Extant Life on Mars - Revision history

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← Older revision		Revision as of 18:59, 25 May 2020
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	== Abstract ==		== Abstract ==

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 Falling near Murchison Australia in 1969, the Murchison meteorite was witnessed falling to the ground. It is one of the most studied meteorites in the world. It is not thought to have originated from Mars, but the scientific findings of this space rock pose many questions for scientists, especially astrobiologists.  This meteorite has been found to contain many amino acids, see figure 8. Some studies say 15 others say 20 or more.  (ISMP 2013 Murchison) Although the Murchison meteorite is not from Mars, it begs the question, if there are amino acids in meteorites falling from the sky onto Earth, then why wouldn’t there be meteorites falling to Mars with the same organic material?   NASA’s Dr. John Grotzinger explained that the organic compounds recently discovered by the Curiosity Rover may not have originated from Mars. It should not matter where the organic material came from.  The organic compounds are there now.  Of course, this excludes contamination from Earth.  Everything on every planet came from somewhere else.  We are a collection of material that came from the same swirling cloud of gas and dust.  Therefore, if organic compounds are on one planet or satellite, then it is logical that all of the bodies in the solar system, and therefore galaxy, have the same ingredients for life.  This has also been confirmed by spacecraft that have taken samples from cometary debris which also had amino acids in them.  (Rietmeijer 2010)
-[[File:ExtantLife18.jpg|thumb|400px|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
+[[File:ExtantLife18.jpg|thumb|500px|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
 The previously discussed meteorite ALH84001 had more surprises for scientists in the form of amino acids.  Scientist used high performance liquid chromatography to examine samples of the meteorite and discovered trace amounts of several amino acids, including glycine, alanine and serine.  It is proposed by the team that most of the amino acids are from terrestrial contamination but left open the possibility of the D-alanine amino acid being preserved in the Allen Hills meteorite from Mars.  (Bada 1998)

@@ Line 158: / Line 158: @@
 The Curiosity Rover continued the search for methane and water, among other things.  It seemed that almost as soon as the Curiosity started exploring her new home on Mars, she made a plethora of discoveries including the above-mentioned dry riverbed where fresh water once flowed in Gale crater.  When MSL’s instruments drilled into and examined the rock dubbed “John Klein” scientists realized that the rock contained what biologists call CHNOPS. Those are the six elements needed for all life on Earth to exist.  Another discovery were “simple organics” in which the molecules included carbon. One of the most important discoveries included more complex organic molecules than previously discovered, such as methane and chlorobenzene.  We know Mars is enriched with all of the same chemicals elements that are found on Earth for life to arise.  This important discovery puts to rest the long debate about whether Mars has organics.
 As NASA continued utilizing MSL to search, in 2018, it was confirmed that the Curiosity Rover’s Sample Analysis at Mars (SAM) instrument’s tunable laser spectrometer again detected organics. A spectrometer is a device that “looks” at a sample of something, in this case atmospheric gases, and takes readings to determine what molecules make up the sample being observed.  A computer-generated graph of some type is then read by scientists to analyze the spectral data.
 The data returned results consistent with methane and other organics on Mars, including kerogens. Kerogens are long-lived larger organic molecules that make up most organic material on Earth.  The methane that was discovered occurs in small localized plumes in Gale Crater. It has been determined that a seasonal cycle of methane exists on Mars, see Figure 7. The amount of difference between the least and most amount of methane detected is much larger than expected.  With the more recent observations the amount of methane detected in Gale Crater changed by a factor of 3x.  Scientists also discovered a phase lag exists which is a clue that something is happening in the subsurface of the planet.  Following up with more detailed research, a paper published in 2019 by Marco Giuranna in Nature Geosciences, confirmed with the PFS on ESA’s Mars Express, confirmed that the 2 spacecraft observed the same magnitude of a methane plume in the same location.  (Giuranna 2019) According to NASA’s astrobiology website, “The clear conclusion of these (and other) recent findings is that Mars is not a ‘dead’ planet where little ever changes. Rather, it’s one with cycles that appear to produce not only methane but also sporadic surface water and changing dune formations.”  (Astrobio3)
 The amount of methane reported over the past forty years on the Red Planet ranges from approximately 0.7-250 ppb from a variety of sources, NASA, ESA, orbiters, rovers, and ground based Earth telescopes.  Methane dissociates and only has a lifespan of approximately 329 years in an atmosphere, which is a short time on a planetary scale. It then breaks down and recombines with other dissociated molecules into water and carbon dioxide.  Therefore, since methane is present on Mars, it must be getting replenished biologically or geologically currently. Many peer reviewed scientific journal articles have been published regarding Martian methane and the possible explanations for its existence.  Some of the potential sources of methane include the presence of life, volcanoes, hydrothermal vents, photochemistry and other geological processes.  Cosmic dust includes organic rich material that may be coming into the atmosphere of Mars and hit by ultraviolet solar particles and converted to methane, then picked up by wind and destroyed by photochemistry.  This seems unlikely with the recent amounts detected at the surface in Gale Crater. The water that is now known to exist on Mars may combine with the olivine present on the surface and serpentinize, causing a release of methane.  A scenario that is looking more likely, due to the seasonal plumes and seepage, is biological life.  Some microbes bloom during warming periods and lie dormant during times of cooler weather. “[A] striking aspect of the Curiosity discovery is that the concentration of methane detected varies sharply over time. That can only be the case if the source of the methane is locally concentrated, as a globally spread source could not cause such sharp variations. Thus, there may be a patch of ground relatively close to Curiosity which is the source of the emissions, and, therefore, a prime target to drill in an attempt to find subsurface life. Similar biologically suspect spots may well exist elsewhere. We need to locate such spots, and then send human explorers to drill and find out what lies beneath,” states Dr. Robert Zubrin, President of the Mars Society. (Zubrin 2020)
@@ Line 173: / Line 173: @@
 Meteorite ALH 84001 was discovered in 1984 in a region of Antarctica called Allen Hills.  The classification for this rock is an OPX.  This category is made up of achondrite meteorites which are a rocks that do not contain round chondrate spherules.  An orthopyroxenite(OPX) is a rock made of orthopyroxene and pyroxenite.  ALH 84001 has gotten more attention than any other in recent history.  (ISMP ALH 84001 2013) The Allen Hills meteorite was studied by Dr. David McKay of NASA.  He published an article in the Journal Science in 1996 that claimed meteorite ALH 84001 contained microfossils.  This sent shockwaves through the scientific community and the world media.  Dr. McKay used scanning electron microscope (SEM) technology to image very fine slices of the meteorite, see image 10. When he saw the images, he and his team determined that they were microfossils of bacteria that had been preserved in the meteorite from Mars, thus concluding there had been life on the Red Planet in the past and may still exist there now.  Immediately other scientists started examining the evidence and some of them came to the conclusion that the results were an artifact of the SEM process and not life.  (NASA 2009)
-[[File:ExtantLife17.jpg|right|thumb|Image 10 (right): Meteorite ALH84001, insert scanning electron micrograph of a micro slice portion of the interior of the meteorite. (NASA)]]
+[[File:ExtantLife17.jpg|right|thumb|400px|Image 10 (right): Meteorite ALH84001, insert scanning electron micrograph of a micro slice portion of the interior of the meteorite. (NASA)]]
 One group of scientists stated that the ‘fossil’ was too small to be a bacterium.  They received pushback from another group proving they had found bacteria even smaller than the ALH84001 ‘fossil’ here on Earth.  (Precambrian) A group of scientists stand by McKay’s results and have helped to continue his research posthumously.   Journal articles supporting and debunking the results are published on a regular basis. The objects inside the Allen Hills meteorite may never be proven to be microfossils. However, with the exponential increase of technological advancements we can use other meteorites to supplement the data we find to determine what the potential for life is on Mars and in our Solar System.
@@ Line 189: / Line 189: @@
 Falling near Murchison Australia in 1969, the Murchison meteorite was witnessed falling to the ground. It is one of the most studied meteorites in the world. It is not thought to have originated from Mars, but the scientific findings of this space rock pose many questions for scientists, especially astrobiologists.  This meteorite has been found to contain many amino acids, see figure 8. Some studies say 15 others say 20 or more.  (ISMP 2013 Murchison) Although the Murchison meteorite is not from Mars, it begs the question, if there are amino acids in meteorites falling from the sky onto Earth, then why wouldn’t there be meteorites falling to Mars with the same organic material?   NASA’s Dr. John Grotzinger explained that the organic compounds recently discovered by the Curiosity Rover may not have originated from Mars. It should not matter where the organic material came from.  The organic compounds are there now.  Of course, this excludes contamination from Earth.  Everything on every planet came from somewhere else.  We are a collection of material that came from the same swirling cloud of gas and dust.  Therefore, if organic compounds are on one planet or satellite, then it is logical that all of the bodies in the solar system, and therefore galaxy, have the same ingredients for life.  This has also been confirmed by spacecraft that have taken samples from cometary debris which also had amino acids in them.  (Rietmeijer 2010)
-[[File:ExtantLife18.jpg|frame|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
+[[File:ExtantLife18.jpg|thumb|400px|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
 The previously discussed meteorite ALH84001 had more surprises for scientists in the form of amino acids.  Scientist used high performance liquid chromatography to examine samples of the meteorite and discovered trace amounts of several amino acids, including glycine, alanine and serine.  It is proposed by the team that most of the amino acids are from terrestrial contamination but left open the possibility of the D-alanine amino acid being preserved in the Allen Hills meteorite from Mars.  (Bada 1998)

@@ Line 152: / Line 152: @@
 The aforementioned Viking I and II Labeled Release Experiment which made an inconclusive discovery of life on Mars also discovered methane at 10.5 parts per billion (ppb) in 1976.  Decades later, while utilizing the NASA Infrared Telescope in Hawaii, Michael Mumma, of NASA Goddard, observed methane using ground-based instrumentation in 2003.  Mumma and his team’s observations were made over a heavily fractured region on Mars called Nilli Fossae. “We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane,” stated Dr. Geronimo Villanueva, part of Mumma’s team, from the Catholic University of America in Washington DC. When he followed up the observations in 2006, the methane had vanished.  Some scientists have stated that is indicative of a seasonal plume.  According to NASA’s astrobiology website Mumma and his team observed 20-60 ppb of methane near the poles and up to 250 ppb near the equator, see image 9.  It is interesting to note that the levels of methane are significantly higher near the equator where the temperature is higher and possibly more conducive to life.
-[[File:ExtantLife15.jpg|frame|none|Image 9: Methane plumes detected in 2003 and published in 2009 by Mumma and his team. (NASA)]]
+[[File:ExtantLife15.jpg|thumb|500px|none|Image 9: Methane plumes detected in 2003 and published in 2009 by Mumma and his team. (NASA)]]
 The European Space Agency (ESA) announced in 2004, they had discovered plumes of seasonal methane on Mars.  ESA announced that the Planetary Fourier Spectrometer (PFS) on Mars Express detected about 10 ppb of methane in the Martian atmosphere.  Although ESA and NASA themselves had previously detected methane on Mars, it was important to continue the search.
@@ Line 160: / Line 160: @@
 The data returned results consistent with methane and other organics on Mars, including kerogens. Kerogens are long-lived larger organic molecules that make up most organic material on Earth.  The methane that was discovered occurs in small localized plumes in Gale Crater. It has been determined that a seasonal cycle of methane exists on Mars, see Figure 7. The amount of difference between the least and most amount of methane detected is much larger than expected.  With the more recent observations the amount of methane detected in Gale Crater changed by a factor of 3x.  Scientists also discovered a phase lag exists which is a clue that something is happening in the subsurface of the planet.  Following up with more detailed research, a paper published in 2019 by Marco Giuranna in Nature Geosciences, confirmed with the PFS on ESA’s Mars Express, confirmed that the 2 spacecraft observed the same magnitude of a methane plume in the same location.  (Giuranna 2019) According to NASA’s astrobiology website, “The clear conclusion of these (and other) recent findings is that Mars is not a ‘dead’ planet where little ever changes. Rather, it’s one with cycles that appear to produce not only methane but also sporadic surface water and changing dune formations.”  (Astrobio3)
-[[File:ExtantLife16.jpg|frame|none|Figure 7: Seasonal methane plumes in Gale Crater including sources and sinks. Data from MSL’s SAM instruments tunable laser spectrometer. (NASA Astrobiology Institute)]]
+[[File:ExtantLife16.jpg|thumb|400px|none|Figure 7: Seasonal methane plumes in Gale Crater including sources and sinks. Data from MSL’s SAM instruments tunable laser spectrometer. (NASA Astrobiology Institute)]]
 The amount of methane reported over the past forty years on the Red Planet ranges from approximately 0.7-250 ppb from a variety of sources, NASA, ESA, orbiters, rovers, and ground based Earth telescopes.  Methane dissociates and only has a lifespan of approximately 329 years in an atmosphere, which is a short time on a planetary scale. It then breaks down and recombines with other dissociated molecules into water and carbon dioxide.  Therefore, since methane is present on Mars, it must be getting replenished biologically or geologically currently. Many peer reviewed scientific journal articles have been published regarding Martian methane and the possible explanations for its existence.  Some of the potential sources of methane include the presence of life, volcanoes, hydrothermal vents, photochemistry and other geological processes.  Cosmic dust includes organic rich material that may be coming into the atmosphere of Mars and hit by ultraviolet solar particles and converted to methane, then picked up by wind and destroyed by photochemistry.  This seems unlikely with the recent amounts detected at the surface in Gale Crater. The water that is now known to exist on Mars may combine with the olivine present on the surface and serpentinize, causing a release of methane.  A scenario that is looking more likely, due to the seasonal plumes and seepage, is biological life.  Some microbes bloom during warming periods and lie dormant during times of cooler weather. “[A] striking aspect of the Curiosity discovery is that the concentration of methane detected varies sharply over time. That can only be the case if the source of the methane is locally concentrated, as a globally spread source could not cause such sharp variations. Thus, there may be a patch of ground relatively close to Curiosity which is the source of the emissions, and, therefore, a prime target to drill in an attempt to find subsurface life. Similar biologically suspect spots may well exist elsewhere. We need to locate such spots, and then send human explorers to drill and find out what lies beneath,” states Dr. Robert Zubrin, President of the Mars Society. (Zubrin 2020)
@@ Line 173: / Line 173: @@
 Meteorite ALH 84001 was discovered in 1984 in a region of Antarctica called Allen Hills.  The classification for this rock is an OPX.  This category is made up of achondrite meteorites which are a rocks that do not contain round chondrate spherules.  An orthopyroxenite(OPX) is a rock made of orthopyroxene and pyroxenite.  ALH 84001 has gotten more attention than any other in recent history.  (ISMP ALH 84001 2013) The Allen Hills meteorite was studied by Dr. David McKay of NASA.  He published an article in the Journal Science in 1996 that claimed meteorite ALH 84001 contained microfossils.  This sent shockwaves through the scientific community and the world media.  Dr. McKay used scanning electron microscope (SEM) technology to image very fine slices of the meteorite, see image 10. When he saw the images, he and his team determined that they were microfossils of bacteria that had been preserved in the meteorite from Mars, thus concluding there had been life on the Red Planet in the past and may still exist there now.  Immediately other scientists started examining the evidence and some of them came to the conclusion that the results were an artifact of the SEM process and not life.  (NASA 2009)
-[[File:ExtantLife16.jpg|right|thumb|Image 10 (right): Meteorite ALH84001, insert scanning electron micrograph of a micro slice portion of the interior of the meteorite. (NASA)]]
+[[File:ExtantLife17.jpg|right|thumb|Image 10 (right): Meteorite ALH84001, insert scanning electron micrograph of a micro slice portion of the interior of the meteorite. (NASA)]]
 One group of scientists stated that the ‘fossil’ was too small to be a bacterium.  They received pushback from another group proving they had found bacteria even smaller than the ALH84001 ‘fossil’ here on Earth.  (Precambrian) A group of scientists stand by McKay’s results and have helped to continue his research posthumously.   Journal articles supporting and debunking the results are published on a regular basis. The objects inside the Allen Hills meteorite may never be proven to be microfossils. However, with the exponential increase of technological advancements we can use other meteorites to supplement the data we find to determine what the potential for life is on Mars and in our Solar System.
@@ Line 189: / Line 189: @@
 Falling near Murchison Australia in 1969, the Murchison meteorite was witnessed falling to the ground. It is one of the most studied meteorites in the world. It is not thought to have originated from Mars, but the scientific findings of this space rock pose many questions for scientists, especially astrobiologists.  This meteorite has been found to contain many amino acids, see figure 8. Some studies say 15 others say 20 or more.  (ISMP 2013 Murchison) Although the Murchison meteorite is not from Mars, it begs the question, if there are amino acids in meteorites falling from the sky onto Earth, then why wouldn’t there be meteorites falling to Mars with the same organic material?   NASA’s Dr. John Grotzinger explained that the organic compounds recently discovered by the Curiosity Rover may not have originated from Mars. It should not matter where the organic material came from.  The organic compounds are there now.  Of course, this excludes contamination from Earth.  Everything on every planet came from somewhere else.  We are a collection of material that came from the same swirling cloud of gas and dust.  Therefore, if organic compounds are on one planet or satellite, then it is logical that all of the bodies in the solar system, and therefore galaxy, have the same ingredients for life.  This has also been confirmed by spacecraft that have taken samples from cometary debris which also had amino acids in them.  (Rietmeijer 2010)
-[[File:ExtantLife17.jpg|frame|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
+[[File:ExtantLife18.jpg|frame|none|Figure 8: Murcheson Meteorite amino acid types and abundance. (Meierhenrich 2004)]]
 The previously discussed meteorite ALH84001 had more surprises for scientists in the form of amino acids.  Scientist used high performance liquid chromatography to examine samples of the meteorite and discovered trace amounts of several amino acids, including glycine, alanine and serine.  It is proposed by the team that most of the amino acids are from terrestrial contamination but left open the possibility of the D-alanine amino acid being preserved in the Allen Hills meteorite from Mars.  (Bada 1998)

@@ Line 152: / Line 152: @@
 The aforementioned Viking I and II Labeled Release Experiment which made an inconclusive discovery of life on Mars also discovered methane at 10.5 parts per billion (ppb) in 1976.  Decades later, while utilizing the NASA Infrared Telescope in Hawaii, Michael Mumma, of NASA Goddard, observed methane using ground-based instrumentation in 2003.  Mumma and his team’s observations were made over a heavily fractured region on Mars called Nilli Fossae. “We observed and mapped multiple plumes of methane on Mars, one of which released about 19,000 metric tons of methane,” stated Dr. Geronimo Villanueva, part of Mumma’s team, from the Catholic University of America in Washington DC. When he followed up the observations in 2006, the methane had vanished.  Some scientists have stated that is indicative of a seasonal plume.  According to NASA’s astrobiology website Mumma and his team observed 20-60 ppb of methane near the poles and up to 250 ppb near the equator, see image 9.  It is interesting to note that the levels of methane are significantly higher near the equator where the temperature is higher and possibly more conducive to life.
-[[[File:ExtantLife15.png|frame|none|Image 9: Methane plumes detected in 2003 and published in 2009 by Mumma and his team. (NASA)]]
+[[File:ExtantLife15.jpg|frame|none|Image 9: Methane plumes detected in 2003 and published in 2009 by Mumma and his team. (NASA)]]
 The European Space Agency (ESA) announced in 2004, they had discovered plumes of seasonal methane on Mars.  ESA announced that the Planetary Fourier Spectrometer (PFS) on Mars Express detected about 10 ppb of methane in the Martian atmosphere.  Although ESA and NASA themselves had previously detected methane on Mars, it was important to continue the search.

@@ Line 141: / Line 141: @@
 Methane persists for only a few centuries in a planetary atmosphere.  Any data consistent with methane on Mars is a major indicator for existing life on Mars.  On December 16, 2014 at the American Geophysical Union conference in San Francisco, a panel of scientists working on the Mars Science Laboratory (MSL) Curiosity Rover data announced what we have all been waiting decades to hear.  John Grotzinger stated unequivocally, “…there is methane occasionally present in the atmosphere of Mars and there are organics preserved in…rocks on Mars.” (Marlow 2014)
 Methane (CH4) is made up of one carbon and four hydrogen atoms. Approximately ninety percent (90%) of methane on Earth is produced by bacteria and other life, whereas ten percent (10%) is produced geologically, see figure 5. We know from studying life forms on Earth that methane is a common organic molecule that is a waste product of bacteria and macro organisms.  According to author Jeffrey Bennett from the University of Colorado, Boulder, “The amount of methane in the atmosphere appears to vary regionally across Mars, and also seems to vary with the Martian seasons.  This has led some scientists to favor a biological origin…if the source is volcanic…the amount of…heat necessary for methane release [could] be sufficient to maintain pockets of liquid water underground.”  (Bennett)
 The Curiosity Rover’s SAM and CheMin instruments found CHNOPS in a sample of the rock called John Klein that was drilled on Mars, see figure 6.  (NASA, JPL) These molecules were also found at the Rocknest site in an earlier soil sample taken by Curiosity.  The discovery of organic molecules is the most important and remarkable evidence that scientists have been waiting for the confirmation of.  (Archer 2013) Another significant find is the electrochemical gradient of the different molecules found inside of the John Klein rock.  An electrochemical gradient is another important piece of the “life on Mars” puzzle because life forms use these gradients to move ions across membranes in order to perform many metabolic and other biological functions.   Some of the molecules found in the rocks have different electric charges; some are more oxidized than others.  This was cleverly illustrated at a NASA press conference, wherein Dr. Grotzinger held up a battery to demonstrate the way rock eating microbes utilize the energy gradients formed by molecules, such as sulfates and sulfides, to their advantage in their metabolic processes.  (NASAtv)

@@ Line 97: / Line 97: @@
 [[File:ExtantLife8.jpg|left|thumb|Image 5: Hematite nodules on Mars imaged by Opportunity Rover and ground and examined by the RAT. (JPL)]]
 The Mars Exploration Rovers Spirit and Opportunity (MER) landed on Mars a few weeks apart in January 2004. Each rover contributed greatly in the search for evidence of water in order to lay a baseline for Martian habitability.  Steve Squyres, Principle Investigator for MER, stated the mission was a “follow the water” mission. (NASA) Early in the history of Mars a large planetesimal hit the planet and melted the entire surface, this is known as the Borealis Impact.  Any water or life that existed on the Red Planet would have been vaporized, unless it was living underground.  The “follow the water” mission of the MER was tasked with finding out if water existed on the surface of Mars after the Borealis Impact.  The Opportunity Rover landed at 1.94°S 354.47°E and explored Eagle Crater at Meridiani Planum shortly after landing on Mars. As images from the area were processed and viewed by the geologists on the team, it was discovered that a vast field of hematite had been discovered.  The hematite was nicknamed “blueberries” due to the bluish hue in the images and the appearance of a spattering of blueberries on the ground.  (Universe)  The Opportunity Rover used the Rock Abrasion Tool (RAT) to grind and examine a blueberry.  The team next used a spectrometer to determine the mineral content of the nodule.  The spectroscopic analysis revealed the concretion to be hematite and jarosite, see Image 5. (Klingelhofer 2004, JPL)
 The Utah desert is home to a vast region of fossilized sand dunes that is a perfect analog to Eagle Crater and the surrounding Meridiani Planum on Mars with its own vast area of fossilized sandstone and hematite.  Hematite only forms in the presence of water.  Water penetrates the sandstone and pours through the cracks.  As the water contacts the rock it brings with it minerals, like iron, that forms concretions around the sand.  The dense iron nodules fall out of the sandstone as wind erosion dissipates the rock around the nodules. Over millennia, more blueberries fall out of the sandstone and pile up on the surface of the planet.  For the tens of thousands of hematite nodules found by the Opportunity Rover, vast amounts of water must have existed on the surface of Mars.  The water could only be sustained in liquid form with a much thicker atmosphere.  The atmosphere also must have been much denser in order to cause the amount of wind erosion seen that caused the hematite to fall out of the sandstone. (Universe)
 Spirit landed in January 2004 at 14.56°S 175.47°E in a dry lake bed.  By March the Spirit Rover found evidence of past water in a rock named Humphrey.  The MER team instructed the rover to examine Humphrey with the RAT which ground 2mm into the surface of the rock.  It was discovered that the crystalline structures inside Humphrey had been in contact with water in order for the crystal to form.  (NASAPress)
 Spirit roved Mars for over 1200 sols when she was nearly crippled by a wheel that was no longer operational but continued to rove and drag the wheel behind her.  As the wheel drug through the regolith, a white powdery substance was revealed.  The substance was examined by the X-ray spectrometer and determined to be 90% pure silica.  Squyres stated, via teleconference, this was a “remarkable discovery”.  Silica is often found on Earth in areas where hot springs exist.  The silica discovered by Spirit may have formed in a hot spring and later have flowed to an area further from the source.  Another option for the formation of silica in the region is possibly the interaction with acidic vapors from volcanic activity combined with the regolith and water.  (NASAmer)

@@ Line 67: / Line 67: @@
 In 1976 a life detecting experiment invented by Dr. Gil Levin was sent on the Viking I and II Landers to investigate whether microbial life existed in the soil on Mars.  Levin’s experiment was called the Labeled Release (LR) experiment.    Viking I and Viking II, which were 4,000 miles away from each other, both carried the LR.  A brief summary of the LR is as follows, first a sample of Martian soil is scooped up and sent into a small tube, then a squirt of nutrient radioactive 14C  is added to the soil sample, and if microorganisms are present they will consume the nutrient and then give off radioactive gas.   When the LR was performed on the surface of Mars, the first scoop of nutrient was added to the soil and a spike was seen on the graph indicating a positive result for life.  The gas that was released by this experiment persisted for the entire seven days it was run.  In order to verify the results a control experiment had been designed by NASA.  The control was designed to determine whether the result was chemical or biological.  The control had a negative result.  Chemistry cannot “die” from an experiment, but biology can.  Since the control came back negative and the LR was positive, it has been ascertained by Levin and others that there is life on Mars.  The LR detected life on Mars according to the criteria set by the Viking team at NASA, see figure 3. Viking I and II both had a positive result for life with the LR experiment.  Two other life detecting experiments were in the payload of Viking.  Each one had varying degrees of sensitivity.  The LR was the only test that was positive for life, but it was much more sensitive than the others.  The sensitivity of the LR was able to detect 1/1 x 106 cells in the soil, while the others were orders of magnitude less sensitive which easily explains why they were negative versus the positive results of the LR.  (Levin & Straat 2016)
-[[File:ExtantLife5.jpg|thumb|left|Figure 3: Labeled Release Experiment Data from Viking I. “LR results at VL-1. A fresh sample was used for of cycles 1 and 3; sample for cycle 4 was stored 141 Sols at 10-26°C prior to use. In cycle 2, a stored portion of the cycle 1 sample was heated for 3 h at 160°C prior to nutrient injection.” (Levin 2010)]]
+[[File:ExtantLife5.jpg|thumb|left|400px|Figure 3: Labeled Release Experiment Data from Viking I. “LR results at VL-1. A fresh sample was used for of cycles 1 and 3; sample for cycle 4 was stored 141 Sols at 10-26°C prior to use. In cycle 2, a stored portion of the cycle 1 sample was heated for 3 h at 160°C prior to nutrient injection.” (Levin 2010)]]
 The Gas Exchange (GEX) and the Pyrolytic Release Experiment (PR) failed to detect life in the soils of Mars.  NASA made a consensus that there was no life on the Red Planet, due to the chance that these results may have been chemical organic reactions.   (Levin) Subsequent rovers and the Phoenix lander detected perchlorate in the regolith on Mars.  Perchlorates have been found to be a source of energy for certain extremophiles on Earth, for example Halomonas elongate, which survived in a 0.4 M perchlorate solution with NaCl. (Oren 2013) Regarding the LR, NASA has determined that heating a sample with perchlorate would destroy any chance of detecting organics. (Cosmology) The scientific method states that results should be reviewed and retested, therefore if one out of three tests is positive, then you must rerun the experiment to get an accurate result.  NASA planetary scientist Chris McKay, PhD. stated that the LR “detected perchlorate and its oxidizing products,” and in order to find extant life on Mars we should send “an instrument to search for amino acids and their homochirality and to search for lipids and their distinctive biological patterns.” (McKay 2020)
@@ Line 76: / Line 76: @@
 === Mars Global Surveyor ===
-[[File:ExtantLife6.jpg|thumb|300px|Image 3: Mars Global Surveyor images of an unnamed crater. Images captured six years apart as indicated in the upper left of each image.  The 1999 image showing a non-distinct crater.  In the 2005 image a sediment trail has been laid down by a mechanism speculated to be water mixed with salts and minerals in order to maintain the liquid state under the temperature and pressure conditions present on Mars. (NASA)]]
+[[File:ExtantLife6.jpg|thumb|400px|Image 3: Mars Global Surveyor images of an unnamed crater. Images captured six years apart as indicated in the upper left of each image.  The 1999 image showing a non-distinct crater.  In the 2005 image a sediment trail has been laid down by a mechanism speculated to be water mixed with salts and minerals in order to maintain the liquid state under the temperature and pressure conditions present on Mars. (NASA)]]
 The Mars Global Surveyor (MGS) orbiter reached orbital insertion in September 1997, shortly after the Pathfinder mission arrived it was tasked with many things, some of which were determining the geological processes that occur; imaging the surface seeking evidence of past water erosion; examining the physical properties of ice; monitoring the polar ice caps; and tracking weather patterns and the seasons.  MGS had a suite of scientific instruments which included cameras, a laser altimeter, and a spectrometer.  The instruments worked together to give planetary scientists a clearer picture of the history of water on Mars.  One such instance occurred when MGS imaged the same crater six years apart.  To the surprise of the scientific community, there had been a change in the crater wall.  The crater lies in the Centauri Montes region at 38.7o S 263.3o W.  The image in 1999 showed a non-distinct crater. In 2005 when the crater was imaged again, a sediment trail was identified, see Image 3. Spectroscopy indicated that the sediment was made up of salts and minerals that could be the result of briny water that flowed down the slope of the crater.  When the water evaporated, a dry sediment of minerals would have been left behind, as indicated by the bright material imaged by MGS. (NASA)