Indian scientist examines possibility of life on other planets

A recent article by Ashwini Kumar Lal, from the Ministry of Statistics and Programme Implementation, Government of India, has examined the possibility of life on planets and satellites within our solar system and beyond.

His article, titled, ''Searching for Life on Habitable Planets and Moons'', has come in the light of findings of numerous space probes and theoretical research undertaken in the fields of astrobiology and observational astronomy over several decades.

In his article, Lal lays stress on the theory of panspermia, which view life as widespread throughout the cosmos.

Panspermia lends support to the possibility of life being found on other planets besides Earth and satellites within the solar system and beyond.

Central to the theories of panspermia is the belief that the "seeds of life" are ubiquitous and that they were embedded in meteors, asteroids, and comets, and deposited upon Earth as well as to other habitable bodies in the universe.

Considerable evidence has been presented in support of pansermia by scientists R.Joseph and by Fred Hoyle and NC Wickramsinghe.

Wickramasinghe and colleagues have provided nearly convincing evidence that dust grains in interstellar clouds could contain spores, desiccated bacteria, and living microbes which survive in comets on cloud condensation to stars and planets.

The large-scale presence of organic molecules in the interstellar clouds, comets and asteroids, and evidence of amino acids in carbonaceous meteorites support a cosmic perspective on the origin of life.

One hundred fifty different chemical compounds, including several organic compounds and amino acids with C, H, O, and N as major constituents have been detected in the interstellar clouds, circumstellar envelopes, and comets since 1965.

Also, biomarkers like glycine and sugar-glycolaldehyde have been identified in Sagittarius B2, a dense star-forming cloud of interstellar gas at the heart of Milky Way Galaxy.

As for the hotspots for search for life within the solar system, Lal cites the research works of Naganuma and Sekine; as well as that of Schulze-Makuch, who have named Mars, the Jovian satellites - Europa, Ganymade, Io, and Callisto; and Saturn''s Enceladus and Titan.

According to Lal, chances for finding life beyond the solar system have brightened up, with the launching of NASA''s Kepler and ESA''s COROT Missions.

While the former has been designed to survey the Milky Way Galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone, the latter will be looking for rocky planets - several times larger than Earth, around nearby stars in our parent galaxy.

The most positive sign for the possibility of life on other worlds has come with the recent discovery of the lightest Earth-like exoplanet with mass only thrice that of Earth with possibly abundant liquid water some 20.5 light years away in the constellation Libra.

ANI

`Blue Moon` eclipse on Dec 31

The year 2009 ends in a "Blue Moon". December has two full moons, the first on Decebmer 2nd and second full moon will take place on December 31.

On December 31, the last day of the year, there will be a partial eclipse of the moon which will be visible from all over India. A small portion of the moon will be darkened.

Technically, the eclipse begins at 22 hours 45 minutes (IST), but for practical purposes the darkening begins 22 minutes after midnight, Dr B G Sidharth, Director, B M Birla Science Centre said in a release here today.

He said that this phenomenon, when two full moons take place within the same month, is not common and when it does happen, the second full moon of the month is called "Blue Moon".

The maximum of the eclipose is reached at 53 minutes past midnight. Even at this time, only a small portion of the moon would appear darkened, he said adding that the eclipse then decreases and is over at 24 minutes past 1 'o' clock of the January, 1.

However, the moon continues to be in the region of partial shadow, which is not a significant sight, till 3.00 am on January 1. There are no precautions to be taken for viewing this eclipse. Similary the belief that one should not move out or eat food during an eclipse has no sceintific bases, he said in the release.

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We might be looking in the wrong places for water on the moon

New observations from the Lunar Reconnaissance Orbiter (LRO) suggest that we might be looking in the wrong places for water on the Moon.

In October, NASA’s LCROSS spacecraft found water when it crashed into a crater called Cabeus that never gets any sunlight.

But, according to a report in New Scientist, new observations from the Lunar Reconnaissance Orbiter (LRO) suggest that many of the permanently shadowed regions near the South Pole are dry and several potentially wet regions are sunlit.

The observations come from the Lunar Exploration Neutron Detector (LEND) experiment, which looks for possible water deposits by measuring neutrons emitted from the moon.

Water or other hydrogen-bearing compounds reduce the number of fast neutrons.

LEND examined 37 permanently shadowed craters near the south pole and found that only three of them – Cabeus, Faustini, and Shoemaker – showed significant amounts of hydrogen.

Several illuminated regions also appear to be hydrogen rich.

“I think we have a paradigm-busting set of observations here,” said Jim Garvin, the chief scientist at NASA’s Goddard Space Flight Center.

LEND’s principal scientist, Igor Mitrofanov of the Russian Space Research Institute, reported these “neutron suppressed regions” last week at the American Geophysical Union meeting in San Francisco.

He believes that a half-metre-thick layer of dry soil may cover a layer of dirty ice, preventing the ice from evaporating into space.

He and his colleagues calculate that the icy layer, which may have been delivered to the moon by asteroids or comets, could contain concentrations of water as high as 3 to 5 per cent.

LRO is expected to continue gathering data for two more years, and LEND’s results will grow more accurate over time.

“I think our story will be a lot sharper by next summer,” Garvin said.

ANI

How bees always manage to land safely

Ever wondered how bees always manage to land on a picnic table, underneath a flower petal, or on a wall of a hive, without crashing or tumbling? Well, scientists have, for the first time, figured out how these insects touch down on all sorts of surfaces, from right side up to upside-down.

To find out, Mandyam Srinivasan, an electrical engineer from the Queensland Brain Institute, The University of Queensland and the Australian Research Council's Vision Centre, and colleagues first built a bee-landing platform that could be inclined at any angle from horizontal to inverted (like a ceiling), then they trained bees to land on it and began filming.

Having collected movies of the bees landing on surfaces ranging from 0deg. to 180deg., and every 10deg. inclination between, the researchers began the painstaking task of manually analysing the bees landing strategies, and saw that the bees'' approach could be broken down into 3 phases.

Initially the bees approached from almost any direction and at any speed, however, as they got closer to the platforms, they slowed dramatically, almost hovering, until they were 16mm from the platform when they ground to a complete halt, hovering for anything ranging from 50ms to over 140ms.

When the surface was horizontal or inclined slightly, the bees' hind legs were almost within touching distance of the surface, so it was simply a matter of the bee gently lowering itself and grabbing hold with its rear feet before lowering the rest of the body.

However, when the insects were landing on surfaces ranging from vertical to ''ceilings'', their antennae were closest to the surface during the hover phase.

The team saw that the antennae grazed the surface and this contact triggered the bees to reach up with the front legs, grasp hold of the surface and then slowly heave their middle and hind legs up too.

"We had not expected the antennae to play a role and the fact that there is a mechanical aspect of this is something that we hadn't thought about," Srinivasan said.

Looking at the antennae's positions, the team realised that in the final stages as the insects approached inverted surfaces, they held their antennae roughly perpendicular to the surface.

"The bee is able to estimate the slope of the surface to orient correctly the antennae, so it is using its visual system," Srinivasan said.

But this is surprising, because the insects are almost completely stationary while hovering and unable to use image movement across the eye to estimate distances. Srinivasan suspected that the bees could be using stereovision over such a short distance, and is keen to test the idea.

Finally the team realised that bees are almost tailor made to land on surfaces inclined at angles of 60deg. to the horizontal.

"When bees are flying fast their bodies are horizontal, but when they are flying slowly or hovering their abdomen tilts down so that the tips of the legs and antennae lie in a plane that makes an angle of 60deg," said Srinivasan: so the legs and antennae all touch down simultaneously on surfaces inclined at 60deg.

"It seems like they are adapted to land on surfaces tilted to 60deg. and we are keen to find out whether many flowers have this natural tilt," Srinivasan said.

The bees'' technique may help engineers design a new generation of automated aircraft that would be undetectable to radar or sonar systems and would make perfectly gentle landings, even in outer space.

The study has been reported in the Journal of Experimental Biology.

ANI

'Habitable moons like in film 'Avatar' could be real'

James Cameron's science fiction 'Avatar' may become fact in the coming years, says a leading US astronomer who believes there is every chance a real-life version of habitable alien moons like the one depicted in the movie exists and will soon be found.

The 3D blockbuster shows a race of blue-skinned giants inhabits an Earth-like moon called Pandora, which orbits a gas giant planet similar to Jupiter that cannot support life.

"If Pandora existed, we potentially could detect it and study its atmosphere in the next decade," said Lisa Kaltenegger, an astronomer from the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts.

Kaltenegger, who has conducted research showing that a planned new space telescope will be able to identify nearby "exomoons" and discover if they are habitable, said hundreds of Jupiter-sized gas giants orbiting stars have already been spotted, but none have conditions suitable for Earth-type life.

However, a rocky moon orbiting a gas giant could harbour life if it was in the parent star's "habitable zone" – the region where temperatures are just right for liquid water, she said.

"All of the gas giant planets in our solar system have rocky and icy moons. That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere," she said.

A Pandora-type moon could be identified when its planet "transits" across the face of the parent star. If the moon has an atmosphere, this will absorb a tiny amount of light from the star, leaving a spectrographic fingerprint of its composition.

Dr Kaltenegger calculated that Alpha Centauri A, the star featured in Avatar, would provide an excellent target for astronomers hunting habitable moons.

Alpha Centauri is the closest star system to the Sun, being only 4.37 light years away. It consists of three stars, the largest being Alpha Centauri A, which is slightly brighter than the Sun.

"Alpha Centauri A is a bright, nearby star very similar to our Sun, so it gives us a strong signal. You would only need a handful of transits to find water, oxygen, carbon dioxide and methane on an earth-like moon such as Pandora.

"If the Avatar movie is right in its vision, we could characterise that moon with JWST in the near future."

She said small, dim red dwarf stars may provide the best evidence of habitable planets or moons. This is because the habitable zone for a red dwarf is closer to the star, which increases the likelihood of a transit as seen from the earth.

Red dwarfs are also the most common kind of star in our galaxy, the Milky Way.

"Alien moons orbiting gas giant planets may be more likely to be habitable than tidally locked Earth-sized planets or super-Earths," said Dr Kaltenegger. "We should certainly keep them in mind as we work toward the ultimate goal of finding alien life."

Dr Kaltenegger's research is published online in Astrophysical Journal Letters.

PTI

How the daisy got its spots

In a new research, scientists have studied how the dark spots on the petals of flowers like daisies are formed.

Dr. Meredith Thomas from the University of Cambridge and associates from England and South Africa have carried out the research. They focused on the South African endemic beetle daisy Gorteria diffusa, which has a unique, raised, dark spot at the base of some of its ray florets. “The spots on the flowers mimic the plant’s pollinator, a small fly, which is attracted to the plant because of the spots. The plant is dependent on the pollinator for reproductive success, so it’s incredibly important that the plant attracts the flies,” said Thomas. “What we found surprising was how complex the petal spots are in a few populations, when other populations seem to get by with a very simple spot or even no petal spot at all,” said Thomas.

By peeling away layers of the tissues that make up the spots on mature ray florets and examining them under a simple dissecting scope, Thomas and associates found that the spots of G. diffusa are more complex than most.

These spots are composed of three different types of specialized epidermal cells: the central highlight cells that reflect UV and lack pigment; the interior cells that are shorter, rounder, variously pigmented, and raised above the highlight cells; and, surrounding the spot, a circle of multicellular papillae that are swollen, shiny, and filled with anthocyanin.

Moreover, each spot spans four congenitally fused petal lobes, meaning that each lobe contained only part of the spot (and only some cell types) in its genetic makeup.

As to what attracts the pollinators, the researchers hypothesized that because there is a lot of spot variation in this species, the elements that are found in common among the various populations, such as the presence of anthocyanin pigment or UV reflectivity, might do the trick.

The researchers also wanted to know how only a subset of the floral rays develops a spot.

Using scanning electron microscopy, the authors looked at how the spot developed, or its ontogeny, over time.

They found that only the first few ray florets that develop contain the spots, whereas the rest do not.

The scientists hypothesize that the genes that control the appearance of the spot are turned on initially and then fade with time, such that only the first, and oldest, rays to develop have the spots.

Thus, the development of the spots is complex not only at the cellular level, but at the organismal level as well.

ANI

New data to shed light on ''ghost mountains'' of Antarctica

An international team of scientists has announced the first set of data about the most enigmatic mountain ranges on Earth, which are popularly dubbed as the ''ghost mountains''.

According to a report in BBC News, the team spent two months in 2008/9 surveying the Gamburtsevs in Antarctica - a series of peaks totally buried under the ice cap.

The group has told a major conference in the US that the hidden mountains are more jagged than previously thought.

They are also more linear in shape than the sparse data collected in the past had suggested. This latter finding hints at a possible origin for the mountains whose existence has perplexed scientists for 50 years.

"If you have a linear structure it makes them more like the Alps or the Appalachians," explained Dr Michael Studinger from the Lamont-Doherty Earth Observatory (LDEO) of Columbia University, New York.

"These are mountain ranges that formed by the collision of tectonic plates," he added. He stressed that the analysis of the survey data was in its infancy and the team would publish their final assessments in forthcoming papers in the formal scientific literature. The mountains were discovered by a Soviet team during the International Geophysical Year in 1957-8.

Studying them has been immensely difficult, however.

It was only with the concerted effort organised around International Polar Year in 2007-8 that a full-scale aerogeophysical survey became possible.

Two instrumented Twin-Otter aircraft were flown out of remote field camps and collected a range of data.

Aircraft flew over the surface, taking images of the ice and rock underneath. The shallowest ice covering the mountains is hundreds of metres thick. The deepest ice detected is about 4,800m thick. The mountains themselves are standing about 2,500m above sea level.

It is now clear the range has a defined linear trend, in contrast to the previously mapped circular feature, and that this trend strikes predominantly to the north-east. The data also reveals a very rugged landscape with high peaks and deeply incised valleys which have been worked in the past by both river and ice processes.

"Before we had this data we couldn''t see the valleys and therefore we had no way of being able to quantify the role of glacial and fluvial processes which is key to understanding cryosphere and climate evolution," said Dr Fausto Ferraccioli from the British Antarctic Survey.

Studying what happened in these valleys could give clues as to how fast the Gamburtsevs became encased in ice.

ANI

Is another mass extinction of mammals on the way?

Thanks to global warming and ecological degradation, the sixth mass extinction is already on the way, equal to the "big five" that occurred over the past 450 million years, the last of which killed off dinosaurs, warn scientists.

Yet, estimates of how dire the current loss of species is have been hampered by the inability to compare species diversity today with the past.

By combining data from three catalogues of mammal diversity in the US between 30 million years ago and 500 years ago, University of California-Berkeley (UC-B) and Penn State researchers show that the bulk of mammal extinctions occurred within a few thousand years after the arrival of humans, with losses dropping after that.

Although modern humans emerged from Africa into Europe and Asia about 40,000 years ago, they didn't reach North America until about 13,000 years ago, and most mammal extinctions occurred in the subsequent 1,000-2,000 years.

"The optimistic part of the study is that we haven't come all that far on extinction in the past 10,000 years," said co-author Anthony Barnosky, UC-B professor of integrative biology.

"We have this pulse when humans had their first effect about 13,000 years ago, but diversity has remained pretty steady for about 10,000 years."

He expects to see a similar pattern in Europe after the invasion of homo sapiens some 40,000 years ago, a UC-B release said.

In the last 100 or so years, however, "we are seeing a lot of geographic range reductions that are of a greater magnitude than we would expect, and we are seeing loss of subspecies and even a few species. So it looks like we are going into another one of these extinction events."

"The only difference is that 13,000 years ago humans appeared on the scene," UC-Berkeley research associate Marc A. Carrasco said. "The bottom line is, mammals in general were able to deal with these changes in the past. Only when humans arrive, do the numbers fall off a cliff."

The analysis appeared online this week in PLoS One.

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Mars had complex hydrological past

In a new research, a tam of scientists has reported new evidence for multiple, water-related geologic processes on Mars, thus indicating that the Red Planet had a complex hydrological past.

Catherine Weitz, a senior scientist at the Tucson-based Planetary Science Institute, and her colleagues studied light-toned deposits (LTDs) within troughs of the Noctis Labyrinthus region in western Valles Marineris using data gathered by three Mars Reconnaissance Orbiter (MRO) instruments.

“We analyzed ten troughs containing well-exposed LTDs, and we found a lot of variability that we didn’t expect to see,” she said.

“We found that each of the troughs with LTDs has a unique mineralogy, and, therefore, the processes occurring in each trough were very localized,” she added.

Weitz and her team identified various types of clays, hydrated silicas, and sulfates in these small basins, which are typically 30 to 100 kilometers across.

One LTD included dozens of beds of varying thickness, brightness, color and erosional structure, suggesting that significant amounts of water once existed there.

In addition, sulfates were mixed with clays within the deposits, indicating that ph levels may have fluctuated between acidic and alkaline conditions.

Another LTD is buried several meters beneath wind-deposited material and is only exposed in the trough’s upper walls, indicating it is older than the trough.

In still another area, clays are buried beneath younger plains along the trough floor, while in the same trough, but a few kilometers away, there are exposures of hydrated silica and calcium sulfate.

The wide variability in deposits and mineralogy in these and the other basins suggests a complex hydrologic history, including multiple events in some troughs, according to Weitz.

“Clearly, these areas were affected by water,” she said. “In some cases, there had to be multiple events. But we don’t know how much water was involved or whether it was always a flowing liquid,” she added.

“It might have been groundwater coming from Tharsis, the large volcanic complex to the west,” she said.

According to Weitz, “There could have been active volcanism that produced water by melting snow, ice, or underground, hydrothermal processes. These little basins could then have filled or partially filled with some of that water.”

“Another possibility is that material was already in several of the troughs, perhaps as volcanic ash or lava flows, and some kind of hydrothermal activity may have altered these pre-existing deposits,” she said.

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Sunspots don’t cause global warming

Leading scientists have dismissed studies which say that global warming is a natural phenomenon connected with sunspots, rather than the result of the man-made emissions of carbon dioxide (CO2).

According to a report in The Independent, the researchers, all experts in climate or solar science, said that the scientific evidence continually cited by skeptics to promote the idea of sunspots being the cause of global warming is deeply flawed.

Studies published in 1991 and 1998 claimed to establish a link between global temperatures and solar activity – sunspots – and continue to be cited by climate skeptics.

However, problems with the data used to establish the correlation have been identified by other experts and the flaws are now widely accepted by the scientific community, even though the studies continue to be used to support the idea that global warming is “natural”.

The issue has gained new importance in the light of opinion polls showing that nearly one in two people now believe global warming is a natural phenomenon unconnected with CO2 emissions.

Powerful support for this idea came in 1991 when Eigil Friis-Christensen, director of the Danish National Space Centre, published a study showing a remarkable correlation between global warming and the length of sunspot cycles.

A further study published in 1998 by Friis-Christensen and his colleague Henrik Svensmark suggested a possible explanation for the warming trend with a link between solar activity, cosmic rays and the formation of clouds.

However, many scientists now believe both of these studies are seriously flawed, and that when errors introduced into the analysis are removed, the correlations disappear, with no link between sunspots and global warming.

According to Peter Laut, a former adviser to the Danish Energy Agency who first identified the flaws, there were practically no observations to support the idea that variations in sunspots played more than a minor role in global warming.

Laut’s analysis of the flaws is accepted by most scientists familiar with the research, including Paul Crutzen, an atmospheric chemist at the Max Planck Institute in Germany, who won a Nobel Prize for his work on understanding the hole in the ozone layer.

“There is definitely a problem (with these studies). Laut has really pinned it down but the (sunspot) argument keeps reappearing and its quite irritating.” Professor Crutzen said.

“I’ve looked into this quite closely and I’m on Laut’s side in terms of his analysis of the data,” said Professor Stefan Rahsmstorf, of Potsdam University.

ANI

Saturn moon Iapetus coated with foreign dust

Scientists at Cornell University have reportedly found foreign dust on Iapetus, Saturn’s most bizarre moon.

Iapetus is known to have starkly contrasting hemispheres -- one black as coal, the other white as snow.

Images taken by the Cassini-Huygens spacecraft, orbiting Saturn since 2004, offer the most compelling evidence to date of why and how the moon got its yin-yang appearance.

The latest images appear in the December 10 online edition of the journal Science.

“This is not the most fundamental problem in the world. “But it’s an enigma that’s been puzzling astronomers for centuries,” claimed researcher Joseph A. Burns, Cornell’s Irving Porter Church Professor of Engineering and professor of astronomy.

Using pictures taken by Cassini, particularly during a September 2007 close fly-by, the scientists assert that Iapetus’ darker half, called Cassini Regio, is the result of the planet’s leading side getting bombarded by dusty debris from another Saturnian moon, Phoebe, which orbits in the opposite direction beyond Iapetus.

In a paper published in the journal Nature in October, three Cornell-trained astronomers announced the discovery of an enormous ring of debris -- 10,000 times the area of Saturn’s famous main ring system -- around Saturn and near Phoebe, pointing to it as the ring’s source.

Burns calls this ring the “smoking gun” supporting dust hitting Iapetus and other moons around Saturn.

Small, white craters that dot Iapetus’ darker half indicate a veneer of dark dust, only meters deep, covering a white, icy surface that matches the rest of the satellite.

The imaging data also revealed that all the materials on the leading side are much redder than the shielded and brighter trailing side -- another indication that the leading side’s dust came from elsewhere.

The pattern, the scientists say, supports a previous theory described in a companion paper in Science that the darker parts of the moon tend to heat up when struck by sunlight, causing the ice to evaporate underneath. This causes any dark spots to get even darker, creating the mottled look.

The research team includes Paul Helfenstein and Peter C. Thomas, both senior research associates at Cornell.

The paper’s first author is Tilmann Denk, Cassini imaging scientist at the Free University in Berlin, Germany. The Cassini program is an international cooperative effort involving NASA, the European Space Agency and the Italian space agency.

ANI

Saturn’s mysterious hexagon emerges from winter darkness

After years of waiting for the Sun to illuminate Saturn’s North Pole again, cameras aboard NASA’s Cassini spacecraft have captured the most detailed images yet of the fascinating hexagon shape crowning the planet.

The new images of the hexagon, whose shape is the path of a jet stream flowing around the North Pole, reveal concentric circles, curlicues, walls, and streamers not seen in previous images.

NASA’s Voyager spacecraft had last captured the visible-light images of the entire hexagon nearly 30 years ago. After the sunlight faded, darkness engulfed the north pole for 15 years, and much to the delight and bafflement of Cassini scientists, the location and shape of the hexagon in the latest images match those they saw in the Voyager pictures.

“The longevity of the hexagon makes this something special, given that weather on Earth lasts on the order of weeks,” said Kunio Sayanagi, a Cassini imaging team associate at the California Institute of Technology.

“It’s a mystery on par with the strange weather conditions that give rise to the long-lived Great Red Spot of Jupiter,” he added.

The hexagon was originally discovered in images taken by the Voyager spacecraft in the early 1980s. It encircles Saturn at about 77 degrees north latitude and has been estimated to have a diameter wider than two Earths. The jet stream is believed to whip along the hexagon at around 100 meters per second.

Early hexagon images from Voyager and ground-based telescopes suffered from poor viewing perspectives. Cassini, which has been orbiting Saturn since 2004, has a better angle for viewing the North Pole. But, the long darkness of Saturnian winter hid the hexagon from Cassini’s visible-light cameras for years.

However, infrared instruments were able to obtain images by using heat patterns. Those images showed the hexagon is nearly stationary and extends deep into the atmosphere. They also discovered a hotspot and cyclone in the same region.

ANI

Geminid meteor shower to peak on December 13-14

The Geminid meteor shower will be at its best on December 13-14.

While most meteor showers can be frustratingly unpredictable, the Geminids are one of the most reliable. Given clear skies, they consistently delight meteor watchers.

This year, skywatchers can expect to see dozens of meteors per hour, rising to more than 100 meteors per hour at the showers predicted peak at 9 p.m. CST.

The tiny sliver of the waning crescent Moon will not overpower any meteors.

Geminid meteors appear to fall from near the star Castor, one of the lheads? of the constellation Gemini, the twins.

The meteors are not actually related to Castor; they are debris from an asteroid called Phaethon. The shower recurs each year when Earth passes through this debris strung along Phaethonas orbit around the Sun.

The Geminid shower was the first to be linked to an asteroid. Most meteor showers occur when Earth crosses the orbit of a comet. Though the Geminid shower was discovered in the 1860s, it was only in 1983 that astronomers identified Phaethon as the showeras source.

ANI

Giant spiral UFO over Norway baffles experts

The appearance of a huge spiral of light over Norway yesterday morning has left experts stunned and bewildered as to its origins.

Thousands of awe-struck Norwegians bombarded the Meteorological Institute with questions about the incredible light, which could be seen in the pre-dawn sky for hundreds of miles.

Experts believe the space spectacle, which has been dubbed ''Star-Gate'', is an entirely new astral phenomenon, though the world’s top scientists and the military have admitted they are baffled.

Theories about the light being a misfired Russian missile, meteor fireball, never-before-seen type of northern light, ''black hole'' and even alien activity were all proposed.

Witnesses across Norway, who first glimpsed the space show at 8.45am, all described seeing a spinning ''Catherine wheel-style'' spiral of white light, centred around a bright moon-like star.

A blue "streaming tail" appeared to anchor the spiral to earth, before the light "exploded" into a rotating ring of white fire.

The spiral spectacle, which lasted for two minutes, was seen by vast swathes of the Scandinavian country’s almost five million population, with sightings as far north as Finnmark to Trondelag in the south.

Totto Eriksen, from Tromso, in northern Norway, was one of the thousands who bombarded Norwegian newspapers with sightings, after nearly crashing his car on spotting the spiral overhead.

"I was driving my daughter to school when this light spun and exploded in the sky," the Sun quoted him as saying.

"We saw it from the Inner Harbour in Tromso. It looked like a rocket that spun around and around - and then went diagonally across the heavens.

"It looked like the moon was coming over the mountain - but then turned into something totally different.

"People just stopped and stared on the pier - it was like something from a Hollywood movie," he said.

Norway’s most celebrated astronomer, Knut Jorgen Roed Odegaard, said he had never seen anything like the spiral before.

"This was seen over an exceptionally large area of the country - in all of north Norway and the Trondelag," he said.

"My first thought was that it was a fireball meteor - but it lasted far too long.

"It may have been a missile from Russia - but I can’t guarantee that is the answer.

"I rang the Air Traffic Control tower in Tromse. They said it was over in two minutes. To me, that is far too long for this to be an astronomical phenomenon.

"This spiral shape is unique. It is definitely not a variation of the aurora borealis - northern lights," he stated.

Chief Scientist Erik Tandberg, at the Norwegian Space Centre, said that he too was "totally amazed" by the spiral.

He agreed with many other experts that a missile from Russia could have caused the spiral pattern, something the Russian military have strongly denied.

"I agree with everyone in the science community that this light was the weirdest thing. I have never seen anything like this ever," Dr Tandberg said.

"It may have been anything from an exploding missile whose launch went wrong - to a comet or other celestial object that for some reason has been behaving strangely.

"If it was a missile - most likely from the launch base in Pletsevsk in Russia or one of the Russian submarines or even from the European Space Agency base in Kiruna - then we are talking about a rocket launch that has gone wrong.

"The spiral suggests the object came off course and balance and entered the spiral movement. Leaking rocket fuel could account for the blue light.

PTI

Proposed exoplanet may not exist after all

If a new research is to be believed, a proposed exoplanet near a star some 6 parsecs from Earth may not exist after all.

Ground-based astrometry has been used for more than a century, but none of the extrasolar planets it has detected has been verified in subsequent studies.

In May, Steven Pravdo of the Jet Propulsion Laboratory in Pasadena, California, and his colleagues raised fresh hopes for the technique when they announced an exoplanet, six times more massive than Jupiter, orbiting VB10, a star about one-thirteenth the mass of the Sun, using a telescope at the Palomar Observatory in southern California.

But now, according to a report by Nature News, a group led by Jacob Bean at the Georg-August University in Gottingen, Germany, has used a different approach, and found nothing.

“The planet is not there,” said Bean.

Bean and his colleagues used a well-honed technique called radial velocity, which has found most of the extrasolar planets detected so far.

The method looks for shifts in the lines of a star’s absorption spectrum to track its motion towards and away from Earth, which would be caused by the influence of a planet.

Radial-velocity measurements typically exploit the visible bands of the electromagnetic spectrum.

But, VB10 is a very dim star and gives off most of its light as infrared radiation.

At the Very Large Telescope in Chile, Bean placed a gas cell filled with ammonia in the path of the starlight, enabling him to calibrate the instrument for the infrared.

“We would definitely have seen a significant amount of variation in our data if the planet was there,” said Bean.

“Unfortunately, astrometry is a very difficult business,” said Bean, explaining that Earth’s atmosphere can introduce distortions that affect the measurements.

Astrometrists rely on watching a field of stars about the same distance away as the target star to calibrate their measurements, and that can be tricky, according to Alessandro Sozzetti, an astrometry expert at the Turin Observatory in Italy.

“Even if we think we have selected a good set of reference stars, we may still be limited by atmospheric effects that cause an extra jitter” in the motion of those stars,” he said.

ANI

No proof found for meteorite impact event 13,000 yrs ago

An international team of scientists has found no evidence supporting a meteorite impact event at the onset of the Younger Dryas - 13000 years ago.

The Younger Dryas is an abrupt cooling event in Earth’s history.

It coincided with the extinction of many large mammals including the woolly mammoth, the saber toothed jaguar and many sloths.

This cooling period is generally considered to be the result of the complex global climate system, possibly spurred on by a reduction or slowdown of the thermohaline circulation in North America.

This paradigm was challenged two years ago by a group of researchers that reported finding high iridium concentrations in terrestrial sediments dated during this time period, which led them to theorise that an impact event was instead the instigator of this climate shift.

A team led by Francois Paquay, a Doctoral graduate student in the Department of Geology and Geophysics at the University of Hawaii at Manoa (UHM) decided to also investigate this theory, to add more evidence to what they considered a conceptually appealing theory.

However, not only were they unable to replicate the results found by the other researchers, but additional lines of evidence failed to support an impact theory for the onset of the Younger Dryas.

To corroborate the theory, Paquay and his colleagues decided to take a three-pronged approach.

The first was to replicate the original researchers data, the second step was to look for other tracers, specifically osmium isotopes, of extraterrestrial matter in those rocks, and the third step was to look for these concentrations in other settings.

“Because there are so many aspects to the impact theory, we decided to just focus on geochemical evidence that was associated with it, like the concentration of iridium and other platinum group elements, and the osmium isotopes,” said Paquay.

“We also decided to look in very high resolution sediment cores across North America, and yet we could find nothing in our data to support their theory,” he added.

Both the marine and terrestrial sediment records do not indicate that an impact event was the trigger for the transition into the Younger Dryas cold period.

“The marine and terrestrial record both complement each other to support this finding,” concluded Paquay.

ANI

Ancient birds may have lost teeth to get airborne

Archaeopteryx

In a new research, scientists have suggested that ancient birds lost their teeth in order to shed some weight to get airborne.

Archaeopteryx, at 150 million years old still the oldest known bird, had an imposing set of teeth. But within 20 million years, at least some birds were toothless.

A team led by Zhonghe Zhou at the Chinese Academy of Sciences in Beijing says that they know the reason behind this phenomenon.

They discovered Zhongjianornis yangi, a toothless bird from 22 million years ago in China’s Liaoning province.

Their analysis shows that Z. yangi belonged to one of four bird groups that independently lost their teeth, implying that this loss was no evolutionary fluke.

Z. yangi’s group is the most primitive among them, suggesting it could provide clues as to why tooth loss occurred.

The team compared the body structure of a number of early birds and found that some toothed species were more adapted for flight.

They think natural selection may have put pressure on weaker fliers to lose their teeth in a bid to improve their skills by losing excess weight.

"It would be especially advantageous to reduce the weight of the head because (it) is further from the centre of gravity,” they said.

ANI

Weed killer affects frogs sexually

The widely used weed killer atrazine affects the sexual development of frogs, raising questions about the effects of its use in the environment, the University of Ottawa said on Thursday.

A study by researchers at the university found that at low levels comparable to those measured in the Canadian environment, fewer tadpoles reached the froglet stage and the ratio of females to males increased.

"Atrazine is one of the top-selling herbicides used worldwide and was designed to inhibit weed growth in cornfields," the university said in a statement.

"It is so widely used that it can be detected in many rivers, streams and in some water supplies. This has raised the alarm on the possibility of other serious detrimental environmental effects."

Syngenta AG, a major Swiss manufacturer of atrazine, has long defended its safety. The company has said it is one of the best-studied herbicides available and pointed to previous safety reviews from the U.S. Environmental Protection Agency (EPA) and World Health Organization, among others.

The EPA said in October that it was reviewing the health impacts of the herbicide. Some studies have tied it to birth defects, low birth weight and premature babies.

PTI

Astronomers witness biggest star explosion yet

Astronomers have witnessed the biggest star explosion yet, that is thought to have generated more than 50 Suns' worth (1032 kilograms) of different elements, which may one day go on to make new solar systems.

According to a report in Nature News, the explosion - dubbed SN2007bi - was spotted as part of a digital survey to hunt for supernovae at the Palomar Observatory near San Diego, California.

One supernova in particular was very unusual, recalls Avishay Gal-Yam, an astronomer at the Weizmann Institute of Science in Rehovot, Israel, a member of the survey team.

"This is definitely something we haven't seen before," he said.

The blast was first seen on April 6, 2007, but unlike most supernovae, which fade over a matter of weeks, this one burned steadily for months.

"It was very, very slow. I came back after a week, after two weeks, after a month and five months and it was still about the same brightness," said Gal-Yam.

Follow-up observations with some of the world's most powerful telescopes - including the WM Keck Observatory atop Mauna Kea, Hawaii, and the Paranal Observatory in Chile - revealed a supernova unlike any other.

Gal-Yam and his colleagues report that the explosion was probably that of a supermassive star, at least two hundred times the mass of the Sun.

The type of supernova that it produced - a ''pair-instability'' supernovae - had been predicted by theory, but never observed.

The explosion generated several Suns' worth of radioactive nickel-56 and vast quantities of other lighter elements, such as carbon and silicon.

Gal-Yam said that it is the radioactive decay of the nickel that kept the explosion glowing for months.

"This is definitely something we haven't seen before. There are no such stars seen in our galaxy or other nearby galaxies. It's a rather spectacular star," he said.

Pair-instability supernovae have been predicted for decades, but none has been seen until now, according to Norbert Langer, an astrophysicist at the University of Bonn in Germany.

In addition to providing confirmation of an old theory, the new supernova could provide insight into the early Universe.

ANI

Why humans outlive apes

Chimpanzees and great apes have lifespans that barely exceed 50 years, in spite of their genetic similarity to humans. The difference is that humans evolved genes that enabled them to better adjust to levels of infection, inflammation and to the high cholesterol levels of their meat-rich diets, says a researcher.

Caleb Finch, gerontology professor at the University of Southern California (USC) has revealed that these evolutionary genetic advantages, caused by slight differences in DNA sequencing and improvements in diet, make humans uniquely susceptible to diseases of aging such as cancer, heart disease and dementia when compared to other primates.

Finch said that a major contributor to longevity is human genes that adapt to higher exposure to inflammation. "Over time, ingestion of red meat, particularly raw meat infected with parasites in the era before cooking, stimulates chronic inflammation that leads to some of the common diseases of aging," Finch said.

In addition to differences in diets between species of primates, humans evolved unique variants in a cholesterol transporting gene, apolipoprotein E, which also regulates inflammation and many aspects of aging in the brain and arteries.

ApoE3 is unique to humans and may be what Finch calls "a meat-adaptive gene" that has increased the human lifespan.

However, the minor allele, apoE4, when expressed in humans, can impair neuronal development, as well as shorten human lifespan by about four years and increase the risk of heart disease and Alzheimer disease by several-fold. ApoE4 carriers have higher totals of blood cholesterol, more oxidized blood lipids and early onset of coronary heart disease and Alzheimer''s disease.

"The chimpanzee apoE functions more like the "good" apoE3, which contributes to low levels of heart disease and Alzheimer''s," Finch said. Correspondingly, chimpanzees in captivity have unusually low levels of heart disease and Alzheimer-like changes during aging.

Finch hypothesizes that the expression of ApoE4 could be the result of the antagonistic pleiotropy theory of aging, in which genes selected to fight diseases in early life have adverse affects in later life.

"ApoeE may be a prototype for other genes that enabled the huge changes in human lifespan, as well as brain size, despite our very unape-like meat-rich diets. Drugs being developed to alter activities of apoE4 may also enhance lifespan of apoE4 carriers," Finch said. The findings have been published in the December issue of PNAS Early Edition.

ANI

Sweden allows first wolf hunt in 45 years

Sweden will this winter allow its first wolf hunt in 45 years following a decision by the Scandinavian country's parliament to limit their number, authorities said on Wednesday.

The Swedish Environmental Protection Agency is to announce by mid-December its quota for the wolf cull, expected to be between 20 and 40 animals, Susanna Loefgren of the agency told a news agency.

"That (number is) what (experts) have offered us, we're working on it and a decision will be taken mid-December," Loefgren said.

The regions where the hunt will be allowed are the province of Dalarna, Gaevleborg county and Oerebro county in the country's centre as well as the provinces of Vaestergoetland in the southwest and Vaermland in the west.

The Swedish parliament decided in October to limit the wolf population to 210 animals, spread out in 20 packs, for the next five years by issuing hunting permits in regions where wolves have reproduced in the past three years.

"The main reason for the decision is to raise the (public's) acceptance of wolves" in Sweden by limiting their number, Loefgren said.

The animal's presence is controversial in the Nordic country as domestic and wild animals are increasingly attacked by wolves, which have been sighted recently near residential areas, including near the capital Stockholm.

The environmental protection agency estimated Sweden's wolf population to be between 182 and 217 animals last winter.

It said the hunt would start in January and end before mating season begins in mid-February.

Wolves almost became extinct in Sweden in the 1970s but their number has increased steadily since efforts were made to reintroduce the animal to the country. Like some other European countries, Sweden allows the hunt of protected species, such as the brown bear and the lynx, in order to cull stocks.

Bureau Report

Oceans can feed the human race

Oceans could become a source of more human food if steps are taken to expand and improve marine aquaculture, says a new study.

As the world's population continues to grow, lack of fresh water and space mean that agriculture is unlikely to meet food demand, says Carlos M Duarte of the University of the Balearic Islands, (UBI) Spain, and his seven co-authors.

Fishery catches have been declining globally for two decades, and although conservation measures and a shift in consumption patterns could allow some recovery, marine aquaculture holds more potential for sustained growth.

Marine aquaculture is already on the rise: production has increased 10-fold over the past 30 years and is expected to exceed fishery catches within 20 years.

Yet Duarte and his colleagues argue that its continued growth will depend on adapting current techniques so that the food needed to feed marine animals is itself derived from marine aquaculture, rather than harvested from the wild or derived from agriculture.

This goal is achievable, they maintain, if more animals low on the food chain are cultivated, including more plankton and algae. These could be used as food for both humans and for fish.

New technology will also help, by allowing marine aquaculture operations to be expanded into more exposed, offshore locations, says a UBI release.

Although some environmental impacts can be expected from the expansion of marine aquaculture, these are modest compared to those resulting from food production on land.

These findings were published in the December issue of BioScience.

IANS

Martian meteorite back in spotlight

The controversial Mars meteorite is once again in the spotlight
(Source: NASA)

New analysis of a 13,000-year-old Mars meteorite, retrieved from Antarctica, has rekindled the debate about whether the ancient rock holds signs of past microbial Martian life.

The study is reminiscent of initial research, published in 1996, suggesting that very, very tiny - nanometre-sized - iron sulfide and iron oxide grains in the meteorite had biological origins, and that tiny, worm-shaped objects in the rock, known as ALH84001, could be the fossilised remains of Martian microbes.

The research was widely panned, and the NASA team making claims for life on Mars subsequently retreated.

New view

Now a team of experts at the NASA Johnson Space Center, including the lead astrobiologist in the 1996 study, Dr David McKay, have looked at the rock again using a new analysis technique, called ion beam milling.

They conclude that there is enough evidence to rule out at least one geological process as the one that formed the nanocrystal iron grains. That leaves something that was once living as a possible cause.

The scientists also point out the similarity between magnetites found in the Martian meteorite and a type of Earth bacteria on land known as magnetotactic bacteria.

"They look virtually identical," says Professor Dennis Bazylinski, a geomicrobiologist at the University of Nevada.

Bazylinski reviewed the paper before it was published in the November issue of Geochimica et Cosmochimica Acta.

About 25% of the magnetites in ALH84001 have an elongated structure typical of magnetic bacteria on Earth.

'No smoking gun'

That's not enough to satisfy Dr Michael Fuller, who researches magnetism at the University of Hawaii's Institute of Geophysics and Planetology.

"The grain-sized distribution is pretty small," says Fuller, adding that once iron particles get smaller than about 20 nanometers, the magnetism breaks down.

"Most of them (the grains discussed in the new research) appear too small. It doesn't look to me that they are very similar to magnetotactic bacteria," he says.

Fuller also says he is not convinced the magnetites in the Mars rock couldn't have been produced by shock when the meteorite blasted through Earth's atmosphere. A similar shock process produces small iron particles in the lunar soil, he says.

"It seems to me that they haven't really solved the whole thing," says Fuller. "I remain a skeptic."

But Bazylinski argues the research puts a nail in the coffin of one geological theory - that the magnetites were formed by the melting of tiny carbonate disks found in the meteorite.

"This is no smoking gun," says Bazylinski. "It'd be great if this was bacteria. I'd be the first one to carry the flag. But this one meteorite is not going to answer the question of whether there was life on ancient Mars or not."

By Irene Klotz

Surface of the Red Planet

South Polar residual cap monitoring - rare stratigraphic contacts

Disappearing sand dunes

Intersecting swirling trails left by the earlier passage
of dust devils across sand dunes

Aeolian features, large and small

Part of the Abalos Undae dune field

An impact crater on the south polar region,
showing layered deposits

Intersecting swirling trails left by the earlier
passage of dust devils across sand dunes

Rocky mesas of Nilosyrtis Mensae region

Layers exposed near the Mouth of Ladon Valles

Lineated valley fill and lobate debris aprons
in the Deuteronilus Mensae region

Exposure of layers and minerals in Candor Chasma

A small crater partially buried in wind-blown
ejecta from a much larger crater

Defrosting dunes in the north

All photos: NASA / JPL / UNIVERSITY OF ARIZONA / BARCROFT MEDIA
Original article: telegraph.co.uk

Saturn’s eccentric orbit may explain puzzling lake asymmetry on Titan

In a new research, scientists have suggested that the unusually uneven distribution of methane and ethane lakes over the northern and southern polar regions of the Saturn’s largest moon, Titan, may be caused by the eccentricity of the planet’s orbit around the sun.

As revealed by Synthetic Aperture Radar (SAR) imaging data taken by NASA’s Cassini spacecraft, which has been surveying Saturn and its moons since 2004, liquid hydrocarbon–filled lakes in Titan’s northern high latitudes cover 20 times more area than lakes in the southern high latitudes.

There are also significantly more partially filled and now-empty lakes in the north.

Assuming that the asymmetry is not a statistical fluke, scientists initially considered the idea that “there is something inherently different about the northern polar region versus the south in terms of topography, such that liquid rains, drains, or infiltrates the ground more in one hemisphere,” said Oded Aharonson, associate professor of planetary science at Caltech.

However, he notes, there are no substantial known differences between the north and south to support this possibility.

According to the seasonal hypothesis, methane rainfall and evaporation vary in different seasons—recently filling lakes in the north while drying lakes in the south.

The problem with this idea, according to Aharonson, is that it explains decreases of about one meter per year in the depths of lakes in the summer hemisphere.

But, Titan’s lakes are a few hundred meters deep on average, and wouldn’t drain (or fill) in just 15 years.

According to Aharonson and his colleagues, a more plausible explanation is related to the eccentricity of the orbit of Saturn—and hence of Titan, its satellite—around the sun.

Like Earth and the other planets, Saturn’s orbit is not perfectly circular, but is instead somewhat elliptical—or eccentric—and oblique.

Because of this, during its southern summer, Titan is about 12 percent closer to the sun than it is during the northern summer.

As a result, northern summers are long and subdued while southern summers are short and intense.

Aharonson and his colleagues think these differences in the characteristics of the seasons could somehow affect the relative amounts of precipitation and evaporation of methane in the hemispheres’ respective summers.

“We propose that, in this orbital configuration, the difference between evaporation and precipitation is not equal in opposite seasons, which means there is a net transport of methane from south to north,” he said.

This imbalance would lead to an accumulation of methane—and hence the formation of many more lakes—in the northern hemisphere.

ANI