Europe's Mars Express Investigates Unusual Deposits on the Red Planet

The Medusae Fossae Formation contains the most mysterious deposits on Mars and ESA's Mars Express was able to uncover new information such as direct measurement of depth and electrical properties. These new data collected by the Mars Express on the Medusae Fossae Formation will provide scientists with clues to their origin.

The Medusae Fossae Formation is found near Mar's equator, between the highlands and lowlands and scientists believe that they may represent the youngest deposits on the surface of the planet since the area seems to lack impact craters on its terrain, unlike the other terrain on Mars. The Medussae Fossae Formation have intrigued scientists because the region have absorbed wavelengths of some Earth-based radar, leading scientists to call the region, "stealth regions" because they give no radar echo. The Earth-based radios that produces no echo on the MFF region has 3.5 to 12.6 centimeters wavelengths but the radar on the Mars Express emits 50 to over 100 meters. The radar on Mars Express was able to reveal the thickness of the Medussae Fossae Formation by calculating the time the radar beam passes through the top layers and bounce off the solid rock. According to the data gathered by Mars Express, the Medussae Fossae Formation's deposits are over 2.5 km thick in some places.

Scientists already proposed theories for the origin and composition of the deposits on the Medussae Fossae Formation. Some say that the deposits are volcanic ash while others say that the deposits could be wind-blown materials that have eroded from Martian rocks. The third theory that scientists proposed is that the deposits contain ice that are similar to the ice deposits at the Martian polar regions but were formed when the axis of Mars tilts, making the equatorial region colder.

The data gathered by Mars Express, however, were still not sufficient to support any of the theories proposed by scientists. According to the ESA report, the layers are poorly packed, fluffy or dusty materials but scientists could not understand how absorbent materials from dust can be so thick but not compacted under the weight of the topmost materials.

The electrical properties of the Medussae Fossae Formation gathered by the Mars Express also reveal that it is the same as the electrical properties of water ice layers but there is no other evidence of the presence of ice on the equatorial region since the water vapor pressure on Mars would not allow any ice to form on the surface since it would quickly evaporate so scientists theorized that any ice layers might be buried several feet below the surface.

Jeffrey Plaut of the Jet Propulsion Laboratory, USA says that the Mystery of the Medussae Fossae Formation will continue as it is still early to draw conclusions based on the data gathered.

SOURCE:

European Space Agency, "Mars Express probes the Red Planet's most unusual deposits." ESA.int