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40-509: The total area of the formation is equal to 20% the size of the continental United States. It is divided into three subunits (members) that are all considered to be of Amazonian age, the youngest era in martian geological history. The formation straddles the highland - lowland boundary near the Tharsis and Elysium volcanic areas, and extends across five quadrangles: Amazonis , Tharsis , Memnonia , Elysium , and Aeolis . The origin of

80-438: A resolution of 1 microradian , or 0.3 meter at a height of 300 km. (For comparison purposes, satellite images on Google Mars are available to 1 meter. ) It can image in three color bands, 400–600 nm ( blue – green or B–G), 550–850 nm ( red ) and 800–1,000 nm ( near infrared or NIR). HiRISE incorporates a 0.5-meter primary mirror, the largest optical telescope ever sent beyond Earth's orbit. The mass of

120-459: A color strip down the middle only. The HiRISE camera is designed to view surface features of Mars in greater detail than has previously been possible. It has provided a closer look at fresh Martian craters, revealing alluvial fans , viscous flow features and ponded regions of pitted materials containing breccia clast . This allows for the study of the age of Martian features, looking for landing sites for future Mars landers, and in general, seeing

160-436: A geologic period represents the time interval over which the strata of a system were deposited, including any unknown amounts of time present in gaps. Periods are measured in years, determined by radioactive dating . On Mars, radiometric ages are not available except from Martian meteorites whose provenance and stratigraphic context are unknown. Instead, absolute ages on Mars are determined by impact crater density, which

200-603: A given system are apt to contain gaps ( unconformities ) analogous to missing pages from a book. In some places, rocks from the system are absent entirely due to nondeposition or later erosion. For example, rocks of the Cretaceous System are absent throughout much of the eastern central interior of the United States. However, the time interval of the Cretaceous (Cretaceous Period) still occurred there. Thus,

240-420: A large deposit might have been emplaced in periodic eruptions over an interval of 500 million years. In some places, the formation appears as a smooth and gently undulating surface, while in others it is wind-sculpted into ridges and grooves. Radar imaging has suggested that the region may contain either extremely porous rock (for example volcanic ash) or deep layers of glacier-like ice deposits amounting to about

280-490: A typical maximum size of 11.2 gigabits. These images are released to the general public on the HiRISE website via a new format called JPEG 2000 . To facilitate the mapping of potential landing sites, HiRISE can produce stereo pairs of images from which the topography can be measured to an accuracy of 0.25 meter. HiRISE images are available to the public, are named according to the following rules: The target code refers to

320-625: Is heavily dependent upon models of crater formation over time. Accordingly, the beginning and end dates for Martian periods are uncertain, especially for the Hesperian/Amazonian boundary, which may be in error by a factor of 2 or 3. 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

360-453: Is limited by the onboard computer's 28 Gbit ( 3.5 GB ) memory capacity. The nominal maximum size of red images (compressed to 8 bits per pixel) is about 20,000 × 126,000 pixels, or 2520 megapixels and 4,000 × 126,000 pixels (504 megapixels) for the narrower images of the B–G and NIR bands. A single uncompressed image uses up to 28   Gbit. However, these images are transmitted compressed, with

400-451: Is sometimes subdivided into the Early, Middle, and Late Amazonian. The Amazonian continues to the present day. The Amazonian period has been dominated by impact crater formation and Aeolian processes with ongoing isolated volcanism occurring in the Tharsis region and Cerberus Fossae , including signs of activity as recently as a tens of thousands of years ago in the latter and within

440-586: Is the youngest of the Martian periods, the chronology of the Amazonian is comparatively well understood through traditional geological laws of superposition coupled to the relative dating technique of crater counting . The scarcity of craters characteristic of the Amazonian also means that unlike the older periods, fine scale (<100 m) surface features are preserved. This enables detailed, process-orientated study of many Amazonian-age surface features of Mars as

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480-449: The MOLA topographic dataset allowed calculation of the density of the deposit; the value is 1.765 ± 0.105 g/cm, similar to the density of terrestrial ignimbrites . This rules out significant amounts of ice in the bulk composition. In combination with the deposit's high content of sulfur and chlorine, it implies an explosive volcanic origin. The total volume of the deposit is 1.4 × 10 km; such

520-486: The prevailing winds that carved them, and demonstrate the erosive power of Martian winds. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash . Yardangs are parts of rock that have been sand blasted into long, skinny ridges by bouncing sand particles blowing in

560-524: The HiWish program. The first is a context image from CTX to show where the HiRISE is looking. The following group of images show some significant images taken by the instrument. Some of these hint at possible sources of water for future colonists. The following set of pictures show first a full image of a scene and then enlargements from parts of it. A program called HiView can be used to produce more detailed views. Some pictures are in color. HiRISE takes

600-694: The Mars Odyssey Neutron Spectrometer revealed that the western lobe of the Medusae Fossae Formation contains some water. This means that this formation contains bulk water ice. During periods of high obliquity (tilt) water ice was stable on the surface. By means of a re-analysis of data from Mars Express ' MARSIS radar, Thomas Watters found evidence about the existence of large underground water deposits in Medusae Fossae up to 3.7 km thick and covered by hundreds of meters of dust. Combining several gravity models of Mars with

640-458: The Martian surface in far greater detail than has previously been done from orbit. By doing so, it is allowing better studies of Martian channels and valleys, volcanic landforms, possible former lakes and oceans, sand dune fields such as Hagal and Nili Patera , and other surface landforms as they exist on the Martian surface. The general public is allowed to request sites for the HiRISE camera to capture (see HiWish ). For this reason, and due to

680-534: The area so the surface is relatively young. Amazonian (Mars) The Amazonian is a geologic system and time period on the planet Mars characterized by low rates of meteorite and asteroid impacts and by cold, hyperarid conditions broadly similar to those on Mars today. The transition from the preceding Hesperian period is somewhat poorly defined. The Amazonian is thought to have begun around 3 billion years ago, although error bars on this date are extremely large (~500 million years). The period

720-499: The camera and prepare it for taking pictures of Mars. On March 10, 2006, MRO achieved Martian orbit and primed HiRISE to acquire some initial images of Mars. The instrument had two opportunities to take pictures of Mars (the first was on March 24, 2006) before MRO entered aerobraking, during which time the camera was turned off for six months. It was turned on successfully on September 27, and took its first high-resolution pictures of Mars on September 29. On October 6, 2006 HiRISE took

760-430: The climate. This has included: Good preservation has also enabled detailed studies of other geological processes on Amazonian Mars, notably volcanic processes , brittle tectonics , and cratering processes . System and Period are not interchangeable terms in formal stratigraphic nomenclature, although they are frequently confused in popular literature. A system is an idealized stratigraphic column based on

800-552: The degradation can be reversed by heating the ADCs. On October 3, 2007, HiRISE was turned toward Earth , and took a picture of it and the Moon . In the full-resolution color image, Earth was 90 pixels across and the Moon was 24 pixels across from a distance of 142 million km. On May 25, 2008, HiRISE imaged NASA's Mars Phoenix Lander parachuting down to the surface of Mars. It was

840-489: The first image of Victoria Crater , a site which was also under study by the Opportunity rover . In February 2007 seven detectors showed signs of degradation, with one IR channel almost completely degraded, and one other showing advanced signs of degradation. The problems seemed to disappear when higher temperatures were used to take pictures with the camera. As of March, the degradation appeared to have stabilized, but

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880-472: The first time that one spacecraft imaged the final descent of another spacecraft onto a planetary body. By 2010, HiRISE had imaged only about one percent of Mars's surface and by 2016 the coverage was around 2.4%. It was designed to capture smaller areas at high resolution—other instruments scan much more area to find things like fresh impact craters. MRO's Context Camera (CTX) captured two fresh impact craters (>130 meter each) formed on Mars in late 2021,

920-453: The formation is unknown, but many theories have been presented over the years. In 2020, a group of researchers headed by Peter Mouginis-Mark has hypothesized that the formation could have been formed from pumice rafts from the volcano Olympus Mons . In 2012, a group headed by Laura Kerber hypothesized that it could have been formed from ash from the volcanoes Apollinaris Mons , Arsia Mons , and possibly Pavonis Mons . An analysis of data from

960-462: The future could be characterised by HiRISE color. On April 1, 2010, NASA released the first images under the HiWish program in which the public suggested places for HiRISE to photograph. One of the eight locations was Aureum Chaos. The first image below gives a wide view of the area. The next two images are from the HiRISE image. The following three images are among the first images taken under

1000-404: The gathering of a coarse covering layer to form an inverted relief . These inverted stream beds are sometimes called sinuous ridges or raised curvilinear features. They have been divided into six classes: flat-crested, narrow-crested, round-crested, branching, non-branching, and multilevel. They may be a kilometer or so in length. Their height ranges from a meter to greater than 10 meters, while

1040-401: The instrument is 64.2 kg. Red color images are at 20,048 pixels wide (6 km in a 300 km orbit), and blue-green and NIR are at 4,048 pixels wide (1.2 km). These are gathered by 14 CCD sensors, 2048 × 128 pixels . HiRISE's onboard computer reads out these lines in time with the orbiter's ground speed , meaning the images are potentially unlimited in height. Practically this

1080-565: The largest discovered by MRO. These seismic events were also detected by Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) . The crater in Amazonis Planitia was discovered independently by both missions, while the crater in Tempe Terra was first observed by Insight and then searched for with CTX images. This identification further allowed development of new techniques by which ice deposits in

1120-430: The latitudinal position of the center of the planned observation relative to the start of orbit. The start of orbit is located at the equator on the descending side (night side) of the orbit. A target code of 0000 refers to the start of orbit. The target code increases in value along the orbit track ranging from 0000 to 3595. This convention allows the file name ordering to be time sequential. The first three digits refers to

1160-470: The necessary details of form of the surface are still visible. Furthermore, the relative youth of this period means that over the past few 100 million years it remains possible to reconstruct the statistics of the orbital mechanics of the Sun , Mars , and Jupiter without the patterns being overwhelmed by chaotic effects, and from this to reconstruct the variation of solar insolation – the amount of heat from

1200-602: The past few million years on Olympus Mons , implying they may still be active but dormant in the present. The Amazonian System and Period is named after Amazonis Planitia , which has a sparse crater density over a wide area. Such densities are representative of many Amazonian-aged surfaces. The type area of the Amazonian System is in the Amazonis quadrangle (MC-8) around 15°N 158°W  /  15°N 158°W  / 15; -158 . Because it

1240-437: The physical rock record of a type area (type section) correlated with rocks sections from many different locations planetwide. A system is bound above and below by strata with distinctly different characteristics (on Earth, usually index fossils ) that indicate dramatic (often abrupt) changes in the dominant fauna or environmental conditions. (See Cretaceous–Paleogene boundary as example.) At any location, rock sections in

Medusae Fossae Formation - Misplaced Pages Continue

1280-476: The same quantity as is stored in Mars' south polar cap. Further evidence for a fine-grained composition is the fact that the area gives almost no radar return. The lower portion (member) of Medusae Fossae Formation contains many patterns and shapes that are thought to be the remains of streams. It is believed that streams formed valleys that were filled and became resistant to erosion by cementation of minerals or by

1320-408: The sun – reaching Mars through time. Climatic variations have been shown to occur in cycles not dissimilar in magnitude and duration to terrestrial Milankovich cycles . Together, these features – good preservation, and an understanding of the imposed solar flux – mean that much research on the Amazonian of Mars has focussed on understanding its climate , and the surface processes that respond to

1360-686: The surface, including the Opportunity rover and the ongoing Curiosity mission . In the late 1980s, Alan Delamere of Ball Aerospace & Technologies began planning the kind of high-resolution imaging needed to support sample return and surface exploration of Mars. In early 2001 he teamed up with Alfred McEwen of the University of Arizona to propose such a camera for the Mars Reconnaissance Orbiter (MRO), and NASA formally accepted it November 9, 2001. Ball Aerospace

1400-479: The underlying cause remained unknown. Subsequent experiments with the Engineering Model (EM) at Ball Aerospace provided definitive evidence for the cause: contamination in the analog-to-digital converters (ADCs) which results in flipping bits to create the apparent noise or bad data in the images, combined with design flaws leading to delivery of poor analog waveforms to the ADCs. Further work showed that

1440-412: The unprecedented access of pictures to the general public, shortly after they have been received and processed, the camera has been termed "The People's Camera". The pictures can be viewed online, downloaded, or with the free HiView software. HiRISE was designed to be a high resolution camera from the beginning. It consists of a large mirror, as well as a large CCD camera. Because of this, it achieves

1480-440: The width of the narrow ones is less than 10 meters. Comparisons of elemental composition suggest that the Medusae Fossae Formation has been a source of Mars' ubiquitous surface dust. In July 2018, researchers reported that it may be the largest single source of dust on the planet. The surface of the formation has been eroded by the wind into a series of linear ridges called yardangs . These ridges generally point in direction of

1520-467: The wind. Layers are seen in parts of the formation. A resistant caprock on the top of yardangs has been observed in Viking, Mars Global Surveyor , and HiRISE photos. Images from spacecraft show that they have different degrees of hardness probably because of significant variations in the physical properties, composition, particle size, and/or cementation . Very few impact craters are visible throughout

1560-514: Was built under the direction of the University of Arizona 's Lunar and Planetary Laboratory by Ball Aerospace & Technologies Corp. It consists of a 0.5   m (19.7 in) aperture reflecting telescope , the largest so far of any deep space mission, which allows it to take pictures of Mars with resolutions of 0.3   m/pixel (1   ft/pixel), resolving objects below a meter across. HiRISE has imaged Mars exploration rovers on

1600-533: Was given the responsibility to build the camera and they delivered HiRISE to NASA on December 6, 2004 for integration with the rest of the spacecraft. It was prepared for launch on board the MRO on August 12, 2005, to the cheers of the HiRISE team who were present. During the cruise phase of MRO, HiRISE took multiple test shots including several of the Moon and the Jewel Box cluster. These images helped to calibrate

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