Titan, has just been explored by an ESA-probe with Austrian participation.
The Earth’s moon is extremely large in comparison to the planet that it orbits. Its influence is also great. Prof. Franz Kerschbaum, astronomer at Vienna University: "It ensures that the axis around which the Earth turns keeps the same as the sun. If the moon were suddenly to disappear then Africa’s Gazelles would have to endure the icy temperatures of the North Pole. It has also provided the stability required in order to facilitate the development of life. In addition, the moon is guilty of making the Earth turn more and more slowly over millions of years: Today a day passes in 24 hours, in the distant future it will take 50 times as long. In the past the Earth would have taken 16 hours and less to stop around its own axis without moon or brakes."
Despite having such a daily routine in fast motion, life would still have developed much more slowly without a moon: tides, which for the most part are caused by the moons gravitational forces, have seen to it that in primitive times the building blocks of life in the sea stirred quickly and therefore accelerated the process. Without the moon functioning as a big blender, living beings as highly developed as us humans would probably not exist for millions of years to come. "Even many types of animals on the oceans coasts would not have come into being", explains evolution biologist Prof. Hannes Paulus.
And how would have been for humans without the influence of the moons power? Prof. Kerschbaum: "At least with regards to gravity nothing would change. The moon’s gravity at this distance is in reality no bigger than that of a train engine 2 metres away. So if you don’t get dizzy standing on a train platform, you will definitely not be able to feel the power of the moon..."