GULA MONS (ON VENUS) BY NASA MAGELLAN MISSION

 

NASA MAGELLAN MISSION (1989-1994)
Gula Mons (3000m/3km -9,843ft/1.9mi)
Planet Venus (Solar system /The Milky Way Galaxy)

The mountain
Gula Mons (3000m/3km -9,843ft/1.9mi high and 276km diameter), named after the Mesopotamian Goddess of Healing, is a shield volcano on planet Venus in western Eistla Regio, located south of Sedna Planitia, west of Bereghinya Planitia and east of Guinervere Planitia, at 21,9° N et 359,1° E.
Its main feature is a NE-SW-oriented rift-like fracture set connecting two summit calderas. There is also a structure which links the northern caldera and ridge system to Idem Kuva corona located NW of Gula Mons. Radially spreading lava flows which have digitate and broad sheet-like forms extend from the summit, including radar-dark flows which overlay several older lava deposits. Radial and circumferential fractures are present on the flanks.

The image capturer
Gula Mons is displayed in this computer-simulated view of the surface of Venus. The viewpoint is located 110 kilometers (68 miles) southwest of Gula Mons at the same elevation as the summit, 3 kilometers (1.9 miles) above Eistla Regio. Lava flows extend for hundreds of kilometers across the fractured plains. The view is to the northeast with Gula Mons appearing at the center of the image. Gula Mons, a 3 kilometer (1.9 mile) high volcano, is located at approximately 22 degrees north latitude, 359 degrees east longitude in western Eistla Regio. Magellan synthetic aperture radar data is combined with radar altimetry to produce a three-dimensional map of the surface. Rays cast in a computer intersect the surface to create a three-dimensional perspective view. Simulated color and a digital elevation map developed by the U.S. Geological Survey are used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced by the JPL Multimission Image Processing Laboratory and is a single frame from a video released at the March 5, 1991, JPL news conference.  
- More about NASA Magellan Mission 

 
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2022 - Wandering Vertexes...
by Francis Rousseau

USHAS MONS BY NASA MAGELLAN MISSION

MAGELLAN MISSION (1989-1994)

Ushas Mons (2,000 m / 2 km - 6,561ft/1.25 mile)  

VENUS

The mountain 
Ushas Mons (2,000 m / 2 km - 6,561ft/1.25 mile) is a volcano in the southern hemisphere of Venus at 25 degrees south latitude, 323 degrees east longitude. Its name is derived from vedic goddess of dawn Ushas .The volcano is marked by numerous bright lava flows and a set of north-south trending fractures, many of which appear to have formed after the lavas were erupted onto the surface. In the central summit area, however, younger flows remain unfractured. An impact crater can be seen among the fractures in the upper center of the image. The association of faulting and volcanism is common on this type of volcano on Venus, and is believed to result from a large zone of hot material upwelling from the Venusian mantle, a phenomenon known on Earth as a "hotspot."


The mission
Magellan was launched on May 4, 1989, at 18:46:59 UTC by the National Aeronautics and Space Administration from KSC Launch Complex 39B at the Kennedy Space Center in Florida, aboard Space Shuttle Atlantis during mission STS-30. Once in orbit, the Magellan and its attached Inertial Upper Stage booster were deployed from Atlantis and launched on May 5, 1989 01:06:00 UTC, sending the spacecraft into a Type IV heliocentric orbit where it would circle the Sun 1.5 times, before reaching Venus 15 months later on August 10, 1990.
Originally, the Magellan had been scheduled for launch in 1988 with a trajectory lasting six months. However, due to the Space Shuttle Challenger disaster in 1986, several missions, including Galileo and Magellan, were deferred until shuttle flights resumed in September 1988. Magellan was planned to be launched with a liquid-fueled, Centaur-G upper-stage booster, carried in the cargo bay of the Space Shuttle. However, the entire Centaur-G program was canceled after the Challenger disaster, and the Magellan probe had to be modified to be attached to the less-powerful Inertial Upper Stage. The next best opportunity for launching occurred in October 1989.
Further complicating the launch however, was the launching of the Galileo mission to Jupiter, one that included a fly-by of Venus. Intended for launch in 1986, the pressures to ensure a launch for Galileo in 1989, mixed with a short launch-window necessitating a mid-October launch, resulted in replanning the Magellan mission. Weary of rapid shuttle launches, the decision was made to launch Magellan in May, and into an orbit that would require one year, three months, before encountering Venus.
On August 7, 1990, Magellan encountered Venus and began the orbital insertion maneuver which placed the spacecraft into a three-hour, nine minute, elliptical orbit that brought the spacecraft 295-kilometers from the surface at about 10 degrees North during the periapsis and out to 7762-kilometers during apoapsis
On September 9, 1994, a press release outlined the termination of the Magellan mission. Due to the degradation of the power output from the solar arrays and onboard components, and having completed all objectives successfully, the mission was to end in mid-October. The termination sequence began in late August 1994, with a series of orbital trim maneuvers which lowered the spacecraft into the outermost layers of the Venusian atmosphere to allow the Windmill experiment to begin on September 6, 1994.

___________________________________________
2019 - Wandering Vertexes...
by Francis Rousseau 

AKNA MOUNTES BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION (1989-1994) 

Akna Mountes (6,000 m / 6km - 19, 685ft / 3, 72mi)

VENUS

The mountain
Akna Montes are a mountain range on Venus centered at 68.9°N, 318.2°E and stretching 830 km long. It is culminating at 6,000 m / 6km -  19, 685ft / 3, 72mi). The Akna range is a north-south trending ridge belt that forms the western border of the elevated smooth plateau of Lakshmi Planum. The Lakshmi plateau plains are formed by extensive volcanic eruptions and are bounded by mountain chains on all sides. The plains appear to be deformed near the mountains. This suggests that some of the mountain building activity occurred after the plains formed. On the Magellan radar image  (above) of the northern portion of the Akna Montes, the round feature is the crater Wanda.

The mission
Magellan was launched on May 4, 1989, at 18:46:59 UTC by the National Aeronautics and Space Administration from KSC Launch Complex 39B at the Kennedy Space Center in Florida, aboard Space Shuttle Atlantis during mission STS-30. Once in orbit, the Magellan and its attached Inertial Upper Stage booster were deployed from Atlantis and launched on May 5, 1989 01:06:00 UTC, sending the spacecraft into a Type IV heliocentric orbit where it would circle the Sun 1.5 times, before reaching Venus 15 months later on August 10, 1990.
Originally, the Magellan had been scheduled for launch in 1988 with a trajectory lasting six months. However, due to the Space Shuttle Challenger disaster in 1986, several missions, including Galileo and Magellan, were deferred until shuttle flights resumed in September 1988. Magellan was planned to be launched with a liquid-fueled, Centaur-G upper-stage booster, carried in the cargo bay of the Space Shuttle. However, the entire Centaur-G program was canceled after the Challenger disaster, and the Magellan probe had to be modified to be attached to the less-powerful Inertial Upper Stage. The next best opportunity for launching occurred in October 1989.
Further complicating the launch however, was the launching of the Galileo mission to Jupiter, one that included a fly-by of Venus. Intended for launch in 1986, the pressures to ensure a launch for Galileo in 1989, mixed with a short launch-window necessitating a mid-October launch, resulted in replanning the Magellan mission. Weary of rapid shuttle launches, the decision was made to launch Magellan in May, and into an orbit that would require one year, three months, before encountering Venus.
On August 7, 1990, Magellan encountered Venus and began the orbital insertion maneuver which placed the spacecraft into a three-hour, nine minute, elliptical orbit that brought the spacecraft 295-kilometers from the surface at about 10 degrees North during the periapsis and out to 7762-kilometers during apoapsis
On September 9, 1994, a press release outlined the termination of the Magellan mission. Due to the degradation of the power output from the solar arrays and onboard components, and having completed all objectives successfully, the mission was to end in mid-October. The termination sequence began in late August 1994, with a series of orbital trim maneuvers which lowered the spacecraft into the outermost layers of the Venusian atmosphere to allow the Windmill experiment to begin on September 6, 1994.

SIF MONS BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION (1989-1994)

Sif Mons (2,000m / 2kms- 6561ft / 1, 24mi) 

Venus 

The volcano 
Sif Mons is a shield volcano located on the planet Venus at 22 ° N and 352.4 ° E, in the west of Eistla Regio. It is south of Sedna Planitia, west of Bereghinya Planitia and east of Guinevere Planitia. It is near Gula Mons, a little bigger and located further east in the extension of Eistla. Its lava flows are clearly visible even from Earth using the Arecibo radio telescope. The volcano is named after Sif, the northern goddess.

The photo
Sif Mons is displayed in this computer-simulated view of the surface of Venus. The viewpoint is located 360 kilometers (223 miles) north of Sif Mons at a height of 7.5 kilometers (4.7 miles) above the lava flows. Lave flows extend for hundreds of kilometers across the fractured plains shown in the foreground to the base of Sif Mons. The view is to the south. Sif Mons, a volcano with a diameter of 300 kilometers (186 miles) and a height of 2 kilometers (1.2 miles), appears in the upper half of the image. Magellan synthetic aperture radar data is combined with radar altimetry to produce a three-dimensional map of the surface. Rays, cast in a computer, intersect the surface to create a three-dimensional perspective view. Simulated color and a digital elevation map developed by the U.S. Geological Survey are used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced at the JPL Multimission Image Processing Laboratory and is a single frame from a video released at the March 5, 1991, JPL news conference.

IRNINI MONS BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION (1989-1994)

Irnini Mons (1,750 m -  5,741ft) 

Venus 

The mountain 

Irnini Mons (1,750 m -  5,741ft) is a volcanic structure on the planet Venus, and is named after the Assyro-Babylonian goddess of cedar-tree mountains.  It has a diameter of 475 km (295 mi) and is located in Venus' northern hemisphere. More specifically, it is located in the central Eistla Regio region at (14°0′N 16°0′E) in the V-20 quadrangle. Sappho Patera, a 225 km (140 mi) diameter wide, caldera-like, depression tops the summit of Irnini Mons.  The primary structural features surrounding Irnini Mons are graben, seen as linear depressed sections of rock, radiating from the central magma chamber. Also, concentric, circular ridges and graben outline the Sappho Patera depression at the summit. The volcano is crossed by various rift zones, including the north-south trending Badb Linea rift, the Guor Linea rift extending to the northwest, and the Virtus Linea rift continuing to the southeast.

The combination of volcanic-tectonic structures around Irnini Mons supports varying intensities of deformation and a multi-directional stress history. Although classified as a shield volcano, Irnini Mons contains many elements of the Venusian coronae, bringing speculation to its formation. If Irnini Mons was originally a corona, a shallow oval-shaped depression, it would support a thin lithosphere on Venus. On the other hand, it being a shield volcano supports the theory of a thicker lithosphere and Irnini Mons' stress history could be summarized simply as a transition from predominantly compressive forces to extensional relaxation, resulting in the observed radiating graben and concentric ridges.

Irnini Mons is a significant structural feature on Venus because the preservation of the geology allows for the analysis of Venus' regional stress orientation in response to a pressurized magma chamber over time.

The mission
Magellan was launched on May 4, 1989, at 18:46:59 UTC by the National Aeronautics and Space Administration from KSC Launch Complex 39B at the Kennedy Space Center in Florida, aboard Space Shuttle Atlantis during mission STS-30. Once in orbit, the Magellan and its attached Inertial Upper Stage booster were deployed from Atlantis and launched on May 5, 1989 01:06:00 UTC, sending the spacecraft into a Type IV heliocentric orbit where it would circle the Sun 1.5 times, before reaching Venus 15 months later on August 10, 1990.
Originally, the Magellan had been scheduled for launch in 1988 with a trajectory lasting six months. However, due to the Space Shuttle Challenger disaster in 1986, several missions, including Galileo and Magellan, were deferred until shuttle flights resumed in September 1988. Magellan was planned to be launched with a liquid-fueled, Centaur-G upper-stage booster, carried in the cargo bay of the Space Shuttle. However, the entire Centaur-G program was canceled after the Challenger disaster, and the Magellan probe had to be modified to be attached to the less-powerful Inertial Upper Stage. The next best opportunity for launching occurred in October 1989.
Further complicating the launch however, was the launching of the Galileo mission to Jupiter, one that included a fly-by of Venus. Intended for launch in 1986, the pressures to ensure a launch for Galileo in 1989, mixed with a short launch-window necessitating a mid-October launch, resulted in replanning the Magellan mission. Weary of rapid shuttle launches, the decision was made to launch Magellan in May, and into an orbit that would require one year, three months, before encountering Venus.
On August 7, 1990, Magellan encountered Venus and began the orbital insertion maneuver which placed the spacecraft into a three-hour, nine minute, elliptical orbit that brought the spacecraft 295-kilometers from the surface at about 10 degrees North during the periapsis and out to 7762-kilometers during apoapsis
On September 9, 1994, a press release outlined the termination of the Magellan mission. Due to the degradation of the power output from the solar arrays and onboard components, and having completed all objectives successfully, the mission was to end in mid-October. The termination sequence began in late August 1994, with a series of orbital trim maneuvers which lowered the spacecraft into the outermost layers of the Venusian atmosphere to allow the Windmill experiment to begin on September 6, 1994. 

SEORITSU FARRA (ON VENUS) BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION  (1989-1994)

Seoritsu Farra ( 750m - 2,475 ft)

Venus 

The mountain 

In the first image: the eastern edge of Alpha Regio is shown centered at 30 degrees south latitude and 11.8 degrees east longitude (longitude on Venus is measured from 0 degrees to 360 degrees east). Seven circular, dome-like hills, averaging 25 kilometers (15 miles) in diameter with maximum heights of 750 meters (2,475 feet) dominate the scene. These features are interpreted as very thick lava flows that came from an opening on the relatively level ground, which allowed the lava to flow in an even pattern outward from the opening. The complex fractures on top of the domes suggest that if the domes were created by lava flows, a cooled outer layer formed and then further lava flowing in the interior stretched the surface. The domes may be similar to volcanic domes on Earth. Another interpretation is that the domes are the result of molten rock or magma in the interior that pushed the surface layer upward. The near-surface magma then withdrew to deeper levels, causing the collapse and fracturing of the dome surface. The bright margins possibly indicate the presence of rock debris on the slopes of the domes. Some of the fractures on the plains cut through the domes, while others appear to be covered by the domes. This indicates that active processes pre date and post date the dome-like hills. The prominent black area in the northeast corner of the image is a data gap. North is at the top of the image.

In the second image:  a portion of the eastern edge of Alpha Regio is displayed in this three-dimensional perspective view of the surface of Venus. The viewpoint is located at approximately 30 degrees south latitude, 11.8 degrees east longitude at an elevation of 2.4 kilometers (3.8 miles). The view is to the northeast at the center of an area containing seven circular dome-like hills. The average diameter of the hills is 25 kilometers (15 miles) with maximum heights of 750 meters (2,475 feet). Three of the hills are visible in the center of the image. Fractures on the surrounding plains are both older and younger than the domes. The hills may be the result of viscous or thick eruptions of lava coming from a vent on the relatively level ground, allowing the lava to flow in an even lateral pattern. The concentric and radial fracture patterns on their surfaces suggests that a chilled outer layer formed, then further intrusion in the interior stretched the surface. An alternative interpretation is that domes are the result of shallow intrusions of molten lava, causing the surface to rise. If they are intrusive, then magma withdrawal near the end of the eruptions produced the fractures. The bright margins possibly indicate the presence of rock debris or talus at the slopes of the domes. Resolution of the Magellan data is about 120 meters (400 feet). Magellan's synthetic aperture radar is combined with radar altimetry to develop a three-dimensional map of the surface. A perspective view is then generated from the map. Simulated color and a process called radar-clinometry are used to enhance small-scale structures. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. 

The images were produced by the JPL Multimission Image Processing Laboratory by Eric De Jong, Jeff Hall, Myche McAuley, and Randy Kirk of the United States Geological Survey, and is a single frame from the movie released at the May 29, 1991 Magellan news conference.

SAPAS MONS BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION (1989-1994)

Sapas Mons (1,500m or 1, 5km -   4,921ft or 0.93mi)

Venus (Alta Regio) 

The mountain 

Sapas Mons 1.5 kilometers (0.93 mi) is a large volcano with twin summit, located in the Atla Regio region of planet Venus. Sapas is named after the Canaanite sun goddess. It measures about 400 kilometers (250 mi) across. Its flanks show numerous overlapping lava flows. The dark flows on the lower right of the radar image are thought to be smoother than the brighter ones near the central part of the volcano. Many of the flows appear to have been erupted along the flanks of the volcano rather than from the double summit. This type of flank eruption is common on large volcanoes on Earth, such as the Hawaiian volcanoes. The summit area has two flat-topped mesas, whose smooth tops give a relatively dark appearance in the radar image. Also seen near the summit are groups of pits, some as large as one kilometer (0.6 mile) across. These are thought to have formed when underground chambers of magma were drained through other subsurface tubes and lead to a collapse at the surface. A 20-kilometer-diameter (12 mi) impact crater northeast of the volcano is partially buried by the lava flows. Little was known about Atla Regio prior to the Magellan probe. The new data, acquired in February 1991, show the region to be composed of at least five large volcanoes such as Sapas Mons, which are commonly linked by complex systems of fractures or rift zones. If comparable to similar features on Earth Atla Regio probably formed when large volumes of molten rock upwelled from areas within the interior of Venus known as 'hot spots.'
Source:
- NASA

The photographer 
Soviet Venera 13 and 14 spacecraft observed in the 1970s have first photographed the twin summit. The Nasa Magellan Mission photographed the region in a more acute way.
- More about NASA Magellan Mission 
- Nasa Magellan Mission to Venus

GULA MONS BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION (1989-1994)

Gula Mons  (3,000m - 9,843ft)

Planet Venus 

The mountain
Gula Mons (3000m/3km -9,843ft/1.9mi high  and 276km diameter), named after the Mesopotamian Goddess of Healing, is a shield volcano on planet Venus in western Eistla Regio, located south of Sedna Planitia, west of Bereghinya Planitia and east of Guinervere Planitia, at 21,9° N et 359,1° E.
Its main feature is a NE-SW-oriented rift-like fracture set connecting two summit calderas. There is also a structure which links the northern caldera and ridge system to Idem Kuva corona located NW of Gula Mons. Radially spreading lava flows which have digitate and broad sheet-like forms extend from the summit, including radar-dark flows which overlay several older lava deposits. Radial and circumferential fractures are present on the flanks.

The photographer 
- More about NASA Magellan Mission 

SKADI MONS BY NASA MAGELLA MISSION

NASA MAGELLAN MISSION (1989-1994)

Skadi Mons (11, 500m or 11, 5 km -  37,730 ft or 7 miles) 

Venus planet (Maxwell Montes)

Photographed on 7 march 1996  

The mountain 

Skadi Mons 10,700m or 10, 7 km -  35,105 ft or 6, 65 mi) is a mountain on planet Venus, in Maxwell Montes, at the center of Ishtar Terra. It is the highest point of the planet with an altitude of about 10,700 meters above the mean planetary radius. On this image it is located along the right hand part. 

Maxwell Montes is a mountain massif on the planet Venus, located on Ishtar Terra, the more northern of the planet's two major highlands. The western slopes are very steep, whereas the eastern slopes descend gradually into Fortuna Tessera. Due to its elevation it is the coolest (about 380 °C or 716 °F) and least pressurised (about 45 bar or 44 atm) location on the surface of Venus. 

By using radar to probe through the permanent and thick clouds in the Venusian atmosphere and make observations of the surface, scientists at the American Arecibo Radio Telescope in Puerto Rico discovered the extensive highland on Venus that came to be called Maxwell Montes in 1967.
In 1978, the space probe Pioneer Venus 1 went into orbit around Venus for the purpose of making radar observations of the Venusian surface. These observations made possible the creation of the first topographic map of the surface of Venus, and confirmed that a point within Maxwell Montes is the highest point above the average level of the planet's surface.
Maxwell Montes, Alpha Regio, and Beta Regio are the three exceptions to the rule that the surface features of Venus are to be named for females.
Maxwell Montes is named for James Clerk Maxwell whose work in mathematical physics predicted the existence of radio waves, which made radar, and thus the surface observations of Venus, possible.
The name, originally given by Ray Jurgens in 1970 on the urging of Tommy Gold, was approved by the International Astronomical Union's Working Group for Planetary System Nomenclature (IAU/WGPSN) between 1976 and 1979.
Source: 
- NASA Jet Propulsion Laboratory / CalTech

The image capturer
This Magellan full resolution radar image is centered at 65 degrees north latitude, zero degrees east longitude, along the eastern edge of Lakshmi Planum and the western edge of Maxwell Montes and its highest peak,  Skadi Mons. The plains of Lakshmi are made up of radar-dark, homogeneous, smooth lava flows. Maxwell is made up of parallel ridges 2 to 7 km (1.2 to 4.2 miles) apart and is interpreted to have formed by compressional tectonics. The image is 300 km (180 miles) wide.
The Magellan spacecraft, named after the 16th century Portuguese explorer whose expedition first circumnavigated the Earth, was launched May 4, 1989, and arrived at Venus on August 10, 1990. Magellan's solid rocket motor placed it into a near-polar elliptical orbit around the planet. During the first 8-month mapping cycle around Venus, Magellan collected radar images of 84% of the planet's surface, with resolution 10 times better than that of the earlier Soviet Venera 15 and 16 missions. Altimetry and radiometry data also measured the surface topography and electrical characteristics.
During the extended mission, two further mapping cycles from May 15, 1991 to September 14, 1992 brought mapping coverage to 98% of the planet, with a resolution of approximately 100m.
Precision radio tracking of the spacecraft will measure Venus' gravitational field to show the planet's internal mass distribution and the forces which have created the surface features. Magellan's data will permit the first global geological understanding of Venus, the planet most like Earth in our solar system.
Magellan Synthetic Aperture Radar (SAR) data is combined with radar altimetry to develop a three-dimensional map of the surface. The vertical scale in this perspective has been exaggerated 22.5 times. Rays cast in a computer intersect the surface to create a three-dimensional perspective view. Simulated color and a digital elevation map developed by the U.S. Geological Survey, are used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced at the JPL Multimission Image Processing Laboratory.
Source: 

- NASA Jet Propulsion Laboratory / CalTech

MAAT MONS SEEN BY NASA MAGELLAN MISSION

NASA MAGELLAN MISSION  (1989-1994)

Maat mons (8,000 m- 26,246ft)

Venus

photographed in 1990-92 in Alta Regio V236 and Stanton V 38 Quadrangle 

The mountain 

Maat Mons (8,000 m - 26,246ft or  8 km - 5.mi according to the way to measure mountains outside Earth planet) is a massive shield volcano located on the solar system planet Venus.  Maat Mons, named for an Egyptian goddess of truth and justice, is the second-highest mountain, and the highest volcano, on the planet Venus. 

Venus, named for the ancient Roman goddess of love and beauty, is the second planet from the sun and the closest planetary neighbor of Earth. Similar in structure and size to Earth, Venus spins slowly in the opposite direction most planets do. Its thick atmosphere traps heat in a runaway greenhouse effect, making it the hottest planet in our solar system with surface temperatures hot enough to melt lead. Glimpses below the clouds reveal volcanoes and deformed mountains.

Maat Mons is displayed in this three-dimensional perspective view of the surface of Venus. The viewpoint is located 560 kilometers (347 miles) north of Maat Mons at an elevation of 1.7 kilometers (1 mile) above the terrain. Lava flows extend for hundreds of kilometers across the fractured plains shown in the foreground, to the base of Maat Mons. The view is to the south with Maat Mons appearing at the center of the image on the horizon. Maat Mons, an 8-kilometer (5 mile) high volcano, is located at approximately 0.9 degrees north latitude, 194.5 degrees east longitude. 

Maat Mons has a large summit caldera, 28x31 km in size. Within the large caldera there are at least five smaller collapse craters, up to 10 km in diameter. A chain of small craters 3–5 km in diameter extends some 40 km along the southeast flank of the volcano, but rather than indicating a large fissure eruption, they seem to also be formed by collapse: full resolution imagery from the Magellan probe reveals no evidence of lava flows from these craters.

At least two large scale structural collapse events seem to have occurred in the past on Maat Mons.

Radar sounding by the Magellan probe revealed evidence for comparatively recent volcanic activity at Maat Mons, in the form of ash flows near the summit and on the northern flank.

Intriguingly for planetary geologists, atmospheric studies carried out by the Pioneer Venus probes in the early 1980s revealed a considerable variation in the concentrations of sulfur dioxide (SO2) and methane (CH4) in Venus' middle and upper atmosphere. One possible explanation for this was the injection of volcanic gases into the atmosphere by Plinian eruptions at Maat Mons.

Although many lines of evidence suggest that Venus is likely to be volcanically active, present-day eruptions at Maat Mons have not been confirmed.

Source: 

- NASA Solar system database 

- NASA Jet Propulsion Laboratory / CalTech

The image capturer

The Magellan spacecraft, named after the 16th century Portuguese explorer whose expedition first circumnavigated the Earth, was launched May 4, 1989, and arrived at Venus on August 10, 1990. Magellan's solid rocket motor placed it into a near-polar elliptical orbit around the planet. During the first 8-month mapping cycle around Venus, Magellan collected radar images of 84% of the planet's surface, with resolution 10 times better than that of the earlier Soviet Venera 15 and 16 missions. Altimetry and radiometry data also measured the surface topography and electrical characteristics.
During the extended mission, two further mapping cycles from May 15, 1991 to September 14, 1992 brought mapping coverage to 98% of the planet, with a resolution of approximately 100m.
Precision radio tracking of the spacecraft will measure Venus' gravitational field to show the planet's internal mass distribution and the forces which have created the surface features. Magellan's data will permit the first global geological understanding of Venus, the planet most like Earth in our solar system.

Magellan Synthetic Aperture Radar (SAR) data is combined with radar altimetry to develop a three-dimensional map of the surface. The vertical scale in this perspective has been exaggerated 22.5 times. Rays cast in a computer intersect the surface to create a three-dimensional perspective view. Simulated color and a digital elevation map developed by the U.S. Geological Survey, are used to enhance small-scale structure. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. The image was produced at the JPL Multimission Image Processing Laboratory.

Source: 
- NASA Jet Propulsion Laboratory / CalTech