Coral reef fish that changes colour

Melbourne, Feb 28: Scientists have discovered a coral reef fish which changes colour to blend in with other fish, giving it the unique opportunity for a surprise attack.

A team at University of Queensland has claimed that the coral reef fish has been successfully living incognito by using its colour-changing ability, the 'Proceedings of the Royal Society: B' journal reported.

According to the study's lead author Dr Karen Cheney, the blue-striped fangblenny uses a number of disguises to pass undetected on coral reefs.

"The fangblenny mimics juvenile cleaner fish, but instead of removing ectoparasites from reef fish, they attack passing reef fish to nip at scales and fins. Fangblennies can also change their colour to hide in a number of different shoaling fish species.

"Many fishes can alter their colouration, but the fangblenny is the first example of a vertebrate that can change their colour at will to mimic a variety of species. The only other example of this occurs in the mimic octopus that can alter its colouration and shape to resemble lionfish, flatfish and sea snakes," he said.

In fact, according to the scientists, part of the fish success as a mimic was attributed to its consideration for the species it imitated.

"The fish that are being mimicked do not seem to react to the presence of fangblenny. Mimics often hang around cleaner fish, but although fish come to visit cleaners to have their parasites removed, fangblennies do not attack these fish but instead target passing reef fish.

"We think that this may help maintain the relationship between cleaner fish and mimic. If fangblennies attacked fish being cleaned, then cleaner fish would probably chase them away from their territory," Dr Cheney said.

Bureau Report
Photos by John Natoli

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World’s smallest periscope

Washington, Feb 27: A team of scientists at Vanderbilt University in the US has invented the world’s smallest version of the periscope and are using it to look at cells and other micro-organisms from several sides at once.

“With an off-the-shelf laboratory microscope you only see cells from one side, the top,” said team member Chris Janetopoulos, assistant professor of biological sciences.

“Not only can we see the tops of cells, we can view their sides as well – something biologists almost never see,” he added.

The researchers have dubbed their devices “mirrored pyramidal wells.”

As the name implies, they consist of pyramidal-shaped cavities molded into silicon whose interior surfaces are coated with a reflective layer of gold or platinum.

They are microscopic in dimension – about the width of a human hair – and can be made in a range of sizes to view different-sized objects.

When a cell is placed in such a well and viewed with a regular optical microscope, the researcher can see several sides simultaneously.

“This technology is exciting because these mirrored wells can be made at very low cost, unlike other, more complex methods for 3D microscopy,” said Assistant Professor of the Practice of Biomedical Engineering Kevin Seale.

According to Ron Reiserer, a lab manager at the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE), “This could easily become as ubiquitous as the microscope slide and could replace more expensive methods currently used to position individual cells.”

So far, the researchers have used the mirrored wells to examine how protozoa swim and cells divide.

“The method is particularly well suited for studying dynamic processes within cells because it can follow them in three dimensions,” said Janetopoulos.

Researchers in his lab have used the wells to track the 3D position of the centrosome – the specialized region of a cell next to the nucleus that is the assembly point where the microscopic polymer tubes that serve as part of the cell’s cytoskeleton are assembled before cell division and broken down afterwards.

The mirrored pyramidal wells provide a high resolution, multi-vantage-point form of microscopy that also makes it easier for researchers to measure a number of important cell properties.

In addition, John P. Wikswo, Gordon A. Cain University Professor and Director of VIIBRE, and, Dmitry A. Markov, research associate in biomedical engineering, plan to create mirrored microchannels to measure how cells are deformed under stress induced by fluid flowing through hair-width channels in order to determine how fluid flow affects cell behavior and attachment.

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Martian moon Phobos would be visited by "Earthlings"

Washington, Feb 26: Soon, the Martian moon Phobos would be visited by "Earthlings", in the form of an assortment of critters and microbes scheduled to make a round-trip journey to the natural satellite as passengers aboard a Russian spacecraft, scheduled to launch in October this year.

According to a report in Discovery News, the mission, called Phobos-Grunt, aims to return samples of the Martian moon to Earth for analysis.

It will be the first Russian-led mission to Mars since the loss of the Phobos 1 and Phobos 2 probes in 1988 and the botched launch of the Mars 96 spacecraft.

"I wish them luck," said University of Colorado planetary scientist Larry Esposito, who was a science team member on two of the failed Russian missions. "It's an opportunity to look at a primitive body in the solar system," he added.

In addition to planetary sciences, two teams of researchers are interested in learning how living organisms fare during the three-year round-trip journey to Mars.

The Pasadena, California-based Planetary Society is flying 10 different species in a small canister to test a theory that life could have been carried to Earth inside meteorites.

The samples include tardigrades - also known as water bears - seeds and microscopic bacteria.

"The organisms are being sent in a dormant state, like spores," program manager Bruce Betts told Discovery News.

Upon return to Earth, the organisms will be revived and tested to see if they can reproduce.

Russia's Space Research Institute in Moscow has a more ambitious plan.

Scientists there are proposing to send crustaceans, mosquito larvae, bacteria and fungi to visit Phobos and then return the critters to Earth.

The point of the Russian experiment is to study how cosmic radiation affects living organisms during the various stages of flight.

Phobos-Grunt also includes a small satellite built by China known as Yinghuo-1, which will ride piggyback with it and then be released for an independent study of Mars.

According to astrobiologist Jack Farmer, with Arizona State University in Tucson, the Phobos-Grunt mission is a good opportunity to test techniques and procedures to assure Mars samples do not become contaminated upon reaching Earth, and vice-versa.

Phobos is not regarded as a potential haven for extraterrestrial life, but it hasn't been ruled out either.

Its visitors will remain contained during their stay on Phobos, but even if they were somehow released, Farmer believes their chances of survival are very slim.

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Ozone-depleting species found

Washington, Feb 26: Using data from the satellite-based MIPAS and GOME-2 instruments, scientists have for the first time detected important ozone-depleting species in the atmosphere.

These new measurements will help scientists to better understand sources of these bromine species and to improve simulations of stratospheric ozone chemistry.

Despite the detection of bromine monoxide (BrO) in the atmosphere some 20 years ago, bromine nitrate (BrONO2) was first observed in 2008 when scientists from the Karlsruhe Institute of Technology discovered the gas's weak signal with data from MIPAS (the Michelson Interferometer for Passive Atmospheric Sounding).

"By comparing the novel MIPAS BrONO2 dataset with model calculations and BrO measurements by SCIAMACHY on Envisat, our general understanding of stratospheric bromine chemistry has been clearly confirmed," said Michael Hopfner of Germany's Karlsruhe Institute of Technology.

"These new observations also enable an independent estimation of the total amount of bromine in the stratosphere, which is important for understanding the origins of stratospheric bromine," he added.

The stratospheric ozone layer that protects life on Earth from harmful ultraviolet rays is vulnerable to the presence of certain chemicals in the atmosphere such as chlorine and bromine.

In spite of its much smaller concentrations, bromine is actually, after chlorine, the second most important halogen species destroying ozone in the stratosphere.

Since chlorine levels in the stratosphere have been dropping since the ban on man-made chlorofluorocarbons (CFCs), bromine will become even more important in stratospheric ozone chemistry.

Bromine's importance will increase in part because there are more natural sources, such as volcanoes, for bromine emissions than for chlorine.

Volcanoes have long been known to play an important role in influencing stratospheric ozone chemistry because of the gases and particles they shoot into the atmosphere.

New findings from space suggest they are also a very important source of atmospheric bromine.

The reactive chemical bromine monoxide (BrO) has been measured in a number of volcanic plumes around the globe, but until recently it had never been measured by a space instrument.

In August 2008, the Kasatochi Volcano in Alaska's Aleutian Islands erupted explosively, sending a cloud of volcanic ash and gas more than 11 km into the atmosphere.

The following day, scientists from the Brussels-based Belgian Institute for Space Aeronomy identified high bromine concentrations in the vicinity of the volcano with Envisat's SCIAMACHY instrument and the Global Ozone Monitoring Experiment-2 (GOME-2) instrument aboard MetOp-A.

According to Michel Van Roozendael from the Belgian Institute for Space Aeronomy, "The total mass of reactive bromine released in the atmosphere was estimated around 50 to 120 tons, which corresponds to approximately 25 percent of the previously estimated total annual mass of reactive bromine emitted by volcanic activity."

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Bizarre ecosystem in Lake Huron

Washington, Feb 25: Scientists have detected sinkholes that host exotic and bizarre ecosystems below the surface of Lake Huron, the third largest of North America’s Great Lakes, where the fish typical of the huge freshwater lake are rarely to be seen.

Instead, brilliant purple mats of cyanobacteria, which are cousins of microbes found at the bottoms of permanently ice-covered lakes in Antarctica, and pallid, floating pony-tails of other microbial life thrive in the dense, salty water that’s hostile to most familiar, larger forms of life because it lacks oxygen.

According to Bopaiah A. Biddanda of Grand Valley State University, in Muskegon, Michigan, groundwater from beneath Lake Huron is dissolving minerals from the defunct seabed and carrying them into the lake to form these exotic, extreme environments.

Those ecosystems are in a class not only with Antarctic lakes, but also with deep-sea, hydrothermal vents and cold seeps.

“You have this pristine fresh water lake that has what amounts to materials from 400 million years ago being pushed out into the lake,” said team co-leader Steven A. Ruberg of the Great Lakes Environmental Research Laboratory of the National Oceanic and Atmospheric Administration (NOAA).

The scientists report that some deep sinkholes act as catch basins for dead and decaying plant and animal matter and collect a soft black sludge of sediment topped by a bacterial film.

In the oxygen-depleted water, cyanobacteria carry out photosynthesis using sulfur compounds rather than water and give off hydrogen sulfide, the gas associated with rotting eggs.

Where the sinkholes are deeper still and light fails, microorganisms use chemical means rather than photosynthesis to metabolize the sulfurous nutrients.

Biddanda, Ruberg, and their team are probing the origins of ancient minerals flowing in from beneath this fresh inland sea, striving to understand how long ago the minerals were deposited that are now entering the lake and how fast the salty brew containing them is arriving.

The scientists also plan to chart transitions from light, oxygen-rich, fresh water near the lake’s surface to dark, anoxic, salty soup down inside the sinkholes.

The sinkhole research may shed light on how similar microbial communities can arise in environments as disparate as Antarctic lakes, deep-sea vents, and freshwater-lake sinkholes.

“It might also lead to the discovery of novel organisms and previously unknown biochemical processes, furthering our exploration of life on Earth,” said Biddanda.

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Harappa

The type site of the Harappan (Indus) civilization, Harappa is a major city located in the Punjab, south asia, and is thought to have been at its height between 2500 and 2000 b.c. Harappa was recognized as an archaeological site in 1826, but research had to wait for nearly a century when, between 1920 and 1921, Rai Bahadur Daya Ram Sahni of the Archaeological Survey of India began to explore the site. M.S. Vats continued the work during the time before the beginning of World War II, and after the war, sir Mortimer Wheeler, during his time at the Archaeological Survey of India, dug for a season in 1946. Another long hiatus in activity was broken in 1986 when George Dales began excavations here.

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One of the most fascinating yet mysterious cultures of the ancient world is the Harappan civilization. This culture existed along the Indus River in present day Pakistan and India. It was named after the city of Harappa which it was centered around. Harappa and the city of Mohenjo-Daro were the greatest achievements of the Indus valley civilization. These cities are well known for their impressive, organized and regular layout, road and street network, drainage and step-wells for water. Over one hundred other towns and villages also existed in this region. Only part of this language has been deciphered today, leaving numerous questions about this civilization unanswered.

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The Harappa civilization existed by the banks of Indus river for more than 3000 years ending somewhere around 2000 - 1500 BC. Their trade activities included both exchange of goods as well as paying by money which was represented by bronze coins that were found at the site during the excavation. Their trade with Mesopotamia took place both by road and river as they had floating goods carriers for the purpose.

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The Harappans used chisels, pickaxes, and saws. The saws they used had undulated edges so that dust escaped from the cut that they were sawing. These tools were most likely made of copper, as copper tools and weapons have been found at Harappan sites.

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By far the most exquisite but most obscure artifacts unearthed to date are the small, square steatite seals engraved with human or animal motifs. Large numbers of the seals have been found at Mohenjo-daro, many bearing pictographic inscriptions generally thought to be a kind of script. Despite the efforts of philologists from all parts of the world, and despite the use of modern cryptographic analysis, the script remains undeciphered. It is also unknown if it reflects proto-Dravidian, proto-Sramanic (Jain), non-Vedic (non-Hindu or non-Brahmnic), or is perhaps related to Brāhmī script. Similar Brāhmī inscriptions can be found at various Jain sites of present day Tamil Nadu in India.

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Each city in the Indus Valley was surrounded by massive walls and gateways. The walls were built to control trade and also to stop the city from being flooded. Each part of the city was made up of walled sections. Each section included different buildings such as: Public buildings, houses, markets, and craft workshops.

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Houses and other buildings were made of sun-dried or kiln-fired mud brick. These bricks were so strong, that they have stood up to thousands of years of wear. Each house had an indoor and outdoor kitchen. The outdoor kitchen would be used when it was warmer (so that the oven wouldn’t heat up the house), and the indoor kitchen for use when it was colder. In present day, village houses in this region (e.g. in Kachchh) have two kitchens (outdoor and indoor). They use indoor kitchen mostly as store house and use as cooking place only when there is raining outside, otherwise prefer using outdoor kitchen. This is because people use dry shrub and cow dung as cooking fuel which is very smoky and makes indoor cooking difficult.

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Some believe that they were overrun by the war-like Aryans, the Indo-Europeans who, like a storm, rushed in from Euro-Asia and overran Persia and northern India. Some believe that the periodic and frequently destructive flooding of the Indus finally took its toll on the economic health of the civilization. It is possible that the periodic changes of course that the Indus undergoes also contributed to its decline. All we know is that somewhere between 1800 and 1700 BC, the Harappan cities and towns were abandoned and finally reclaimed by the rich soil they had sprung from.

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Dino-killing meteorite did not start wildfires 65 million years ago

London, Feb 24: The results of a new research indicate that the ‘dinosaur-killing’ meteorite that struck Earth at the end of the Cretaceous period 65 million years ago did not start global wildfires.

The impact of a huge meteorite at the end of the Cretaceous period 65 million years ago is generally held responsible for the sudden demise of 60–80 percent of all species on Earth.

But, according to a report in Nature News, new results challenge the common idea that the extinctions were partly caused by global wildfires triggered by the violent impact.

Researcher Claire Belcher and colleagues at Royal Holloway University of London in Surrey, UK, have said that the widespread soot deposits in sedimentary rocks formed at the time of the putative impact are not, as previously asserted, evidence of runaway fires caused by the meteorite’s impact.

They have analysed the mixtures of carbon-based molecules called polycyclic aromatic hydrocarbons (PAHs) in the sooty material from these rocks, and find that the compositions of the mixtures don’t match those typically produced by burning vegetation.

Instead, they resemble those formed when hydrocarbons such as gas and oil are burnt.

The researchers think that the soot comes from combustion of hydrocarbons within the rocks of the impact site itself — thought to be the region around Chicxulub on the north coast of the Mexican Yucatan peninsula, where a now partly submerged crater about 180 km across has been dated to the time of the mass extinction that separates the Cretaceous from the Tertiary period.

For several years now, Belcher and her colleagues have been casting doubt on the idea that the Earth was engulfed in flames for years after the impact.

In 2003, they reported that rock strata in North America dating to the Cretaceous–Tertiary boundary showed little evidence of charcoal, which would be expected to be produced from burning vegetation.

Instead, they speculated that the soot in these layers came from combustion of hydrocarbons.

Now, the team claim to have clinching proof of that: Chemical fingerprints of the source of the soot, in the form of 21 different PAHs separated and identified using the technique of gas chromatography.

According to Belcher, the new results also answer criticisms of their earlier work on the apparent lack of charcoal in the soot.

“The soot itself undoubtedly had a significant impact on life at the time, but it is unlikely to represent the signature of global wildfires”, said Belcher.

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"Einstein's telescope" to know the universe

Washington, Feb 21: Scientists are using the phenomenon of gravitational lensing, which they call "Einstein's telescope", as a scientific "instrument" in their quest to determine the makeup of the universe.

The University of Chicago's Evalyn Gates's new book, "Einstein's Telescope: The Hunt for Dark Matter and Dark Energy in the Universe", explains how it works.

Although based on Albert Einstein's general theory of relativity, the effect is easily demonstrated.

According to Gates, look at a light through the bottom of a wine glass, and see the resulting light distortion.

"Einstein's telescope is using the universe itself as a lens through which we can seek out galaxies that would otherwise be too faint to be seen," said Gates, Assistant Director of the University's Kavli Institute for Cosmological Physics.

Long ago, Einstein recognized the potential existence of gravitational lensing, a consequence of his theory of general relativity.

According to general relativity, celestial objects create dimples in space-time that bend the light traveling from behind.

Einstein realized that the gravitational influence of a foreground star could theoretically bend the light of another star sitting almost directly far beyond it, producing two images of the background star.

"Gravitational lensing magnifies things as well as making multiple images and distorting the shape of images, so you can actually use it as a magnifying glass," Gates explained.

But, assuming that the effect would be too weak to detect, Einstein immediately dismissed its significance.

"What he didn't anticipate, among other things, were the incredible leaps forward in telescope technology," said Gates.

Astronomers now use gravitational lensing to look for dark matter and the imprint of dark energy, two of the greatest modern scientific mysteries.

"We can't see dark energy directly by any means, but we're looking for how it has sculpted the matter distribution of the universe over the past few billion years, since it's been the dominant factor, and also how it has affected the rate at which the Universe is expanding," Gates said.

Gravitational lensing is essentially the only method astronomers have for tracing out the web of dark matter that pervades the Universe, and determining how dark energy has impacted the evolution of this web.

"It's really hot scientifically," she said.

"Gravitational lensing is going to allow us to image the universe in ways that wouldn't have been possible even 50 years ago," said Gates.

"It may lead us to another revolution in our understanding of the most fundamental aspects of the universe, time, matter, and energy," she added.

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Laser imaging investigates how fat or thin dinos were

Washington, Feb 21: Scientists at the University of Manchester, UK, are using laser imaging to investigate how fat or thin Tyrannosaurus Rex and his fellow dinosaurs were.

Karl Bates and his colleagues in the palaeontology and biomechanics research group have reconstructed the bodies of five dinosaurs, two T. rex (Stan at the Manchester Museum and the Museum of the Rockies cast MOR555), an Acrocanthosaurus atokensis, a Strutiomimum sedens and an Edmontosaurus annectens.

The team found that the smaller Museum of the Rockies T rex could have weighed anywhere between 5.5 and 7 tonnes, while the larger specimen might have weighed as much as 8 tonnes.

Acrocanthosaurus atokensis was a large predatory dinosaur that looked like T rex, but with large spines on its back and roamed the earth much earlier in the mid Cretaceous period, around 110 million years ago.

The team suggests that Acrocanthosaurus probably weighed in at a similar mass to MOR555 and other medium sized adult T rex at about 6 tonnes.

The Strutiomimum sedens, whose name means “ostrich mimic”, lived alongside T rex in the late Cretaceous period and probably weighed somewhere between 0.4 – 0.6 tonnes

The reconstruction of Edmontosaurus annectens, a plant-eating hadrosaur was based on a juvenile specimen, but still weighed in at between 0.8 – 0.95 tonnes.

The team used laser scanning (LiDAR) and computer modelling methods to create a range of 3D models of the specimens, attempting to reconstruct their body sizes and shape as in life.

This has allowed calculation of body segment masses, centres of mass and moments of inertia for each animal – all the information that is needed to analyse body movements.

Having created their ‘best-guess’ reconstruction of each animal, they then varied the volumes of body segments and respiratory organs to find the maximum plausible range of mass for the animals.

According to the team, the lower weight estimates are most likely to be correct as there is no good reason for the dinosaurs to weigh more than they need to as this would affect their speed, energy use and demands on the respiratory system.

“Our technique allows people to see and decide for themselves how fat or thin the dinosaurs might have been in life. You can see the skeleton with a belly,” Karl said.

“Anyone from a five-year-old to a Professor can see it and say, ‘I think this reconstruction is too fat or too thin’,” he added.

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Space rock seen ahead of collision with Earth

London, Feb 20: Scientists have, for the first time, detected a space rock ahead of a collision with Earth, watched it streak through the atmosphere, and then recovered pieces of it.

An analysis of the meteorites could shed light on conditions in the early solar system more than 4 billion years ago.

When the asteroid, called 2008 TC3, was discovered on 6 October last year, it was just 20 hours away from hitting Earth.

Though the warning period was short, it was the first time a space rock had been found before it impacted the planet.

Orbital calculations predicted the object would plunge into the atmosphere above Sudan at 0246 GMT on 7 October, and it arrived right on time.

Observations suggested it was no more than 5 meters across, too small to survive intact all the way to the ground and cause damage.

The brilliant fireball it made as it descended through the atmosphere was seen far in the distance by the crew of a KLM airliner, and was observed by various satellites, including a weather satellite called Meteosat-8.

Now, according to a report in New Scientist, a team of meteorite hunters has found fragments of the object.

The meteorites are a unique group in that they come from an object seen hurtling through space before its plunge into Earth’s atmosphere.

Students from the University of Khartoum found the first fragments, led by Dr Muawia Shaddad, using data provided by NASA to hone in on where fragments were likely to be found.

Lindley Johnson, head of NASA’s Near-Earth Object Program office at the agency’s headquarters in Washington, DC, reported the find in Vienna, at a United Nations meeting discussing near-Earth object (NEO) impacts.

Donald Yeomans, who manages NASA’s efforts to find and track NEOs at the Jet Propulsion Laboratory (JPL) in Pasadena, California, confirmed that “quite a few” fragments have been found.

Before the fragments were found, meteorite expert Peter Brown of the University of Western Ontario in Canada said that the asteroid was likely made of relatively weak material, given that 2008 TC3 broke up unusually quickly once it hit the atmosphere, exploding about 37 kilometres above ground.

According to researchers, the 2008 TC3 meteorites could be especially illuminating because the parent object was observed in space before the breakup, allowing scientists to calculate its former orbit around the Sun.

This provides precious information connecting the meteorites to their place of origin in the solar system.

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First mission to search Earth-like planets outside the solar system

New York, Feb 20: NASA is scheduled to launch its first mission to search Earth-like planets outside the solar system.

Liquid water is believed to be essential for the formation of life.

The US agency's Kepler spacecraft will be blasted into space from Cape Canaveral Air Force Station, Florida, on March 5 aboard a Delta II rocket.

"Kepler is a critical component in NASA's broader efforts to ultimately find and study planets where Earth-like conditions may be present," Jon Morse, Astrophysics Division Director at the agency's Headquarters in Washington said.

Some solar systems are oriented in such a way that when their planets cross in front of their stars, as seen from our Earthly point of view, cause their stars' light to slightly dim, or wink.

The Kepler, equipped with an especially designed telescope to detect the periodic dimming of stars that planets cause as they pass by, will note even the faintest of these winks, registering changes in brightness of only 20 parts per million, the Director said.

By staring at one large patch of sky for the duration of its lifetime, the telescope will be able to watch planets periodically transit their stars over multiple cycles. This will allow astronomers to confirm the presence of planets.

The mission will spend three and a half years surveying more than 100,000 sun-like stars in the Cygnus-Lyra region of our Milky Way galaxy, Morse said.

Earth-size planets in habitable zones would theoretically take about a year to complete one orbit, so Kepler will monitor those stars for at least three years to confirm their presence, he said.

"If Earth-size planets are common in the habitable zone, Kepler could find dozens; if those planets are rare, Kepler might find none," Morse added.

"Finding few or no Earths indicates that we might be alone".

"Kepler is a critical cornerstone in understanding what types of planets are formed around other stars," exoplanet hunter Debra Fischer of San Francisco State University said.

"The discoveries that emerge will be used immediately to study the atmospheres of large, gas exoplanets with Spitzer.

And the statistics that are compiled will help us chart a course toward one day imaging a pale blue dot like our planet, orbiting another star in our galaxy."

"In the end, the mission will be our first step toward answering a question posed by the ancient Greeks: are there other worlds like ours or are we alone?" NASA said.

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Solved a major mystery about the origins of life on earth

Toronto, Feb 20: Canadian scientists claim to have solved a major mystery about the origins of life on earth.

The claims come at a time when the world is celebrating the bicentennial anniversary of the Father of Evolution, Charles Darwin.

Two Montreal University scientists have proposed a new theory to show how a universal molecular machine, called ribosome self-assembled or self-organized itself to become a critical step in generating all life on earth.

''While the ribosome is a complex structure, it features a clear hierarchy that emerged based on basic chemical principles,'' said biochemistry professor Sergey Steinberg, who made the discovery with student Konstantin Bokov, in a university statement on Thursday.

He said his theory explains what people imagine as ''unseen forces at work when such complex structures emerge in nature.''

The Canadian scientist said the ribosome is an enormous molecule responsible for translating the messages (carried in the genetic code of all organisms) into proteins that carry out all functions, including replicating the genome itself.

Compared to biological molecules, he said, ribosomes are immense and very complex.

''Though visible only through lenses of the most powerful microscopes, comparing most other biological molecules to this behemoth (ribosome) is like comparing a tricycle to a jumbo jet,'' said Steinberg.

He said he spent years pondering how a complex ribosome could have assembled itself from smaller building blocks that existed on the early earth.

His work, he said, led to the discovery that the ribosome must have assembled itself from basic building blocks ''in a very specific order; otherwise it would have fallen apart.''

Though chemists have observed examples of self-organizing behaviour in simple molecules, there has been no such explanation about the complex self-assembly of ribosome’s to this date, he said.

''Thanks to the research of Sergey Steinberg and Konstantin Bokov, scientists now have a glimpse of one key event that emerged spontaneously out of the primordial chemical soup of the early earth,'' the university statement quoted Stephen Michnick, who is Canada Research Chair in Integrative Genomics, as saying.

'''Perhaps in the near future we may look forward to more discoveries that will take us beyond the world of Darwin into an understanding of the basic chemical principles that drove the emergence of life on our planet and perhaps beyond.''

The study has been published in the journal Nature.

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NASA may have found water on Mars

London, Feb 18: If reports are to be believed, NASA’s Phoenix Lander may have captured the first images of liquid water on Mars, droplets that apparently splashed onto the spacecraft’s leg during landing.

According to a report in New Scientist, the controversial observation could be explained by the mission’s previous discovery of perchlorate salts in the soil, since the salts can keep water liquid at sub-zero temperatures.

Researchers have said that this antifreeze effect makes it possible for liquid water to be widespread just below the surface of Mars, but point out that even if it is there, it may be too salty to support life as we know it.

A few days after Phoenix landed on 25 May 2008, it sent back an image showing mysterious splotches of material attached to one of its legs.

Strangely, the splotches grew in size over the next few weeks, and Phoenix scientists have been debating the origin of the objects ever since.

One intriguing possibility is that they were droplets of salty water that grew by absorbing water vapour from the atmosphere.

Arguments for this idea are laid out in a study by Phoenix team member Nilton Renno of the University of Michigan in Ann Arbor, and co-authored by 21 other researchers, including the mission’s chief scientist, Peter Smith of the University of Arizona in Tucson.

Gaping canyons and river-like channels attest to the fact that large amounts of liquid water once flowed on Mars.

The surface now appears dry, though the changing appearance of some crater gullies over a period of several years has hinted at the existence of subsurface aquifers that occasionally release bursts of water.

At Phoenix’s landing site in the Martian arctic, it is too cold for pure water to exist in liquid form - the temperature never rose above –20 degrees Celsius during the five-month-long mission.

But, salty water can stay liquid at much lower temperatures. And perchlorate salts, which were detected for the first time on Mars by Phoenix, would have an especially dramatic ‘antifreeze’ effect.

An extremely salty mixture of water and perchlorates could stay liquid all the way down to –70 degrees C.

If perchlorates are widespread on Mars at high concentrations, then pockets of liquid water might also be widespread below the planet's surface.

“According to my calculations, you can have liquid saline solutions just below the surface almost anywhere on Mars,” Renno told New Scientist.

And Phoenix may have already snapped images of water kept liquid thanks to perchlorate salts.

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Dark and gloomy future for our Universe

Washington, Feb 17: A cosmologist has predicted a dark and gloomy future for our Universe, where an observer would see that all evidence of the big bang has disappeared and the entire cosmos have gone into a static eternity.

The prediction has been made by Lawrence Krauss, a theoretical physicist and cosmologist at Arizona State University (ASU).

In his lecture, titled “Our Miserable Future,” Krauss discussed the impact of new discoveries, including the key facts that the universe is flat and the dominant form of energy in the universe resides in empty space.

While significantly impacting our understanding of the future of our universe, these changes have also effected the questions asked in modern cosmology, forcing researchers to confront several profound questions.

“Are fundamental cosmological questions falsifiable? Are the laws of nature fixed, or environmental? Are there fundamental cosmological limits to knowledge, and to life?” asked Krauss, a professor in ASU’s College of Liberal Arts and Sciences, where he is a faculty member in the School of Earth and Space Exploration and the Physics Department.

“The revolutionary developments of the past decade have forced us to confront truly fundamental questions at the basis of science,” he added.

“In the far future, all evidence of the big bang will disappear and scientists will think we live in a static eternal universe,” explained Krauss.

According to Krauss, looking out at a night sky twinkling with distant light, it’s a disturbing challenge to imagine that one day – far in the future – we will be alone in a dark empty universe.

The rest of the universe will disappear before our very eyes, he added.

“We may live at a very special time in the history of the universe. Understanding why that appears to be the case is one of the biggest open questions in cosmology,” said Krauss.

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Earth-like planets in our neighborhood

Earth-like planets with life-sustaining conditions are spinning around stars in our galactic neighbourhood, US astrophysicists say. They just haven't been found yet.

"There are something like a few dozen solar-type stars within something like 30 light years of the sun, and I would think that a good number of those -- perhaps half of them have Earth-like planets," Alan Boss told the annual meeting of the American Association for the Advancement of Science (AASS).

"So I think there is a very good chance that we will find some Earth-like planets within 10, 20 or 30 light years of the Sun," the astrophysicist from the Carnegie Institution for Science told his AAAS colleagues meeting here since Thursday.

One light year equals the distance light travels in one year at the speed of 300,000 kilometers (186,000 miles) per second, or 9.46 trillion kilometers (5.88 trillion miles).

Boss is convinced that the Earth-sized planets could be found either by the Kepler space telescope US space agency NASA plans to launch on March 5, or by the French-European telescope-equipped COROT satellite that has been in orbit since 2006.

"I will be absolutely astonished if Kepler or COROT didn't find any earth-like planets, because basically we are finding them already," Boss told a press conference Saturday when asked why he felt so confident.

COROT has already discovered the smallest extraterrestrial planet so far. At a little over twice the Earth's diameter, the planet is very close to its star and very hot, astronomers reported earlier this month.

Boss said Kepler and COROT will likely find so many Earth-like planets that they will "tell us how to go ahead and build the next space telescope to go and examine these planets, after we know they are there."

The images from those new planets, he added, should identify "light from their atmosphere and tell us if they have perhaps methane and oxygen. That will be pretty strong proof they are not only habitable but actually are inhabited."

"I am not talking about a planet with intelligence on it. I simply say if you have a habitable world ... sitting there, with the right temperature with water for a billion years, something is going to come out of it.

"At least we will have microbes," said Boss.

Raymond Jeanloz, professor of astronomy, earth and planetary science at the University of California at Berkeley, delved further into the matter.

"I can strongly reinforce Alan Boss's point that life from this perspective that is very much driven by our understanding from the genome, is in some sense 'inevitable,'" if the same basic building blocks of life that exist on Earth are present.

"The distinction will be more between a class of life form that can communicate with us versus ... the vast abundance of life forms recorded in our fossil records, namely microbial life."

On the possibility of finding an extra-terrestrial civilization, Boss said the research "is an interesting one and an important one to do because, even though there is a small probability of success, if you actually find something, it is an immense discovery to make.

"So you say, 'yes, this is worth doing.'"

Bureau Report

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US cosmologist explores notion of 'alien' life on Earth

Chicago, Feb 15: Internationally acclaimed theoretical physicist and cosmologist Paul Davies has decided to challenge the orthodox view that there is only one form of life on Earth.

In a lecture titled "Shadow Life: Life As We Don''t Yet Know It" to be delivered today at the annual meeting of the American Association for the Advancement of Science, Davies is likely to espouse the view that there is alien life on Earth.

His presentation is part of the symposium "Weird Life."

"Life as we know it appears to have had a single common ancestor, yet, could life on Earth have started many times? Might it exist on Earth today in extreme environments and remain undetected because our techniques are customized to the biochemistry of known life?" asks Davies, who also is the director of the BEYOND Center for Fundamental Concepts in Science at Arizona State University in the College of Liberal Arts and Sciences.

In the lecture, Davies will present, challenge and extend some of the conclusions from a July 2007 report by the National Research Council.

That report looked at whether the search for life should include "weird life" – described by the Council as "life with an alternative biochemistry to that of life on Earth."

"If a bio-chemically weird microorganism should be discovered, its status as evidence for a second genesis, as opposed to a new branch on our own tree of life, will depend on how fundamentally it differs from known life," wrote Davies in the November 19, 2007, issue of Scientific American.

Davies and other pioneers who speculate that life on Earth may have started many times are wondering "why we have overlooked this idea for so long?"

The concept of a shadow biosphere, according to Davies, "is still just a theory.”

“If someone discovers shadow life or weird life it will be the biggest sensation in biology since Darwin. We are simply saying, ''Why not let''s take a look for it?'' It doesn''t cost much (compared to looking for weird life on Mars, say), and, it might be right under our noses," he said.

Davies, whose research is steeped in the branches of physics that deal with quantum gravity – an attempt to reconcile theories of the very large and the very small – is a prolific author (27 books, both popular and specialty works) and is a provocative speaker (he delivered the 1995 Templeton Prize address after receiving the prestigious award for initiating "a new dialogue between science and religion that is having worldwide repercussions").

He is putting the finishing touches on "The Eerie Silence," to be published in 2010 to coincide with the 50th anniversary of the SETI Institute. According to Davies, the book is "a comprehensive fresh look at the entire SETI enterprise."

ANI

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Water near Mars’ surface

London, February 15: Scientists believe that the dark streaks that appear on Mars’ polar dunes every spring may be caused by liquid water near the surface, a fillip for the hunt for life.

The dark streaks of sand a few metres wide slide downslope at about a metre a day.

"They show a branching pattern, so it seems like some liquid material is flowing," New Scientist magazine quoted Akos Kereszturi, of the Collegium Budapest in Hungary, as saying.

Kereszturi is of the opinion that they appear when molecules in surface water ice are attracted to molecules in the minerals below.

Using computer models, his team has come to the conclusion that this melts an ultrathin layer, which lubricates grains within the dune so they flow downwards.

"That liquid water could exist near Mars's surface at this moment is really interesting, especially for its impact on the search for life," says Matt Balme of the UK's Open University in Milton Keynes.

ANI

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'Pre-historic Viagra' found in Siberian mammoth DNA could boost your sex life and let you live longer

Russian scientists working at a 'graveyard' of extinct mammoths and woolly rhinos in Siberia claim to have found a bacterium which could prolong human virility and life span.

Already nicknamed 'pre-historic Viagra', experiments on mice show it increases mental alertness, physical prowess and sexual activity, with females reportedly having babies into old age.

The findings are an unexpected byproduct of detailed research into the extinct creatures whose well-preserved remains have been found in the permafrost Yakutia region of eastern Russia.

Scientists in Russia, America and Japan are working on DNA studies which could lead to attempts to clone both the mammoth and the woolly rhinoceros, bringing them back from the dead.

But after an expedition to 'Mammoth Mountain' - a remote graveyard of pre-historic creatures in the frozen Yakutia region of Siberia - Professor Anatoli Broushkov of Tyumen University said: 'We have found what seems to be a very old bacterium which is still living in the sandy soil of the permafrost.

'We decoded a part of the DNA, and the preliminary results confirmed there is no record of such a bacterium in the world.

'It is a truly unique event, absolutely extraordinary, as scientists never before managed to prove such phenomenally long life for a bacterium.'

The bacterium was located in the same permafrost where scientists have discovered the remains of the extinct mammoths, but they do not believe it is linked to these creatures.

The mammoths lived from about 4.8 million years ago to around 4,500 years ago.

Russian scientists say that the age of the bacterium is three to five million years old, but the first results of laboratory experiments are seen as sensational.

'We made a set of tests and the results prove that simple organisms like fruit flies and mice live longer after being vaccinated with the ancient bacterium extract,' said Professor Broushkov.

'We multiplied the bacterium and tested it on typical laboratory living biological systems', said scientist Vera Samsonova.

'Some elderly mice demonstrated a growth of physical, mental and sexual activity, while some females even had babies aged at the human equivalent of 70.'

Professor Broushkov said: 'We can't promise an immortality lotion, but realistically if we find out why this bacterium lives so long, it will have implications for anti-ageing cures.

'Even if we managed to prolong life for ten years, it would be fantastic.'

He said interest has been show already by Russian oligarchs keen to invest in developing possible anti-ageing drugs.

Source

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Dark comets may pose deadly threat to Earth

London, Feb 12: Astronomers have claimed that swathes of dark comets may be prowling the solar system, posing a deadly threat to Earth.

According to a report in New Scientist, UK-based astronomers Bill Napier at Cardiff University and David Asher at Armagh Observatory in Northern Ireland have made the claim that many such comets could be going undetected.

“There is a case to be made that dark, dormant comets are a significant but largely unseen hazard,” said Napier.

In previous work, Napier and Janaki Wickramasinghe, also at Cardiff, have suggested that when the solar system periodically passes through the galactic plane, it nudges comets in our direction.

These periodic comet showers appear to correlate with the dates of ancient impact craters found on Earth, which would suggest that most impactors in the past were comets, not asteroids.

Now, Napier and Asher warn that some of these comets may still be zipping around the solar system. Other observations support their case.

The rate that bright comets enter the solar system implies there should be around 3000 of them buzzing around, and yet only 25 are known.

According to the astronomers, we may not see them, simply because they are too dark.

Such dark comets are not unheard of. They occur when an “active” comet’s reflective water ice has evaporated away, leaving behind an organic crust that only reflects a small fraction of light.

Clark Chapman at the Southwest Research Institute in Boulder, Colorado, said that such dark comets “would absorb sunlight very well” and so could be detected by the heat they would emit.

ANI

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Scientists map Neanderthal genome

Chicago, Feb 12: In a development which could reveal the links between modern humans and their prehistoric cousins, scientists said they have mapped a first draft of the Neanderthal genome.

Researchers used DNA fragments extracted from three Croatian fossils to map out more than 60 percent of the entire Neanderthal genome by sequencing three billion bases of DNA.

"The Neanderthal genome sequence will clarify the evolutionary relationship between humans and Neanderthals as well as help identify those genetic changes that enabled modern humans to leave Africa and rapidly spread around the world," Germany's Max Planck Institute for Evolutionary Anthropology said in a press release.

"These DNA sequences can now be compared to the previously sequenced human and chimpanzee genomes in order to arrive at some initial insights into how the genome of this extinct form differed from that of modern humans."

Research suggests that the last common ancestor of Neanderthals and humans lived about 660,000 years ago. Neanderthals are widely believed to be the hominid form most closely related to present-day humans, although the precise relationship remains unclear.

The squat, low-browed Neanderthals lived in parts of Europe, Central Asia and the Middle East for around 170,000 years but traces of them disappear some 28,000 years ago, their last known refuge being Gibraltar.

Bureau Report

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Computer simulation reveals dawn of cosmos

Washington, Feb 11: Scientists have used a computer simulation to come up with images that show the formation of the first big galaxies in the Universe, which is literally the ‘cosmic dawn’.

The images, produced by scientists at Durham University’s Institute for Computational Cosmology, predict what the very early Universe would have appeared like 500 million years after the Big Bang.

The Cosmic Dawn began as galaxies began to form out of the debris of massive stars which died explosively shortly after the beginning of the Universe.

The Universe 590 million years after the Big Bang. Credit: Alvaro Orsi, Institute for Computational Cosmology, Durham University.

The Durham calculation predicts where these galaxies appear and how they evolve to the present day, over 13 billion years later.

Gravity produced by dark matter is an essential ingredient in galaxy formation and by studying its effects the scientists eventually hope to learn more about what the substance is.

The Universe 1 billion years after the Big Bang. Credit: Alvaro Orsi, Institute for Computational Cosmology, Durham University.

The work combined a massive simulation showing how structures grow in dark matter with a model showing how normal matter, such as gas, behaves to predict how galaxies grow.

Gas feels the pull of gravity from dark matter and is heated up before cooling by releasing radiation and turning into stars.

The Universe 1.9 billion years after the Big Bang. Credit: Alvaro Orsi, Institute for Computational Cosmology, Durham University.

The simulation images show which galaxies are forming stars most vigorously at a given time.

Although the galaxies are biggest at the present day, the rate at which they are making new stars has dropped greatly compared with the rate in the early Universe.

The calculations of the Durham team, supported by scientists at the Universidad Catolica in Santiago, Chile, can be tested against new observations reaching back to early stages in the history of the Universe almost one billion years after the Big Bang.

According to lead author, Alvaro Orsi, a research postgraduate in Durham University’s Institute for Computational Cosmology (ICC), “We are effectively looking back in time and by doing so we hope to learn how galaxies like our own were made and to understand more about dark matter.”

“The presence of dark matter is the key to building galaxies. Without dark matter, we wouldn’t be here today,” he said.

The Universe today. Credit: Alvaro Orsi, Institute for Computational Cosmology, Durham University.

“Our research predicts which galaxies are growing through the formation of stars at different times in the history of the Universe and how these relate to the dark matter,” said co-author Dr Carlton Baugh, a Royal Society Research Fellow, in the ICC, at Durham University.

“We give the computer what we think is the recipe for galaxy formation and we see what is produced which is then tested against observations of real galaxies,” he added.

ANI

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Life may exist in Mars' Olympus Mons

Washington, Feb 11: A new study has suggested that Olympus Mons, the biggest volcano on Mars, could shelter some sort of life form.

Rising three times higher than Mount Everest, Olympus Mons was active at least 40 million years ago and perhaps more recently.

Magma may still be close enough to the surface to support heat-loving bacteria like those found near hydrothermal vents on Earth.

But, bacteria likely need water to live in, too.

Now, according to a report in Discovery News, Patrick McGovern and Julia Morgan think they may have found it, locked in thick layers of clay-rich sediments beneath the mountain.

Spreading out over an area about the size of Arizona, Olympus Mons’ massive lava flows are bunched up in the southeast, and stretched out in the northwest.

In a detailed computer simulation of the volcano, the researchers found the volcano would only assume its oblong shape if the erupted lava piled on top of layers of weak, water-laden sediments.

Scientists aren’t certain how old Olympus Mons is, but it’s likely that its first eruptions were billions of years ago.

If so, it could have formed in a time when Mars was much warmer and wetter, and trapped a large reservoir beneath it.

Whether or not that reservoir is still warm - and whether is contains life - remains a tantalizing uncertainty. No heat signatures have yet been detected from satellites orbiting the planet, but their instruments can’t penetrate into the subsurface.

“If we were to go there and shove a probe a meter below the surface, you’d get a very different picture of heat flow,” said Brian Hynek of the University of Colorado at Boulder, suggesting the mountain is probably still warm.

Though the blackest depths of a volcano might not seem like the best place to go alien-hunting, life on Earth has been found subsisting two miles down in the crust, and a mile beneath the ocean floor.

“So finding life a mile or so below Olympus Mons’ lava flows is well within the realm of possibility,” Hynek said.

The flows may even act as a kind of insulating blanket, keeping water and heat in, and Mars’ cold, corrosive surface conditions out.

“It’s the natural place I’d go first on an astrobiological expedition to Mars, given that it’s the place where volcanism is strongest and youngest on the planet,” McGovern said.

ANI

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30 mummies found in newly discovered tomb in Egypt

A storehouse of 30 Egyptians mummies has been unearthed inside a 2,600-year-old tomb, in a new round of excavations at the vast necropolis of Saqqara outside Cairo, archeologists said Monday.

The tomb was located at the bottom of a 36 foot (11-meter) deep shaft, announced Egypt's top archaeologist Zahi Hawass and eight of the mummies were in sarcophagi, while the rest had been placed in niches along the wall.

Hawass described the discovery as a "storeroom for mummies," dating to 640 B.C. and the 26th Dynasty, which was Egypt's last independent kingdom before it were overthrown by a succession of foreign conquerors beginning with the Persians.

The tomb was discovered at an even more ancient site dating back to 4,300-year-old 6th Dynasty.

Most of the mummies are poorly preserved and archeologists have yet to determine their identity or why so many are in a single room. One of the sarcophagi is made of wood and bears the name Badi N Huri, but no title.

"This one might have been an important figure, but I can't tell because there was no title," Hawass" assistant Abdel Hakim Karar told The Associated Press.

He added that the rest of the sarcophagi — including four which are tightly sealed — have yet to be opened yet.

Karar added that it was quite unusual for mummies of this late period to be stored in rocky niches.

"Niches were known in the very early dynasties, so to find one for the 26th Dynasty, is something rare," Karar said.

Excavations have been ongoing at Saqqara for 150 years, uncovering a vast necropolis of pyramids and tombs dating mostly from the Old Kingdom, but including sites as recent as the Roman era.

In the past, excavations have focused on just one side of the two nearby pyramids — the famous Step Pyramid of King Djoser and that of Unas, the last king of the 5th Dynasty. The area where the current tomb was found, to the southwest, has been largely untouched by archeologists.

But despite the years of excavation, new finds are constantly being made. In December last year, two tombs were found near the current discovery. The two were built for high officials — one responsible for the quarries used to build the nearby pyramids and other for a woman in charge of procuring entertainers for the pharaohs.

In November, Hawass announced the discovery of a new pyramid at Saqqara, the 118th in Egypt, and the 12th to be found just in Saqqara.

According to Hawass only 30% of Egypt's monuments have been uncovered, with the rest still under the sand.

Copyright 2009 The Associated Press
Photo AP

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