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.
blog 10 alh84001 nature com
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!~
blog 10 collection fernlea tripod com
                                                                                                                          
 [Images: geology.com, Nature.com, Sci-News.com, Museum of Natural History, Fernlea-tripod.com]

The Martians of Fiction Are No More – Astrobiology and Extreme Organisms (Issue #8)

blog 8 mdrs nasaby: Nicole Willett

Astrobiology is a growing field in scientific research.  It is the study of organisms that live under extreme conditions.  These organisms are called extremophiles. Astrobiology encompasses many different sciences, including biology, astronomy, chemistry, and geology.  One goal of astrobiology is to search for habitable environments outside of Earth, on planets such as Mars.  Another is to find out how far to the extreme life can be pushed and still thrive.  Not long ago, we had a very small definition of where and under what conditions life can exist.  Since the implementation of Astrobiology into the world of true scientific research, we have redefined where life can flourish.  The purpose of the rovers and landers on Mars has been to find evidence of past water and possible organic compounds. Astrobiologists are also looking for any evidence of prebiotic chemistry on Mars.  By doing field research and laboratory studies on Earth, we can make comparisons to what we are currently finding on Mars.  Our narrow definition of life from 20 to 30 years ago has been blown wide open.It is now known that life can exist under tremendously stressful conditions.  There are many new terms for these organisms.  Some of which are alkaliphile, halophile, radioresistant, polyextremophile, lithoautotroph, oligotroph, and cryophile.  All of these organisms live in areas that are very far from the traditional areas where life was once believed to thrive.  Previously we believed life needed sunlight, water, a food source, and to exist between 32oF (0oC) and 212oF (100oC).

blog 8 ky cave shrimp pubs usgs govThis narrow niche has changed to a very broad area.  There have been organisms found living in deep caves completely without sunlight and thriving.  One example of this is called the Kentucky cave shrimp.  It is a blind and almost transparent troglobite shrimp. Also, several organisms, such as diatoms and algae, have been discovered living happily in the Arctic and Antarctic Sea ice.  In addition, the bottom of the ocean contains hydrothermal vents that are under extreme pressure and high temperature.  At these vents are entire ecosystems of extremophiles.  They include millions of bacteria, several species of tube worms, shrimp, crabs, fish and many other organisms.  The pH at the vents throughout the world have been measured to be as low as 2.8 (acidophile) and as high as 10 (alkaliphile). An alkaliphile lives in soil that has a high pH usually 9 or above.  The results from the Phoenix Lander that studied the Martian soil in 2008 came back with a pH between 8 and 9.  We know there are organisms on Earth that thrive in alkaline soil.  One example is the Bacillus okhensis.  This organism has been found on salt flats in India.  It is also considered a halophile or salt tolerant bacterium.  Halophiles can be found in environments with a salt content at least five times greater than ocean salinity.  They are found in the Great Salt Lake in Utah, salt flats, and even in the Dead Sea.

Deinococcus radiodurans
is a bacterium that is known to Astrobiologists as an extremely radiation resistant organism.  A lethal dose of radiation for a human is 5 Gy (grey units).  A typical medical x-ray is about 1 mGy (milli grey unit= 0.001 Gy).  This hardy organism can resist a dose of 5,000 Gy wwith no loss of viability and 15,000 Gy with a 37% viability rate. Deinococcus has also been known to be resistant to cold, dehydration, the vacuum of space, and acidic environments.   It is known as a polyextrmophile.  A polyextremophile is an organism that possesses many different characteristics of extreme organisms.
 
blog 8 tardigrade BBCAnother example of a polyextremophile that is a more complex organism is the tardigrade, more commonly known as a water bear.  These animals are amazingly resistant to almost anything nature sends its way.  They are approximately 0.5 mm in length, with four stubby legs, and a slightly segmented chubby body.   Water bears can be found just about anywhere one looks. They have been found from the Himalayas to 13,000 feet below the ocean and everywhere in between.  The pressure differential is tremendous between these areas.  Tardigrades can be heated to over 304oF (150oC) and chilled to -328oF (-200oC) and survive.  They have been taken to space, exposed to the vacuum and solar radiation, brought back to Earth, and survived.  Water bears have the ability to resist exposure to 5,000 Gy of radiation.  It has also been said, by some researchers that Tardigrades go into a state of chemobiosis to resist any environmental toxins that they are exposed to.  How would we know if a water bear were on Mars?  The Curiosity Rover has the ability to detect lipids that exist in the cell walls of organisms such as a tardigrade or any other microorganisms. This is possible even if the organism is in a state of suspended animation.

blog 8 lake vida NASA JPL

On November 28, 2012 it was widely reported that scientists had finally reached the salty water of Lake Vida in Antarctica.  This lake has been isolated from the rest of the world for at least 2,800 years.  The water in this lake has a salt content five times that of the ocean and is below the freezing point.  Even with all of these extreme conditions, scientists discovered 32 species of bacteria.  This number was higher than expected.  Scientists are already comparing this find to what may potentially be found on Mars.

There are many other examples of extreme organisms that are fascinating and may seem alien to people.  Astobiologists wish to use Earth analogues for their research.  The goal is to find the limits of life, if there are any.  This will help us to more readily recognize life when and if we find it on Mars or other bodies in the solar system.  Our rovers are working diligently on Mars to help us find the answer to the question, “Is there life on Mars?” 

On December 3rd, Curiosity Rover Scientists reported the latest findings on Mars.  Curiosity has discovered chlorinated hydrocarbons in the soil.  Included in these results are chloromethane (CH3Cl), dichloromethane (CH2Cl2), chloroform (CHCl3), and carbon tetrachloride (CCl4).  Many of these are found naturally on Earth in marine organisms.  However, the scientists at NASA have stated that these simple organics may not be indigenous to Mars.  They may be contaminants from Earth, asteroids, meteors, or comets, or they may have formed as a result of the chemical reaction in the SAM instrument itself.  Further tests will be performed to determine the nature of the simple organics. Another interesting find was that the percent of H2O in the soil was higher than expected.  In addition there was deuterium (heavy water), sulfur, and chlorine in the soil.  Sulfur is an essential element for all life on Earth.  Please be aware that it is a large leap to go from simple organics to “life” on Mars.  These results are still being verified and studied.  ~Stay Tuned…….

blog 8 mars warm season cold season secosky email dec 4 12

Images [The Mars Society, pubs.usgs.gov, pbworks, NASA/JPL, (Secosky)]

The Incredible Shrinking Martian – From Whales to Microbes (Issue #7)

Recently NASA’s Dr. John Grotzinger has made some exciting statements regarding the recent discoveries on Mars by the Curiosity Rover.  Later the news broke that there has not been any “definitive evidence of Martian organics.”  The results in question will be announced December 3rd at 9:00 am PST / 12:00 pm EST at the American Geophysical Union Conference in San Francisco, Ca.  As of December 1, 2012, there is no official recognition by the world-wide scientific community of life being found on the Red Planet…. Stay tuned…..

Nicole Willett, Education Director

Guest Blog by Robert B. Bruner

Derived from the Robert B. Bruner Book Collection at the Lowell Observatory, Flagstaff, Arizona

Robert Bruner has spent many years searching for and collecting books about Mars.  It is important to note that before 1900 there were very few books exclusively about Mars.  Mr. Bruner has donated almost 400 books to the collection at the Lowell Observatory.  He has generously compiled the following quotes and information exclusively for The Mars Society.  It is interesting to see the pattern of belief and data about life on Mars over such a long time period.

See the Recommended Reading tab of the Mars Society’s Education Page or click the link  for access to the Bibliography. www.lowell.edu/Research/library  Many of these books are available online.

Celestial Scenery(1838) Dick, Thomas

As it is probable that one-third of the surface of Mars is covered with water, should we subtract one-third from these sums there would still remain accommodation for twelve times the number of the population of our globe.  The long duration of winter in the polar regions of Mars seems to require a moon to cheer them during the long absence of the sun; and if there be none, the inhabitants of those regions must be in a far more dreary condition than the Laplanders and Greenlanders of our globe.blog 7 whale informationsentinel com

Plurality of Worlds, (1854) Whewell, William

Perhaps we are not quite certain about the existence of an atmosphere; and without such an appendage, we can hardly accord him tenants. But if he have inhabitants, let us consider of what kind they must be conceived to be, according to any judgment which we can form. The force of his gravity is so small, that we may allow his animals to be large, without fearing that they will break down by their own weight. In a planet so dense, they may very likely have solid skeletons. The ice about his poles will cumber the seas, cold even for the want of solar heat, as it does in our Arctic and Antarctic oceans; and we may easily imagine that these seas are tenanted, like those, by huge creatures of the nature of whales and seals, and by other creatures which the existence of these requires and implies.

Other Worlds Than Ours, (1870) Proctor, Richard

Surely, if it is rashly speculative to say of this charming planet that it is the abode of life- if we must, indeed, limit ourselves to the consideration of what has been absolutely seen-it is yet to speculate, ten thousand times more rashly to assert, in the face of so many probable arguments to the contrary, that Mars is a barren waste, either wholly untenanted by living creatures, or inhabited by beings belonging to the lowest orders of animated existence.

In the High Heavens, (1893) Ball, Thomas

That there may be types of life on Mars of some kind or other is, I should think, very likely.  Two of the elements, carbon and hydrogen, which are most intimately associated with the phenomena of life here, appear to be among the most widely distributed elements throughout the universe, and their presence on Mars is in the highest degree probable. But what course the progress of evolution may have taken on such a globe as Mars, it seems totally impossible to conjecture. It has been sometimes thought that the ruddy color of the planet may be due to vegetation of some peculiar hue, and there is certainly no impossibility in the conception that vast forests of some such as trees like copper-beeches might impart to continental masses hues not unlike those which come from Mars.

Mars as the Abode of Life, (1908) Lowell, Percival

blog 7 canals on Mars NASA JPLFor the construction of these residuary filaments we have a plethora of capabilities to  draw upon: in the first place, beings on a small planet could be both bigger and more effective than on a large one, because of the lesser gravity on the smaller body. An elephant on Mars could jump like a gazelle. In the second place, age means intelligence, enabling them to yoke nature to their task, as we are yoking electricity. Finally, the task itself would be seven times as light. For gravity on the surface of Mars is only about 38 per cent of what it is on the surface of the earth; and the work which can be done against a force like gravity with the same expenditure of energy is inversely as the square of that force. A ditch, then, seven times the length of one on earth could be dug as easily on Mars. Thus, not only do the observations we have scanned lead us to the conclusion that Mars at this moment is inhabited, but they land us at the further one that these denizens are an order whose acquaintance was worth the making. Whether we ever shall come to converse with them in any more instant way is a question upon which science at present has no data to decide.

There is Life on Mars, (1955)  Nelson, Earl

One of these beings declared he had come from Venus, the other from Mars. One, the Martian, was actually photographed. Both resemble terrestrial men in all respects. The Venusian is described as being young and handsome, slightly built and with rather long fair hair.  The Martian was estimated to have been about six feet tall, with a high forehead and, so far as one can judge, not so good looking. Apparently, the Venusian was able to breathe quite comfortably in our atmosphere without artificial aid of any kind. The Martian, on the other hand, appears to have had a small tube up his nose. After chatting amicably with the authors, in sign language, both men returned to their saucers, which took off again.

A Field Guide to the Stars and Planets, (1964) Menzel, Donald

The conspicuous red color apparently comes from regions not too different from various deserts of the earth, such as the Painted Desert of Arizona. White “buttons” on the two polar caps which vary in size with Martian seasons, are undoubtedly formed from ice- presumably a thin layer of hoarfrost- which completely vanishes during the Martian summer. Water is a scarce commodity; the planet possesses no discernible oceans or lakes. The grayish areas, once thought to be water, show seasonal changes suggestive of vegetation, but their precise nature has not yet been determined. They may be a form of moss or lichen.

 Caption of JPL Viking Press Release P-17384, (1976)

The picture shows eroded mesa-like landforms. The huge rock formation in the center, which resembles a human head, is formed by shadows giving the illusion of eyes, nose and mouth. The feature is 1.5 kilometers (one mile) across, with the sun angle at approximately 20 degrees. The speckled appearance of the image is due to bit errors, emphasized by enlargement of the photo. The picture was taken on July 25 from a range of 1873 kilometers (1162 miles). Viking 2 will arrive in Mars orbit next Saturday (August 7) with a landing scheduled for early September.

blog 7 alh84001 marsnews com (1)Abstract of Johnson Space Center Announcement 19970003266, (1996)Fresh fracture surfaces of the Martian meteorite ALH84001 contain abundant poly cyclic aromatic hydrocarbons (PAHs). These fresh fracture surfaces also display carbonate globules.  Contamination studies suggest the PAHs are indigenous to the meteorite. High resolution scanning and transmission electron microscopy study of surface textures and internal structures of selected carbonate globules show that the globules contain fine-grained, secondary phases of single-domain magnetite and Fe-monosulfides. The carbonate globules are similar in texture and size to some terrestrial bacterially induced carbonate precipitates. Although inorganic formation is possible, formation of the globules by biogenic processes could explain many of the observed features including PAHs. The PAHs, the carbonate globules, and their associated secondary mineral phases and textures could thus be fossil remains of a past Martian biota.

Beyond UFO’s(2008) Bennett, Jeffrey

Because Mars has no liquid water on its surface today, any extant life would presumably be underground at depths where heat can keep water liquid. In other words, Martian life today would probably resemble the terrestrial microbes known as endoliths that live in subsurface rock on Earth. Searching for Martian life therefore presents several difficult challenges: We’d need to drill down to bring up rock from fairly deep underground; we’d need to do that at a location where a heat source is keeping some of the water liquid; and then we’d need to conduct careful experiments to detect the presence of microscopic life.

From Dying Stars to the Birth of Life(2011) Cranford, Jerry

So, what is the story today with respect to the possibility of life on Mars? With the gradual demise of its atmosphere, greenhouse effect, and other sources of geothermal heat, Martian life, if it ever existed, may have been forced to go underground to survive. Life on the surface today would be continually bombarded by lethal doses of ionizing radiation from the Sun as was the Earth prior to the development of the protective oxygen ozone layer in the atmosphere. The fact that many different species of such tenacious critters have chosen to live in such locations on Earth would suggest that this might have occurred on Mars as well.

 

The Search for Aliens, (2012) Bizony,Piers

blog 7 bacteria dragonartz net

No one today seriously anticipates finding anything larger or more complex on Mars than single-celled organisms. At this tiny scale, it was better to focus on the kind of measurable chemical activity that Martian microbes might demonstrate, thus betraying their presence indirectly.  In December, 2003, the European-built Mars Express orbiter detected significant traces of methane in the planet’s thin veil of atmosphere. More than nine-tenths of terrestrial methane (a hydrocarbon consisting of four hydrogen atoms bound to one of carbon) is a by-product of life, whether in the form of fossil fuels and rotting swamps, or puffing out from the backsides of cows. The small fraction not produced biologically is geologic. In theory, it could be a waste product from microorganisms living under the Martian ice or buried deep under the soil.

[Images: informationsentinel.com, NASA/JPL, marsnews.com, dragonartz.net]

Next Blog — Extreme Organisms

Warm Water on Mars? (Issue #6)

by: Nicole Willett

The issue of water on Mars has been debated for over a century.   The observations of Giovanni Schiaparelli in approximately 1877 started the frenzy over water on Mars.  When Schiaparelli observed what he thought were channels on Mars he called them canali which means channelsWhen his findings were published, the term was misinterpreted as canals.  There is a distinct difference between channels and canals.  A channel is a naturally occurring groove in the ground where water or some other fluid has eroded the soil away to make a riverbed.  A canal is thought to be something made by people or other beings, for water to flow through.   So the speculation of water on the Red Planet began.

Percival Lowell built a telescope specifically to observe Mars.  He was intrigued with the findings of Schiaparelli.   He studied the planet for 15 years with his new telescope in Flagstaff, Az.  His sketches show many features that at the time were considered to be evidence of intelligent beings on Mars.  Many people disagreed with Lowell’s observations and he was ostracized by some.  As technology advanced, we discovered that some of the geological features were present, but not in the exact state recorded by Lowell.  The Mariner 4 and 9 spacecraft proved that the drawings Lowell made were not accurate.  However, the spacecraft proved that there were many channels that once held liquid that flowed over the surface of Mars.

alluvial fanEach spacecraft that visited the Red Planet gave more and more clues to its watery past.

There are two types of channels that have been identified.  One type is called a runoff channel.  These are often found in the southern highlands and can be hundreds of miles long. They look analogous to interconnecting riverbeds on Earth.  The other type of channel is called an outflow channel.  These are found in the equatorial region and appear to be relics of catastrophic flooding.  They are not interconnected and are thought to be paths of huge volumes of water.As more and more data has come in, the estimates for the period when water existed in liquid form on the surface of Mars has changed dramatically.  These estimates have gone from billions of years ago to millions, thousands, hundreds, and more recently it has been said there may have been water on the surface mere decades ago.  NASA actually coined the term, “follow the water” in an effort to prove that there was liquid water on Mars in the past and to look for possible organic material that may have existed or may now exist there.   

Today NASA released an article titled, Meltwater on Mars Could Sustain Life on their Astrobio.net website.  Click the link for the full article:  http://www.astrobio.net/pressrelease/5150/meltwater-on-mars-could-sustain-life.  Researchers from the University of Gothenburg, Sweden have compared satellite images of areas on Mars and Earth.  The areas studied show correlations between the two planets where scientists believe there have been repeated freeze and thaw cycles.   While comparing satellite images and doing field research on Earth, the researchers believe that some of the gullies on Mars were formed by melting snow and flowing water. 

We know the surface temperature at the Gale Crater was 40o F when the Curiosity Rover took its first measurements.  That is above the freezing point of water.  The pressure on Mars would cause pure water to evaporate very quickly.    We also know that the soil on Mars is full of many salts and minerals that when present in water will allow it to remain in a liquid state at the surface.  

tardigrade

On Earth there are organisms that survive under extreme circumstances, with no water for decades or even centuries. These organisms lie dormant or in a state of extreme metabolic stasis for very long periods of time until the proper environmental conditions become available for normal metabolism and reproduction.  It is known that the requirements for life are available on Mars.  These conditions may seem foreign to some, but to astrobiologists, the conditions are no different than many places on Earth.  So to paraphrase Dr. Chris McKay, if we do not find life on Mars, where the conditions are present, then I will be surprised if we find it anywhere else.  

The discoveries of Curiosity, Opportunity, and the fleet of Martian orbiters will continue to add to the mounting evidence we have.  They will reveal whether or not the conditions for the presence of life are available and details about the history of water on the Red Planet.  Curiosity is also searching for organic material.  If there is organic material detected, the data will be tested and retested until it is proven unequivocally that what we think is evidence of life, definitely is life.                
Stay tuned…..
Images [wikipedia.org, NASA JPL, The Taxonomicon]