Astrobiology

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1 Does the definition of a habitable zone consider microbial life as well, or does it only consider availability of liquid water?
By Kinsuk Acharyya · S.N. Bose National Centre for Basic Sciences

Ejner Fulsang · NASA

Strictly speaking a star system's habitable zone is defined as the region that could support liquid surface water subject to the presence of a suitabl... [more]

Strictly speaking a star system's habitable zone is defined as the region that could support liquid surface water subject to the presence of a suitable atmosphere. The top name on the subject is James Kasting. However, a good URL can be found at http://www.planetarybiology.com/calculating_habitable_zone.htm Meanwhile, there are numerous other factors that contribute in a practical way to the support of life on a planet. These would include a magnetic field to defend against cosmic radiation and solar electric particles--hence look for signs of plate tectonics. An oxygenated atmosphere is necessary to form an ozone layer which in turn is necessary to protect against UV radiation. Without an ozone layer life is limited to water environments or subterranean environments. See M. Ivarsson and also Lewis Dartnell. Bear in mind that even radiation resistant microbes like D. radiodurans is just as susceptible to radiation damage as you and I--it mainly excels at repair. But if it is frozen it cannot affect repairs, so the issue is whether it can thaw out often enough to make repairs. At some point a frozen D. radiodurans will become overwhelmed with radiation damage.

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6 Is There a Methane Habitable Zone?
By Philip Metzger · ResearchGate

James Garry · Red Core Consulting ltd

Philip, This business of 'habitable zones' is a bit of a misnomer. Consider Europa. Clearly it is host to vast sub-surface bodies of water - and has ... [more]

Philip, This business of 'habitable zones' is a bit of a misnomer. Consider Europa. Clearly it is host to vast sub-surface bodies of water - and has sufficient heat input via tidal dissipation to allow that water to stay liquid for Long Periods of time. So, is Europa in the 'Habitable Zone'? As for methane as a biological liquid, it lacks many of the properties that make water so useful. The specific heat of CH4 is rather small, its range between its boiling point and its freezing point is laughable small too, and its powers of solvation are rather puny too. That doesn't by any means rule out its utility as a biological fluid - and I've read of similar studies examining other compounds (ammonia got good press in the 70s, I recall). Chris' work is the most rigorous so far, but Titan's surface temperature makes kinematics painfully slow. However, dig a little on Titan and there's likely a hydrosphere down there, and at the interface things could be very interesting.

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1 How microbes that originated in sea later evolved to survive in mud/permafrost as the seafloor uplifted exposing the area to UV, aridity, and cold?
By Ejner Fulsang · NASA

Juan Bueno · Instituto Nacional de Salud

Dear Dr Fulsang in antimicrobial resistance was described a bacterial SOS response, which is a mechanism acitvated as inducible DNA repair system, tha... [more]

Dear Dr Fulsang in antimicrobial resistance was described a bacterial SOS response, which is a mechanism acitvated as inducible DNA repair system, that allows bacteria to survive sudden increases in DNA damage, this SOS response is ancient in microorganisms and exist before antibiotic implementation, could be an interesting evolutive factor for survival. With best regards http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0030255 http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002778 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2958807/ http://jac.oxfordjournals.org/content/early/2012/05/22/jac.dks196.abstract

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3 Are there any papers about earths radioactive sources being an energy source for biogenesis?
By Jovana Kabic · Petnica Science Center

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1 so, what happens if a hot jupiter stays in the orbit less then 1 AU from its parent star?
By Prahesti Husnindriani · Bandung Institute of Technology

Michel Dobrijevic · Université Bordeaux 1

What is exactly your question? Are you questioning the orbital stability, the atmospheric stability or the evolution of the atmospheric composition? C... [more]

What is exactly your question? Are you questioning the orbital stability, the atmospheric stability or the evolution of the atmospheric composition? Concerning the last point, the strong stellar UV flux and the hot atmospheric temperature is responsible of a complex photo-thermo-chemistry in the atmosphere. Details can be found in the following paper.

A chemical model for the atmosphere of hot Jupiters × Olivia Venot, Eric Hébrard, Marcelino Agùndez, Michel Dobrijevic, Franck Selsis, Franck Hersant, Nicolas Iro, Roda Bounaceur

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20 comet crash
By Mahdi Sadati · Islamic Azad University

luis fernando Tume Farfán · Universidad Nacional de Piura

I believe that if. .porque if we reviewed to the hipertermofilos microorganisms the conclusions are clear. Clearly! lack to discover much. .principalm... [more]

I believe that if. .porque if we reviewed to the hipertermofilos microorganisms the conclusions are clear. Clearly! lack to discover much. .principalmente in the depths of the Earth.! in aim the nature always surprises to us!

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4 Replication or Metabolism??
By Sam Ochotta · Quest University Canada

Marco Parigi · James Cook University

I think metabolism is a little over thought, in the sense that anything that is reproduced uses energy to achieve that reproduction. For instance, the... [more]

I think metabolism is a little over thought, in the sense that anything that is reproduced uses energy to achieve that reproduction. For instance, the processes that generate amino acids use energy, can generate a lot of them ( reproducing them), and dissipates heat as part of the process. Something way bigger than a cell would do fine as a kind of incubator for cycle of catalysis reactions. It could theoretically be as big as a planet, or perhaps better the size of a comet/asteroid. Of course the issue of the centre of the comet needing to be permanently liquid would need to be resolved.

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1 Http://www.bbc.co.uk/news/technology-15618759

Deleted

An interesting article about Harvard's Origins of Life programme.

An interesting article about Harvard's Origins of Life programme.

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Open Will commercial access to long term microgravity be properly utilized by the R&D community?
DragonLab is a project of SpaceX. It is our intent to provide a regularly scheduled low earth orbit microgravity platform commercially within the next... [more]

DragonLab is a project of SpaceX. It is our intent to provide a regularly scheduled low earth orbit microgravity platform commercially within the next few years. PI's with an interest should contact me here for details.

http://www.spacex.com/downloads/dragonlab-datasheet.pdf ×

By Richard Godwin · Third Millennium Affiliates Inc.

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4 LIFE WE KNOW
By Rohit Pasrija · National Geophysical Research Institute

Mario Rivas · National Autonomous University of Mexico

Of curse my friend, do you have any in mind? Why don't you try looking in the abstracts of the articles included in the reference I leaved before and ... [more]

Of curse my friend, do you have any in mind? Why don't you try looking in the abstracts of the articles included in the reference I leaved before and tell me which of those you would like to read first. I guess I have accesses to almost all of them in my lab.

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Question:
Open Self Gravity in living organism-unexplored invisible foundation explored
visit: http://www.indianscience.in/i3GB/blog/35/ http://www.indianscience.in/i3GB/blog/38/ http://www.indianscience.in/sciface/blogs/166/50/biomecha... [more]

visit: http://www.indianscience.in/i3GB/blog/35/ http://www.indianscience.in/i3GB/blog/38/ http://www.indianscience.in/sciface/blogs/166/50/biomechanics-of-intrinsic-gravit http://www.researchgate.net/group/Self_gravitation_bio

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