Tractus Catena is a set of pits in the Arcadia quadrangle of

Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

. Its location is centered at . It is long and was named after a classical albedo feature name. The term "Catena" refers to a chain of craters. The line of pits that make up Tractus Catena make it related to fossa which are common on Mars. Dark slope streaks are visible in one of the pictures below. Such streaks are common on Mars. They occur on steep slopes of craters, troughs, and valleys. The streaks are dark at first. They get lighter with age. Sometimes they start in a tiny spot, then spread out and go for hundreds of meters. They have been seen to travel around obstacles, like boulders.http://www.space.com/image_of_day_080730.html It is believed that they are avalanches of bright dust that expose a darker underlying layer. Image:Tractus Catena.JPG, Tractus Catena, as seen by

HiRISE High Resolution Imaging Science Experiment is a camera on board the '' Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction ...

. Scale bar is long. Click on image for good view of dark slope streaks Image:Tractus Catena Floor.JPG, Tractus Catena Floor, as seen by HiRISE. Scale bar is long.

References

See also