Arcadia quadrangle
Encyclopedia
The Arcadia quadrangle
is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey
(USGS) Astrogeology Research Program
. The quadrangle is located in the north-central portion of Mars’ western hemisphere and covers 240° to 300° east longitude (60° to 120° west longitude) and 30° to 65° north latitude. The quadrangle uses a Lambert conformal conic projection
at a nominal scale of 1:5,000,000 (1:5M). The Arcadia quadrangle is also referred to as MC-3 (Mars Chart-3).
The southern and northern borders of the Arcadia quadrangle are approximately 3,065 km and 1,500 km wide, respectively. The north to south distance is about 2,050 km (slightly less than the length of Greenland). The quadrangle covers an approximate area of 4.9 million square km, or a little over 3% of Mars’ surface area.
located at 45° north latitude (N) and 260° east longitude (E) on Mars. The feature was named after a mountainous region in southern Greece. The name was approved by the International Astronomical Union
(IAU) in 1958.
, the largest volcano
(by area and volume) in the solar system
and Tempe Terra
, a highly fractured block of ancient crust about the size of Alaska.
, in northern New York State, is a lake that sits in a graben. Pit craters are often associated with graben. Pit craters do not have rims or ejecta around them, like impact craters do. Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dilates. This widening causes a void to form with a relatively high volume. When surface material slides into the void, a pit crater or a pit crater chain forms. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped. Other ideas have been suggested for the formation of fossae and pit craters. There is evidence that they are associated with dikes of magma. Magma might move along, under the surface, breaking the rock and more importantly melting ice. The resulting action would cause a crack to form at the surface. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by limestone
being dissolved thereby causing a void.
Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of water. Many grabens are found in the Arcadia quadrangle. Pictures below show examples of grabens in Arcadia.
Dust Devil Tracks
Many areas on Mars, including the Arcadia quadrangle, experience the passage of giant dust devils
. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil goes by it blows away the coating and exposes the underlying dark surface. Dust devils have been seen from the ground and from orbit. They have even blown the dust off of the solar panels of the two Rovers
on Mars, thereby greatly extending their lives. The twin Rovers were designed to last for 3 months, instead they have lasted more than six years. The first Rover, Spirit, was last heard from in March 2010. Opportunity Rover is still exploring the Red Planet, after more than seven years. The pattern of the tracks have been shown to change every few months. The image below from HiRISE
shows some dust devil tracks in the shape of X's. You may need to click on the image for a larger view to see the tracks clearly.
Several ideas have been advanced to explain the streaks. Some involve water or even the growth of organisms.
It is most generally accepted that they represent avalanches of dust. The streaks appear in areas covered with dust. When a thin layer of dust is removed, the underlying surface is dark. Much of the Martian surface is covered with dust. Fine dust settles out of the atmosphere covering everything. We know a lot about this dust because the solar panels of the Mars Rovers get covered with dust, thus reducing the electrical energy. The power of the Rovers has been restored many times by the wind, in the form of dust devils, cleaning the panels and boosting the power. So we know that dust falls from the atmosphere and is returned by dust devils over and over.
Dust storms are frequent, especially when the spring season begins in the southern hemisphere. At that time, Mars is 40% closer to the sun. The orbit of Mars is much more elliptical then the Earth's. That is the difference between the farthest point from the sun and the closest point to the sun is very great for Mars, but only a slight amount for the Earth. Also, every few years, the entire planet is engulfed in a global dust storm. When NASA's Mariner 9
craft arrived there, nothing could be seen through the dust storm. Other global dust storms have also been observed, since that time. Dark streaks can be seen in the image below of Tractus Catena
that was taken by HiRISE
.
Quadrangle (geography)
In geology or geography, the word "quadrangle" usually refers to a United States Geological Survey 7.5-minute quadrangle map, which are usually named after a local physiographic feature. The shorthand "quad" is also used, especially with the name of the map; for example, "the Ranger Creek, Texas...
is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology,...
(USGS) Astrogeology Research Program
Astrogeology Research Program
The USGS Astrogeology Science Center has a rich history of participation in space exploration efforts and planetary mapping, starting in 1963 when the Flagstaff Science Center was established by Gene Shoemaker to provide lunar geologic mapping and assist in training astronauts destined for the...
. The quadrangle is located in the north-central portion of Mars’ western hemisphere and covers 240° to 300° east longitude (60° to 120° west longitude) and 30° to 65° north latitude. The quadrangle uses a Lambert conformal conic projection
Lambert conformal conic projection
A Lambert conformal conic projection is a conic map projection, which is often used for aeronautical charts. In essence, the projection superimposes a cone over the sphere of the Earth, with two reference parallels secant to the globe and intersecting it. This minimizes distortion from projecting...
at a nominal scale of 1:5,000,000 (1:5M). The Arcadia quadrangle is also referred to as MC-3 (Mars Chart-3).
The southern and northern borders of the Arcadia quadrangle are approximately 3,065 km and 1,500 km wide, respectively. The north to south distance is about 2,050 km (slightly less than the length of Greenland). The quadrangle covers an approximate area of 4.9 million square km, or a little over 3% of Mars’ surface area.
Origin of Name
Arcadia is the name of a telescopic albedo featureClassical albedo features on Mars
The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the features they could see. The most popular system of...
located at 45° north latitude (N) and 260° east longitude (E) on Mars. The feature was named after a mountainous region in southern Greece. The name was approved by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
(IAU) in 1958.
Physiography and Geology
The quadrangle contains Alba PateraAlba Patera
Alba Mons is an immense, low-lying volcano located in the northern Tharsis region of the planet Mars. It is the largest volcano on Mars in terms of area, with volcanic flow fields that extend for at least 1350 km from its summit...
, the largest volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
(by area and volume) in the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
and Tempe Terra
Tempe Terra
Tempe Terra is a heavily cratered highland region in the northern hemisphere of the planet Mars. Located at the northeastern edge of the Tharsis volcanic province, Tempe Terra is notable for its high degree of crustal fracturing and deformation...
, a highly fractured block of ancient crust about the size of Alaska.
Fossa
Large troughs (long narrow depressions) are called fossae in the geographical language used for Mars. This term is derived from Latin; therefore fossa is singular and fossae are plural. These troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano. Fossae/pit craters are common near volcanoes in the Tharsis and Elysium system of volcanoes. A trough often has two breaks with a middle section moving down, leaving steep cliffs along the sides; such a trough is called a graben. Lake GeorgeLake George (New York)
Lake George, nicknamed the Queen of American Lakes, is a long, narrow oligotrophic lake draining northwards into Lake Champlain and the St. Lawrence River Drainage basin located at the southeast base of the Adirondack Mountains in northern New York, U.S.A.. It lies within the upper region of the...
, in northern New York State, is a lake that sits in a graben. Pit craters are often associated with graben. Pit craters do not have rims or ejecta around them, like impact craters do. Studies have found that on Mars a fault may be as deep as 5 km, that is the break in the rock goes down to 5 km. Moreover, the crack or fault sometimes widens or dilates. This widening causes a void to form with a relatively high volume. When surface material slides into the void, a pit crater or a pit crater chain forms. On Mars, individual pit craters can join to form chains or even to form troughs that are sometimes scalloped. Other ideas have been suggested for the formation of fossae and pit craters. There is evidence that they are associated with dikes of magma. Magma might move along, under the surface, breaking the rock and more importantly melting ice. The resulting action would cause a crack to form at the surface. Pit craters are not common on Earth. Sinkholes, where the ground falls into a hole (sometimes in the middle of a town) resemble pit craters on Mars. However, on the Earth these holes are caused by limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
being dissolved thereby causing a void.
Knowledge of the locations and formation mechanisms of pit craters and fossae is important for the future colonization of Mars because they may be reservoirs of water. Many grabens are found in the Arcadia quadrangle. Pictures below show examples of grabens in Arcadia.
Dust Devil TracksDust Devil TracksMany areas on Mars experience the passage of giant dust devils. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil goes by it blows away the coating and exposes the underlying dark surface, which within a few weeks assumes its former bright colour, either from...
Many areas on Mars, including the Arcadia quadrangle, experience the passage of giant dust devilsDust Devils
Dust Devils is an independently published role-playing game set in the Old West, written by Matt Snyder. It was voted the 2002 Indie RPG of the Year; it also won the Best Synergy of Game and Rules category, as well as placing in the Best Production and Most Innovative Game categories.The game uses...
. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil goes by it blows away the coating and exposes the underlying dark surface. Dust devils have been seen from the ground and from orbit. They have even blown the dust off of the solar panels of the two Rovers
Mars Exploration Rover
NASA's Mars Exploration Rover Mission is an ongoing robotic space mission involving two rovers, Spirit and Opportunity, exploring the planet Mars...
on Mars, thereby greatly extending their lives. The twin Rovers were designed to last for 3 months, instead they have lasted more than six years. The first Rover, Spirit, was last heard from in March 2010. Opportunity Rover is still exploring the Red Planet, after more than seven years. The pattern of the tracks have been shown to change every few months. The image below from HiRISE
HiRISE
High Resolution Imaging Science Experiment is a camera on board the Mars Reconnaissance Orbiter. The 65 kg , $40 million instrument was built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp....
shows some dust devil tracks in the shape of X's. You may need to click on the image for a larger view to see the tracks clearly.
Dark slope streaks
Many places on Mars show dark streaks on steep slopes like crater walls. It seems that the youngest streaks are dark; then they become lighter with age. Often they begin as a small narrow spot then widen and extend downhill for hundreds of meters. They have been seen to travel around obstacles, like boulders.Several ideas have been advanced to explain the streaks. Some involve water or even the growth of organisms.
It is most generally accepted that they represent avalanches of dust. The streaks appear in areas covered with dust. When a thin layer of dust is removed, the underlying surface is dark. Much of the Martian surface is covered with dust. Fine dust settles out of the atmosphere covering everything. We know a lot about this dust because the solar panels of the Mars Rovers get covered with dust, thus reducing the electrical energy. The power of the Rovers has been restored many times by the wind, in the form of dust devils, cleaning the panels and boosting the power. So we know that dust falls from the atmosphere and is returned by dust devils over and over.
Dust storms are frequent, especially when the spring season begins in the southern hemisphere. At that time, Mars is 40% closer to the sun. The orbit of Mars is much more elliptical then the Earth's. That is the difference between the farthest point from the sun and the closest point to the sun is very great for Mars, but only a slight amount for the Earth. Also, every few years, the entire planet is engulfed in a global dust storm. When NASA's Mariner 9
Mariner 9
Mariner 9 was a NASA space orbiter that helped in the exploration of Mars and was part of the Mariner program. Mariner 9 was launched toward Mars on May 30, 1971 from Cape Canaveral Air Force Station and reached the planet on November 13 of the same year, becoming the first spacecraft to orbit...
craft arrived there, nothing could be seen through the dust storm. Other global dust storms have also been observed, since that time. Dark streaks can be seen in the image below of Tractus Catena
Tractus Catena
Tractus Catena is a set of pits in the Arcadia quadrangle of Mars. Its location is centered on 28.17° north latitude and 102.77° west longitude. It is 897 km long and was named after a classical albedo feature name....
that was taken by HiRISE
HiRISE
High Resolution Imaging Science Experiment is a camera on board the Mars Reconnaissance Orbiter. The 65 kg , $40 million instrument was built under the direction of the University of Arizona's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp....
.
See also
- Fretted terrainFretted terrainFretted terrain is a type of surface feature common to certain areas of Mars and discovered in Mariner 9 images. It lies between two different types of terrain...
- Dark slope streak
- Dust Devil TracksDust Devil TracksMany areas on Mars experience the passage of giant dust devils. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil goes by it blows away the coating and exposes the underlying dark surface, which within a few weeks assumes its former bright colour, either from...
- Fossa (geology)Fossa (geology)Fossa is a term used in planetary geology to describe a long, narrow depression on the surface of an extraterrestrial body, such as a planet or moon...
- Impact craterImpact craterIn the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
- Lobate Debris ApronLobate Debris ApronLobate debris aprons are geological features on Mars, first seen by the Viking Orbiters, consisting of piles of rock debris below cliffs. These features have a convex topography and a gentle slope from cliffs or escarpments, which suggest flow away from the steep source cliff...