Start with terra firma...and then sky is the limit.

I am an Origins man so a bit biased but understanding where we came from and how we came into being makes for a better understanding of life in the cosmos and the future in my eyes.

It also includes the search of habitable environment in our solar system or even outside our solar system if possible. A typical astrobiologist always thinks that nucleic acids are not the only biomolecules capable of passing information from one generation to another.

Do we know if the description of Kepler 22b, as it appeared last year, is true? A terrestrial exoplanet with ambient temperature of about 72F...if it has water, its long planetary evolution must have cooked up some elements of life. Alas, it is nearly 600 long light years away!

To be frank, I think our scientific achievements thus far are not adequate yet for astrobiology. A few generations later, I am sure, we (I mean, humanity; I shall be long gone by then) shall have some credible basis to ask such meaningful questions.

But we need to talk about these questions right now--even as we are unprepared as yet. As a quick guess-work, the areas of focus could be the following, but I shall add other possibilities later after some thinking:

1. emergence of carbon-based ingredients of life on Earth

2. possibility of non-carbon, non-aqueous systems of life

3. possible systems of life that comprises of alternate chirality

I would say the main astrobiological research areas are already covered with studies being undertaken on the: origins of life on Earth, types of extreme biota on Earth linked to the possible habitats for water+carbon based life elsewhere, search for potentially habitable exoplanets, and search for water-based life on Mars and icy moons. However, I would say more experimental research is required in the area of synthetic astrobiology, related to the possibility of life that is not like that we find on Earth, in order to determine what may, or may not, be possible. This would involve experimental research focusing on the possibility of non-water based life on Venus and Titan, rather than simply theoretical work. As I work in this area I am biased, but it does seem to be a rather neglected area in terms of experimental work.

There is still a possibility that life exists in the clouds of Venus.  The "Mode 3" droplets,. or particles, observed in the lowest cloud layer, are candidates for hosting microorganisms (Grinspoon and Bullock 2007).  While the surface is hostile to life, acidophile microorganisms would find the clouds to be quite pleasant: Sunlight, favorable temperature and pressure, and some water vapor.

We need to put balloon-borne probes back into the clouds of Venus to further analyze the atmosphere, the clouds, and the mysterious Mode 3 particles.

REFERENCE:

Grinspoon, D. H., & Bullock, M. A. (2007). Astrobiology and venus exploration. 369 Exploring Venus as a Terrestrial Planet, (176), 191.

I think we should do these things in our research:

The definition of life.

The habitable zones of galaxies and planetary systems.

From molecular clouds to the prebiotic chemistry.

Origin and evolution of life on Earth.

Life in the extreme environments.

Viable transfer of microorganisms in the solar system and beyond.

The habitability of life in the universe.

Are there experiments or simulations probing the probably that known types of microbial life could be transferred in the solar system?

Also I am interested to know about the data on the clouds of Venus for acidophiles. In this and other regards the idea of synthetic astrobiology seems exciting.

Dear John,

I remember having come across reports (on sciencedaily.com) of independent studies that (1) looked for microbiota on the exterior of jet planes, and (2) smeared plasmid-bearing bacteria of known genotype on the exterior of the planes, let the planes fly, and retrieved the smear later to evaluate the survival of the bacteria. I may be wrong in technical terms, but this is probably true to the studies. Interestingly, many microbial life forms were found on the jet exterior, and also the plasmid-bearing bacteria survived long hours of high-altitude flights. These data indicate that microbial life is sustainable in conditions we usually consider inhospitable (ultra-low gravity, ultra-low pressure, acute desiccation, very low temperature, radiations...) and that can possibly migrate in the space. I shall try to retrieve the references and publish here.

Going back to the type of experiments astrobiology should be doing, here is an excellent new review towards identifying signatures of life on exoplanets:

http://advances.sciencemag.org/content/advances/1/2/e1500047.full.pdf

In my opinion, two subjects are the most important: 1) Propose a mechanism for the the formation of formation and replication of complex molecules of intermediate complexity (10-100,000 DNA bases or a corresponding number of aminoacids in the protein sequence). Here is why it is a problem: formation of aminoacids in refluxing water/electric charges/UV radiation was demonstrated. It is also clear that reproduction-mutations-selections could result in evolution of living organisms that have >175000 base pairs in their DNAs. But now it is unclear what the intermediate forms of life were - and how 1000-base-pair pieces of DNA (or RNA) could reproduce with any fidelity - before they hydrolized.

I myself wrote a proposal on research that would test my own hypothesis; waiting for a chance to work on it.

2) Making a numerical model of distribution of various forms of life as a function of their complexity and energy flux passing through their bio-eco-socio-system. IMHO, this is the key to understanding of why we don't see the other civilizations even though there are so many planets in the Universe.

Over the past several years, one of these early models—that of autocatalytic sets—has been explored in more detail, both mathematically and with computer simulations. Autocatalytic sets are self-sustaining networks of chemical reactions that create and are catalyzed by components of the system itself. Recent research has overturned early criticisms regarding the plausibility of the spontaneous origin of such networks, and scientists have even applied the theoretical concepts to real chemical and biological systems, yielding important insights regarding the possible emergence, structure, and evolution of such systems.

http://www.the-scientist.com/?articles.view/articleNo/43082/title/The-Living-Set/

It is customary in science to formulate a testable scientific hypothesis then devise experiments capable of testing it. There was no scientfic theory capable of explaining the bizarre lack of evidence for extraterrestrial civilisations until recently, and there is still only one meeting that description. Indeed, many of its predictions are already known to be upheld. Neutrinos do have a little mass, as th theory expects far smaller than that of an electron. That this mass is comparable to the energy scale associated with liquid water provides quite a hint as to their intended function in nature. There are no other dark matter particles known to exist other than neutrinos, despite desperate attempts to search for other candidates. The expansion of the universe is accelerating, and at the right rate to permit the decay of dark energy at an opportune moment as the life-cultivating stars become scarce, potentially sustaining aquaic life for 10^25 years thereafter.

As it happens, the experiments needed to further corroborate the theory are already underway, due to the fact that the physics of active (and possibly also sterile) neutrinos demonstrate the incompleteness of the Standard Model.

Article A cosmological hypothesis potentially resolving the mystery ...