* Astronomy

A new study by the University of Puerto Rico at Arecibo shows the first quantitative evaluation of planetary habitability. The study identifies some potential habitats in the solar system and also shows how the habitability of our planet has changed in the past, with some periods being even better than today.
Abel Mendez presented his results on Monday, October 5, at the 41st Annual Meeting of the Division for Planetary Sciences of the American Astronomical Society in Fajardo, Puerto Rico.
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EPSC09/17: Exotic life beyond Earth? Looking for life as we don't know it
Scientists at a new interdisciplinary research institute in Austria are working to uncover how life might evolve with 'exotic' biochemistry and solvents, such as sulphuric acid instead of water. Their research was presented at the European Planetary Science Congress in Potsdam by Dr Johannes Leitner on Friday 18 September.
The University of Vienna established a research group for Alternative Solvents as a Basis for Life Supporting Zones in (Exo-)Planetary Systems in May 2009, under the leadership of Maria Firneis.
Traditionally, planets that might sustain life are looked for in the 'habitable zone,' the region around a star in which Earth-like planets with carbon dioxide, water vapour and nitrogen atmospheres could maintain liquid water on their surfaces. Consequently, scientists have been looking for biomarkers produced by extraterrestrial life with metabolisms resembling the terrestrial ones, where water is used as a solvent and the building blocks of life, amino acids, are based on carbon and oxygen. However, these may not be the only conditions under which life could evolve.
One requirement for a life-supporting solvent is that it remains liquid over a large temperature range. Water is liquid between 0 C and 100 C, but other solvents exist which are liquid over more than 200 C. Such a solvent would allow an ocean on a planet closer to the central star. The reverse scenario is also possible. A liquid ocean of ammonia could exist much further from a star. Furthermore, sulphuric acid can be found within the cloud layers of Venus and we now know that lakes of methane/ethane cover parts of the surface of the Saturnian satellite Titan.
Consequently, the discussion on potential life and the best strategies for its detection is ongoing and not only limited to exoplanets and habitable zones. The newly established research group at the University of Vienna, together with international collaborators, will investigate the properties of a range of solvents other than water, including their abundance in space, thermal and biochemical characteristics as well as their ability to support the origin and evolution of life supporting metabolisms.

Source: European Planetology Network

Critique on Vindication of Panspermia

Mumbai scientist challenges bacteria theory
A young Mumbai scientist claims to have disproved a theory that living bacteria from space called 'Cometary Panspermia' could have led to the origin and spread of diseases like SARS (Severe Acute Respiratory Syndrome) that ravaged many countries in early 2000.

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On the 50th anniversary of NASA, Stephen Hawking , Newton's heir as the Lucasian Professor of Mathematics at the University of Cambridge, was asked the question, "Are we alone?" His answer was short and simple; "probably not".

Source dailygalaxy