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Post Info TOPIC: Viking Lander 1 and Mars Pathfinder


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Probe spies landers on Red Planet
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New images have been released of past and present US landing craft on the surface of Mars taken by Nasa's Mars Reconnaissance Orbiter (MRO) probe.

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Cydonia region
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Recently, ESA's Mars Express delivered photos of the famous 'Face on Mars' in the Cydonia region. The High Resolution Stereo Camera images are some of the most spectacular views of the Red Planet ever taken. Now, there's a stunning 3D animation of the area.
The High Resolution Stereo Camera (HRSC) science team have produced a dramatic 3D animation that beautifully simulates a flight over the Cydonia 'Face on Mars', one of the most famous surface features on the planet.

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Cydonia
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ESA's Mars Express has obtained images of the Cydonia region, site of the famous 'Face on Mars.' The High Resolution Stereo Camera photos include some of the most spectacular views of the Red Planet ever.
After multiple attempts to image the Cydonia region from April 2004 until July 2006 were frustrated by altitude and atmospheric dust and haze, the High Resolution Stereo Camera (HRSC) on board Mars Express finally obtained, on 22 July, a series of images that show the famous 'face' on Mars in unprecedented detail.


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Credits: ESA/DLR/FU Berlin (G. Neukum), Malin Space Science Systems

The data were gathered during orbit 3253 over the Cydonia region, with a ground resolution of approximately 13.7 metres per pixel. Cydonia lies at approximately 40.75° North and 350.54° East.
Cydonia is located in the Arabia Terra region on Mars and belongs to the transition zone between the southern highlands and the northern plains of Mars. This transition is characterised by wide, debris-filled valleys and isolated remnant mounds of various shapes and sizes.

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RE: Viking Lander 1 and Mars Pathfinder
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The planet-wide dust storms that periodically cloak Mars in a mantle of red may be generating a snow of corrosive chemicals, including hydrogen peroxide, that would be toxic to life, according to two new studies published in the most recent issue of the journal Astrobiology.

Based on field studies on Earth, laboratory experiments and theoretical modelling, the researchers argue that oxidising chemicals could be produced by the static electricity generated in the swirling dust clouds that often obscure the surface for months, said University of California, Berkeley, physicist Gregory T. Delory, first author of one of the papers. If these chemicals have been produced regularly over the last 3 billion years, when Mars has presumably been dry and dusty, the accumulated peroxide in the surface soil could have built to levels that would kill "life as we know it".

"If true, this very much affects the interpretation of soil measurements made by the Viking landers in the 1970s" - Gregory T. Delory, senior fellow at UC Berkeley's Space Sciences Laboratory.

A major goal of the Viking mission, comprised of two spacecraft launched by NASA in 1975, was testing Mars' red soil for signs of life. In 1976, the two landers aboard the spacecraft settled on the Martian surface and conducted four separate tests, including some that involved adding nutrients and water to the dirt and sniffing for gas production, which could be a telltale sign of living microorganisms.

Source University of California Berkeley

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Martian Life
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Electricity generated in dust storms on Mars may produce reactive chemicals that build up in the Martian soil, according to NASA-funded research. The chemicals, like hydrogen peroxide (H2O2), may have caused the contradictory results when NASA's Viking landers tested the Martian soil for signs of life, according to the researchers.
Lead authors Gregory Delory, senior fellow at the University of California Berkeley Space Sciences Laboratory, and Sushil Atreya, planetary science professor at the University of Michigan, Ann Arbor, reported their results in a tandem set of papers in the June 2006 issue of the journal "Astrobiology".
Dust particles become electrified in Martian dust storms when they rub against each other as they are carried by the winds, transferring positive and negative electric charge in the same way you build up static electricity if you shuffle across a carpet.

"From our field work, we know that strong electric fields are generated by dust storms on Earth. Also, laboratory experiments and theoretical studies indicate that conditions in the Martian atmosphere should produce strong electric fields during dust storms there as well." - co-author William Farrell of NASA's Goddard Space Flight Center, Greenbelt, Md.

Delory's team calculated that electric fields generated by the swirling dust are strong enough to break apart carbon dioxide and water molecules in the Martian atmosphere.

"Our calculations indicate that once these electric fields are produced by dust storms on Mars, they free more electrons from atoms and molecules in the thin Martian atmosphere. These electrons then collide with and break apart molecules such as water and carbon dioxide, creating new chemical products that continue to react with other constituents in Mars' atmosphere" - Gregory Delory.

Atreya's team then identified the various ways the broken molecules recombine into reactive chemicals like hydrogen peroxide and ozone (O3), and calculated the amounts that might accumulate in the Martian soil over time.

"Once carbon dioxide and water are broken apart, the resulting products interact with the other molecules in the Martian atmosphere to produce large quantities of the highly-reactive hydrogen peroxide. In fact hydrogen peroxide produced by dust electrification can greatly exceed the rate that it is produced by the conventional energy source of ultraviolet radiation from the sun, so much so that hydrogen peroxide would snow out of the atmosphere and permeate the Martian soil" - Sushil Atreya.

In 1976, the twin Viking landers scooped up Martian soil and added nutrients mixed with water to it. If microscopic life were present, the nutrients would be used up and waste products would be released. Three different experiments involved in this test gave conflicting results. The Labelled Release and the Gas Exchange experiments indicated something active was in the soil, because the nutrients were broken down. However, the Mass Spectrometer experiment did not find any organic matter in the soil.
In 1977, Viking researchers suggested that the apparent contradiction could be explained if a very reactive nonorganic substance that imitated the activity of life by breaking down the nutrients was embedded in the soil. Hydrogen peroxide and ozone were considered possible candidate reactive compounds. While ultraviolet radiation from the sun could produce a certain amount of reactive chemicals in the atmosphere, there were no physical processes known to explain how large amounts of such reactive material could accumulate in the Martian soil. Some researchers at the time considered the possibility that dust storms might be electrically active in a way similar to terrestrial thunderstorms, and that these storms might be a source of the new reactive chemistry.
This dust storm suggestion remained dormant for close to 30 years. The Astrobiology papers now provide detailed analysis to support this theory, based on results from field and laboratory studies by the team over the past five years. The theory could be tested further by an electric field sensor working in tandem with an atmospheric chemistry system on a future Mars rover or lander, according to the teams.

The team includes Delory, Atreya, Farrell, and Nilton Renno & Ah-San Wong, (University of Michigan), Steven Cummer (Duke University, Durham, N.C.), Davis Sentman (University of Alaska), John Marshall (SETI Inst., Mountain View, Calif.), Scot Rafkin (Southwest Research Institute, San Antonio, Texas) and David Catling (University of Washington). The research was funded by NASA's Mars Fundamental Research Program and NASA Goddard internal institutional funds.

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RE: Viking Lander 1 and Mars Pathfinder
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Viking Landing—30th Anniversary: JPL Podcast
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NASA Marks 30th Anniversary of Mars Viking Mission

www.nasa.gov/mission_pages/viking/index.html

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Thirty years ago this week, on June 19, 1976, Viking 1 entered orbit around Mars, and spent its first month imaging the surface and transmitting those images back to ground controllers, who were trying to find appropriate landing sites.
On July 20, 1976, the Viking 1 lander separated from the orbiter and touched down at Chryse Planitia, at 22.48 degrees north latitude and 49.97 degrees west. After transmitting images for seven years, two months and four days, the stationary probe apparently ran out of power on Nov. 13, 1982, and stopped transmitting.

NASA launched Viking 2 on Sept. 9, 1975. Taking a less direct route, it entered Mars orbit Aug. 7, 1976. A little less than four weeks later, on Sept. 3, the lander touched down at Utopia Planitia at 47.97 degrees north and 225.74 degrees west. It continued to transmit images for a mere three years, eight months and four days, its last transmission received April 11, 1980.

During their photographic operations, the landers also took Martian surface samples and analysed them for composition and signs of life, studied atmospheric composition and meteorology, and deployed seismometers.

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Face on Mars
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The Face on Mars is a large feature on the surface of the planet Mars located in the Cydonia region. It measures approximately 3 km long and 1.5 km across and lies some 10 degrees North of the Martian equator. It was first photographed on July 25, 1976 by the Viking 1 space probe orbiting the planet at the time. It was brought to the attention of the public in a NASA press release of the photo six days later.
Most interpretations of the photo suggest that the feature is a natural landform, one of many mesas that scatter Cydonia.


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The "Face on Mars", photographed by Mars Orbital Camera

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Viking missions
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NASA's Viking Mission to Mars was composed of two spacecraft, Viking 1 and Viking 2. Each spacecraft consisted of an orbiter and a lander. The lander descended to the surface with the aid of a heat shield, a parachute, and retrorockets.

The discovery by Mariner of river and lake beds on the surface rekindled visions of life on Mars, and the Viking craft were equipped with experiments to probe for bacterial life. The twin Viking orbiters had cameras, an infrared thermal mapper, and a Mars atmospheric water detector. The landers also carried instrumentation to measure the composition and structure of the Martian atmosphere during descent.

Viking 1 was launched on August 20, 1975 and arrived at Mars on June 19, 1976. The first month of orbit was devoted to imaging the surface to find appropriate landing sites for the Viking Landers. On July 20, 1976 Viking Lander 1 separated from the Orbiter and touched down at Chryse Planitia. Viking 2 was launched September 9, 1975 and entered Mars orbit on August 7, 1976. Viking Lander 2 touched down at Utopia Planitia on September 3, 1976.
The Orbiters imaged the entire surface of Mars at a resolution of 150 to 300 meters, and selected areas at 8 meters. Viking Orbiter 2 was powered down on July 25, 1978 after 706 orbits, and Viking Orbiter 1 on August 17, 1980, after over 1,400 orbits.

The Viking Landers transmitted images of the surface, took surface samples and analysed them for composition and signs of life, studied atmospheric composition and meteorology, and deployed seismometers. Viking Lander 2 ended communications on April 11, 1980, and Viking Lander 1 on November 13, 1982, after transmitting over 1400 images of the two sites.

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