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Kerala Red Rain
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At the end of February, Godfrey Louis, a physicist at Mahatma Gandhi University in
Kottayam in Kerala, sent samples of the red rain to Wickramasinghe, a champion of the panspermia theory. His team has analysed the samples, as has a second team led by Milton Wainwright, a microbiologist at the University of Sheffield.

Both teams say microscopy confirms that the particles are biological cells. They are not red blood cells because they do not contain haemoglobin. It's unlikely that they are fungal spores or red algae. They don't contain chitin, a key component of fungal cell walls. Nor do they contain the chloroplasts, the organelles in which photosynthesis takes place, that are typical of red algae.
But they do, after all, contain DNA. A simple DNA stain test in Sheffield came back positive. However, more rigorous tests in Cardiff that try to amplify specific DNA sequences have so far failed.

"That doesn't mean there's no DNA, it means that the DNA is probably unusual" - Chandra Wickramasinghe Astronomer who is studying the cells with microbiologists at Cardiff University.

The red cells have unusually thick, sturdy walls, and some contain daughter cells that Wainwright says are puzzling. He stresses, though, that the cells could be ordinary, terrestrial organisms he is not familiar with.
Something like the Trentepohlia alga, perhaps? That's the conclusion of microbiologists at the Tropical Botanic Garden and Research Institute in Kerala, who say they have cultured the cells and grown Trentepohlia, an alga common in Kottayam, where the first report of the red rain originated. Formal DNA identification awaits.

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The "red rains" in Kerala five years ago was the result of the atmospheric disintegration of a comet, according to a study.

The study conducted at the School of Pure and Applied Physics of the MG University in India by Dr Godfrey Louis and his student a Santosh Kumar shows that red rain cells were devoid of DNA which suggests their extra-terrestrial origin.
The findings published in the international journal 'Astrophysics and Space Science' state that the cometery fragment contained dense collection of red cells.

What makes this study most important is the similarity of the red particles with living cells. If the red rain cells are finally proved to be of extra-terrestrial origin then that would be one of the most important discoveries in human history. It will change our concept about the universe and life" - Dr N Chandra Wikramesinghe, Director at the Cardiff Centre for Astrobiology, UK, commenting on the study at a press conference.

The red coloured rains were reported in different parts of Kerala from July to September 2001.

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Posts: 131070
Date:
Extraterrestrial Life
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The great search for extraterrestrial life has focused on water at the expense of a crucial element, say geobiologists at the University of Southern California.

Writing in the Perspectives section of the May 5 issue of Science, four University of Southern California (USC) researchers propose searching for organic nitrogen as a direct indicator of the presence of life. Nitrogen is essential to the chemistry of living organisms.
Even if NASA were to find water on Mars, its presence only would indicate the possibility of life, said Kenneth Nealson, Wrigley Professor of earth sciences in the USC College of Letters, Arts and Sciences.

"It's hard to imagine life without water, but it's easy to imagine water without life" - Kenneth Nealson.

The discovery of nitrogen on the Red Planet would be a different story.

"If you found nitrogen in abundance on Mars, you would get extremely excited because it shouldn't be there" - Kenneth Nealson.

The reason has to do with the difference between nitrogen and carbon, the other indispensable organic element.
Unlike carbon, nitrogen is not a major component of rocks and minerals. This means that any substantial organic nitrogen deposits found in the soil of Mars, or of another planet, likely would have resulted from biological activity.
Dimming the hopes of life-on-Mars believers is the makeup of the planet's atmosphere. The abundant nitrogen in Earth's atmosphere is constantly replenished through biological activity. Without the ongoing contribution of living systems, the atmosphere slowly would lose its nitrogen.
The extremely low nitrogen content in the Martian atmosphere suggests that biological nitrogen production is close to zero.
However, the authors write, it is possible that life existed on Mars at some hypothetical time when nitrogen filled the atmosphere.
Co-author Douglas Capone, Wrigley Professor of environmental biology in USC College, said NASA should establish a nitrogen detection program alongside its water- seeking effort. He noted that next-generation spacecraft will have advanced sampling capabilities.

"What we're suggesting here is basically drilling down into geological strata, which they're going to be doing for water anyway." - Douglas Capone.

"The real smoking gun would be organic nitrogen...If your goal is to search for life, it would be wise to include nitrogen."- Kenneth Nealson.

In their acknowledgments, the authors thanked the students of the Spring 2004 Geobiology & Astrobiology course at USC, with whom Nealson and Capone began their discussion on how to search for life outside earth.
The authors also thanked NASA, the Department of Energy and the National Science Foundation for their financial support.
Along with Nealson and Capone, USC graduate student Beverly Flood and former USC Research Professor Radu Popa (now a professor of biology at Portland State University) contributed to the Perspectives paper.

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Interstellar Organics
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Like an interplanetary spaceship carrying passengers, meteorites have long been suspected of ferrying relatively young ingredients of life to our planet. Using new techniques, scientists at the Carnegie Institution’s Department of Terrestrial Magnetism have discovered that meteorites can carry other, much older passengers as well—primitive, organic particles that originated billions of years ago either in interstellar space, or in the outer reaches of the solar system as it was beginning to coalesce from gas and dust.

These tiny particles, from carbonaceous chondrite meteorites, are just a few millionths of a meter wide and have different proportions of nitrogen (N) and hydrogen (H and D) isotopes.
Image courtesy Henner Busemann


The study shows that the parent bodies of meteorites—the large objects from the asteroid belt—contain primitive organic matter similar to that found in interplanetary dust particles that might come from comets. The finding provides clues about how organic matter was distributed and processed in the solar system during this long-gone era.
The work is published in the May 5, 2006, issue of Science.

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Date:
PAHs
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The components of life may have been under attack in the hostile environments of the universe's first galaxies.

A science team led by graduate student Yanling Wu of Cornell University, Ithaca, N.Y., recently came to this conclusion after studying the formation and destruction of polycyclic aromatic hydrocarbons molecules (PAHs) in more than 50 blue compact dwarf (BCD) galaxies using the Spitzer Space Telescope. These organic molecules, comprised of hydrogen and carbon, are believed by many scientists to be among the building blocks for life.

"One of the outstanding problems in astronomy today is whether complex organic molecules of hydrogen and carbon, similar to those responsible for life on Earth, are present in the early universe" - Yanling Wu.

Mature massive galaxies like our Milky Way formed from the merging of smaller galaxies, probably about the size of nearby BCD galaxies. Since current technology is not sensitive enough to easily identify and study in detail the universe's first galaxies, astronomers must infer the physical properties of the early structures by observing similar nearby galaxies like BCDs.

"We believe that BCD galaxies are similar to the universe's first galaxies because they are infant galaxies, actively forming stars, and are not very chemically polluted" - Yanling Wu.

Because most atomic elements other than hydrogen and helium are born from the death of stars, astronomers suspect that in the first few million years after the big bang galaxies were not "chemically polluted" with elements other than hydrogen and helium. In astronomy, these relatively unpolluted galaxies are said to have low metallicity.
The BCD galaxies' blue colours tell astronomers that these structures are actively forming massive stars. By logically combining the galaxy's blue colour with the fact that it is low in metals, astronomers can infer that this is a young galaxy.
In her research, Wu found that nearby BCD galaxies with lowest metallicity also had little or no PAHs. As the galaxies became more chemically polluted, more traces of PAHs were found.
This phenomenon makes sense because heavy metal elements like carbon are formed from the death of stars, and some of these galaxies may just be too "young" to have produced enough carbon to create PAHs.
However, in some of the BCD galaxies where the conditions allow for the formation of PAHs, Wu found that those molecules were being destroyed by intense ultraviolet radiation from the young massive stars.

"Because BCD galaxies are metal poor and very compact, the intense ultraviolet radiation from young stars will destroy PAH molecules even if they are formed. The threshold for when these PAH molecules stop being destroyed is still uncertain." - Yanling Wu

"This leads to an interesting paradox, where the young stars responsible for the formation of PAHs may also be the main culprit of their destruction" - co-author Dr. Vassilis Charmandaris, University of Greece, Heraklion.

The organic PAHs were detected using Spitzer's Infrared Spectrometer (IRS).

"Yanling has made significant progress in a research area first opened by International Space Observatory. With Spitzer, Yanling is able to extend BCDs observations to a much larger sample; the new results provide a glimpse into the formation of galaxies in the early Universe" - Dr. Jim Houck of Cornell University.

Houck is Wu's academic advisor and a co-author of the paper. He is also the Principal Investigator for Spitzer's IRS instrument and played a vital role in its creation.

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RE: Alien life
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The red rain phenomenon of Kerala and its possible extraterrestrial origin
Authors: Godfrey Louis, A. Santhosh Kumar (Mahatma Gandhi University, Kottayam, India)


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 kilometres 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.

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Posts: 131070
Date:
PAHs
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NASA Discovers Life's Building Blocks Are Common In Space

After A team of exobiology researchers revealed today organic chemicals that play a crucial role in the chemistry of life are common in space.

"Our work shows a class of compounds that is critical to biochemistry is prevalent throughout the universe. NASA's Spitzer Space Telescope has shown complex organic molecules called polycyclic aromatic hydrocarbons (PAHs) are found in every nook and cranny of our galaxy. While this is important to astronomers, it has been of little interest to astrobiologists, scientists who search for life beyond Earth. Normal PAHs aren't really important to biology. However, our work shows the lion's share of the PAHs in space also carry nitrogen in their structures. That changes everything" - Douglas Hudgins, astronomer at the Ames Research Centre, Moffett Field, California.

Douglas Hudgins is principal author of a study detailing the team's findings that appears in the October 10 issue of the Astrophysical Journal.

"Much of the chemistry of life, including DNA, requires organic molecules that contain nitrogen . Chlorophyll, the substance that enables photosynthesis in plants, is a good example of this class of compounds, called polycyclic aromatic nitrogen heterocycles, or PANHs. Ironically, PANHs are formed in abundance around dying stars. So even in death, the seeds of life are sewn" - Louis Allamandola, team member, astrochemist at Ames.

The team studied the infrared "fingerprint" of PANHs in laboratory experiments and with computer simulations to learn more about infrared radiation that astronomers have detected coming from space. They used data from the European Space Agency's Infrared Space Observatory satellite.

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Posts: 131070
Date:
Alien life
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The chances of finding life somewhere else in the Universe depends on how many planets are capable of supporting life. According to new calculations by astronomers at Open University, as many as half of all star systems could contain habitable planets. The team created mathematical models of known exoplanetary systems, and then added Earth-sized planets into the mix. They found that in half of all planetary systems they simulated, the gravity of the gas giants won't catastrophically affect the orbits of these smaller planets, giving life a chance to evolve.


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