Publications

 Published Papers

                             Papers in ASTROBIOLOGY

• 1. Red Rain Cells of Kerala as a Possible Carrier of the Diffuse Interstellar Bands and the UV Extinction Bump  A. Santhosh Kumar,         N. Chandra Wickramasinghe and Godfrey Louis  https://dx.doi.org/10.22606/adap.2019.42003 

Abstract: Despite various proposals, no conclusive identification exists for the carriers of diffuse interstellar absorption bands DIBs and the UV extinction bump at 217.5 nm. The red rain cells of Kerala show strong absorption features near 216.5 nm and several weak absorption features in the wavelength region 400 to 900 nm which are superimposed on a broader blue-UV absorption peak. The red pigment extracted from the cells show strong peaks at 334 nm and 440 nm along with multitude of weak peaks. The measured absorption peaks are compared with that of DIBs and the UV bump. The higher peak widths for red cells in comparison with DIBs is attributed to the temperature difference between space environment and laboratory. Our results of the absorption spectra of red rain cells show significant correlation with the reported wavelengths of numerous DIBs and the UV extinction bump of the interstellar medium, thus showing that the red rain cells, which are of suspected extraterrestrial origin, is a plausible carrier of DIBs and the UV extinction bump.

• 2.  Autofluorescence characteristics of the red rain cells  Kumar A Santhosh, Godfrey Louis Proc. SPIE 8865, Instruments, Methods, and Missions for Astrobiology XVI, 88650I (September 26, 2013); doi:10.1117/12.2024366

Abstract:  Red rain cells are the microscopic biological cells which appear mixed in rain water in large quantity imparting visibly red color to the rain water in a strange event called red rain phenomenon. Our study of this phenomenon which happened in Kerala, India in 2001 has shown that the origin of these cells is possibly extraterrestrial. These cells are not so far successfully identified as any organism known on earth. The cells have unusual property like ability to reproduce at extreme high temperature and the colorless daughter cells cultured from the red cells show unusual autofluorescence characteristics. In this paper we report the autofluorescence characteristics of the original red rain cells. High resolution fluorescence microscopy is employed to study the fluorescence images of the cells under UV-Visible excitation. The results are discussed.  Download full paper: http://dx.doi.org/10.1117/12.2024366  

• 3.  A COMPARATIVE STUDY OF TRENTEPOHLIA AND RED RAIN CELLS Santhosh Kumar A, Chandra Wickramasinghe, Godfrey Louis  International Journal of Recent Scientific Research Vol. 4, Issue, 8, pp.1205- 1209, August, 2013

Abstract :The red cells that caused the coloration of the red rain of Kerala gained scientific significance due to their possible extraterrestrial origin. A competing theory is that the red cells are spores of the Trentepohlia-genus that originated locally was lifted to the clouds and came down in rain. Hence a comparative study is required to decide whether the red rain cells are different from or indeed the same as Trenetepohlia spores. A comparative study was made of red rain cells and two species of Trentepohlia genus, namely Trentepohlia aurea and Trentepohlia umbrina. Red rain cells and Trentepohlia spores were differentiated on the basis of its morphology, absorption in the uv- vis regions, presence of DNA, ultrastructure, stability with regard to temperature, percentage of nitrogen and phosphorous in the cells and survivability in water. Our study showed that the red rain cells cannot be equated with Trentepohlia and still remain identified and distinct from known microbe on the earth     Download Full text

• 4. Unusual autofluorescence characteristic of cultured red-rain cells, Godfrey Louis and A. Santhosh Kumar Proc. SPIE, , Vol. 7097, 709712 (2008); DOI:10.1117/12.794041

 Abstract: The red cells found in the red rain in Kerala, India are now considered as a possible case of extraterrestrial     lifeform. These cells can undergo rapid replication even at an extreme high temperature of 300 deg C. They can also be cultured in diverse unconventional chemical substrates. The molecular composition of these cells is yet to be identified.This paper reports the unusual autofluorescence characteristic of the cultured red rain cells. A spectrofluorimetric study has been performed to investigate this, which shows a systematic shift of the fluorescence emission peak wavelength as the excitation wavelength is increased. Conventional biomolecules are not known to have this property. Details of this investigation and the results are discussed1117/12.794041

Download the  full text from here: http://link.aip.org/link/?PSISDG/7097/709712/1   DOI link: http://dx.doi.org/10.1117/12.794041   or download from here : spiepaper709712.pdf

• 5.   An optical spectroscopic study correlating the yellow rain and cultured red rain Microbes    Kumar, A. Santhosh; Louis, Godfrey, Instruments and Methods for Astrobiology and Planetary Missions XII. Edited by Hoover, Richard B.; Levin, Gilbert V.; Rozanov, Alexei Y.; Retherford, Kurt D.. Proceedings of the SPIE, Volume 7441 (2009)., pp. 74410N-74410N-6 (2009) 

ABSTRACT: A number of cases of yellow colored rain occurred in Kerala, India in July-August 2001 along with the red rain phenomenon. Recently during the end of July 2008 a few cases of yellow colored rain again occurred in Kerala and during the same time, unusual rain, termed as “blood rain” occurred in Bagado, Colombia. In this paper we show that the yellow rain and red rain can have a common origin. The yellow rainwater also exhibits the same unusual autofluorescence reported earlier for the cultured red rain microbes. Reasons for considering extraterrestrial origin for these colored rains are discussed.

Download the full text from here: http://link.aip.org/link/?PSISDG/7441/74410N/1  or download from SPIE digital                 library: SPIE_2009_7441B-21.pdf DOI link: http://dx.doi.org/10.1117/12.826780      

• 6.  Red rain phenomenon of Kerala and its possible extraterrestrial Origin, Godfrey  Louis and A. Santhosh Kumar,   Astrophysics and Space Science Volume 302, Numbers 1-4 175 - 187( 2006)                                                  

ABSTRACT: A red rain phenomenon occurred in Kerala, India starting from 25th July 2001, in which the rainwater appeared coloured in various localized places that are spread over a few hundred     kilometers in Kerala. Maximum cases were reported during the first 10 days and isolated cases were found to occur for about 2 months. The striking red colouration of the rainwater was found to be due to the suspension of microscopic red particles having the appearance of biological cells. These particles have no similarity with usual desert dust. An estimated minimum quantity of 50,000 kg of red particles has fallen from the sky through red rain. An analysis of this strange phenomenon further shows that the conventional atmospheric transport processes like dust storms etc. cannot explain this phenomenon. The electron microscopic study of the red particles shows fine cell structure indicating their biological cell like nature. EDAX analysis shows that the major elements present in these cell like particles are carbon and oxygen. Strangely, a test for DNA using Ethidium Bromide dye fluorescence technique indicates absence of DNA in these cells. In the context of a suspected link between a meteor airburst event and the red rain, the possibility for the extraterrestrial origin of these particles from cometary fragments is discussed. Comment: 18 pages, 15 figures,            Full text download:Link to journal paper:DOI: http://dx.doi.org/10.1007/s10509-005-9025-4         

• 7.  Growth and replication of red rain cells at 121oC and their red Fluorescence Rajkumar Gangappa, Chandra Wickramasinghe, Milton Wainwright , A. Santhosh Kumar and Godfrey Louis   Proc. of SPIE Vol. 7819 78190N-1, 2010    SPIE Proceedings: SPIE Conference 7819 Instruments, Methods, and Missions for Astrobiology XIII Aug. 3-5 2010 San Diego, California, USA      

Abstract: We have shown that the red cells found in the Red Rain (which fell on Kerala, India, in 2001) survive and grow after incubation for periods of up to two hours at 121 oC . Under these conditions daughter cells appear within the original mother cells and the number of cells in the samples increases with length of exposure to 121 oC. No such increase in cells occurs at room temperature, suggesting that the increase in daughter cells is brought about by exposure of the Red Rain cells to high temperatures. This is an independent confirmation of results reported earlier by two of the present authors, claiming that the cells can replicate under high pressure at temperatures up to 300 oC. The flourescence behaviour of the red cells is shown to be in remarkable correspondence with the extended red emission observed in the Red Rectangle planetary nebula and other galactic and extragalactic dust clouds, suggesting, though not proving, an extraterrestrial origin.    

Download the full text from Arxiv.org  http://arxiv4.library.cornell.edu/abs/1008.4960v1 AIP Link : http://link.aip.org/link/?PSISDG/7819/78190N/1                                  

• 8.  Growth characteristics of red rain microbes at temperatures below 100° C G Louis, AS Kumar   Proceedings of the SPIE.Instruments, Methods, and Missions for Astrobiology XIII, San Diego, California, USA; 08/2010 Proc. SPIE 7819, 78190R (2010)  

Abstract : The red rain microbes, which caused red rain phenomenon in Kerala, India, exhibit many characteristics much different from conventional microorganisms. Previous study indicates that these microbes are possibly of extraterrestrial origin. Their ability to multiply at extreme high temperature of 300 oC and the unusual autofluorescence of their biomolecules are some of their extraordinary properties. Their molecular composition is yet to be identified. In this paper we report the growth pattern of these novel microbes at temperatures below 100 oC as a minimal approach to show their biological nature. Automated turbidity measurement of the cell culture indicate standard microbial growth curve. Increase in the cell population is faster at higher temperatures. Details of this investigation and results are discussed.                                  

Download preprint: SPIE7819_24_2010.pdf     or   http://link.aip.org/link/?PSISDG/7819/78190R/1

• 9.  New biology of red rain extremophiles prove cometary panspermia  Godfrey Louis, A Santhosh Kumar  Arxiv preprint astro-ph/0312639 

  10. 10. Cometary panspermia explains the red rain of Kerala G Louis, AS Kumar Arxiv preprint astro-ph/0310120      

     Papers In Material Science                                                                                                                                              

1. Enhancing the NIR shielding ability and controlling the surface wettability of RF magnetron sputter deposited WO3-x thin films by tuning the oxygen vacancies Anjana S. Nair, Keerthana C S, Sreepriya K, A. Santhosh Kumar, N.V. Unnikrishnan, Saritha A C  Optical Materials Volume 142, August 2023, 114066

2. Understanding the effects of annealing induced structural transformations on the UVC absorbance and other optical properties of RF sputter deposited Ga2O3 thin films    Keerthana C S, Anjana S Nair, Sreepriya K, Jiya James, Santhosh Kumar, N V Unnikrishnan and Saritha A C∗ Semicond. Sci. Technol. 39 (2024) 045008 (9pp)

3. Regulating NIR reflecting property of hydrothermally synthesized tungsten oxide nanostructures via calcination Anjana S Nair, C S Keerthana, Jiya James, A Santhosh Kuma1, M Vinod and A C Saritha   November 2023 Physica Scripta  DOI: 10.1088/1402-4896/ad0c3a

4. A Study on the Effect of Oxygen Flow Rate on Optical Properties of RF Sputtered a-GaOx Thin Films on Corning Glass Substrate CS Keerthana, Anjana S Nair, Jisha Elsa Abraham, A Santhosh Kumar, NV Unnikrishnan, AC Saritha ECS Journal of Solid State Science and Technology 10 (10), 101007 

5. Dielectric properties of Sr0. 5Ca0. 5TiO3: x Pr3+ ceramics V Vidyadharan, E Sreeja, Santhosh Kumar A, C Joseph, NV Unnikrishnan, PR Biju

Ceramics International 43 (8), 6268-6275

6. Characterization and Elastic properties of wurtzite ZnO: Ce Nanocrystallites George Varughese, Crysty V.G , Praveen G K.T. Usha , A.S. Kumar Asian Journal of Research in Chemistry 01/2015; 8(3):183. DOI: 10.5958/0974-4150.2015.00033.4

7. Microhardness studies of sulfamic acid single crystal A Santhosh Kumar, Cyriac Joseph, Reshmi Paulose, Rajesh R, Georgekutty Joseph and Godfrey Louis  2015 IOP Conf. Ser.: Mater. Sci. Eng. 73 012108 doi:10.1088/1757-899X/73/1/012108

8. Measurement of Elastic Parameters of Lithium Hydroxylammonium Sulphate Single Crystal, by Ultrasonic Pulse Echo Overlap Technique G Varughese, S Kumar, Open Journal of Acoustics 4 (03), 138, 2014

9. Ultrasonic Investigation of Elastic Anomalies in Lithium Sodium Sulphate Hexahydrate Single Crystal G Varughese, S Kumar, Open Journal of Acoustics 4 (03), 131, 2014

10. Zinc Sulphide nanomaterials doped with rare earth Neodymium-An Optical study George Varughese, KT Usha, AS Kumar, International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 3, Issue 4, July 2014

11. Synthesis and Elastic Study in Cuo: La Nanofluid , George Varughese, M Suma, JM Abraham, AS Kumar,  The International Journal Of Engineering And Science (IJES) Volume 3  Issue| 7 Pages  09-12,  2014  

12. Electrical conductivity of sulfamic acid single crystals  A. Santhosh Kumar, G. Varughese, L. Iype, R. Rajesh, G. Joseph, and G. Louis, Cryst. Res. Technol., 1 – 4 (2010) / DOI 10.1002/crat.201000196

13. Detection of elastic and electric conductivity anomalies in Potassium  Sulphamate single crystal, George Varughese, A. SanthoshKumar and Godfrey Louis, Physica B 405 (2010) 1813–1816

14. Growth and DC Conductivity Studies of Tripotassium Sodium Dichromate Single Crystal . Georgekutty Joseph, A. Santhosh Kumar, Rajesh R and Godfrey Louis , Indian jour Physics (in Press)

15. Anisotropy in elastic properties of lithium sodium sulphate hexahydrate single crystal—An ultrasonic study     GEORGE VARUGHESE, A SANTHOSH KUMAR, J PHILIP and GODFREY LOUIS, Bull. Mater. Sci., Vol. 32, No. 6, December 2009, pp. 621–6

16. Anisotropy in elastic properties of lithium sodium sulphate hexahydrate 

17. single crystal—An ultrasonic study GEORGE VARUGHESE, A S KUMAR, J PHILIP and GODFREY LOUIS Bull. Mater. Sci., Vol. 36, No. 1, pp. 143–148 (2013)

18. DC conductivity studies in K3Na(SeO4)2 single crystals, G. Joseph, A. Santhosh Kumar, L. Iype, R. Rajesh2, and G. Louis, Cryst. Res. Technol. 44, No. 7, 759 – 762 (2009)

19. Elastic study of Potassium Sulphamate crystal using ultrasonic Pulse Echo Overlap technique, George Varughese, A. Santhosh Kumar , J. Philip and Godfrey Louis, Solid State Communications Volume 149, Issues 15-16, April 2009, Pages 645-647

20. Dielectric and Conductivity Anomaly Near 370 K in Lithium Hydoxylammonium Sulphate Single Crystal, Kumar, A.S., Varughese, G., Iype, L., Rajesh, R., Joseph, G. and Louis, G., 2009, In Dielectrics and Ferroelectrics: Modern Perspectives, R.N.P. Choudhary and A.K. Thakur (Eds.), Anamaya Publishers, New Delhi, India, (In Press).

21. Elastic constant measurements of super ionic LiKSO4:Na single crystals, G. Varughese, A. Santhosh Kumar, J. Philip, and G. Louis , Cryst. Res. Technol.,  300, (2009) DOI: 10.1002/crat.200800475

22. Elastic Properties of Potassium Lithium Hydrogen Sulphate Crystal: An Ultrasonic Study   GEORGE VARUGHESE, A. S. KUMAR, A. V. ALEX, J. PHILIP, AND L. GODFREY Ferroelectrics, 323:133–137, 2005

23. Growth and dielectric dc conductivity studies in MnSeO4.2H2O single crystal,  R. Rajesh, A. Santhosh Kumar, Leesal Iype,  Georgekutty Joseph and Godfrey Louis,  Indian J. Phys. 79, No 7 691-693, (2005)

24. AC Conductivity and dielectric studies of K3Na(SeO4)2 single crystal,  Georgekutty Joseph, A. Santhosh Kumar, Leesal Iype and Godfrey Louis,     Indian J. Phys. 79, No. 7, 699-702, (2005)

25. Dielectric and conductivity studies of NiSeO4.6H2O single crystal below room temperature, Rajesh R, A. Santhosh Kumar, Georgekutty Joseph and Godfrey Louis, Proceedings of the DAE Solid State Physics Symposium, Vol 50, 745-747, (2005)

26. Dielectric properties of NiSeO4.6H2O single crystals, Rajesh R, A. Santhosh Kumar, Georgekutty Joseph and Godfrey Louis, Proceedings of the DAE Solid State Physics Symposium, Vol 51, 963-964,  (2006)

27. Optical Band Gap of Wurtzite Zinc Sulphide Doped with Lanthanum Ions  George Varughese, Sreeja R. Aswathy, K.T. Usha, A.S. Kumar  Advanced Materials Research , 622 - 623,  752-756 (2013) 

28. Elastic study of Potassium Sulphamate crystal using ultrasonic Pulse Echo Overlap technique G Varughese, AS Kumar, J Philip, G Louis Solid State Communications 149 (15-16), 645-647  (2009)

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  Abstracts of few publications

  Journal Article:New biology of red rain extremophiles prove cometary panspermia                Godfrey Louis, A. Santhosh Kumar

ABSTRACT: This paper reports the extraordinary biology of the microorganisms from the mysterious red rain of Kerala, India. These chemosynthetic organisms grow optimally at an extreme high temperature of 300 degrees C in hydrothermal conditions and can metabolize inorganic and organic compounds including hydrocarbons. Stages found in their life cycle show reproduction by a special multiple fission process and the red cells found in the red rain are identified as the resting spores of these microbes. While these extreme hyperthermophiles contain proteins, our study shows the absence of DNA in these organisms, indicating a new primitive domain of life with alternate thermostable genetics. This new biology proves our earlier hypothesis that these microbes are of extraterrestrial origin and also supports our earlier argument that the mysterious red rain of Kerala is due to the cometary delivery of the red spores into the stratosphere above Kerala

Journal Article:Cometary panspermia explains the red rain of Kerala Godfrey Louis, A. Santhosh Kumar

Full text download from Arxiv.org

 ABSTRACT: Red coloured rain occurred in many places of Kerala in India during July to September 2001 due to the mixing of huge quantity of microscopic red cells in the rainwater. Considering its correlation with a meteor airbust event, this phenomenon raised an extraordinary question whether the cells are extraterrestrial. Here we show how the observed features of the red rain phenomenon can be explained by considering the fragmentation and atmospheric disintegration of a fragile cometary body that presumably contains a dense collection of red cells. Slow settling of cells in the stratosphere explains the continuation of the phenomenon for two months. The red cells under study appear to be the resting spores of an extremophilic microorganism. Possible presence of these cells in the interstellar clouds is speculated from its similarity in UV absorption with the 217.5 nm UV extinction feature of interstellar clouds.

  Journal Article: Electrical conductivity and dielectric properties of potassium sulfamate single crystals A. S. Kumar, L. Iype R. Rajesh, G. Varughese, G. Joseph, G. Louis Crystal Research and Technology. 07/2011; 46(10):1027-1034.

  Journal Article: Electrical conductivity of sulfamic acid single crystals  A. Santhosh Kumar, G. Varughese, L. Iype, R. Rajesh, G. Joseph, G. Louis Crystal Research and Technology. 06/2010;    45(8):879-882.

ABSTRACT: Single crystals of sulfamic acid have been grown by the method of slow evaporation at constant temperature. DC electrical conductivity was measured in the temperature range 300 - 440 K along a, b and c-axes. Conductivity measurements show slope change near 330 K and 410 K. The slope change observed around 330 K may be attributed as due to a phase transition which has been well supported by the DSC and DTA measurements. Slope change observed around 410 K is attributed as the onset of the thermal decomcoposition as evidenced by TGA curve. TGA studies show the crystal is very stable up to 440 K. Activation energies for the conduction process are calculated for all measured crystallographic directions.

Journal Article: Detection of elastic and electric conductivity anomalies in Potassium Sulphamate single crystal   George Varughese, A. Santhosh Kumar, Godfrey Louis Physica B: Condensed Matter. 04/2010; 405(7):1813-1816.

ABSTRACT: Elastic anomalies in Potassium Sulphamate, (KNH2SO3), above room temperature were detected from temperature variation of elastic constants measured by ultrasonic Pulse Echo Overlap technique. Potassium Sulphamate has been reported to be a ferroelectric and piezo electric material. The elastic constants C11, C44, C55 and C66 have exhibited weak anomalies around 350 K. The DC conductivity measurement along a, b, and c axes also supports this conclusion.