Washington, Jan 28: If presence of a woman on Mars was not enough to give jitters to scientists, there is another mystery seeking explanation -- ''complex, wind-sculpted landforms'' on the red planet.
NASA's Mars Reconnaissance Orbiter has sent detailed images of the landforms which may give scientists a tough time to answer qestions whether winds on present-day Mars are strong enough to form and change geological features, or if wind-constructed formations were made in the past, perhaps when winds speeds and atmospheric pressures were higher.
The images of wind-driven Mars geology has been provided by University of Arizona's High Resolution Imaging Science Experiment camera (HiRISE). As the orbiter flies at about 7,500 mph between 250 and 315 kilometers above the Martian surface, this camera can see features as small as half a meter.
''We're seeing what look like smaller sand bedforms on the tops of larger dunes, and, when we zoom in more, a third set of bedforms topping those,'' said HiRISE co-investigator Nathan Bridges of NASA.
''On Earth, small bedforms can form and change on time scales as short as a day.'' HiRISE also shows detail in sediments deposited by winds on the downwind side of rocks. Such ''windtails'' show which way the most current winds have blown, Mr Bridges said.
Scientists discovered miles-long, wind-scoured ridges called ''yardangs'' with the first Mars orbiter, Mariner 9, in the early 1970s. New HiRISE images reveal surface texture and fine-scale features that are giving scientists insight into how yardangs form.
New images show that some layers in the yardangs are made of softer materials that have been modified by wind, he added. The soft material could be volcanic ash deposits, or the dried-up remnants of what once were mixtures of ice and dust, or something else.
''The fact that we see layers that appear to be rocky and layers that are obviously soft says that the process that formed yardangs is no simple process but a complicated sequence of processes,'' Mr Bridges said.