MOVING STONES

One of the gifts that nature gives humans is moving stones. Over the years they move and leave long tracks behind them. The long tracks show that the stones have moved along the ground. But how do they move? Scientists have searched for the answer to this question for 50 years.

These famous moving stones are in Death Valley, USA. Many of the stones are small but a few of them are very big. Some of the big stones are bigger than a man. The biggest stones weigh 350 kilograms. They are four times heavier than a human!

The stones only move at night and only once every year or two. There isn’t anyone who has seen the stones moving so far, but today scientists know the secret of this movement: The wind! When the wind comes from the west, the stones move to the east. When the wind is from the south, they always move to the north. But how can the wind move a stone that weighs 350 kilograms?

This answer is more complicated. Death Valley is the hottest place in the world, but it is also one of the coldest places at night. The nights sometimes can be stormy. When it rains, the ground becomes soft and wet. Because the valley is windy and cold, the water on the ground turns into ice. Then the strong wind can move flat stones along the flat ground. In the morning, the sun comes up and dries the ground. And nature shows its magic: The moving stones!