What if the earth has life

Life on earth

Nobody knows how or why life began. What we do know, however, is that life on earth arose at least 3.8 billion (3.8 billion) years ago. By that time the young planet had cooled and a rocky crust had formed. According to some scientists, life originated either in a rock temple or in the sea. Others believe that it could have reached Earth in comets and asteroids from space.

As far as we know, the only place where there is life is on earth. Wherever we look on our planet, bacteria and other simple forms of life have made their home.

Plants and animals need sunlight to grow. Until the 1970s, people thought that life was only possible near the surface of the earth.

Plants and animals need sunlight to grow. Until the 1970s, people thought that life was only possible near the surface of the earth. In the meantime, however, bacteria have even been discovered several kilometers below the surface of the earth, trapped in massive rock. They live on gases and minerals found in the rocks. Bacteria have also been found in strong acids, in the freezing cold of Antarctica, and near hot springs on the dark ocean floor. Some species even manage to survive in highly radioactive places. As long as water is available, life can take hold.

If life is so robust, couldn't it emerge and survive in other worlds as well? The most likely planet in our solar system is Mars.

Last modified December 21, 2004

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