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Sattler B.,University of Innsbruck | Storrie-Lombardi M.C.,Kinohi Institute | Foreman C.M.,Montana State University | Tilg M.,University of Innsbruck | Psenner R.,University of Innsbruck
Annals of Glaciology | Year: 2010

Laser-induced fluorescence emission (LIFE) images were obtained in situ from a 27 cm long ice core at Lake Fryxell, Antarctica. The excitation was accomplished with a simple 532 nm green laser pen light, and the fluorescence images were captured with a small compact digital camera. The targets for the experiment were mm-scale cryoconite assemblages found in the ice covers of this perennially frozen Antarctic lake. The fluorescence response originates from photo-pigments in cyanobacteriadominated cryoconite assemblages with phycoerythrin (PE) exhibiting the optimal target cross section. This inexpensive, low-mass, low-energy method avoids manipulation of the in situ habitat and individual target organisms and does not disturb the microbial community or the surrounding ice matrix. We establish the correlation between fluorescence intensity and PE concentration. We show that cryoconite fluorescence response does not appear to decrease with depth in the ice cover, in agreement with similar findings at Lake Untersee, a perennially ice-covered lake in Dronning Maud Land, Antarctica. Optical reflection and refraction events at the air/ice interface can complicate quantitative estimates of total pigment concentrations. Laser targeting of a single mm-scale cryoconite can result in multiple neighboring excitation events secondary to reflection and refraction phenomena in the multiple air/ice interface of the bubbles surrounding the primary target.


Storrie-Lombardi M.C.,Kinohi Institute | Hall A.P.,Harvey Mudd College | Hang S.,Harvey Mudd College | Lyzenga G.A.,Harvey Mudd College | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

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. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).


Tilg M.,University of Innsbruck | Storrie-Lombardi M.,Kinohi Institute | Kohstall C.,Institute of Quantum Physics | Trenkwalder A.,Institute of Quantum Physics | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

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). © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).


Groemer G.,Austrian Space Forum | Sattler B.,Austrian Space Forum | Weisleitner K.,Austrian Space Forum | Hunger L.,University of Innsbruck | And 6 more authors.
Astrobiology | Year: 2014

We have developed a portable dual-wavelength laser fluorescence spectrometer as part of a multi-instrument optical probe to characterize mineral, organic, and microbial species in extreme environments. Operating at 405 and 532?nm, the instrument was originally designed for use by human explorers to produce a laser-induced fluorescence emission (L.I.F.E.) spectral database of the mineral and organic molecules found in the microbial communities of Earth's cryosphere. Recently, our team had the opportunity to explore the strengths and limitations of the instrument when it was deployed on a remote-controlled Mars analog rover. In February 2013, the instrument was deployed on board the Magma White rover platform during the MARS2013 Mars analog field mission in the Kess Kess formation near Erfoud, Morocco. During these tests, we followed tele-science work flows pertinent to Mars surface missions in a simulated spaceflight environment. We report on the L.I.F.E. instrument setup, data processing, and performance during field trials. A pilot postmission laboratory analysis determined that rock samples acquired during the field mission exhibited a fluorescence signal from the Sun-exposed side characteristic of chlorophyll a following excitation at 405?nm. A weak fluorescence response to excitation at 532nm may have originated from another microbial photosynthetic pigment, phycoerythrin, but final assignment awaits development of a comprehensive database of mineral and organic fluorescence spectra. No chlorophyll fluorescence signal was detected from the shaded underside of the samples. Key Words: Biosensor -Life-detection instruments -Mars -Biomarkers -Planetary protection. Astrobiology 14, 391-405. © Copyright 2014, Mary Ann Liebert, Inc. 2014.


Dartnell L.R.,University College London | Dartnell L.R.,Birkbeck, University of London | Patel M.R.,Open University Milton Keynes | Storrie-Lombardi M.C.,Kinohi Institute | And 2 more authors.
Meteoritics and Planetary Science | Year: 2012

Even in the absence of any biosphere on Mars, organic molecules, including polycyclic aromatic hydrocarbons (PAHs), are expected on its surface due to delivery by comets and meteorites of extraterrestrial organics synthesized by astrochemistry, or perhaps in situ synthesis in ancient prebiotic chemistry. Any organic compounds exposed to the unfiltered solar ultraviolet spectrum or oxidizing surface conditions would have been readily destroyed, but discoverable caches of Martian organics may remain shielded in the subsurface or within surface rocks. We have studied the stability of three representative polycyclic aromatic hydrocarbons (PAHs) in a Mars chamber, emulating the ultraviolet spectrum of unfiltered sunlight under temperature and pressure conditions of the Martian surface. Fluorescence spectroscopy is used as a sensitive indicator of remaining PAH concentration for laboratory quantification of molecular degradation rates once exposed on the Martian surface. Fluorescence-based instrumentation has also been proposed as an effective surveying method for prebiotic organics on the Martian surface. We find the representative PAHs, anthracene, pyrene, and perylene, to have persistence half-lives once exposed on the Martian surface of between 25 and 60h of noontime summer UV irradiation, as measured by fluorescence at their peak excitation wavelength. This equates to between 4 and 9.6 sols when the diurnal cycle of UV light intensity on the Martian surface is taken into account, giving a substantial window of opportunity for detection of organic fluorescence before photodegradation. This study thus supports the use of fluorescence-based instrumentation for surveying recently exposed material (such as from cores or drill tailings) for native Martian organic molecules in rover missions. © The Meteoritical Society, 2012.


Groemer G.E.,Austrian Space Forum | Storrie-Lombardi M.,Kinohi Institute | Sattler B.,University of Innsbruck | Hauser O.,Austrian Space Forum | And 7 more authors.
Acta Astronautica | Year: 2011

As part of the "PolAres" research programme, we are investigating techniques to detect and reduce forward contamination of the Mars regolith during human exploration. We report here on the development of a spacesuit simulator-prototype dubbed "Aouda.X," document the inability of current technology to produce a static charge sufficient to minimize dust transport on the suit, and present preliminary results employing laser induced fluorescence emission (L.I.F.E.) techniques to monitor fluorescent microspherules as biological contamination proxies. © 2010 Elsevier Ltd. All rights reserved.


Cousins C.R.,University College London | Cousins C.R.,Birkbeck College | Griffiths A.D.,University College London | Crawford I.A.,University College London | And 8 more authors.
Astrobiology | Year: 2010

The Panoramic Camera (PanCam) instrument will provide visible-near IR multispectral imaging of the ExoMars rover's surroundings to identify regions of interest within the nearby terrain. This multispectral capability is dependant upon the 12 preselected "geological" filters that are integrated into two wide-angle cameras. First devised by the Imager for Mars Pathfinder team to detect iron oxides, this baseline filter set has remained largely unchanged for subsequent missions (Mars Exploration Rovers, Beagle 2, Phoenix) despite the advancing knowledge of the mineralogical diversity on Mars. Therefore, the geological filters for the ExoMars PanCam will be redesigned to accommodate the astrobiology focus of ExoMars, where hydrated mineral terrains (evidence of past liquid water) will be priority targets. Here, we conduct an initial investigation into new filter wavelengths for the ExoMars PanCam and present results from tests performed on Mars analog rocks. Two new filter sets were devised: one with filters spaced every 50nm ("F1-12") and another that utilizes a novel filter selection method based upon hydrated mineral reflectance spectra ("F2-12"). These new filter sets, along with the Beagle 2 filter set (currently the baseline for the ExoMars PanCam), were tested on their ability to identify hydrated minerals and biosignatures present in Mars analog rocks. The filter sets, with varying degrees of ability, detected the spectral features of minerals jarosite, opaline silica, alunite, nontronite, and siderite present in these rock samples. None of the filter sets, however, were able to detect fossilized biomat structures and small (<2mm) mineralogical heterogeneities present in silica sinters. Both new filter sets outperformed the Beagle 2 filters, with F2-12 detecting the most spectral features produced by hydrated minerals and providing the best discrimination between samples. Future work involving more extensive testing on Mars analog samples that exhibit a wider range of mineralogies would be the next step in carefully evaluating the new filter sets. Key Words: Analogue-Biosignatures- Mars-Reflectance spectroscopy-Remote sensing. Astrobiology 10, 933-951. © Mary Ann Liebert, Inc.


Dartnell L.R.,University College London | Storrie-Lombardi M.C.,Kinohi Institute | Mullineaux C.W.,Queen Mary, University of London | Ruban A.V.,Queen Mary, University of London | And 4 more authors.
Astrobiology | Year: 2011

Primitive photosynthetic microorganisms, either dormant or dead, may remain today on the martian surface, akin to terrestrial cyanobacteria surviving endolithically in martian analog sites on Earth such as the Antarctic Dry Valleys and the Atacama Desert. Potential markers of martian photoautotrophs include the red edge of chlorophyll reflectance spectra or fluorescence emission from systems of light-harvesting pigments. Such biosignatures, however, would be modified and degraded by long-term exposure to ionizing radiation from the unshielded cosmic ray flux onto the martian surface. In this initial study into this issue, three analytical techniques-absorbance, reflectance, and fluorescence spectroscopy-were employed to determine the progression of the radiolytic destruction of cyanobacteria. The pattern of signal loss for chlorophyll reflection and fluorescence from several biomolecules is characterized and quantified after increasing exposures to ionizing gamma radiation. This allows estimation of the degradation rates of cyanobacterial biosignatures on the martian surface and the identification of promising detectable fluorescent break-down products. © Copyright 2011, Mary Ann Liebert, Inc. 2011.


Dartnell L.R.,University College London | Dartnell L.R.,Birkbeck, University of London | Storrie-Lombardi M.C.,Kinohi Institute | Ward J.M.,University College London
International Journal of Astrobiology | Year: 2010

The work reported here represents a study into the total fluorescence exhibited by a broad selection of model, extremophilic and photosynthetic bacterial strains, over a great range of excitation and emission wavelengths from ultraviolet (UV) through visible to near infrared. The aim is to identify distinctive fluorescent features that may serve as detectable biosignatures of remnant microbial life on the Martian surface. A lab-bench fluorescence spectrometer was used to generate an excitation-emission matrix (EEM) for the unpigmented Escherichia coli, radiation-resistant Deinococcus radiodurans, Antarctic Dry Valley isolates Brevundimonas sp. MV.7 and Rhodococcus sp. MV.10, and the cyanobacterium Synechocystis sp. PCC 6803. Detailed EEMs, representing the fluorescence signature of each organism, are presented, and the most significant features suitable for biosignature surveys are identified, including small-molecule cellular metabolites, light-harvesting photosynthetic pigments and extracellular UV-screening compounds. E. coli exhibits the most intense emission from tryptophan, presumably due to the absence of UV-screening pigments that would shield the organism from short-wavelength light-exciting intracellular fluorescence. The efficacy of commonly available laser diodes for exciting cellular fluorescence is treated, along with the most appropriate filter wavelengths for imaging systems. The best combination of available laser diodes and PanCam filters aboard the ExoMars probe is proposed. The possibility of detecting fluorescence excited by solar UV radiation in freshly exposed surface samples by imaging when both sunlit and shadowed, perhaps by the body of the rover itself, is discussed. We also study how these biological fluorophore molecules may be degraded, and thus the potential biosignatures erased, by the high flux of far-ultraviolet light on Mars. © 2010 Cambridge University Press.

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