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]

Terraforming Mars (Issue #24)

By:  Nicole Willett

The Sun has an approximate lifespan of ten billion years.  Most scientists believe we are about halfway through that life span.  Recently scientists have stated that the Sun will begin its death throes in about 2.8 billion years.  If humans behave in a way conducive to the health of the planet and themselves, we may still be in existence by then.  If that is the case we must be able to take humanity to a new home.  The Red Planet is a perfect first stop in this process.  He will survive longer than Earth.  But Mars will eventually perish as well.  In that case we must use Mars as a “practice” ground for learning how to take humanity to extrasolar planets in order to spread humanity around the galaxy.

blog 24NASA and other science organizations have been discussing a process called terraforming for a very long time.  Terraform means to make like Earth.  Many proposals have been submitted on the best way to make Mars like Earth.  The timelines proposed have varied from 100 years to 100,000 years.  We must find a balance between moving too fast and too slowly.  If we terrraform too fast, we may end up with a runaway greenhouse effect similar to what we see on Venus.  If we move too slow, we run the risk of other complications, such as the natural rhythms of the Red Planet changing during the process which could interfere and complicate any progress we may be making.  Terraforming Mars is of utmost importance in order to learn to live on other worlds.  Humanity must have the ability to be a multi-planet species in order to preserve Homo sapiens for millions or billions of years.

How could we go about terraforming Mars?  The 1,000 year plan seems to be a reasonable timeline.  If you utilize a version of Dr. Robert Zubrin’s, President and Founder of The Mars Society, Mars Direct plan, we would send up a series of habitats ahead of humans.  An automated system to manufacture fuel on the surface of Mars would be included in the initial payload.  This would allow the visitors to Mars to have a fuel supply ready for the return to Earth at a later date.   Humans would then take the six month trip and each crew would stay for 18 months, some may eventually choose to stay on the Red Planet.   Crews of Marsonauts would have an enormous responsibility to lay the groundwork for future Martians.

blog 24 natgeo3The first visitors would set up the habitat modules and start the greenhouse work.  When each successive group arrives at the initial home base, all necessary groundwork will have been laid for them to immediately begin working on the next set of tasks. This may include creature comforts.  In order for the settlers to feel at home on Mars, the habitats would need to be comfortable and roomy.  We would like the crew to feel at home, which will help with psychological concerns.  The greenhouses must also be a top priority.  COis already present in the atmosphere of Mars for plants to utilize for respiration, and they will return the favor by “exhaling” breathable O2 for the settlers.  Humans may feel depressed and isolated, but the aesthetic value of plants could make them feel more at home.  Plants will also serve as a major source of food which is essential to our survival.  They will also provide oxygen for breathing.  The Curiosity Rover has confirmed that the Martian soil is at least 2% water, so we will be able to heat up buckets of soil and extract water for plants and it must also be used for human consumption.  The H2O can also be divided into hydrogen for fuel and oxygen for breathing when necessary.  After we have perfected plants in greenhouses on the Red Planet, we may be able to allow bacteria and lichens, which are able to survive in arctic environments, to grow on the outside of the habitats and greenhouses.   The rovers on Mars have confirmed that the soil is already conducive to certain types of plants.

blog 24 natgeoNow we are ready for the next set of terraforming duties.  What is needed next is a nice thick and warm atmosphere.  Several suggestions have been proposed as to which approach for this is best.  Ideas have been as varied as giant orbiting mirrors to nuclear explosions and everything in between.  A common suggestion has been to release the CO2 frozen in the soil and in the polar ice caps into the atmosphere using factories spewing out what we consider greenhouse gases on Earth.  Whichever tactic is utilized to thicken the atmosphere, once it is warm enough for the polar ice and ground ice to melt and turn some H2O to liquid and some to gas then we are well on our way to add more complex plant life.  The water cycle should begin to look more Earthlike.  Rivers should start to flow, seas will develop, and rain will fall.  Regular weather patterns will develop and Martian meteorologists will surely scramble to predict weather as they do now on Earth.  Next we will add insects and flowering plants.  The soil will become more enriched with the addition of each more complex organism.  This will allow for the addition of even more complex plants and animals in succession periodically, for instance large trees will allow forests to take hold.

blog 24 natgeo2Energy is a must for the spread of civilization.  It is hoped that we have learned from our mistakes on Earth, and we will use all clean energy with little waste on Mars.  Transportation and city planning systems will be developed.  An entire new branch of humanity will start to evolve on the new Mars.  Plants and animals will grow and change over time being separated from their parent species on Earth.  Entire ecosystems will develop on their own trajectory, separate from all life on Earth.  Over the 1,000 year period Mars will be turned from a vast desert with a coral sky into a bountiful planet full of life with a beautiful blue sky.  It may look similar to Earth, but the inhabitants will become truly Martian.

Recently Dr. Zubrin spoke about the importance of humanity rallying from different countries to go together to Mars.  This is an important step in terraforming the planet.  We are all aware that people from all over the world may have important contributions to make to a manned mission to Mars.  Our lack of sociological maturity should not stand in the way of such a humanity altering event.  Borders on maps should not prevent the forward motion of science, technology, and exploration.  It is time to band together as Earthlings to accomplish this goal.  There is nothing beyond our technological ability to stop us from reaching Mars and settling there.  Terraforming is the next necessary step in this plan.

[Images: Wikipedia, NatGeo, NatGeo, NatGeo]

Consumable Water on Mars Confirmed by Opportunity and Curiosity (Issue #18) UPDATE

by: Nicole Willett

*****UPDATED 9/28/2013*****

mars-rover-landing-sequence-landed_57831_600x450Several papers have been published regarding the findings of Curiosity’s first few month’s on the surface of Mars.  The findings are of great importance with regard to water.  The rover has confirmed an incredible two percent of the surface soil is composed of water.  Scientists said if humans were to land on Mars, they could scoop up soil and heat it up and extract water from it.  Estimates suggest that approximately two pints of water is available per cubic foot of soil.  This is an astonishing discovery.  The benefits for humans that wish to travel to and settle on the Martian surface are immense.  NASA stated water is likely spread across the entire planet bound to the soil.  The implications of this finding make it much more likely that humans will be able to inhabit the Red Planet in the near future.  It also opens up more of the planet for human landing places and settlement opportunities.

Original blog published June 9, 2013:

As we anxiously await the results of the latest drill sample from the Curiosity Rover, we have received exciting news from the long lived Opportunity Rover team. Steve Squyres, who will be the recipient of the Mars Pioneer Award 2013 at the 16th Annual Mars Society Convention Aug 15-18th, participated in a NASA teleconference regarding the exciting findings about water on Mars. The fact that once again we have reconfirmed water on Mars is not the exciting part.

Esperance imaged from above
Esperance imaged from above

Opportunity has spent quite a lot of time working at Endeavor Crater and had to maneuver very strategically to get in position to study a small rock named Esperance. This was a very difficult task for the aging rover, since she has a bad shoulder joint. However the team stated that Opportunity is in extremely good health and has no major concerns as of right now. The rover used several samples from the rock which is the oldest rock that Opportunity has studied. The team showed a graphic, displaying the chemistry of the rocks, with seven measurements taken from different layers. The elements found in Esperance were Aluminum, Iron, Magnesium, Calcium, Potassium, and Sodium. The results from the Alpha Particle X-ray Spectrometer indicate that the

APXS graphic Esperance Rock results
APXS graphic Esperance Rock results

rock was higher in Aluminum and Silica and lower in Calcium and Iron than rocks previously studied by Opportunity. Below the dashed lines are igneous rocks; above the line are rocks including clays (Montmorillomite) that have been altered by water. The lower black square indicates the readings from the average Martian crust. The yellow circles closest to that block indicate the samples taken from the surface of the rock. As the samples ascend vertically above the dashed line it indicates samples that are further inside the rock. The Opportunity team used the Rock Abrasion Tool to reach the subsurface of the rock. Starting at the surface she discovered that the water that had most recently covered Esperance was acidic and the soil more closely resembled the average Martian crust. As the rover progressively scraped and studied Esperance, it was discovered that Mars went through several cycles of water activity in the region where Opportunity is now working. The cycle of water described by the team was that water was present in the area before the Endeavor Crater formed, next the crater formed and the rocks piled up on the crater rim, and then setting water produced gypsum. This is indicative of lengthy multistep and continual water activity. At Esperance the water flowed through the rocks and had a higher clay concentration than the rocks studied at Matijevic Hill. A high clay concentration is evidence of water that had a neutral pH. “There appears to have been extensive, but weak, alteration of Whitewater Lake, but intense alteration of Esperance along fractures that provided conduits for fluid flow,” Squyres said. “Water that moved through fractures during this rock’s history would have provided more favorable conditions for biology than any other wet environment recorded in rocks Opportunity has seen.”

Esperance Rock
Esperance Rock

The big news was that the Opportunity team stated was that water with a neutral pH is very conducive to prebiotic chemistry. We know there are organisms on Earth that survive in an acidic environment, but the science points to prebiotic chemistry favoring a neutral pH. Squyres stated that this is the best that we have found with Opportunity, the most compelling evidence for habitability. The most fundamental conditions for habitability were present at this location. The NASA team also stated that this was water that could have been consumed. This is a familiar statement to that of the Curiosity team a few months ago. The Curiosity team found an ancient riverbed in Gale

Ancient Riverbed imaged by the Curiosity Rover in Gale Crater
Ancient Riverbed imaged by the Curiosity Rover in Gale Crater

Crater and also found that the water that flowed there was freshwater that was neutral in pH and could have also been consumed. At a press conference in March 2013 Dr. John Grotzinger, project scientist for the Curiosity mission, went so far as to state, “We have found a habitable environment. The water that was here was so benign and supportive of life that if a human had been on the planet back then, they could drink it.”

This pattern may seem redundant to some; however we must follow the scientific method of testing and retesting, confirming and reconfirming. We must verify these results many times because there will be humans on Mars and we must know as much about our future home as possible. There are many reasons for this, some are obvious and some we haven’t even thought of yet. These results are exciting and very important to the future exploration and settlement of the Red Planet. ~On To Mars

[Images: NASA/JPL]