Mars "Tracks" Explained?
(Note: the following quote comes from a scientist within the NASA space program and offers an explanation of the "Tracks" theory.)

 

 

Funny how we sometimes forget that something so familiar to us can appear strange to those unfamiliar with satellite and aerial views.

 

These vertical lines in the picture are simply transverse dunes on the floor of Nirgal Vallis. Nirgal is about a kilometer deep in this area, and so presents quite a trap for wind-blown material.

 

Many of us suspected that we would have a hard time seeing the channel's actual trace (called the "thalweg") on the floor of the canyon, because they are so old and have been dry for so long. This has resulted in the blanketing of the floor of the valley with sand dunes. The MOC camera has confirmed our suspicions in this case at least.

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Story from October 12, 1997


On Monday, October 6, 1997, a startling photograph from the Mars Global Surveyor was posted on the Astronomy Picture of the Day website. The photo, taken by Surveyor from an altitude of 250 miles (400 kilometers), shows a subsided rift valley ten miles (16 kilometers) long in the Vallis Nigral region of Mars. The rift valley is similar to the one in East Africa here on Earth. The rimrock on the valley's rim shows clear evidence of water erosion. Towards the photo's center, just above a square depression in valley floor, is a line of uniform tracks extending for an estimated distance of just over two miles (3.7 kilometers). One observer estimated that, based on the formula that one Surveyor pixel equals 30 feet (9 meters), the tracks are 415 feet (126 meters) wide. This suggests that the tracks were made by an immense vehicle, perhaps similar to the one used by the Jawas in the movie "Star Wars." The age of the tracks is unknown. However, it appears that they are recent and appeared after the great dust storm on Mars back in the early 1970s.

The photo can be found at the following URL:http://antwrp.gsfc.nasa.gov/apod/ap971006.html
(Many thanks to Twitch and Chris for pointing out this Surveyor photo.)

Link to photo here or past it on this page:

http://antwrp.gsfc.nasa.gov/apod/ap971006.html