Los Angeles, Oct. 9 (xinhua) -- tan jingjing NASA says the curiosity rover has found deposits rich in mineral salts in gale crater, suggesting salt-water lakes in the crater, indicating climate fluctuations that have transformed Mars from a once warm and humid environment into a frozen, dry one.
The salts were found in a region of sedimentary rock called Sutton island. The researchers say the early conditions on earth and Mars were similar, and that the salt lakes in the Sutton island region may be similar to those on the altiplano plateau in South America, which also suffered from climate change. During dry periods, the plateau salt lakes become shallow and in some places completely dry. The salt lake area has no vegetation, similar to the environment on Mars.
Lead author William lapin, a researcher at the California institute of technology in the United States, said curiosity went to gale because of the evidence of a changing Martian environment. Understanding when and how the changes began could help solve another mystery: when and how long Mars had environments that supported microbial life. The paper on the new findings appears in a new issue of the British journal nature geoscience.
Remnants of rivers and lakes were found in gale crater, where sediments slowly piled up to form mount sharp, which curiosity is climbing at the center of the crater. Each layer of sediment bears witness to conditions on Mars at different times.
Using Sutton island sedimentary rocks and other clues, the curiosity team is piecing together the story of climate change on Mars, revealing a cycle of wet to dry conditions.
The curiosity rover landed in gale crater, a 154-kilometer-wide crater on Mars in 2012. Its main mission was to find out whether the planet's historical environment was once hospitable to life. Curiosity's original two-year mission has been extended several times and it is still exploring Mars.