London, June 24 (IANS/EFE): The slopes on Mars experienced frequent slides of waterlogged debris as a result of the "recent" presence of flowing water on the red planet's surface, a study published by the British journal Nature said.
The study, conducted by a team of scientists from the Netherlands, Germany, Britain and Sweden, concluded that "until a relatively recent period, Mars's environment was a lot more dynamic" than now.
Liquid water is now extremely rare on Mars, but it was more abundant in the past.
The planet's tilt has shifted from a slight 15 degrees to a strong 35 degrees over its eons circling the sun, the study said.
The proof of this change is the widespread presence of gullies with a medium latitude that became small fan-shaped systems of water capture, the authors said.
Mars is now "a very cold and dry planet", which, combined with its thin atmosphere, makes the presence of water on the surface "an exceptional phenomenon", the authors said.
The most recent discovery of well-preserved gullies and reservoirs created by slides of debris on the slope of craters indicates that these features have been carved by flowing water "in a recent geological period".
The lead researcher, Tjalling de Haas, of the University of Utrecht, and his colleagues studied features present on a slope of the Istok crater, which is, at most, about 1 million years old, and they calculated the size of the "slides" of debris and the volume of water present.
The "capture areas" on the crater's slopes facing toward Mars's north pole accumulated "centimetres of liquid water" from the melting of ice and that caused "frequent debris slides", the scientists said.
The thawing of those regions of Mars occurred in "cyclical periods" of warmer climate caused by changes in the planet's orbit.
The findings point to capture areas that accumulated snow and ice masses "much larger" than what scientists previously estimated.
Martian slopes with the same polar orientation as the one studied on the Istok crater "are extremely active environments where the frequency of debris slides was similar to the Earth's in a very recent geological past", the study said.