Interests

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My research interests are largely organised in the above four domains

 

I am interested in understanding the structure and composition of ultracomplex organic/carbonaceous astromaterials. 
Asteroids and other small Solar System bodies are harbingers of  such astromaterials, as they have been synthesised in space over billions of years, are thermodynamically stable, radiation resistant and could have many other exotic physicochemical properties.
Astromaterials are going to be vital for satiating the demands of emerging technologies of near-future. Asteroid mining would not only be limited to extraction of water and rare-earth minerals but also would extend to mining of organic/carbonaceous cosmomaterials
Exploring celestial bodies for both potentially prebiotic and abiotic astromaterials prompt in situ and sample return space missions which in turn prompts R&D of novel material analyses instrumentation. I am interested in the end-to-end R&D of such payloads having had a prior experience in optimisation and calibration of COSAC, a payload on Rosetta spacecraft.

 

COSAC ON BOARD E.S.A. ROSETTA MISSION

 

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Animated Image of Philae touching the surface of comet 67P/Churyumov-Gerasimenko.
(Credits: Deutsches Zentrum für Luft- und Raumfahrt e.V.; C.C-BY 3.0)
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Comets are widely known to be abundant with organic material. The earliest knowledge about the presence of such material only came from remote astronomical observations, however it is only recently, after the arrival of Rosetta at the comet 67P/Churyumov-Gerasimenko, in situ compositional characterisation has been initiated. COSAC’s objective is to elucidate the organic composition of comet nuclei from in situ analysis.  During my nearly four year association with COSAC, I extensively worked with its test-bed and optimised and calibrated both the GC (gas chromatography) and MS (mass spectrometer) components. I also participated in the analysis of MS “sniffing” data that was telemetry’d from the 67P’s nucleus. On November 12, 2014 COSAC successfully reported the presence of sixteen distinct organic chemical species, with potential prebiotic disposition, native to the 67P’s cometary environment.
Krüger H, Goesmann F, Giri C, Wright I, Morse A, Bredehöft JH, Ulamec S, Cozzoni B, Ehrenfreund  P, Gautier T, McKenna-Lawlor S, Raulin F, Steininger H, Szopa C. Decay of COSAC and PTOLEMY mass spectra at comet 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics, 600, A56 (2017)
Goesmann F, Rosenbauer H, Bredehöft JH, Cabane M, Ehrenfreund P, Gautier T, Giri C, Krüger H, McDermott A, McKenna-Lawlor S, Meierhenrich UJ, Muñoz Caro G, Raulin F, Roll R, Rosenbauer H, Steele A, Steininger H, Sternberg R, Szopa C, Thiemann W, Ulamec S. Organic compounds on comet 67P/Churyumov-Gerasimenko revealed by COSAC mass spectrometry. Science DOI: 10.1126/science.aaab0689 (2015).
Giri C, Goesmann F, Steele A, Steininger H, Gautier T, Krüger H, Meierhenrich UJ. Competence evaluation of COSAC Flight Spare Model mass spectrometer: In preparation of arrival of Philae Lander on comet 67P/Churyumov-Gerasimenko. Planetary and Space Science 106:132-141 (2015).

 

MACROMOLECULAR ORGANIC/CARBONACEOUS COSMOMATERIALS

 

 

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Anthracite Coal has the highest carbon content amongst all coals. (Credits: House Committee on Natural Resources)
I am also interested in the processes that convert simple organic gases into macromolecular organic/carbonaceous material on extra-terrestrial surfaces and on circumstellar/interstellar dust grains. Such processes could potentially synthesize exotic material that could garner niche industrial applications and be of astrobiological relevance.
Giri C, McKay CP, Goesmann F, Schäfer N, Li X, Steininger H, Brinckerhoff W, Gautier T, Reitner J, Meierhenrich UJ. Carbonization in Titan Tholins: Implications for low albedo on surfaces of Centaurs and Trans-Neptunian Objects. International Journal of Astrobiology DOI: 10.1017/S1473550415000439. 

 

 

GEOLOGICAL FEATURES ON EXTRATERRESTRIAL SURFACES

 

 

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The Arima Twins in the Thaumasia Planum region of Mars are presumed to have been created by underground explosions with water ice playing major role. Arima is one example of the diversity of geological features present on extraterrestrial surfaces.(Credits: ESA/DLR/FU Berlin/G. Neukum)
Extraterrestrial planetary surfaces exhibit a great variety of features that are windows into the their past. Not all planets or satellites in our Solar System possess a distinct land terrain and those which possess it are studied for understanding their surface composition, geological stratigraphy, and identify morphologies and biological signatures similar to those found on Earth’s land surface. Finding signatures of hydrological activities on seemingly waterless Mars, and finding signatures of complex organic matter on extraterrestrial surfaces and determining its origin, composition and structure are some of the research pursuits I am part of.
Komatsu G, Senthil Kumar P, Goto K, Sekine Y, Giri C, Matsui T. Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation. Planetary and Space Science 95, 45-55 (2014).

 

AMINO ACIDS IN INTERSTELLAR/CIRCUMSTELLAR “ORGANIC ABUNDANT’ ICES

 

 

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Animation of volatile molecules condensing on a naked circumstellar/interstellar dust grain that subsequently attain complexity via irradiation-driven ultra-low temperature chemistry, resulting in the formation of amino acids. (Credits: Andy Christie, Slimfilms.com)
The empty void between two star systems is interestingly “not empty” and dust forms its major constituent. Interstellar dust far away from a heat source tends to condense simple interstellar molecules (CO, H2, CO2, CH4, H2O) on its grain surfaces. Such icy surfaces when exposed to radiation undergo chemical transformation (low-temperature/solid-state chemistry) to form complex molecules some of which could be amino acids. In a similar setting if interstellar ices containing chiral molecules are irradiated with circular polarized light, would homochirality set in?. Homochirality is a crucial biological signature of life on Earth and studying its interstellar origins are of great interest to the quest for knowing the origin of life.
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Meinert C, Hoffmann S, Cassam-Chenaï P, Evans AC, Giri C, Nahon L, Meierhenrich UJ. Photonenergy-controlled Symmetry Breaking with Circularly Polarized Light. Angewandte Chemie International Edition 126, 214-218 (2014).
Giri C, Goesmann F, Meinert C, Evans AC, Meierhenrich UJ. Synthesis and Chirality of Amino Acids under Interstellar Conditions. In Biochirality: Origins, Evolution and Molecular Recognition, Pedro Cintas, Ed., Springer-Verlag Berlin-Heidelberg (2013).
Evans AC, Meinert C, Bredehoeft JH, Giri C, Jones NC, Hoffmann SV, Meierhenrich UJ. Anisotropy spectra for chiral differentiation of biomolecular building blocks. In Differentiation of Enantiomers II, Volker Schurig, Ed., Springer-Verlag Berlin-Heidelberg (2013).
Evans A, Meinert C, Giri C, Goesmann F, Meierhenrich UJ. Chirality, photochemistry and detection of amino acids in interstellar ice analogues and comets. Chemical Society Reviews 41, 5447-5458 (2012).

 

(All images shown above are duly credited. No copyright infringement intended.)