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TOPIC: Alien life
Blobrana


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Alien Photosynthesis
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A team of NASA scientists led by a member of the Spitzer Science Centre believe they have found a way to predict the colour of plants on planets in other solar systems.
Green, yellow or even red-dominant plants may live on extra-solar planets, according to scientists whose two scientific papers appear in the March issue of the journal, Astrobiology. The scientists studied light absorbed and reflected by organisms on Earth, and determined that if astronomers were to look at the light given off by planets circling distant stars, they might predict that some planets have mostly non-green plants.
According to scientists, the Sun has a specific distribution of colours of light, emitting more of some colours than others. Gases in Earth's air also filter sunlight, absorbing different colours. As a result, more red light particles reach Earth's surface than blue or green light particles, so plants use red light for photosynthesis. There is plenty of light for land plants, so they do not need to use extra green light. But not all stars have the same distribution of light colours as our Sun. Study scientists say they now realize that photosynthesis on extrasolar planets will not necessarily look the same as on Earth.

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Blobrana


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Posts: 131433
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Photosynthesis
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The greenery on other planets may not be green. Astrobiologists say plants on Earth-sized planets orbiting stars somewhat brighter than the Sun may look yellow or orange, while those on planets orbiting stars much fainter than the Sun might look black.
Vegetation colour matters to astrobiologists because they want to know what to look for as a sign of life on planets outside the solar system. Terrestrial photosynthesis depends mostly on red light, the most abundant wavelength reaching the Earth's surface, and blue light, the most energetic. Plants also absorb green light, but not as strongly, so leaves look green to the eye.
Extraterrestrial plants will look different because they have evolved their own pigments based on the colours of light reaching their surfaces, says Nancy Kiang of the NASA Goddard Institute for Space Sciences in New York, US.
To determine the best colours for photosynthesis on other planets, Kiang worked with NASA's Virtual Planetary Laboratory at Caltech to determine the light reaching the surfaces of Earth-sized worlds orbiting their host stars at distances where liquid water and therefore life could exist. The results depended on the star's brightness and the planet's atmosphere.

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Blobrana


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RE: Alien life
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NASA scientists believe they have found a way to predict the colour of plants on planets in other solar systems.
Green, yellow or even red-dominant plants may live on extra-solar planets, according to scientists whose two scientific papers appear in the March issue of the journal, Astrobiology. The scientists studied light absorbed and reflected by organisms on Earth, and determined that if astronomers were to look at the light given off by planets circling distant stars, they might predict that some planets have mostly non-green plants.

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Blobrana


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Posts: 131433
Date:
Panspermia hypothesis
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Did life arrive from space? Rather than developing here, could the first life forms have been catapulted to Earth on a chunk of rock from outer space? Investigations show that microbes are capable of surviving just such a journey.
At the mention of life forms from other planets, images of green Martians, ET-like creatures or Klingons immediately spring to mind, largely influenced by the film industry. They travel through space in UFOs in order to conquer the Earth. Something similar may well have happened a long time ago: The UFOs could have been lumps of rock that broke off from a planet when it was hit by a meteorite, and their crews could have been microbes.

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Blobrana


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Botswana: Is There Life Out There?
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Ever watched those sci-fi movies where cars fly to the moon and there are penthouses in Mars? You cannot help but imagine yourself on those planets. You go to bed and you dream of flying one of those faster-than light saucer-shaped planes. It is a great but also disturbing feeling.

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Blobrana


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RE: Alien life
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Researchers who've found strange nanoparticles in a handful of kidney stones say these self-replicating specks may play a role in disease.
The US researchers are not sure whether these tiny particles, 50 to 100 nanometres across, are living nanobacteria or just some strange non-living self-assembling ball of chemicals.

"We have some evidence that would support either possibility" - Dr John Lieske, kidney specialist at the Mayo Clinic College of Medicine.

He and colleagues report their findings in the December issue of the Journal of Investigative Medicine.
At some point in their life about 10% of people will get kidney stones, a painful condition in which calcium deposits clog the kidneys.
Scientists aren't sure what causes these deposits. But one theory that Lieske and colleagues are investigating is that tiny calcium-covered particles are partly to blame.
Previous research has found such particles in human serum, urine, renal cysts from patients with kidney disease, as well as in kidney stones.
Lieske says some researchers dub the particles nanobacteria, and propose they are a new disease-causing agent.
But Lieske says there is not yet enough evidence these particles are alive.

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Blobrana


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Posts: 131433
Date:
Panspermia
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In July 2001, a mysterious red rain started falling over a large area of southern India.
Locals believed that it foretold the end of the world, though the official explanation was that it was desert dust that had blown over from Arabia.
But one scientist in the area, Dr Godfrey Louis, was convinced there was something much more unusual going on.
Not only did Dr Louis discover that there were tiny biological cells present, but because they did not appear to contain DNA, the essential component of all life on Earth, he reasoned they must be alien lifeforms.

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Blobrana


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Space Microbes
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Russian scientists have found out that microbes are able to survive in outer space for long periods of time.

These are the first results of the “Biorisk” project. Last year three containers with spores of various fungi and some Bacillus were placed on the outer surface of the Russian part of the International space station. The containers for the micro-organisms were made from materials, usually used for building space ships.
Severe conditions of outer space, where temperatures fluctuate from —100 to +100 degrees Centigrade didn’t prevent the micro-organisms from living on the various chemical compounds — metals, polymers and etc.
Thus, while preparing for space flights, one should be sure that vehicles delivering astronauts to other planets won’t be damaged by micro-organisms.

Source Voice of Russia

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Blobrana


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Posts: 131433
Date:
Drake Equation
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Are we alone? Seth Shostak doesn't think so.
In May's Discover magazine, the scientist, broadcaster and author reviewed the famous Drake Equation, which calculates the probability of life elsewhere in the universe and asks whether life is a "onetime fluke or a near-inevitable phenomenon."

"More and more, the evidence points toward the latter" - Shostak, senior astronomer at the Search for Extra-Terrestrial Intelligence Institute, or SETI, in California, made famous in the 1997 movie "Contact."

Shostak is part of a team that uses radio telescopes to try to eavesdrop on alien broadcasts.
Shostak and fellow astronomer Chris McKay will bring us up to date on the hunt for life elsewhere tonight in "Searching for Life in the Universe," at the University of Hawai'i-Manoa Art Auditorium.

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Blobrana


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Of all the sci-fi films and programmes to have hit the screens since 1902, when George Melies' celebrated Le Voyage de le Moon showed chicken-headed selenites greeting the intrepid Earthling explorers, Contact stands apart.

There've been plenty of low-budget sci-fi films that have saved on costumes and makeup by aliens assuming human form, or films featuring benign aliens - think of the loveable ET.
There have been even those in which Earth is, for once, not under attack by an advanced alien civilisation - in 2001: A Space Odyssey it is superior aliens who help primitive humans to develop technological skills.
What makes Contact special, even nine years after its release, is simply that it is more real.

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See also Drake`s Equation

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