Ares Vallis

Ares Vallis

Discussion
Ask a question about 'Ares Vallis'
Start a new discussion about 'Ares Vallis'
Answer questions from other users
Full Discussion Forum
 
Encyclopedia
Ares Vallis is an outflow channel on Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, named after the Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

  name for Mars: Ares
Ares
Ares is the Greek god of war. He is one of the Twelve Olympians, and the son of Zeus and Hera. In Greek literature, he often represents the physical or violent aspect of war, in contrast to the armored Athena, whose functions as a goddess of intelligence include military strategy and...

, the god of war; it appears to have been carved by fluids, perhaps water
Water on Mars
Water on Mars is a psychedelic rock and electronic music group from Quebec City, Québec, Canada. The music trio is led by Philippe Navarro, guitarist, vocalist, arranger, producer, principal lyricist, and music composer....

. The valley 'flows' northwest out of the hilly Margaritifer Terra
Margaritifer Terra
Margaritifer Terra is an ancient, heavily cratered region of Mars. It is centered just south of the Martian equator at and covers 2600 km at its widest extent. The area reveals "chaos terrain", outflow channels, and alluvial plains that are indicative of massive flooding. Wind erosion patterns are...

, where the Iani Chaos
Iani Chaos
Iani Chaos, the source region of Ares Vallis on Mars, is centered at ~342°E, 2°S. The chaotic terrain is widely believed to have formed via the removal of subsurface water or ice, resulting in flooding at the surface, and the formation of Ares Vallis...

 depression long and wide) is connected to the beginning of Ares Vallis by a wide transition zone centered around 342.5° East (17.5 West) and 3° North. It then continues through the ancient Xanthe Terra
Xanthe Terra
Xanthe Terra is a large area on Mars, centered just north of the Martian equator. Its coordinates are and it covers 2465 km at its broadest extent. Its name means "golden-yellow land." It is in the Lunae Palus quadrangle and the Oxia Palus quadrangle....

 highlands, and ends in a delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

-like region of Chryse Planitia
Chryse Planitia
Chryse Planitia is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region to the west, centered at . Chryse Planitia lies partially in the Lunae Palus quadrangle and partially in the Oxia Palus quadrangle...

. Ares Vallis was the landing site of NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Mars Pathfinder
Mars Pathfinder
Mars Pathfinder was an American spacecraft that landed a base station with roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight wheeled robotic rover named Sojourner.Launched on December 4, 1996 by NASA aboard a Delta II booster a...

spacecraft, which studied a region of the valley near the border with Chryse in 1997.

It has been argued that Uzboi
Uzboi Vallis
Uzboi Vallis is a valley on Mars. It is named after a dry river valley in USSR, now in Turkmenistan.The valley begins on the northern rim of the Argyre basin, and cuts through several craters, before ending at Holden crater....

, Ladon
Ladon Valles
Ladon Valles is a river valley on the planet of Mars in the Margaritifer Sinus quadrangle located at 22.6° South and 28.7° West. It is 278 km long and was named after an ancient name for a Greek river...

, Margaritifer and Ares
Ares Vallis
Ares Vallis is an outflow channel on Mars, named after the Greek name for Mars: Ares, the god of war; it appears to have been carved by fluids, perhaps water...

 Valles, although now separated by large craters, once comprised a single outflow channel flowing north into Chryse Planitia
Chryse Planitia
Chryse Planitia is a smooth circular plain in the northern equatorial region of Mars close to the Tharsis region to the west, centered at . Chryse Planitia lies partially in the Lunae Palus quadrangle and partially in the Oxia Palus quadrangle...

. The source of this outflow has been suggested as overflow from the Argyre
Argyre
In Greek and Roman mythology, Argyre was a mythical island of silver, located in the east. The name comes from the Greek argyros ....

 crater, formerly filled to the brim as a lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 by channels (Surius, Dzigai, and Palacopus Valles) draining down from the south pole. If real, the full length of this drainage system would be over 8000 km, the longest known drainage path in the solar system. Under this suggestion, the extant form of the outflow channel Ares Vallis would thus be a remolding of a pre-existing structure.

Research, published in January 2010, suggests that Mars had lakes, each around 20 km wide, along parts of the equator. Although earlier research showed that Mars had a warm and wet early history that has long since dried up, these lakes existed in the Hesperian Epoch, a much earlier period. Using detailed images from NASA's Mars Reconnaissance Orbiter
Mars Reconnaissance Orbiter
Mars Reconnaissance Orbiter is a NASA multipurpose spacecraft designed to conduct reconnaissance and Exploration of Mars from orbit...

, the researchers speculate that there may have been increased volcanic activity, meteorite impacts or shifts in Mars' orbit during this period to warm Mars' atmosphere enough to melt the abundant ice present in the ground. Volcanoes would have released gases that thickened the atmosphere for a temporary period, trapping more sunlight and making it warm enough for liquid water to exist. In this new study, channels were discovered that connected lake basins near Ares Vallis. When one lake filled up, its waters overflowed the banks and carved the channels to a lower area where another lake would form. These lakes would be another place to look for evidence of present or past life.

External links