 Map ofCoprates quadrangle showing details ofValles Marineris, the largest canyon system in the solar system. Some of the canyons may have once been filled with water. | |
| Coordinates | 16°48′S46°54′W / 16.8°S 46.9°W /-16.8; -46.9 |
|---|---|
| Naming | the Greek name of Aurora, an albedo feature |
Eos Chaos is a rough, collapsed area in theCoprates quadrangle on Mars at 16.8° south latitude and 46.9° west longitude. It is about 490 km long and was named after the Greek name of Aurora, an albedo feature.[1]
Eos Chaos is a part of the largest canyon system in theSolar System; this great canyon would go almost all the way across the United States. The name for the whole system of canyons is Valles Marineris. Starting at the west withNoctis Labyrinthus in thePhoenicis Lacus quadrangle, the canyon system ends in theMargaritifer Sinus quadrangle with Capri Chasma andEos Chasma (in the south). The word Chasma has been designated by the International Astronomical Union to refer to an elongate, steep-sided depression. Valles Marineris was discovered by and named for the Mariner 9 mission. Moving east from Noctis Labyrinthus, the canyon splits into two troughs, Tithonium andIus Chasma in the south. In the middle of the system are very wide valleys of Ophir Chasma (north),Candor Chasma, andMelas Chasma (south). Going farther to the east, one comes to Coprates Chasma. At the end of Coprates Chasma, the valley gets wider to form Capri Chasma in the north andEos Chasma in the south. The walls of the canyons often contain many layers. The floors of some of the canyons contain large deposits of layered materials. Some researchers believe that the layers were formed when water once filled the canyons. The canyons are deep as well as long. In places they are 8-10 kilometers deep. Remember the Earth'sGrand Canyon is only 1.6 kilometers deep.[2]
Images of rocks in the canyon walls almost always show layers. Some layers appear tougher than others. Because of its closeness to the Tharsis volcanic region, the rock layers may be made of layer after layer oflava flows, probably mixed with deposits of volcanic ash that fell out of the air following big eruptions. It is likely the rock strata in the walls preserve a long geological history of Mars.[3] Dark layers may be due to dark lava flows. The dark volcanic rockbasalt is common on Mars. However, light-toned deposits may have resulted from rivers, lakes, volcanic ash, or wind blown deposits of sand or dust.[4] The Mars Rovers found light-toned rocks to contain sulfates. Probably having been formed in water, sulfate deposits are of great interest to scientists because they may contain traces of ancient life.[5]
