On Earth, the ice of the lakes, glaciers, and caves of the cryosphere (from the ancient Greek word cryos, meaning
"cold" or "ice") harbors rich, complex biotic communities. Ice cave habitats have been posited for the Mars
cryosphere. Ice in such caves would protect microbes from UV, X-rays, and heavy particle radiation and might be
accessible during robotic or astronaut missions. Detection of putative biota-rich ice will require in situ detection of
biosignatures in cave walls, floor, and ceiling a few centimeters to tens of meters distant from the investigating rover
or astronaut. We describe the development of a prototype for a non-destructive, non-contact device that rapidly
generates reflectance and fluorescence images and a midline target profile of 960 reflectance and fluorescence
spectra. Spectral Profiling and Imaging (SPI) requires no irreplaceable consumables and can be sufficiently
miniaturized to be used by a single astronaut or a small robotic explorer. The current laboratory instrument is
designated SPI2 since it generates data sets for two optical phenomena: reflectance and fluorescence. In final form
SPI4 will be integrated with an autonomous rover and generate data for four optical phenomena: reflectance,
fluorescence, Raman scattering, and circular polarization. SPI4 will be useful for the Remote Evaluation of Life in
Ice Caves (R.E.L.I.C.) on planetary bodies whose distance from Earth prohibits real-time mission control.
The cryosphere harbours diverse microbial communities which are contributing to the global carbon
budget. Various ice ecosystems like ice covers of freshwater lakes, sea ice and supraglacial areas are
highly sensitive to temperate rise due to resulting enhanced availability of liquid water which is the
prerequisite for life. To assess the overall importance of these communities we require a non-invasive
tool which provides high resolution measurements of photosynthetic pigments such as phycoerythrin.
Here we present the preliminary calibration processes for L.I.F.E. (laser induced fluorescence
emission).
Extreme conditions such as low temperature, aridness, low availability of organic matter, high salinity and UV-radiation
in terrestrial Antarctica are key factors limiting the habitation of biotic communities and ecosystem dynamics. In recent
studies, it has been discovered that the bacterial communities are highly diverse and distributed widely in the extreme
ecosystem of Antarctica. Besides available morphometric data, geology, and thermal profile, limited study on the
microbial identification, phylogenetic analysis, diversity and distribution of microorganisms in different lakes of
Schirmacher Oasis in East Antarctica has been reported. The objective of this study was to assess the microbial
biodiversity and distribution using culture-independent and culture-dependent methodologies based upon bacterial 16S
rRNA gene analysis in three categories of lakes, i.e., the land-locked (L), epi-shelf (E), and pro-glacial (P) lakes in
Schirmacher Oasis. The water and ice samples were collected during the 2008 Tawani International Scientific
Expedition. Direct culturing of the samples on R2A agar media exhibited a wide variety of pigmented bacteria. Two of
the pigmented bacteria that were cultured belong to the genera, Hymenobacter, and Flavobacterium. Cultureindependent
methodology of one of the land-locked lakes L27C identified a rich microbial diversity consisting of six
different phyla of bacteria. The majority of bacteria (56%) belong to the Class γ-proteobacteria within the phylum
Proteobacteria. Within the Class γ-proteobacteria, Acinetobacter dominated (48%) the total microbial load.
Characterization of the microbial diversity within the three different types of Antarctic lakes is important because it will
help give us a better understanding of the survival mechanisms and the functionality of these bacteria in extremely cold
and harsh Antarctic ecosystems.
Once thought to be a barren desert devoid of life, it now appears that Earth's cryosphere is an ice ecosystem harbouring a
rich community of metabolically active microorganisms inhabiting ice, snow, water, and lithic environments. The ability
to rapidly survey this ecosystem during in situ and orbital missions is of considerable interest for monitoring Earth's
carbon budget and for efficiently searching for life on Mars or any exoplanet with an analogous cryosphere. Laser
induced fluorescence emission (L.I.F.E.) imaging and spectroscopy using excitation in ultraviolet (UV) wavelengths
have been proposed as non-destructive astrobiological survey tools to search for amino acids, nucleic acids, microbial
life, and polycyclic aromatic hydrocarbons (PAHs) deep in the Mars regolith. However, the technique is easily adapted
to search for larger, more complex biomolecular targets using longer wavelength sources. Of particular interest is the
ability for excitation at blue, green, and red wavelengths to produce visible and near infrared fluorescence of
photosynthetic pigments in cyanobacteria-dominated microbial communities populating the ice of alpine, Arctic, and
Antarctic lakes, glaciers, ice sheets, and even the supercooled water-ice droplets of clouds. During the Tawani 2008
International Antarctic Expedition we tested the in situ use of the technique as part of a field campaign in the Dry
Valleys of Schirmacher Oasis and Lake Untersee, Queen Maud Land, Antarctica. In the spring of 2009, we performed
airborne remote sensing tests of the technology in Alaska. In this paper we review our in situ laser detection experiments
and present for the first time preliminary results on our efforts to detect cryosphere L.I.F.E. from an airborne platform.
A permanent ice covered water body, called Lake Paula, was detected in Patriot Hills in the West Antarctic and sampled for the first time ever for microbial life.
The ice sheet measured approximately 2,5m thickness and the water body has a depth of about 10m. The lake is situated near a moraine which partly ablates from snow and provides meltwater from the slopes to the lake during austral summer. These running waters which are kept liquid by the heating up of the dark soil are penetrating the lower ice cover and thus softening up the lakeside part if the ice core. It is inoculated by nutrients, active microbes and diatoms of terrestrial origin. A distinct gradient concerning bacterial numbers, biomass and production which is 10 fold at the ice-water interface compared to the exposed part is observable. Temperature sensitivity of the embedded microbes reflect the gradient as well: Bacteria isolated from the upper part showed growth optima at 10°C, the lower part at 25°C, phylogenetic properties done by 16s rDNA reveal distinct communities depending on their vertical position, some clones are similar to those retrieved in Lake Vostok ice cores.
These results offer the conclusion that even in this harsh environment like the Antarctic continent a dynamic system like microbial ice aggregates can be sustained as long as the supply of liquid water which is essential for an active bacterial metabolism is provided at least for a small time frame.
In January 2002 the Planetary Studies Foundation returned to Antarctica to conduct a systematic search for meteorites on the blue ice fields near the Pecora Escarpment. The Pecora Escarpment area was previously searched by two National Science Foundation (NSF) teams that collectively recovered 526 meteorites. The two primary goals of the PSF Antarctica 2002 expedition were to determine if a significant number of meteorites could be found in a previously searched area, and to collect ice core samples to determine the presence or absence of microbial life. Several days' fieldwork resulted in the recovery of 33 meteorites, which included one stony-iron, two achondrites, an enstatite chondrite, and the collection of numerous ice samples. One particularly intriguing question that needed to be answered concerned the possibility that microbial life present in the ice may contaminate the meteorites. Antarctica was once considered to be a pristine environment with little or no biological contamination. This concept was particularly significant to the study of carbonaceous chondrites in order to insure that the organic compounds present in the meteorite were truly extraterrestrial in origin and not a product of terrestrial contamination. The preliminary results of this study indicated that microbial life was present in every ice sample.
Transformation of organic and inorganic material in the atmosphere has been presumed to be caused by physical and chemical processes in the gas phase and in aerosol particles. Here we show that bacterial metabolism can play a measurable role in the production and transformation of organic carbon in cloud droplets collected at high altitudes, even at temperatures at or well below 0 degree(s)C. Although bacterial abundance and biomass in cloud water is low, compared to other oligotrophic aquatic environments, growth and carbon production rates per cell are approximately as high as in aquatic ecosystems. We hypothesize that microorganisms could play a crucial role in the transformation of airborne organic matter and the chemical composition of snow and rain. It has been recognized, the microbes can act as cloud condensation nuclei but we consider the impact on the global climate as low. With an increasing trend in cloudiness cloud systems can be seen as an ecosystem for active microbes with a seeding effort both for aquatic and terrestrial realms. Furthermore, air currents can distribute microbes over long distances to remote areas e.g. like ice caps and snow fields.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.