Analysis of the mud cracks on the surface of Mars is revealing the history of the lake that existed long ago and filled Gale Crater. Scientists who are examining Curiosity Rover's findings have confirmed that the desiccation cracks in the crater are an indicator of the fluctuations in the water level of lake that existed roughly around 3.5 billion years ago. Cracks in the surface of the rocks have a polygonal shape that resembles like a wet sediment that has dried out. Curiosity landed on the crater's northern side in 2012 and has been moving to the South. It has taken pictures of slab of rock that is close to crater's center and is nicknamed Old Soaker.
The cracks are filled with sediment whose chemical composition is same as that of the rock. The cracks were filled soon after the level of the lake rose again. Sediment inside the water would have settled inside the mud cracks slowly. The rover is finding out the history of water on Mars and is making its way to the Murray foundation - which is a mountainous region in the center of the crater. There is still no possible explanation of why water disappeared from Mars. Some of the possible explanations include Mar's loss of magnetic field but it is not confirmed. Curiosity will help the scientists to create a wider picture on the history of water on Mars.
By: Neha Maheshwari