Water and dry ice at the Martian north polar ice cap
Click for original image. Click here for full image.
In our third Martian cool image of the day, we go to the north pole of Mars, as seen from orbit by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Taken on March 30, 2022 and cropped and reduced to post here, this picture shows some of the distinct and unique geological features found only on the polar caps of Mars. From the caption by Candy Hansen of the Planetary Science Institute in Tucson, Arizona:
Both water and dry ice have a major role in sculpting Mars’ surface at high latitudes. Water ice frozen in the soil splits the ground into polygons. Erosion of the channels forming the boundaries of the polygons by dry ice sublimating in the spring adds plenty of twists and turns to them.
Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.
The top layer of translucent dry ice falls as dry ice snow during the winter, than sublimates away with the arrival of spring. Since this photo was taken in autumn, we are looking at features left over from the activity from the spring and summer.
Click for original image. Click here for full image.
In our third Martian cool image of the day, we go to the north pole of Mars, as seen from orbit by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Taken on March 30, 2022 and cropped and reduced to post here, this picture shows some of the distinct and unique geological features found only on the polar caps of Mars. From the caption by Candy Hansen of the Planetary Science Institute in Tucson, Arizona:
Both water and dry ice have a major role in sculpting Mars’ surface at high latitudes. Water ice frozen in the soil splits the ground into polygons. Erosion of the channels forming the boundaries of the polygons by dry ice sublimating in the spring adds plenty of twists and turns to them.
Spring activity is visible as the layer of translucent dry ice coating the surface develops vents that allow gas to escape. The gas carries along fine particles of material from the surface further eroding the channels. The particles drop to the surface in dark fan-shaped deposits. Sometimes the dark particles sink into the dry ice, leaving bright marks where the fans were originally deposited. Often the vent closes, then opens again, so we see two or more fans originating from the same spot but oriented in different directions as the wind changes.
The top layer of translucent dry ice falls as dry ice snow during the winter, than sublimates away with the arrival of spring. Since this photo was taken in autumn, we are looking at features left over from the activity from the spring and summer.