Aurion Mission

Thursday, August 11, 2011

The detection of evidence of viable microbial life in ancient ice (Abyzov et al., 1998, 2003; Hoover and Pikuta, 2010) and the presence of microfossils of filamentous cyanobacteria and other trichomic prokaryotes in the CI1 carbonaceous meteorites has direct implications to possible life on comets and icy moons with liquid water oceans of Jupiter (e.g. Europa, Ganymede or Callisto) and Enceladus (Fig. 8.a) Saturn’s spectacular moon that is exhibiting cryovolcanism and spewing water, ice and organics into space from the region of the blue and white “tiger stripes.” Europa exhibits red, orange, yellow and ochre colors and fractured regions indicating the icy crust is floating on a liquid water ocean. The possibility of life on Europa has been discussed by Hoover et al. (1986): Chyba et al. (2001) Dalton et al. (2003), and in edited books by Russell (2011), and Wickramasinghe (2011) and in Volumes 5, 11, and 13 of the Journal of Cosmology. Hoover et al. (1986) argued while deep blue and white colors in the Galileo images of the Jovian moon Europa were typical of glacial ice, ice bubbles and snow on Earth as seen in this image of ice bubbles from the Schirmacher Oasis of East Antarctica (Fig, 8.b). The red, yellow, brown, golden brown, green and blue colors detected by the Galileo spacecraft in the Conamara Chaos region (Fig. 8.c.) and the deep red lines of the icy crust of Europa (Fig. 8.d.) are consistent with microbial pigments rather than evaporite minerals. The 1986 paper suggested that the colors seen in Europa images resulted from microbial life in the upper layers of the ice. A number of more recent studies and books have been published concerning the significance of ice microbiota to the possibility of life elsewhere in the Solar System (e.g. Russell 2011; Wickramasinghe 2011; Volumes 5, 7, 13 of the Journal of Cosmology).
Diatoms are golden brown and cyanobacteria exhibit a wide range of colors from blue-green to red, orange, brown and black. Bacteria recovered from ice are often pigmented. For example, the extremophiles isolated from the ancient Greenland ice cores produce pigmented colonies. Herminiimonas glaciei colonies are red (Fig. 8.e) and the colonies of “Chryseobacterium greenlandensis” exhibit yellow pigments (Fig. 6.b.). Figure 5.c. shows the red pigmented colonies of the new genus of psychrophile, Rhodoglobus vestali isolated from a lake near the McMurdo Ice Shelf, Antarctica (Sheridan et al. 2003). Colonies of Hymenobacter sp. (Fig. 6.d.) isolated from the Schirmacher Oasis Ice Cave are red-ochre in color (Hoover and Pikuta, 2009, 2010). The possibility of life on Enceladus and the detection of biomarkers in the plumes of water, ice and organic chemicals ejected from the “Tiger Stripes” of Enceladus has been discussed by McKay et al., (2008) Hoover and Pikuta ( 2010) and in a number of articles published in volumes 5, 7, and 13 of the Journal of Cosmology.

Figure 8.a. Blue and white snow and glacial ice tiger stripes on Saturn’s moon Enceladus and b. ice bubbles from Lake Glubokoye, Antarctica. Color images from the Galileo spacecraft of c. the Conamara Chaos region and d. the Thrace region of Europa. Colonies of pigmented bacteria from the deep Greenland glacier ice core: e. red Herminiimonas glacei and f. yellow Chryseobacterium greenlandensis. From the McMurdo Valley ice sheet are colonies of g. red Rhodoglobus vestalii; and from the Schirmacher Oasis Ice Cave h. the red-ochre colony of Hymenobacter sp. strain IS118C-5s. Photos Courtesy: a.,c., & d. NASA/JPL/Arizona State University; b. R. B. Hoover; e.,f.,&g. Jennifer Loveland-Curtze/Penn State University and h. Asim K. Bej/UAB. 6. CONCLUSIONS
It is concluded that the complex filaments found embedded in the CI1 carbonaceous meteorites represent the remains of indigenous microfossils of cyanobacteria and other prokaryotes associated with modern and fossil prokaryotic mats. Many of the Ivuna and Orgueil filaments are isodiametric and others tapered, polarized and exhibit clearly differentiated apical and basal cells. These filaments were found in freshly fractured stones and are observed to be attached to the meteorite rock matrix in the manner of terrestrial assemblages of aquatic benthic, epipelic, and epilithic cyanobacterial communities comprised of species that grow on or in mud or clay sediments. Filamentous cyanobacteria similar in size and detailed morphology with basal heterocysts are well known in benthic cyanobacterial mats, where they attach the filament to the sediment at the interface between the liquid water and the substratum. The size, size range and complex morphological features and characteristics exhibited by these filaments render them recognizable as representatives of the filamentous Cyanobacteriaceae and associated trichomic prokaryotes commonly encountered in cyanobacterial mats. Therefore, the well-preserved mineralized trichomic filaments with carbonaceous sheaths found embedded in freshly fractured interior surfaces of the Alais, Ivuna, and Orgueil CI1 carbonaceous meteorites are interpreted as the fossilized remains of prokaryotic microorganisms that grew in liquid regimes on the parent body of the meteorites before they entered the Earth’s atmosphere.
The Energy Dispersive X-ray spectroscopy data reveals that the filaments detected in the meteorites typically exhibit external sheaths enriched in carbon infilled with minerals enriched in magnesium and sulfur. These results are interpreted as indicating that the organisms died on the parent body while aqueous fluids were present and the internal cells were replaced by epsomite and other water soluble evaporite minerals dissolved in the liquids circulating through the parent body. The nitrogen level in the meteorite filaments was almost always below the detection limit of the EDS detector (0.5% atomic). However, nitrogen is essential for all amino acids, proteins, and purine and pyrimidine nitrogen bases of the nucleotides of all life on Earth.
Extensive EDS studies of living and dead cyanobacteria and other biological materials have shown that nitrogen is detectable at levels between 2% and 18% (atomic) in cyanobacterial filaments from Vostok Ice (82 Kya) and found in stomach milk the mammoth Lyuba (40 Kya); mammoth hair/ tissue (40-32 Kya); pre-dynastic Egyptian and Peruvian mummies (5-2 Kya) and herbarium filamentous diatom sheaths (1815). However, Nitrogen is not detected in ancient biological materials such as fossil insects in Miocene Amber (8 Mya); Cambrian Trilobites from the Wheeler Shale (505 Mya) or cyanobacterial filaments from Karelia (2.7 Gya). Consequently the absence of nitrogen in the cyanobacterial filaments detected in the CI1 carbonaceous meteorites indicates that the filaments represent the remains of extraterrestrial life forms that grew on the parent bodies of the meteorites when liquid water was present, long before the meteorites entered the Earth’s atmosphere. This finding has direct implications to the distribution of life in the Cosmos and the possibility of microbial life in liquid water regimes of cometary nuclei as they travel within the orbit of Mars and in icy moons with liquid water oceans such as Europa and Enceladus.