|
|
Fans on Ice (Natural Colors; credits: Lunar Explorer Italia)
|
Every Southern Winter the South Polar Region of Mars is covered with an approximately 1 meter deep layer of frozen CO2 (dry ice). In the Spring, when the Sun begins to warm the surface below the translucent ice, gas flow under the ice carries loose dust from the surface up onto the top.
The dust falls to the surface in "Fans", whose orientation is determined by the direction of the local wind flow. Fans from one source region pointing in multiple directions show how the wind direction has changed. Narrow Fans pointing in just one direction are the most recent. Alternatively, the vent from the surface may have re-annealed, such that these Fans were formed over a very limited time span.
Mars Local Time: 18:19 (sunset - early evening)
Coord. (centered): 85,2° South Lat. and 181,6° East Long.
Spacecraft altitude: 247,4 Km (such as about 154,6 miles)
Original image scale range: 99,0 cm/pixel (with 1 x 1 binning) so objects ~2,97 mt across are resolved
Map projected scale: 1 mt/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 4,2°
Phase Angle: 86,4°
Solar Incidence Angle: 90° (meaning that the Sun is about 0° on the Local Horizon)
Solar Longitude: 181,2° (Northern Autumn)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer Italia
|
|