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

Mars and Meteorites (Issue #10) UPDATED 10/27/2013

by: Nicole Willett

*****UPDATE*****

blog 22 MarsAsteroidImpactNASA has released information pertaining to the origin of Martian meteorites.  The Curiosity Rover has used its Sample Analysis at Mars instrument to analyze the composition of the atmosphere of the Red Planet.  The scientists paid close attention to two isotopes of Argon that are present in the atmosphere of Mars.  The forms of interest were Argon-36 and Argon-38.  There are specific ratios of Argon throughout the solar system.  The gaseous ratio on Mars is of particular interest in order to compare the gases trapped inside the meteorites that have landed on Earth and have long been suspected to have originated on the Red Planet.  Mars has lost a significant amount of its atmosphere over the history of the solar system.  The lighter form of Argon has been lost to space and the heavier form has remained more intact in what is left of the atmosphere.  The inert nature of Argon, which is a noble gas, makes it especially relevant to the research of the origin of meteorites from Mars.  Being inert means it does not react readily with other gases, so it is stable for a significant amount of time.  When taking all of these compelling pieces of evidence into consideration, the team at NASA has concluded that the meteorites are from Mars.

Original blog:

A meteorite is a piece of rock that falls from space to Earth and lands.  There are different classifications of meteorites each with a distinct composition of elements.  A meteorite tells the geologic history of the body it originates from.  There are several classifications of meteorites, the basic categories are: chondrites, stony, stony-iron, and iron.  Each category has sub groups and some crossovers and exceptions.  Like anything else in science, the more data we gather the more complex the situation gets before we figure it out completely.  

The estimates vary greatly for the amount of material that falls to the Earth each year.  Some scientists estimate that 37,000 to 87,000 tons of material falls to Earth each year, but of that only 4-5 tons are big enough to land and be collected.  However, finding them takes time and patience. Meteorites could conceivably come from anywhere in the solar system.  However, of particular interest to scientists are meteorites from Mars.  There is an estimated 250-300 pounds of known Martian meteorite material in the hands of scientists  and collectors on Earth.   Meteorites can be found anywhere on Earth.  However, there are places that make it a lot easier to find them, such as desert regions and Antarctica because of the contrast of the light sand or white snow and the dark colored meteorites. 

Meteorite ALH 84001 was discovered in 1984 in a region of Antarctica called Allen Hills.  This meteorite has gotten more attention than any other in recent history.  This little rock from Mars made such a sensation, even President Bill Clinton had to get involved.  The Allen Hills meteorite was being studied by Dr. David McKay of NASA.  He published an article in the Journal Science in 1996 that claimed meteorite ALH 84001 had micro-fossils inside of it.  This sent shock-waves through the scientific community and the world media.  Dr. McKay used scanning electron microscope (SEM) technology to image very fine slices of the meteorite.  When he saw the images he determined that they were micro-fossils 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 maybe there is life there now.
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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.  Others stood by McKay’s results and helped to continue his research.  To this day there are articles supporting and debunking these results.  We may never know if the objects inside the Allen Hills meteorite are microfossils, but we can use other meteorites to extrapolate the data we find to make educated guesses about what the potential for life is in our Solar System.
blog 10 murchison natl museum of nat historyFalling 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. Some studies say 15 others say 20 or more.  An amino acid is an organic compound.   It is a three part grouping of nucleotide bases. These amino acids make up proteins and they encode genes which then make up a DNA strand.   To better understand the significance of the amino acid discovery, imagine a nucleotide base as a letter in the alphabet, then group three together to make an amino acid which is like a word in a sentence, next a protein is analogous to a sentence, a gene is like a chapter in a book, and the DNA strand is like an entire book telling the story of an organism.  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?  When NASA’s Dr. John Grotzinger explained that the organic compounds recently discovered by the Curiosity Rover may not have originated from Mars, my question is, does it 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.  So 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.  Refer to Blog Issue #4 for Bob Bruner’s Life On Mars In A Box display
blog 10 black beauty sci news comThe Sahara Desert in Africa is where the most recent headline grabbing meteorite was found.  This meteorite dubbed NWA 7034 has been found to be a 2.1 billion year old volcanic meteorite from Mars.  This was determined by examining the chemical signature of the object.   It is nicknamed “Black Beauty” because it has a beautiful dark sheen on its surface.  It is said to have been part of a Martian volcanic eruption that sent it off the planet’s surface or by a large meteorite that struck the surface of Mars with enough force to send the rock into the solar system, where it travelled for a couple of billion years until it landed in Africa.  When the meteorite was examined it gave off a small amount of water vapor, but compared to other Martian meteorites Black Beauty contained much more water.   It also appears to have been altered by an interaction with surface or ground water on the surface of the Red Planet.  Scientists are excited because, while they vacillate a Mars Sample Return Mission, they now have a piece of Mars that they can hold in their hands and study here on Earth.  They have stated  that this is the richest geo-chemical meteorite found to date.  Researchers are excited about all of the new discoveries that will be made with the latest addition to the Martian meteorite collection on Earth.  ~Stay Tuned!~
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 [Images: geology.com, Nature.com, Sci-News.com, Museum of Natural History, Fernlea-tripod.com]