The Curious Case for Methane on Mars, methane and active organics discovered on Mars (Issue #32)

 

By:  Nicole Willett

methane molecule 2 drsusanrubinOn 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.”

Why is this important?  All life on Earth that we have discovered so far is carbon based, aka organic.  Carbon is found in the DNA of all life forms on Earth.  Carbon can bind with many other elements to form thousands of molecules that are involved in biological processes.  Needless to say, finding organics and methane is a game changer for all of science, from astronomy to zoology.  Organics in general refer to molecules that are often found as components of life.  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.  In fact approximately 90% of Earth’s methane has a biological origin.  However, about 10% of methane on Earth is a result of geological activity.  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.”  Pockets of liquid water would be conducive to life.

blog 32 eath marsThe Earth and Mars have many similarities including a 24 hour and 24 hour 37 minute day respectively, a similar axial tilt causing seasons to occur, a rocky surface with many of the same types of rocks and minerals (which may be used as a source of energy), volcanic activity and hydrothermal vents past and/or present, water that is/was fresh, salty, acidic, and/or basic.  Now and perhaps most important of all, organic matter and methane.  In addition to the aforementioned facts, the fleet of rovers and orbiters that have arrived at Mars have proven an environment conducive to microorganisms existed and may currently exist on the Red Planet.   We know this thanks to the many spacecraft that have visited Mars and sent back ample amounts of data.

blog 32 natgeo3The Viking missions were sent to Mars in the mid 1970’s.  They carried a variety of scientific instruments.  Some of them sampled the atmosphere and some examined the regolith.  The results of these experiments have been studied repeatedly since they were performed.  The Labeled Release Experiment, designed by Dr. Gil Levin, made a controversial and still contested discovery of life on Mars.  Viking also discovered methane at 10.5 parts per billion (ppb) in 1976.  It seems both of these discoveries were discounted over the past four decades.

While utilizing the NASA Infrared Telescope in Hawaii, Michael Mumma, of NASA Goddard, observed methane using ground based instrumentation in 2003.  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.  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.

Concentrations_of_methane_on_Mars esaA decade ago the European Space Agency (ESA) announced they had discovered plumes of seasonal methane on Mars.  In March of 2004, ESA announced that the Planetary Fourier Spectrometer on Mars Express detected about 10 ppb of methane in the Martian atmosphere.  A spectrometer is a device that “looks” at a sample of something, in this case atmospheric gases, and takes reading(s) 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.

Although ESA and NASA themselves had previously detected methane on Mars, it was important to for NASA to continue the search, using the MSL Curiosity, on the ground in order to again verify the results.  The public may get frustrated with the continuous “discoveries” of methane, but science is always retesting results to essentially try to “disprove” itself in order to make sure the facts are real.  The Curiosity Rover landed on Mars in August of 2012.  It seemed that almost as soon as the Curiosity Rover started exploring her new home on Mars she discovered a dry riverbed where fresh water once flowed in Gale crater.  When she drilled into the rock dubbed “John Klein” scientists realized that the rock contained what biologists call CHNOPS. That acronym stands for Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur. Those are the six elements needed for all life on Earth to exist.  Another discovery were molecules that included carbon which scientists called “simple organics”.  The most recent and most important discovery includes more complex organic molecules than previously discovered, such as methane and chlorobenzene.  We know Mars is enriched with all of the same chemicals to make life that the Earth has.  This latest and greatest discovery puts to rest the long debate about whether Mars has organics.  Some scientists and laymen have been vehemently denying that it is possible.  For the community of “believers” in Martian organics, we feel Methane SAM graph nasa 2vindicated.

The amount of methane reported over the past forty years on the Red Planet ranges from 5-250 ppb from a variety of sources, NASA, ESA, orbiters, rovers, and ground based Earth telescopes.  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, and several other geological processes.  Methane breaks up and only has a lifespan of several decades to 300 years, which is a short time on a planetary scale. It then breaks down into water and carbon dioxide.  That being said, since methane is present on Mars, it must be getting replenished biologically or geologically currently.

Over the last few decades scientists have discovered amino acids in comets and meteorites, which we know slam into planets, so it is common sense to see that whether Mars originally had organics or not that organics would have landed there sometime in the last 4.5 billion years.  In 2012 it was announced that even Mercury has organics on its surface.  The moon Enceladus, orbiting Saturn, has organics spewing out of the ice covered surface from the salty ocean below.  It seems that everywhere we look we find organics.  We must ask ourselves, how easy is it to form organics and life?  Is life everywhere?

Mars Society Logo (High quality)“[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.

~Humans to Mars as a bridge to the stars

[Images: drsusanrubin.com, NASA, NatGeo, ESA, NASA, TMS]

Note: The article snip above is from the Jan 1977 National Geographic magazine.  Below are the next few paragraphs.

blog 32 natgeo4blog 32 NatGeo1blog 32 Natgeo2

Eyes in the Martian Sky (Issue #28)

by:  Kathryn Sharp

aaWhile the rovers Opportunity and Curiosity cruise the surface of Mars, three operating satellites orbit above, keeping a keen eye on the planet. In addition to documenting the surface of Mars with an unprecedented level of detail, these satellites continue to provide critical support for ground missions. They relay vital communications between the rovers and Earth, monitor surface weather, look for safe driving paths around large boulders, and identify points of interest for further study. Although they often work in tandem to support the rovers, each orbiter has made its own fundamental contributions to our understanding of the red planet.

Mars Odyssey over Mars South PoleThe oldest of the three currently operational satellites orbiting Mars is the 2001 Mars Odyssey. Named as a tribute to science fiction writer Arthur C. Clarke’s beloved work “2001: A Space Odyssey,” Mars Odyssey has been plugging away for well over a decade in low Mars orbit and has set the record as the longest serving spacecraft orbiting a planet other than Earth. Early in its mission, Mars Odyssey surprised scientists by detecting levels of water ice in the Martian soil that far exceeded expectations. This discovery intensified interest in the history of water on Mars and what that history could mean for the possibility of life there. Though perhaps its most important science work is done, Mars Odyssey has been granted numerous mission extensions, primarily to serve as a telecommunications relay between rovers Opportunity and Curiosity and Earth.

In 2003, the European Space Agency launched its Mars Express orbiter in with the goal of further investigating the presence of water and looking for chemical indicators of life. Mars Express is equipped with a host of instruments to accomplish these goals, including: two spectrometers, sub-surface radar intended to look for and map out frozen water beneath Mars’ soil, and among others, the High Resolution Stereo Camera (HRSC) which can take high-resolution photos of large regions on the surface.

040824_mars_express_02In the past decade, Mars Express has made remarkable discoveries. In January of 2004, ESA announced that water ice had been discovered in the Southern polar ice cap using its infrared spectrometer OMEGA. This discovery confirmed the 2002 findings of Mars Odyssey, which noted large quantities of water ice locked in the soil. Later that year, a large plume of methane was detected in the atmosphere. Since methane deteriorates in the Martian atmosphere in only 400 years or so, scientists postulated that the source of the gas must be ongoing: either organic life or volcanic activity. In either case, this exciting finding indicates Mars is, or was, more active than previously thought. However, recent measurements by Curiosity detect no significant quantities of methane in the atmosphere, calling into question earlier hypotheses. The topic presents a puzzle that will be the focus of several future missions, including the ESA’s Trace Gas Orbiter, set for launch in 2016.

The newest satellite to reach Mars, NASA’s Mars Reconnaissance Orbiter (MRO), carries a suite of state-of-the-art instruments intended to address many of the burning questions left unanswered from previous missions. The most compelling of these is whether or not water persisted on the surface of Mars long enough for organic life to arise. Answering this question continues to be one of the primary science goals of NASA’s entire Mars Exploration Program, and would likely be the focus of any manned mission in the future.

MRO_image-brThankfully, Mars Reconnaissance Orbiter has been incredibly prolific, returning an unprecedented amount of data from Mars since its insertion into orbit in 2006. In 2013, NASA reported that the MRO has returned in total over 200 terabits of data: more than all other missions operating on the Deep Space Network and significantly more than all other previous Mars communications combined.

The majority of this data has come in the form of high-resolution images from the HiRISE camera, which works in conjunction with other instruments aboard the MRO to help scientists understand in detail the dynamics of Martian geology. To do so, the CTX (Context Camera) takes large regional surveys around features of interest, after which HiRISE narrows in to take a close-up photo of that feature. Simultaneously, the onboard spectrometer CRISM analyzes the mineral composition of that same region. By compiling data from these three instruments, scientists can distinguish between sediment deposited by moving water, wind, or other geologic processes and begin to piece together a picture of Mars’ fascinating history.

Warm-season Flows HiRISENot only are these images important for their scientific relevance, but they have also played a powerful role in engaging the public interest in Mars. Never before have we been able to see the surface of another planet in such striking detail. In these images, we are afforded more than a glimpse at a planet that is alive in many ways. Changing seasons, fresh impact craters, landslides, recurring flow-like features, and dunes shifting in the Martian winds, all witnessed from here on Earth. The HiRISE team has reached out to professionals, amateurs, and students with its HiWish Public Suggestion Page. HiWish is a tool that allows any interested citizen to log in and select a target where they think HiRISE should take an image. This is a fantastic opportunity for young scientists to engage with Mars and play a part in exploring its rich topography.

Each day, NASA and the ESA receive an enormous amount of data from the instruments aboard these three spacecraft, providing an invaluable link between the Earth and Mars. When humans finally arrive on the surface of Mars, it will be due in large part to the continued success of these three missions. We have sent them ahead of us to be our mapmakers: to chart safe passage, to help us find resources vital for our survival, and to unlock the secrets of a planet that does not readily tip its hand.

[Images: NASA, JPL, ESA, JPL, JPL]

Understanding the Risks: Radiation Exposure During Interplanetary Travel (Issue #26)

Guest blog by Kathryn Sharp

RadiationRecent years have seen an exciting uptick in the number of humans-to-Mars mission plans, from manned fly-bys to permanent settlements. Each lays out its own priorities and objectives, suggesting creative solutions to challenges common to all of them. One important challenge each mission will face is the danger of space radiation exposure over the course of lengthy interplanetary travel.

There are two major types of radiation: ionizing and non-ionizing. Many forms of nonionizing radiation will sound familiar: your car radio, cell phone, microwave, all of which operate at frequencies low enough that their energy isn’t sufficient to damage human DNA. These are therefore not considered to be carcinogenic, or cancer-causing. On the other hand, ionizing radiation carries energy high enough to break chemical bonds and damage DNA, which in turn increases the risk of developing cancer. Some examples include medical X-rays and CT scans, which, when used infrequently, do not significantly increase cancer risk, and radioactivity remaining from the era of atmospheric nuclear testing.

Insp mars shipOf course, these are only man-made sources of radiation. The sun showers the Earth every moment with both ionizing and non-ionizing radiation. Thankfully, our protective atmosphere and magnetosphere shield us from a majority of the harmful radiation, with only some UV rays reaching the surface. Beyond our atmosphere however, solar energetic particles (SEPs), ejected from the sun by solar flares and coronal mass ejections, as well as galactic cosmic rays (GCRs) from interstellar space blast through our solar system unmitigated.

In space, astronauts face much higher radiation exposure from these sources than we do down here on the surface. On average, an astronaut on the International Space Station (ISS) will receive as much radiation in one six-month stay as they would in twenty years back home on Earth. As humans venture beyond low-Earth orbit and the sheltering bands of Earth’s magnetic field, their lives will depend on proper shielding in their spacecraft.

ss-121109-mars-curiosity-tease.photoblog900In 2011, when the Mars Science Laboratory (MSL) Curiosity Rover launched from Cape Canaveral it carried with it a small instrument for measuring space radiation in a shielded environment similar to that of a manned mission. Based on the measurements of the unit called the Radiation Assessment Detector (RAD), Marsonauts would receive a dose equivalent of roughly 0.6 Sieverts (Sv) in 360 days of travel to-and-from Mars, not counting any radiation received while operating on the surface of Mars itself. This dose is akin to receiving 1 to 2 abdominal CT scans each week over the course of a year.

Currently, NASA limits the cumulative lifetime dose for its astronauts at 1 Sievert. This dose is associated with a roughly 5% increase in lifetime cancer risk. For reference, the current lifetime risk of dying of cancer for someone in the US is around 20%, so a dose of 1 Sv would raise this risk from 20 to 25%. While 0.6 Sieverts is a large dose of radiation in a relatively short period, clearly it is within established limits and should not halt further development of manned missions to Mars.

Although this dose falls within NASA’s established limit, developers of any future crewed Mars mission shoulder the responsibility of sheltering its astronauts and reducing their exposure to the lowest levels possible. How can we limit the radiation dose to Marsonauts in an efficient and cost-effective way?

victoria2_opportunityThree major factors limit a person’s exposure to radiation: time, distance, and shielding. Limiting the time astronauts are exposed to space radiation is a surefire way to reduce their dose. However, the only way to reduce the time of exposure is to speed up the spacecraft: no easy feat. Existing spacecraft rely on heavy fuels, which in turn lead to heavier payloads, resulting in slower speeds and higher costs. Conceptual space vehicles that rely on other sources of energy, such as nuclear power, are on the drawing board, but waiting through the long development period for such technologies will only further delay a crewed mission.

Because the source of solar energetic particles, the sun, is a fixed source, and because galactic cosmic rays are pervasive throughout the solar system, we cannot significantly increase the distance between the astronauts and the source of the radiation. At this time, the most convincing method of reducing exposure is effective shielding. Unfortunately, different materials are necessary to shield against different types of radiation. For example, high-energy gamma rays require very dense, thick materials, such as lead, to shield, whereas neutrons are best-shielded by hydrogen-rich materials such as concrete. These are both heavy materials that will add significant mass to the payload, requiring more fuel and incidentally, more money.

Current radiation shielding plans minimize the amount of these materials by allowing for a narrow shelter in the center of the spacecraft to be used during large SEP-producing events such as solar flares or coronal mass ejections. The measurements taken by the RAD aboard Curiosity confirmed that this type of arrangement would be sufficient to shield the majority of SEPs, but astronauts would still be vulnerable to, and receive the majority of their dose from, galactic cosmic rays. This constant stream of heavy, high energy particles presents the biggest shielding challenge.

Several mitigation strategies are being considered to reduce the dose from GCRs. We could utilize existing resources aboard the ship, such as the crew’s water or fuel supply, as shielding agents. Water is an excellent shield for GCRs, but it is heavy. A water shield around the crew’s living quarters would need to be several meters thick, and could add hundreds of tons to the payload. This is an insurmountable weight for current mission designs, and would send launch costs skyrocketing.

Alternatively, we could construct the spacecraft from light, hydrogen-rich plastics such as polyethylene rather than the aluminum shell that the ISS employs. This could reduce both the payload weight and cost, but further research is necessary in order to improve the strength and heat tolerance of these materials.  Another theoretical strategy would be to generate a small magnetic field to deflect incoming radiation much the same way Earth’s magnetic field functions. Generating a magnetic field requires energy however, and generating one large enough to shield an entire spacecraft would require considerable energy: a precious commodity when you are 35 million miles from home.

a Mission to Mars Pic 06While all possible ways of limiting radiation exposure ought to be explored, it is important to keep these risks in context. In his book, The Case for Mars, Mars Society President Dr. Robert Zubrin puts these concerns in perspective: “While such doses are not to be recommended to the general public, they represent a small fraction of the total risk of not only space travel, but such common recreations such as mountain climbing or sailboarding. Radiation hazards are not a showstopper for a piloted Mars mission.”

As Zubrin’s statement suggests, we must bear in mind that a manned Mars mission is not a routine endeavor, it is an extraordinary one. Every extraordinary mission in the history of mankind has involved significant risk, and with it, the potential for remarkable reward. We can and should do our best to limit these risks, but must understand that we cannot eliminate them.

 

[Images: publicdomainpictures.net, Inspiration Mars, NASA]

Will Drilling Find Extant Life on Mars? (Issue #21)

by: Nicole Willett

blog 21 family portraitI recently attended the online NASA/JPL Mars Exploration Program Analysis Group (MEPAG) meeting that was held on July 23, 2013. The meeting’s purpose was to discuss the Mars 2020 rover and many other Mars exploration issues. Many people wonder why NASA keeps sending rovers to Mars without stating that they will unequivocally search for extant life. The term extant means, still in existence.   We know that MSL Curiosity has the equipment to detect life and that Mars 2020 will have many of the same instruments. However, Jack Mustard, Brown University professor, who presented at the MEPAG meeting, stated, “To date, the evidence that we have from observations of Mars and Martian samples is that we don’t have the clear indication that life is at such an abundance on the planet that we could go there with a simple experiment like Viking [had] and detect that [life is] there.” Mustard went on to explain that it makes more sense financially and scientifically to search for past life instead of current life. He believes that we must continue studying the past geology of the planet in order to better understand whether past life existed on Mars.

As we anxiously await the analysis from Curiosity’s second drill sample, which was taken on May 20, 2013, we can discuss the search for present life on Mars. As indicated above the Mars 2020 rover will not search for extant life. Some people do not understand why we must wait seven years to launch a rover similar to MSL with a sample return cache that will sit on the planet for an unknown period of time with no plan as to how it will be returned to Earth. However, there are other missions planned for Mars which may search for and possibly find current life on Mars. Two such missions are ExoMars and the Icebreaker Life Mars mission.

blog 21 exomarsExoMars is collaboration between the European Space Agency and the Russian Federal Space agency. It is a mission that includes an orbiter and lander planned for 2016 and a rover with a drill that can reach two meters beneath the toxic surface, planned for 2018. The 2018 mission objective is to search for past or present life on Mars. During the MEPAG meeting, the question was asked, “What if ExoMars finds life, and how will that affect Mars 2020?” The answer was given by Jim Green, Director of NASA Planetary Science, who stated, “It would be a great problem to have.”  This also started a discussion about whether this would be a “Sputnik moment” and possibly encourage a new race for humans to Mars.

The Icebreaker Life mission could also be funded for a 2018 launch under the Discovery/New Frontier program, a separate funding scheme like the 2016 Insight mission. In a paper published in the journal Astrobiology on April 5, 2013, Dr. Chris McKay, Dr. Carol Stoker, and other leading scientists stated, “The search for evidence of life on Mars is the primary motivation for the exploration of that planet. The results from previous missions and the Phoenix mission in particular, indicate that the ice-cemented ground in the north polar plains is likely to be the most recently habitable place that is currently known on Mars.” The goals of the Icebreaker Life mission include:

“(1) Search for specific biomolecules that would be conclusive evidence of life.

(2) Perform a general search for organic molecules in the ground ice.

(3) Determine the processes of ground ice formation and the role of liquid water.

(4) Understand the mechanical properties of the Martian polar ice-cemented soil.

(5) Assess the recent habitability of the environment with respect to required elements to support life, energy sources, and possible toxic elements.

(6) Compare the elemental composition of the northern plains with midlatitude sites.”  [Source: http://online.liebertpub.com/doi/abs/10.1089/ast.2012.0878 – Journal Astrobiology 4/5/2013]

This mission is very similar to the Phoenix lander but will have more advanced scientific equipment, including a drill that will reach a meter below the surface, an instrument called the Signs of Life Detector (SOLID), an Alpha Particle X-ray Spectrometer, a Wet Chemistry Lab, and many other instruments. This combination of instruments may potentially alter how we view life in the universe. The SOLID instrument has the ability to detect compounds with a biological origin such as whole cells and complex organic molecules.  It has an advanced digital camera and what is known as a “lab on a chip” that can perform various chemistry tests using equipment the size of microchips. The technological advances being made are greatly improving the field of robotic exploration and experimentation in ways never thought possible in the past.

DCIM100GOPROThe Icebreaker Life mission will search for biomarkers in the same region near the north pole of Mars where the Phoenix Lander executed its mission in 2008. A biomarker is any molecule that indicates the presence of life, such as an enzyme.   These biological molecules carry organic biochemical information. The Icebreaker drill is capable of drilling one meter into the subsurface of the Red Planet in order to search for biomarkers. The ice shavings retrieved from the drill would be analyzed for molecules that are too complex to be present from a non-biological source. It is important to drill below the surface in order to retrieve samples that have not been exposed to the radiation and perchlorates (salts) that exist on the surface of Mars. The radiation and perchlorates could potentially destroy any biomarkers or biological material present, hence the importance of a subsurface mission.

Many opinions exist regarding the search for life on Mars, past or present. The sheer number of planned missions is a clear indicator of the widespread scientific interest. When asked about the search for life on the Red Planet, McKay stated, “Why search for a second genesis of life? The implication is that life is common in the universe.”

[Images: NASA, ExoMars, Astriobio.net]

The Search for Life on Mars from Viking to Curiosity (Issue #3)

by: Nicole Willett

For centuries there has been speculation about life on Mars, from microbes to little green men.  Scientists have spent an enormous amount of time and resources searching for clues to previous or current life on the Red Planet.  The latest mission to search for the clues to life on Mars is NASA’s Mars Science Laboratory (MSL) Curiosity.

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With much fanfare, on August 5, 2012, the MSL Curiosity landed successfully in Gale Crater on Mars.  The landing site was named Bradbury Landing site in honor of the late science fiction author Ray Bradbury.  There have been many predecessors to the Curiosity Rover on Mars, including orbiters, rovers, and landers.  Over the past few years NASA has been using the “follow the water” strategy in an effort to find evidence of past or current life on Mars.  We know that everywhere we have water on Earth we have life.

The Viking 1 & 2 landed on Mars in 1976.  The main purpose of the scientific experiments was to search for life.  The first soil test for Viking yielded positive results for life, however the tests that followed all yielded negative results.   These results are controversial and are still being studied and debated to this day.  Another important finding from the Viking missions was that water vapor was released from the soil samples that were heated in the gas chromatograph mass spectrometer.

The Pathfinder Sojourner Rover landed on July 4, 1997.  The Sojourner Rover was the first rover deployed on another planet.  The X-ray spectrometer examined the soil and determined that Mars clearly had a warmer and wetter past.  The Sojourner Rover confirmed previous volcanic activity by discovering basaltic rock.  Scientists state that volcanic ash increases soil fertility.  The rover also found many elements including magnetite.  The discovery of magnetite is important because it is found on Earth in bacteria, brains of bees, termites, fish, mollusk teeth, some birds, and humans.  Scientists must use Earth as an analog for any discoveries made on Mars.

The European Space Agency launched the spacecraft, Mars Express, which arrived at the Red Planet in December 2003.  This orbiter is tasked with high resolution imaging of the entire surface as well as mapping the mineral and atmospheric composition.  The information gained from Mars Express helps space agencies determine landing sites for future rovers and landers.

The Mars Exploration Rovers (MER) Spirit and Opportunity landed on Mars three weeks apart in early 2004.  These two wonderful rovers were scheduled to work only 90 days, which they far exceeded.  Spirit landed January 4, 2004 and sent its last communication to Earth March 22, 2010.  The Opportunity Rover landed on January 25, 2004 and continues to roam the Martian surface.  The twin rovers were sent to assess habitability and evidence of past water. Both have discovered evidence of past water on Mars.  One discovery was hematite, a mineral that forms in the presence of standing water over a long period of time.  The principal investigator for the MER’s, Steven Squyres, has stated that not only did Mars have water, but it had at one time large quantities of water on its surface. 

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The Phoenix Lander arrived on the surface of the Red Planet in the north polar region on May 25, 2008.  Phoenix was searching for environments suitable for microbial life.   Phoenix discovered water ice and when scientists watched as it sublimated in front of the lander’s cameras.  Phoenix’s wet chemistry lab tested the ingredients of the soil and found perchlorate (ClO4).  This chemical could be used by future colonists for everything from rocket fuel and a source of oxygen. 

The Mars Society Convention hall, in Pasadena, was filled as we watched Curiosity land flawlessly in Gale Crater on August 5, 2012.  The rover landed to a worldwide audience anxiously watching.  This landing site was picked for many reasons, such as, the alluvial fan (ancient river delta), the depth of the crater, and the height of the peak (Mount Sharp).  Curiosity is equipped with 17 cameras, an entire science laboratory, and is tasked with assessing the habitability of Mars.   

Previous missions have found elements in the atmosphere and in the soil as well as previous liquid water which are all clues to previous life on Mars.  One piece of evidence still missing from the puzzle is organic carbon.  Curiosity’s Sample Analysis at Mars (SAM) is a suite of instruments that will analyze the contents of the Martian soil.  SAM will look for carbon containing compounds and other elements associated with life, such as, hydrogen, nitrogen, and oxygen.  Scientists are hoping to find organic carbon with a biological origin.  If found this will have to be studied and tested many times to prove what the origin actually is.  There will likely be debates about whatever Curiosity finds until there is unequivocal inarguable evidence. 

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On October 8, 2012 the Curiosity Rover, scratched the surface of Mars, scooping up its first soil in order to clean the inside of the rovers sample handling mechanism.  The sample will be shaken vigorously and then emptied onto the ground.  This procedure will be repeated several times.  The cleaning is to ensure that any contaminants left over from Earth will be discarded before any true testing takes place.  Once the instruments are cleaned and the soil tests take place, they will determine whether or not the area was once a favorable environment for microbial life.  Curiosity is equipped with more scientific instruments than any spacecraft deployed on Mars.  Her planned two year mission is sure to make many wonderful discoveries. 

Stay tuned for further updates.  ~OnToMars~
 
Images  [NASA.gov, Planetary.org, Time.com]