Putative Martian Microbes Formed Plentiful Ooids on Mars.
First published in a journal: https://www.longdom.org/open-access/putative-martian-microbes-formed-plentiful-ooids-on-mars-2332-2519-1000150.pdf
Last updated on Aug. 10, 2018
Abstract
NASA’s Mars Rover Curiosity discovered plentiful indigenous spherical ooids at High Dune and Namib Dune in Bagnold dune field, Gale Crater, Mars. The spherical Martian ooids contain nuclei and range from 0.1 mm to 0.5 mm in diameter. Colors of the spherical Martian ooids are various, including white, yellow translucent, green, gray, and yellow. The spherical Martian ooids should have been formed by microbes, because 1) ooids of Earth have recently been found to be formed by microbes and 2) microbial borings are found in ooids of Earth and of Mars. There is no evidence that proves ooids are formed by agitated water.
Keywords: Martian microbes; Martian ooids; Past life on Mars
Introduction
NASA’s Mars Rover Curiosity visited Bagnold dune field in Gale Crater, Mars, to study sands there from December 2015 to February 2016 (from Sol 1182 to Sol 1260) (See Figure 1 and http://www.hou.usra.edu/meetings/lpsc2016/pdf/2298.pdf ).
Figure 1: Route map of Mars Rover Curiosity from Sol 1172 to Sol 1260
NASA’s Mars Rover Curiosity visited Bagnold dune field in Gale Crater, Mars, to study sands there from December 2015 to February 2016 (from Sol 1182 to Sol 1260) (See Figure 1 and http://www.hou.usra.edu/meetings/lpsc2016/pdf/2298.pdf ).
Figure 1: Route map of Mars Rover Curiosity from Sol 1172 to Sol 1260
Geological context of Bagnold Dune is seen in these three photos: http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=7658
http://mars.nasa.gov/msl/multimedia/images/?ImageID=7640
http://photojournal.jpl.nasa.gov/catalog/PIA16064
http://mars.nasa.gov/msl/multimedia/images/?ImageID=7640
http://photojournal.jpl.nasa.gov/catalog/PIA16064
During its visit there, Curiosity Rover did a lot of science on Martian sands there, including the morphology, mineralogy, and chemistry of the sands. This article focuses on the rover’s discovery of putative ooid sand there. Curiosity rover used its Mars Hand Lens Imager (MAHLI) to acquire a lot of microscopic images of the sands there. Many of the microscopic images show ooids, some of which are marked in the following figures in the result section below.
Result
Figure 2 was acquired by NASA’s Mars rover Curiosity on Dec. 3, 2015 (Sol 1182) near High Dune, Gale Crater, Mars. Eight red arrows and 17 yellow lines mark ooids. They are about 0.5 mm in diameter. Scale bar: 2 mm. Image width: ~3.3 cm. Above figure in the largest size:
https://www.flickr.com/photos/fossil_lin/30445874575/sizes/o/
Image Credit: NASA/JPL-Caltech/MSSS
Image Credit: NASA/JPL-Caltech/MSSS
Location: at the lower left in http://i.imgur.com/VK79Uz2.jpg
For comparison with ooids of Earth that resemble Martian ooids, see Figure 8 and photos in http://wretchfossil.blogspot.tw/2016/01/earthly-ooids-for-comparison.html .
NASA’s Mars Rover Curiosity acquired the above microscopic image (Figure 3) on Jan. 19, 2016 (Sol 1228) at Gobabeb in Namib Dune in Bagnold dune field, Gale Crater, Mars. Seventeen red arrows point to well-preserved ooids. The ooids measure roughly about 0.2 mm to 0.5 mm in diameter. Scale bar: 2.2 mm. Image width: ~3.5 cm. Above figure in the largest size:
https://www.flickr.com/photos/fossil_lin/30409147796/sizes/o/
https://www.flickr.com/photos/fossil_lin/30409147796/sizes/o/
Image Credit: NASA/JPL-Caltech/MSSS
Context: beside the scoop trench in
Above figure (Figure 4) in the largest size:
https://www.flickr.com/photos/fossil_lin/30445873175/sizes/o/
NASA’s Mars Rover Curiosity acquired the above microscopic image on Jan. 19, 2016 (Sol 1228) at Gobabeb in Namib Dune in Bagnold dune field, Gale Crater, Mars. Twelve red arrows point to well-preserved ooids. These ooids are between 0.1 mm and 0.2 mm in diameter, as they have been sieved with a mesh of 0.15 mm holes. The rover dumped the scooped and sieved particles onto the ground after analyzing similar particles for their chemistry and mineralogy in its laboratory instruments. Image Credit: NASA/JPL-Caltech/MSSS
https://www.flickr.com/photos/fossil_lin/30445873175/sizes/o/
NASA’s Mars Rover Curiosity acquired the above microscopic image on Jan. 19, 2016 (Sol 1228) at Gobabeb in Namib Dune in Bagnold dune field, Gale Crater, Mars. Twelve red arrows point to well-preserved ooids. These ooids are between 0.1 mm and 0.2 mm in diameter, as they have been sieved with a mesh of 0.15 mm holes. The rover dumped the scooped and sieved particles onto the ground after analyzing similar particles for their chemistry and mineralogy in its laboratory instruments. Image Credit: NASA/JPL-Caltech/MSSS
Context: Dump Pile A in http://planetary.s3.amazonaws.com/assets/images/4-mars/2016/20160210_MAHLI_1241_Namib_sample_area.jpg
Additional images of well-preserved ooids at Namib Dune:
Figure 5: Most particles in this photo are ooids.
NASA’s Mars Rover Curiosity acquired the above image (Figure 5) with Mars Hand Lens Imager (MAHLI) on Jan. 23, 2016 (Sol 1231) at Gobabeb in Namib Dune in Bagnold dune field, Gale Crater, Mars. Most of the particles in this image are eroded ooids. Red lines mark some of the ooids. They measure roughly 0.2 mm to 0.4 mm across. Image width: ~2.8 cm. Largest-sized figure:
https://www.flickr.com/photos/fossil_lin/30445875115/sizes/o/
Image Credit: NASA/JPL-Caltech/MSSS
Image Credit: NASA/JPL-Caltech/MSSS
Image source: www.flickr.com/photos/105796482@N04/24483811912/
Context: Dump Pile B in http://planetary.s3.amazonaws.com/assets/images/4-mars/2016/20160210_MAHLI_1241_Namib_sample_area.jpg
Figure 6. Three green arrows point to three spots at Gobabeb, where Mars Rover Curiosity scooped samples for chemical and mineralogical analyses with onboard instruments SAM and CheMin. After analyses, some samples were dumped onto ground and imaged with Mars Hand Lens Imager. The material imaged in Figures 3, 4, and 5 are from arrow 1 (Figures 4 & 5) and arrow 2 (Figure 3). Image Credit: NASA/JPL-Caltech/MSSS
NASA’s full-sized image with description:
http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=7658
NASA’s full-sized image with description:
http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=7658
Figure 7. Microbes of Earth often bore holes in ooids (Ref. 1, notes 1, 2, 3). Microbes on Mars did the same thing in this figure (Figure 7), which is the same as Figure 2 above. In the red circles are Martian ooids with holes bored by Martian microbes. Such borings prove indirectly the existence of microbes. Image width: ~3.3 cm. The largest-sized figure:
https://www.flickr.com/photos/fossil_lin/24749890260/sizes/o/
https://www.flickr.com/photos/fossil_lin/24749890260/sizes/o/
Context: the left side in http://i.imgur.com/VK79Uz2.jpg
Image Credit: NASA/JPL-Caltech/MSSS
More evidence for microbial borings:
http://wretchfossil.blogspot.tw/2016/04/more-martian-microbes-boring-holes-in.html
http://wretchfossil.blogspot.tw/2016/04/more-martian-microbes-boring-holes-in.html
Note 1: “The ooids have the same pattern of microboring alteration across the region. The surface and outer cortex of the ooids are punctuated with unfilled microborings, whereas the inner cortex contains two morphologies of aragonite cement filling the microborings.” (quoted from the abstract of article in Ref. 1)
Note 2: “Some modern (and ancient) ooids partially or totally lack clear layering and have a micritic (very fine grained) texture. Examination of such micritic ooids by scanning electron microscopy often shows evidence of microbial borings later filled by fine cement.” (quoted from Wikipedia article on ooids)
Note 3: Photo of Earth ooids bored by microbes:
http://wretchfossil.blogspot.tw/2016/09/microbial-borings-differentiate-ooids.html
http://wretchfossil.blogspot.tw/2016/09/microbial-borings-differentiate-ooids.html
Figure 8: Earthly ooids identified during field trip
Figure 8. Original description: “Mega ooids! Dave’s finger for scale.” The above photo (Figure 8) shows ooids in China Ranch, California, USA. Red lines in the photo mark ooids that have been eroded into hemispheres. Image source: the last fifth photo in http://daveandiztakeonthewest.blogspot.tw/2012/11/china-ranch-and-stretchoween.html
Figure 9: These spheres differ from ooid spheres.
Figure 9 shows spheres that are different from ooids. Original description: “The Utah concretions shown on the left range in diameter from one twenty-fifth of an inch to 2 inches (1 mm to 50 mm), while the Martian versions on the right all measure less than one-fifth of an inch (5 mm) in diameter. (Scale of photos is different.)” (Quoted from http://www.innovations-report.com/html/reports/earth-sciences/report-30313.html )
Figure 10 is a microscopic image taken at Gobabeb in Namib Dune in Bagnold dune field, Gale Crater, Mars. In the white circles are ooids that have been eroded into hemispheres. Red arrows point to nucleus of ooids. The ooid at top left exposes its concentric layers and nucleus. The hemispheres measure 0.2 mm to 0.4 mm across. Scale bar: 1.6 mm. Image width: ~2.7 cm. For comparison with Earthly ooids that have been eroded into hemispheres, see Figure 8 above. Above figure in the largest size:
https://www.flickr.com/photos/fossil_lin/30445874495/sizes/o/
https://www.flickr.com/photos/fossil_lin/30445874495/sizes/o/
Above image is enlarged from
https://www.flickr.com/photos/lunexit/24626790060/in/dateposted/
Image Credit: NASA/JPL-Caltech/MSSS/2di7 & titanio44
NASA’s original raw image: http://mars.nasa.gov/msl/multimedia/raw/?rawid=1242MH0005620020403663C00_DXXX&s=1242 (flipped 180 degrees into the above image)
https://www.flickr.com/photos/lunexit/24626790060/in/dateposted/
Image Credit: NASA/JPL-Caltech/MSSS/2di7 & titanio44
NASA’s original raw image: http://mars.nasa.gov/msl/multimedia/raw/?rawid=1242MH0005620020403663C00_DXXX&s=1242 (flipped 180 degrees into the above image)
History of the material: from scoop 2 in
http://planetary.s3.amazonaws.com/assets/images/4-mars/2016/20160210_MAHLI_1241_Namib_sample_area.jpg,
then transported to Dump Pile D in the same photo.
http://planetary.s3.amazonaws.com/assets/images/4-mars/2016/20160210_MAHLI_1241_Namib_sample_area.jpg,
then transported to Dump Pile D in the same photo.
See additional image of nuclei in Martian ooids:
Discussion
In paragraphs A to E below, this article discusses putative ooids discovered on Mars and their possible formation by microorganisms.
A. Are they ooids?
A1. Putative Martian ooids match ooids of Earth. An ooid often consists of a nucleus (a fragment of shell, a grain of sand, etc.) around which complex material is deposited in concentric layers to form roughly spherical or oval grains. A website named Sandatlas has the following webpage for 20 types of sand on Earth: http://www.sandatlas.org/sand-types/
Of the 20 types of sand on Earth, only ooid sand matches the material described in Figures 2 to 5, because those Martian ooids are unique for their combination of spherical shape, similar size of ~0.1 mm to 0.5 mm in diameter, and various colors that include white, yellow translucent, green, grey, and yellow. These features can be seen by comparing Figures 2 to 5 with the 20 types of sand on Earth. The combination of these features is also seen in nearly every Focus Merge Data Product at
http://mars.nasa.gov/msl/multimedia/raw/?s=1231&camera=MAHLI and http://mars.nasa.gov/msl/multimedia/raw/?s=1228&camera=MAHLI
Such shape, size, and color are characteristic of ooid sand.
A2. Putative Martian ooids are seen not only at High Dune (Figure 2) and Namib Dune (Figures 3, 4, 5) but also seen at 18 other places in Gale Crater. (see http://wretchfossil.blogspot.tw/2016/06/numerous-martian-microbes-produced.html). Some of the ooids are still embedded in oolite and many others were drilled out of rocks in 2016.
The environment of Gale Crater over 3.5 billion years ago was a freshwater lake near the Martian equator (see http://authors.library.caltech.edu/60940/). Such concentration, distribution, and environment fit those of ooid sand on Earth. Regarding the geological context of Martian ooids, Martian wind had blown the ooids in the above figures away from the site where they were originally formed (see the third paragraph inhttp://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=7658). Anyway, geologists do not need geological context in order to correctly identify ooids (see Figure 8).
A3. Ooid spheres differ from other kinds of spheres in sizes, colors, and internal structures. Ooids of Earth are mostly 0.25 mm to 1 mm in diameter (note 1). Martian ooids at Bagnold Dune measure ~0.1 mm to 0.5 mm in diameter (Figures 2 to 5).
However, “On Mars, most of the hematite rocks (“blueberries”) are about 0.16 inches (4 millimeters) in diameter, and no larger than 0.24 inches (6.2 millimeters). By contrast, Earth spherules exhibit a large range of sizes, not limited to only a quarter of an inch.” (Quoted from the ninth paragraph in http://news.nationalgeographic.com/news/2014/02/140224-mars-blueberries-water-meteorite-space-science/ )
The colors of Martian ooids include white, yellow translucent, green, grey, and yellow as shown in figures above. Other kinds of spheres do not show all of these colors.
Regarding internal structures, ooids contain nuclei and concentric layers (Figure 10), which are usually lacking in spherical look-alikes, such as chondrules, Martian Blueberries, Utah’s Moqui marbles, etc. Ooids are not ”impact spherules” because no mechanisms allow meteor impacts to form spherules with nuclei and concentric layers. Nothing matches the spherical “ooids” on Mars except ooids of Earth.
In view of the above, yes, they are ooids.
Note 1: See the third paragraph in https://en.wikibooks.org/wiki/Historical_Geology/Ooids_and_oolite and the first paragraph in http://www.sandatlas.org/ooid-sand/.
B. Were the ooids on Mars formed by microbes?
Regarding the formation of ooids, there are non-biological hypotheses, in which ooids get their spherical shape owing to highly agitated water (Ref. 3), such as sea waves pounding on the beaches, that rolls the ooids into the spherical shape. However, there is no highly agitated water in lakes. The spherical ooids at Bagnold Dune are unlikely to have been formed by the non-biological mechanisms because the Martian ooids are in a former lake and there is no evidence that proves ooids are formed by agitated water. On the other hand, there is ample evidence for the biological formation of ooids. Some of the evidence are listed below in B1, B2, and Ref. 3 to Ref. 15. In view of the above and the microbial borings in Martian ooids (Figure 7), the Martian ooids should have been formed by microbes.
B1. Microbes of Earth form ooids in the freshwater lake. Evidence: “Here, we show that photosynthetic microbes not only enhance early carbonate precipitation around the ooid nucleus but also control the formation of the entire cortex in freshwater ooids from Lake Geneva, Switzerland.” (Quoted from the abstract of the article in Ref. 4: “Going nano: A new step toward understanding the processes governing freshwater ooid formation”, displayed at http://geology.gsapubs.org/content/40/6/547.abstract)
The water in Gale Crater of Mars was once fresh water in a lake as mentioned in paragraph A2 above.
B2. Recent research confirms that microbes of Earth form ooids in seawater, as reported in the abstract of Ref. 5:
http://www.hou.usra.edu/meetings/abscicon2015/pdf/7317.pdf
More evidence for microbes forming ooids are listed in Ref. 3 to Ref. 15 below.
C. Ooids Prove Microbial Activities.
Microbes of Earth often bore holes in ooids and Martian microbes did the same thing (see Figure 7). Microbial borings in Figure 7 prove indirectly the existence of Martian microbes. Ooids are not only formed by microbes (see paragraph B) but also contain high organic matter content (Ref. 5).
A2. Putative Martian ooids are seen not only at High Dune (Figure 2) and Namib Dune (Figures 3, 4, 5) but also seen at 18 other places in Gale Crater. (see http://wretchfossil.blogspot.tw/2016/06/numerous-martian-microbes-produced.html). Some of the ooids are still embedded in oolite and many others were drilled out of rocks in 2016.
The environment of Gale Crater over 3.5 billion years ago was a freshwater lake near the Martian equator (see http://authors.library.caltech.edu/60940/). Such concentration, distribution, and environment fit those of ooid sand on Earth. Regarding the geological context of Martian ooids, Martian wind had blown the ooids in the above figures away from the site where they were originally formed (see the third paragraph inhttp://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=7658). Anyway, geologists do not need geological context in order to correctly identify ooids (see Figure 8).
A3. Ooid spheres differ from other kinds of spheres in sizes, colors, and internal structures. Ooids of Earth are mostly 0.25 mm to 1 mm in diameter (note 1). Martian ooids at Bagnold Dune measure ~0.1 mm to 0.5 mm in diameter (Figures 2 to 5).
However, “On Mars, most of the hematite rocks (“blueberries”) are about 0.16 inches (4 millimeters) in diameter, and no larger than 0.24 inches (6.2 millimeters). By contrast, Earth spherules exhibit a large range of sizes, not limited to only a quarter of an inch.” (Quoted from the ninth paragraph in http://news.nationalgeographic.com/news/2014/02/140224-mars-blueberries-water-meteorite-space-science/ )
The colors of Martian ooids include white, yellow translucent, green, grey, and yellow as shown in figures above. Other kinds of spheres do not show all of these colors.
Regarding internal structures, ooids contain nuclei and concentric layers (Figure 10), which are usually lacking in spherical look-alikes, such as chondrules, Martian Blueberries, Utah’s Moqui marbles, etc. Ooids are not ”impact spherules” because no mechanisms allow meteor impacts to form spherules with nuclei and concentric layers. Nothing matches the spherical “ooids” on Mars except ooids of Earth.
In view of the above, yes, they are ooids.
Note 1: See the third paragraph in https://en.wikibooks.org/wiki/Historical_Geology/Ooids_and_oolite and the first paragraph in http://www.sandatlas.org/ooid-sand/.
B. Were the ooids on Mars formed by microbes?
Regarding the formation of ooids, there are non-biological hypotheses, in which ooids get their spherical shape owing to highly agitated water (Ref. 3), such as sea waves pounding on the beaches, that rolls the ooids into the spherical shape. However, there is no highly agitated water in lakes. The spherical ooids at Bagnold Dune are unlikely to have been formed by the non-biological mechanisms because the Martian ooids are in a former lake and there is no evidence that proves ooids are formed by agitated water. On the other hand, there is ample evidence for the biological formation of ooids. Some of the evidence are listed below in B1, B2, and Ref. 3 to Ref. 15. In view of the above and the microbial borings in Martian ooids (Figure 7), the Martian ooids should have been formed by microbes.
B1. Microbes of Earth form ooids in the freshwater lake. Evidence: “Here, we show that photosynthetic microbes not only enhance early carbonate precipitation around the ooid nucleus but also control the formation of the entire cortex in freshwater ooids from Lake Geneva, Switzerland.” (Quoted from the abstract of the article in Ref. 4: “Going nano: A new step toward understanding the processes governing freshwater ooid formation”, displayed at http://geology.gsapubs.org/content/40/6/547.abstract)
The water in Gale Crater of Mars was once fresh water in a lake as mentioned in paragraph A2 above.
B2. Recent research confirms that microbes of Earth form ooids in seawater, as reported in the abstract of Ref. 5:
http://www.hou.usra.edu/meetings/abscicon2015/pdf/7317.pdf
More evidence for microbes forming ooids are listed in Ref. 3 to Ref. 15 below.
C. Ooids Prove Microbial Activities.
Microbes of Earth often bore holes in ooids and Martian microbes did the same thing (see Figure 7). Microbial borings in Figure 7 prove indirectly the existence of Martian microbes. Ooids are not only formed by microbes (see paragraph B) but also contain high organic matter content (Ref. 5).
D. Can the ooids and the microbes be contaminants to Mars?
No. The reasons: 1) meteorites usually do not contain ooids or microbes, except in meteorite ALH84001 (see http://wretchfossil.blogspot.com/2016/04/ooids-found-in-martian-meteorite-alh.html); 2) Gale Crater of Mars has 18 other places that produce numerous ooids (see http://wretchfossil.blogspot.tw/2016/06/numerous-martian-microbes-produced.html). Some of the ooids are still embedded in oolite and many others were drilled out of rocks in 2016.
E. Are chemical experiments essential for identifying ooids?
No. Geologists usually identify ooids with visual observation (Figure 8), because ooids possess unique morphology and unique internal structures. Ooids sometimes may not be identified even when chemical measurement results contain the chemistry of ooids. For example, meteorite ALH84001 contained ooids as evidenced in
http://aem.asm.org/content/68/8/3663/F1.expansion.html
but no scientists identified ooids in the meteorite.
Conclusion
Nothing matches the spherical “ooids” on Mars except ooids of Earth. No evidence proves ooids are formed by agitated water. Ample evidence proves microbes form ooids on Earth. The “ooids” found on Mars should have been formed by microbes, as there is no other proven way for forming such spheres. So, ooids are an apparent and widespread biosignature on Mars.
References
13. Folk RL, Lynch FL (2001) Organic matter, putative nannobacteria and the formation of ooids and hardgrounds. Sedimentology 48: 215–229.
14. Thompson JB, Huber JA (1997) Microbe and ooid associations; a possible microbial role in the origin of ooids. Abstracts with Programs – Geological Society of America 29: 130.
14. Thompson JB, Huber JA (1997) Microbe and ooid associations; a possible microbial role in the origin of ooids. Abstracts with Programs – Geological Society of America 29: 130.
