Nuclear explosion may have given birth to the Moon

A team of scientists have proposed a new theory regarding the formation of the Moon, which suggests that a massive nuclear explosion that occurred at the edge of Earth’s core might have led to the formation of the natural satellite.

According to a report in Discovery News, some scientists are of the opinion that a massive nuclear explosion occurred at the edge of Earth’s core, flinging red-hot, liquid rock into space.

The orbiting detritus gradually congealed into what is now our planet’s lone satellite – the Moon. Most scientists believe that the Moon formed from the debris left over when a Mars-sized object hit our newly-formed planet around 4.5 billion years ago.

This is based on several modeling studies that provide a pile of evidence in favor of the idea. But, there are some loopholes in this theory.

For one, the Moon’s chemistry is very similar to Earth’s, which makes one wonder that in a titanic impact like the one proposed, a good portion of the offending object would be melted, vaporized, and incorporated into the wreckage that eventually formed the Moon.

But if scientists were to reject the earlier theory and accept the nuclear explosion hypothesis, the question then raises that how do you get a nuclear bomb to go off in the middle of the planet?

According to researchers supporting the new theory, as the molten Earth spun, radioactive thorium and uranium accumulated at the boundary between the core and mantle in large enough quantities to spark a runaway fission reaction.

Heat and energy built up and formed a nuclear jet that pushed giant globs of molten rock into space, which eventually might have formed into the Moon.

A way to test the idea would be for scientists to look for isotopic signatures on the Moon left over from when the “geo reactor” exploded.

If they are there, it’s a good chance that Earth once went critical in a huge way, and our ghostly galleon was tossed into the heavens by the world’s first nuclear detonation.

ANI

NASA to unlock sun’s secrets

US space agency NASA is set to embark on an ambitious mission which will try to discover the causes of extreme solar activity, such as sun spots and solar winds and flares.

Solar Dynamics Observatory (SDO) will be launched in nine days’ time, reports The Times.

With the project’s help, scientists will be able to understand solar phenomena – such as disturbances on the sun – and hope to be able to produce reliable forecasts of “space weather” and provide advance warnings of any threat.

The observatory will orbit the Earth at a distance of 22,300 miles, and will measure fluctuations in the sun’s ultraviolet output, map magnetic fields and photograph its surface and atmosphere.

Barbara Thompson, project scientist, said: “It is Nasa’s first weather mission and it aims to characterise everything on the sun that can impact on the Earth and near Earth.

“We know things happen on the sun which affect spacecraft, communications and radio signals. If we can understand the underlying causes of what is happening then we can turn this information into forecasts.

“The key thing about the mission is that it is not just pure science for its own sake. There is likely to be a direct and immediate benefit for people.”

Solar magnetic storms and space weather disturbances have had a number of dramatic consequences over the years.

ANI

How volcanoes snuffed out ocean life 100 mn yrs ago

A new research has suggested that a spate of volcanic activity may have triggered environmental changes that led to widespread destruction of life in the oceans some 100 million years ago.

Oxygen disappeared from much of the seas nearly 100 million years ago, wiping out one third of ocean life.

When the Earth erupted in a flurry of volcanic activity during the Cretaceous period, marine life briefly bloomed but took the oxygen from the sea, creating a dead zone where marine animals could not survive.

According to a report in The Times, sulphur from volcanoes could have been the cause.

The volcanoes created a bloom in photosynthetic life near the surface.

As that plankton sank, it fed a secondary boom among the bacteria below, consuming much of the oxygen in deeper waters.

Unable to survive, the bacteria disappeared from the deep, along with 27 percent of all marine genera.

But, plankton at the surface thrived, and its remains began to accumulate on the seabed in greater quantities than normal.

But the mechanism by which the volcanoes fertilised the ocean has remained mysterious.

Until now, the main suspect has been the carbon dioxide (CO2) put into the atmosphere, changing the weather and washing more nutrients into the ocean.

At the same time, the world warmed and slowed the ocean circulation that usually replenishes oxygen in the deep.

Evidence of mounting levels of sulphur in the half million years before the Ocean Anoxic Event that occurred 94.5 million years ago suggests a different explanation.

Although sulphates are not a key nutrient for ocean life, the scientists involved in the study, suggest a new mechanism by which its arrival could lead to a widespread bloom.

“Sulphates help the ocean hang on to its phosphorous,” said Professor Matthew Hurtgen, one of the research authors.

“Along with nitrogen and iron, phosphorous is a key limiting nutrient in the ocean. Without it, phytoplankton cannot grow. But when massive volcanism delivered more, it changed the amount of phosphorous available, and drove these anoxic events,” he added.

As to the current situation of the world’s oceans, scientists are warning that in wide areas of ocean, the amount of oxygen is dropping, while localised dead zones are spreading because of agricultural fertiliser being flushed into the water.

ANI

Newborn black holes can give an extra boost to exploding stars

Astronomers studying two exploding stars, or supernovae, have found evidence the blasts received an extra boost from newborn black holes.

The supernovae were found to emit jets of particles traveling at more than half the speed of light.

Previously, the only catastrophic events known to produce such high-speed jets were gamma-ray bursts, the universe''s most luminous explosions.

"The explosion dynamics in typical supernovae limit the speed of the expanding matter to about three percent the speed of light," explained Chryssa Kouveliotou, an astrophysicst at NASA''s Marshall Space Flight Center in Huntsville, Ala., co-author of one of the new studies.

"Yet, in these new objects, we''re tracking gas moving some 20 times faster than this," Kouveliotou added.

The astronomers discovered the ultrafast debris by studying two supernovae at radio wavelengths using numerous facilities, including the National Science Foundation''s Very Large Array in Socorro, N.M., and the Robert C. Byrd Green Bank Telescope in West Virginia.

One team used the real-time operating mode of the European Very Long Baseline Interferometry Network, an international collaboration of radio telescopes, to rapidly analyze data.

"In every respect, these objects look like gamma-ray bursts, except that they produced no gamma rays," said Alicia Soderberg at the Harvard-Smithsonian Center for Astrophysics.

Soderberg led a team that studied SN 2009bb, a supernova discovered in March 2009.

It exploded in the spiral galaxy NGC 3278, located about 130 million light-years away.

The other object is SN 2007gr, which was first detected in August 2007 in the spiral galaxy NGC 1058, some 35 million light-years away.

The researchers searched for gamma-ray signals associated with the supernovae using archived records in the Gamma-Ray Burst Coordination Network located at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The project distributes and archives observations of gamma-ray bursts by NASA's Swift spacecraft, the Fermi Gamma-ray Space Telescope and many others.

However, no bursts coincided with the supernovae.

Unlike typical core-collapse supernovae, the stars that produce gamma-ray bursts possess what astronomers call a "central engine" - likely a nascent black hole - that drives particle jets clocked at more than 99 percent the speed of light.

By contrast, the fastest outflows detected from SN 2009bb reached 85 percent the speed of light and SN 2007gr reached more than 60 percent of light speed.

"These observations are the first to show some supernovae are powered by a central engine," Soderberg said.

"These new radio techniques now give us a way to find explosions that resemble gamma-ray bursts without relying on detections from gamma-ray satellites," she added.

ANI

A microbe that can make fuel from biomass!

Deploying the tools of synthetic biology, the JBEI researchers engineered a strain of Escherichia coli (E. coli) bacteria to produce biodiesel fuel and other important chemicals derived from fatty acids.

“The fact that our microbes can produce a diesel fuel directly from biomass with no additional chemical modifications is exciting and important,” said Jay Keasling, the Chief Executive Officer for JBEI, and a leading scientific authority on synthetic biology.

“Given that the costs of recovering biodiesel are nowhere near the costs required to distill ethanol, we believe our results can significantly contribute to the ultimate goal of producing scalable and cost effective advanced biofuels and renewable chemicals,” he added.

Keasling led the collaboration, which was was made up of a team from JBEI’s Fuels Synthesis Division that included Eric Steen, Yisheng Kang and Gregory Bokinsky, and a team from LS9, a privately-held industrial biotechnology firm based in South San Francisco.

E. coli is a well-studied microorganism whose natural ability to synthesize fatty acids and exceptional amenability to genetic manipulation make it an ideal target for biofuels research.

The combination of E. coli with new biochemical reactions realized through synthetic biology, enabled Keasling, Steen and their colleagues to produce structurally tailored fatty esters (biodiesel), alcohols and waxes directly from simple sugars.

“Biosynthesis of microbial fatty acids produces fatty acids bound to a carrier protein, the accumulation of which inhibits the making of additional fatty acids,” Steen said.

“Normally E. coli doesn’t waste energy making excess fat, but by cleaving fatty acids from their carrier proteins, we’re able to unlock the natural regulation and make an abundance of fatty acids that can be converted into a number of valuable products,” he added.

“Further, we engineered our E. coli to no longer eat fatty acids or use them for energy,” he further added.

After successfully diverting fatty acid metabolism toward the production of fuels and other chemicals from glucose, the JBEI researchers engineered their new strain of E. coli to produce hemicellulases – enzymes that are able to ferment hemicellulose, the complex sugars that are a major constituent of cellulosic biomass and a prime repository for the energy locked within plant cell walls.

ANI

Alien life could already be on Earth

Scientists and other experts are gathering in London to consider new ways — and new places — to search for alien beings.

Britain's Royal Society — an eminent group equivalent to the US Academy of Sciences — is hosting a two-day event to consider the progress made and the challenges posed in the hunt for alien beings.

One astrobiologist says the best place to look for aliens may be right here on Earth. Paul Davies of Arizona State University said Tuesday that extraterrestrial life may have found its way to this planet at several different times.

If so, Davies says, the aliens could be "right under or noses — or even in our noses."

Bureau Report

Solar system 'on fire' burned up Earth's carbon

In a discovery that may solve millions of year-old mystery behind Earth's carbon-deficiency, a new research found that fire sweeping through the inner solar system had burned up much of the carbon from the planet.

Though our planet supports carbon-based life, it has a mysterious carbon deficit, but the element is thousands of times more abundant in comets in the outer solar system than on the Earth, even the sun is rich in carbon.

The conventional explanation for the deficit is that in the inner region of the dust disc where Earth formed, temperatures soared above 1800 kelvin, enough for carbon to boil away, journal New Scientist reported.

But observations of developing solar systems suggested that at Earth's distance from the sun, the temperature would be too cool to vaporise carbon dust.

Now a team of astronomers from Sejong University in Seoul and the University of Michigan in Ann Arbor wrote in The Astrophysical Journal Letters that fire sweeping through the inner solar system had "scorched away much of the carbon from Earth and the other inner planets".

"Hot oxygen atoms in the dusty disc would have readily combined with carbon, burning it to produce carbon dioxide and other gases," said Jeong-Eun Lee of Sejong University. "Any solid carbon in the inner solar system would have been destroyed within a few years," Lee added.

PTI

Outer planets of our solar system may have oceans of diamonds

Scientists have said that the outer planets of our solar system may have oceans of diamonds.

A new report has suggested that oceans of liquid diamond, filled with solid diamond icebergs, could be floating on Neptune and Uranus.

The research is based on the first detailed measurements of the melting point of diamond.

It found, diamond behaves like water during freezing and melting, with solid forms floating atop liquid forms.

The surprising revelation gives scientists a new understanding about diamonds and some of the most distant planets in our solar system.

"Diamond is a relatively common material on Earth, but its melting point has never been measured," said Dr Jon Eggert of the Lawrence Livermore National Laboratory in California.

"You can''t just raise the temperature and have it melt; you have to also go to high pressures, which makes it very difficult to measure the temperature," he added.

When diamond is heated to extreme temperatures it physically changes, from diamond to graphite.

The graphite, and not the diamond, then melts into a liquid.

The trick for the scientists was to heat the diamond up while simultaneously stopping it from transforming into graphite.

Ultrahigh pressures, the kind of pressures found in huge gas giants like Neptune and Uranus are some of the places where ultrahigh temperatures and ultrahigh pressures exist.

Eggert and his colleagues placed a small, natural, clear diamond, about a tenth of a carat by weight and half a millimetre thick, and blasted it with lasers at ultrahigh pressures.

The scientists liquefied the diamond at pressures 40 million times greater than what a person feels when standing at sea level on Earth.

From there, they slowly reduced the temperature and pressure.

When the pressure dropped to about 11 million times the atmospheric pressure at sea level on Earth and the temperature dropped to about 50,000 degrees, solid chunks of diamond began to appear.

The pressure kept dropping, but the temperature of the diamond remained the same, with more and more chunks of diamond forming.

Then, the diamond did something unexpected.

The chunks of diamond didn't sink. They floated and became microscopic diamond ice burgs floating in a tiny sea of liquid diamond.

"An ocean of diamond could help explain the orientation of the planet''s magnetic field as well," said Eggert.

Up to 10 percent of Uranus and Neptune is estimated to be made from carbon.

A huge ocean of liquid diamond in the right place could deflect or tilt the magnetic field out of alignment with the rotation of the planet.

ANI

Snail shells to inspire next gen ‘impermeable’ armor

In a new research, a team of materials scientists has found new facts about a tiny snail that lives on the ocean floor, which could help scientists design better armor for soldiers and vehicles.

The team, led by MIT Associate Professor Christine Ortiz, report that the shell of the so-called “scaly-foot” snail is unlike any other naturally occurring or manmade armor.

The study suggests that its unique three-layer structure dissipates energy that would cause weaker shells to fracture.

Copying various aspects of the structure could help scientists design better armor for military use, according to Ortiz, who is a member of MIT’s Institute for Soldier Nanotechnologies.

Ortiz’ attention was drawn to this interesting gastropod in 2003, when its discovery was first reported.

The snail lives in a relatively harsh environment on the floor of the Indian Ocean, near hydrothermal vents that spew hot water.

Therefore, it is exposed to fluctuations in temperature as well as high acidity, and also faces attack from predators such as crabs and other snail species.

When a crab attacks a snail, it grasps the snail’s shell with its claws and squeezes it until it breaks — for days if necessary.

The claws generate mechanical energy that eventually fractures the shell, unless it is strong enough to resist.

In the new research, Ortiz and her colleagues, including MIT Dean of Engineering Subra Suresh, report that the shell of the hot vent gasotropod has several features that help dissipate mechanical energy from a potential penetrating predatory attack.

Of particular importance is its tri-layered shell structure, which consists of an outer layer embedded with iron sulfide granules, a thick organic middle layer, and a calcified inner layer.

Most other snail shells have a calcified layer with a thin organic coating on the outside.

In the scaly foot gastropod, simulations suggest that the relatively thick organic middle layer can absorb much energy during a penetrating attack.

ANI

Scientists locate breeding ground of rarest bird

Researchers have located the breeding ground of a species dubbed "the world's least known bird" -- the large-billed reed warbler, in the remote Wakhan reaches of Afghanistan.

The recent discovery represents a watershed moment in the study of this bird. The first specimen of such warblers was discovered in India in 1867, with well over a century elapsing before a second discovery of a single bird in Thailand in 2006.

Using a combination of astute field observations, museum specimens, DNA sequencing, and the first known audio recording of the species, researchers verified the discovery by capturing and releasing almost 20 birds earlier this year, the largest ever recorded.

"Practically nothing is known about this species, so this discovery of the breeding area represents a flood of new information on the large-billed reed warbler," said Colin Poole, executive director of Wildlife Conservation Society (WCS) Asia Programme.

The find serves as a case study in the detective work needed to confirm ornithological discoveries. The story begins in 2008, when Robert Timmins of the WCS was conducting a survey of bird communities along the Wakhan and Pamir rivers.

He immediately heard a distinctive song coming from a small, olive-brown bird with a long bill. Timmins taped the bird's song. He later heard and observed more birds of the same species.

Initially, Timmins assumed these birds to be Blyth's reed warblers, but a visit to a Natural History Museum in Tring in Britain to examine bird skins resulted in a surprise: the observed birds were another species.

Lars Svensson - an expert on the family of reed warblers and familiar with their songs -then realised that Timmins' tape was probably the first recording of the large-billed reed warbler.

The following summer (June 2009), WCS researchers returned to the site of Timmins' first survey, this time with mist nets used to catch birds for examination.

The research team broadcast the recording of the song, a technique used to bring curious birds of the same species into view for observation and examination.

The recording brought in large-billed reed warblers from all directions, allowing the team to catch almost 20 of them for examination and to collect feathers for DNA, said a WCS release.

Later lab work comparing museum specimens with measurements, field images, and DNA confirmed the exciting finding: the first-known breeding population of large-billed reed warblers.

A preliminary finding appears in the latest edition of BirdingASIA.

IANS

Polar bear poo helps in superbug hunt

Polar bear droppings are helping scientists shed light on the spread of deadly antibiotic-resistant superbugs.

Bacteria such as methicillin-resistant staphylococcus aureus (MRSA) are a growing problem in hospitals and researchers are anxious to understand how they evolve.

Norwegian researchers said they had found little sign of such microbes in the feces of polar bears in the remote Arctic, suggesting the spread of resistance genes seen in the droppings of other animals may be due to human influence.

In contrast to the results from polar bears on the Svalbard archipelago, antibiotic resistance has been discovered in a range of animals including deer, foxes, pigs, dogs and cats that live close to humans.

Trine Glad of the University of Tromso said her team's research, published on Thursday in the journal BMC Microbiology, was important evidence in the debate as to whether resistance occurs naturally or is caused by exposure to human antibiotics.

The rise of superbugs is prompting some drug companies to look again at antibiotics, a field that has been neglected in recent years. Both AstraZeneca and Sanofi-Aventis have signed new antibiotic research collaborations this week.

PTI

Astronauts urine clogs space station water recycler

NASA is finding it is not just mechanical glitches that make the International Space Station a tough place to operate.

Engineers trouble-shooting a problem with the station's $250 million water recycling system, which processes urine into clean water for drinking, believe the cause is a high concentration of calcium in the astronauts' urine, which clogs the system.

Scientists do not yet know if the high calcium concentration is due to bone loss, a consequence of living in a zero-gravity environment, or other factors.

"We've learned a lot more about urine than we ever needed or wanted to know -- some of us anyway," said station flight director David Korth.

The $100 billion space station project involving 16 nations has been under construction 220 miles above the Earth for more than a decade.

Before the urine recycler was started up in November 2008, it was fully tested by NASA.

"Folks had good knowledge of the content of the urine going in, but the chemistry changes as it works through the processor are not always understood," said program scientist Julie Robinson. "There are a lot of parameters including urine calcium and pH (acidity) that everyone is looking at."

Engineers at the Marshall Space Flight Center in Huntsville, Alabama, are hoping to come up with a fix in time to fly replacement parts out on the shuttle Endeavour, which is scheduled for launch on February 7 on a construction mission.

Bureau Report

Mystery object to whizz by Earth today

An image of the mystery object from space that is about to whiz close by Earth taken from Skylive-Grove Creek Observatory in NSW.

A mystery object from space is about to whizz close by Earth on Wednesday. It won't hit our planet, but scientists are stumped by what exactly it is.

Astronomers say it may be space junk or it could be a tiny asteroid, too small to cause damage even if it hit. It's 33 to 50 feet wide at most.

NASA says that on Wednesday at 7:47 am EST, it will streak by, missing Earth by about 80,000 miles. In the western United States it may be bright enough to be seen with a good amateur telescope

Bureau Report

Moon’s crystal mountains reveal its molten past

The crystal mountains, which were found on the Moon by India's Chandrayaan-1 probe, are a sign that a roiling ocean of magma once engulfed the rocky body of our satellite, say scientists.

And heavy, iron-bearing minerals are thought to have sunk through this magma to form the moon''s mantle, while lighter, iron-poor minerals called plagioclases should have crystallised and floated to the surface.

But it has been difficult to find direct evidence of the Moon's primordial crystalline crust, as it was likely jumbled by meteoroid impacts and paved over by lava flows early in the Moon's history.

Until recently, the only evidence came from lunar samples collected at a few sites by the Apollo astronauts.

However, last year, Japan's Kaguya probe spotted patches of the stuff inside a number of craters.

And now, Chandrayaan-1, which orbited the Moon for almost 10 months until it failed in August, seems to have found the mother lode - vast outcrops of plagioclase crystal along a mountain range inside the moon''s 930-kilometre-wide Orientale basin.

Lava has resurfaced less of Orientale than other craters of its size.

In 1994, the US orbiter Clementine found regions inside Orientale that seemed to be virtually iron-free, hinting at plagioclase, but Chandrayaan-1 was able to detect the light absorbed by the crystal itself.

It found that the rock containing the crystal spans at least 40 kilometres and is quite pure - less than 5 per cent of it is composed of iron-rich minerals.

This is purer than a number of Apollo samples, which until now have been the primary source of information on the Moon's ancient crust.

"This is a game-changer. We now have to rethink a lot of lunar science; issues such as the way the crust originally floated over the denser melt of the magma ocean [and] the extent to which the crust was jumbled by large impacts," New Scientist quoted Paul Warren of the University of California, Los Angeles, as saying.

Finding widespread, pure plagioclase suggests a more global process behind moon’s formation.

"It really pretty much ties up the magma ocean part of the story," said Carle Pieters of Brown University in Providence, Rhode Island.

He presented the Chandrayaan-1 results at the American Geophysical Union meeting in December in San Francisco.

ANI

Trees on Mars?

A Mars probe has baffled NASA scientists by sending images of what look like trees on the red planet.

The images show rows of dark conifer type trees emerging from Martian hills.

However, the scene is an incredible optical illusion.

What is seen are sand dunes covered with a thin layer of frozen carbon dioxide (dry ice) less than 240 miles from Mars’ north pole.

The "trees" are actually trails of debris caused by landslides when the ice melts in spring.

The photo was taken by HiRISE, the most powerful camera sent to another planet.

"The streaks are sand, dislodged as ice evaporates, which slide down the dune," the Sun quoted NASA''''s Candy Hansen, as saying.

"At this time of the martian year the whole scene is covered by CO2 frost," Hansen added.

ANI

Just like in humans, sleep helps solidify birds’ memories

It is known that sleep helps humans stabilize information and tasks learned during the preceding day. But now, researchers say the same is true of birds.

Researchers at the University of Chicago have found that sleep helps starlings remember how to perform a specific task.

The birds were trained to distinguish two five-second birdsong clips using what the researchers called a "go-no go" procedure.

When the "go" birdsong was played, the bird was given a food pellet if it poked its beak through a hole in its cage. When the "no go" song was played, the bird poking its beak through the hole didn''t release a food pellet and caused the lights in the cage to briefly turn off.

Groups of starlings were trained in the task at different times of day and tested later to see how well they learned.

In all the groups, the birds'' performance at the task improved after the birds slept.

"We really wanted to behaviourally show that these types of sleep-dependent memory benefits are occurring in animals," said graduate study and lead author Timothy Brawn.

"What was remarkable was that the pattern here looks very similar to what we see in humans. There wasn''t anything that was terribly different," Brawn added.

Previous studies have shown that humans can perform a learned task better after a night''s sleep. Brawn and his colleagues demonstrated this in a 2008 study involving people learning to play a first-person shooter game.

Other studies have shown that sleep pays an important role in allowing birds to learn new songs.

The researchers say their work will open new ways to study how the brain learns and retains information. Daniel Margoliash, a professor of organismal biology, psychology and neuroscience at the University of Chicago, said: "The result suggests this is a very broad, general phenomenon that might be shared across a great many vertebrates.” The study appears in The Journal of Neuroscience.

ANI

Tiny wasps provide hope for vanishing species

They may only be 1.5 mm in size, but the tiny wasps that pollinate fig trees can transport pollen 10 times faster than previously recorded by any insect and make the trees resistant to forest fragmentation, says a new study.

Scientists from the University of Leeds said fig wasps travel these distances seeking trees to lay their eggs, which offers hope that trees pollinated by similar creatures have a good chance of surviving if they become isolated through deforestation.

"Fig trees provide very important food for vertebrates," explains Stephen Compton of the Leeds Faculty of Biological Sciences.

"More birds and animals feed on fig trees than on any other plant in the rainforest. Our research shows that trees pollinated by this type of insect should be very resistant to forest fragmentation."

"Fig wasps are weak flyers," added Compton. "They fly up in an air column and are then carried by wind until they sense host figs at which point they drop close to the ground and hunt out the scent of the tree which is specific to them.

"As adult wasps live for just 48 hours, they must have travelled these distances incredibly fast. It took our field scientists and volunteers nearly two weeks to walk 250 km and map the fig trees used in the research."

Using a unique mix of field work and genetic tests, the researchers tracked the movement of pollen between trees and used this as the marker for insect movement.

The scientists mapped all the African fig trees (Ficus sycomorus) along 250 km of the Ugab River valley in the Namib Desert, said a Leeds release.

Due to the climate, the trees were only able to survive near the river, which made it possible to identify each of the 79 trees in the area individually.

These findings were published in the Proceedings of the National Academy of Sciences.

Bureau Report

Origin of life? Scientists rule out 'metabolism first' theory

A new study has rejected the long-held theory that the origin of life stems from a system of self-catalytic molecules capable of experiencing Darwinian evolution without the need of RNA, DNA and their replication.

The research, led by Mauro Santos of Universitat Autònoma de Barcelona, has demonstrated through the analysis of what some researchers name "compound genomes", these chemical networks cannot be considered evolutionary units as they lose properties which are essential for evolution when they reach a critical size and greater level of complexity.

The scientific theories on the origin of life revolve around two main ideas: one focuses on genetics -- with RNA or DNA replication as an essential condition for Darwinian evolution to take place -- and the other on metabolism.

It is clear that both situations must have begun with simple organic molecules formed by prebiotic processes.

The point in which these two theories differ is that the replication of RNA or DNA molecules is a far too complex process which requires a correct combination of monomers within the polymers to produce a molecular chain resulting from the replication, say scientists.

Until now no plausible chemical explanation exists for how these processes occurred. In addition, defenders of the second theory argue that the processes needed for evolution to take place depend on primordial metabolism.

The researchers in this study nevertheless reveal that these systems are incapable of undergoing a Darwinian evolution. For the first time a rigorous analysis was carried out to study the supposed evolution of these molecular networks using a combination of numerical and analytical simulations and network analysis approximations.

Their research demonstrated that the dynamics of molecular compound populations which divide after having reached a critical size do not evolve, since during this process the compounds lose properties which are essential for Darwinian evolution.

The researchers concluded this fundamental limitation of "compound genomes" should lead to caution towards theories that set metabolism first as the origin as life, even though former metabolic systems could have offered a stable habitat in which primitive polymers such as RNA could have evolved.

They say that different prebiotic Earth scenarios can be considered. However, the basic property of life as a system capable of undergoing Darwinian evolution began when genetic information was finally stored and transmitted such as occurs in nucleotide polymers (RNA and DNA).

PTI

Solar system more compact than thought

The solar system may be significantly more compact than previously thought, American scientists have claimed.

Astronomers at the University of Washington in Seattle have developed a computer simulation of the cloud of comets that enshrouds the solar system.

The work suggests the cloud may not contain as much material as once suspected, which could resolve a long-standing problem in models of how the planets formed.

Long-period comets, which take longer than 200 years to orbit the sun, come from all directions in the sky, an observation that has long led scientists to believe that they were nudged out of a diffuse halo of icy objects or the Oort Cloud that is surrounding the solar system.

The objects probably formed from the same disc of material that gave rise to the planets but were scattered outwards by Jupiter and Saturn a few hundred million years after their birth, the New Scientist reported.

"There may not be nearly as much stuff as far out as we thought," says Nathan Kaib, who presented the findings at an American Astronomical Society meeting recently.

Kaib said, "The region of the Oort Cloud that is not supposed to produce any comets may be the dominant producer of comets."

PTI

Turtles dying en-masse in Orissa’s Gahirmatha sanctuary

Sighting of bloated and motionless bodies of Olive Ridley sea turtles lend credence to the belief that unlawful trawling operation despite prohibition is in full swing along the Gahirmatha marine sanctuary in Orissa's Kendrapara district.

Bodies of dead turtles are sporadically dispersed along the stretch of the beach from Dhamra to Paradip coast.

Unofficial estimates put the toll at more than 5,000 while the forest officials restrict the death figure at 671.

The turtles death toll is on the lower side this time. The vigil and surveillance on trawl fishing is stepped up. That’s why, the marine visitors are comparatively safer this year, Prasanna Kumar Behera, divisional forest officer, Rajnagar Mangrove (wildlife) forest division, claimed.

However, ground reality is grim and it hardly substantiates official claim.

Wildlife activists argue that turtles are dying en-masse in several strategic locations and accidental death of the amphibians is due to uninterrupted trawling.

''Though marine fishing has been banned along the Gahirmatha water territory under OMFRA, 1982, trawl fishing has become a daily ritual. Turtles get hit by trawler propellers and are killed," said Sudhansu Parida, an activist of People for Animals.

"The animals are getting entangled in the mono-filament nets that are being used by fishing trawls. The mute species are dying of asphyxiation," Parida said.

The beaches at places like Satabhaya, Pentha, Agarnasi and Barunei have turned into a graveyard for the Olive Ridley sea turtles. Any day, one would come across the ghastly sight of rows of decomposed bodies of these delicate marine species, he said.

Forest officials admitted the sighting of turtle carcasses at these places. However, they declined to elaborate on the death toll.

PTI

Evidence of ancient lakes on Mars

NASA/JPL

Spectacular satellite images suggest that Mars was warm enough to sustain lakes three billion years ago, a period that was previously thought to be too cold and arid to sustain water on the surface, according to research published today in the journal Geology.

The research, by a team from Imperial College London and University College London (UCL), suggests that during the Hesperian Epoch, approximately 3 billion years ago, Mars had lakes made of melted ice, each around 20km wide, along parts of the equator.

Earlier research had suggested that Mars had a warm and wet early history but that between 4 billion and 3.8 billion years ago, before the Hesperian Epoch, the planet lost most of its atmosphere and became cold and dry. In the new study, the researchers analysed detailed images from NASA's Mars Reconnaissance Orbiter, which is currently circling the red planet, and concluded that there were later episodes where Mars experienced warm and wet periods.

The researchers say that there may have been increased volcanic activity, meteorite impacts or shifts in Mars' orbit during this period to warm Mars' atmosphere enough to melt the ice. This would have created gases that thickened the atmosphere for a temporary period, trapping more sunlight and making it warm enough for liquid water to be sustained.

Lead author of the study, Dr Nicholas Warner, from the Department of Earth Science and Engineering at Imperial College London, says:

"Most of the research on Mars has focussed on its early history and the recent past. Scientists had largely overlooked the Hesperian Epoch as it was thought that Mars was then a frozen wasteland. Excitingly, our study now shows that this middle period in Mars' history was much more dynamic than we previously thought."

The researchers used the images from the Mars Reconnaissance Orbiter to analyse several flat-floored depressions located above Ares Vallis, which is a giant gorge that runs 2,000 km across the equator of Mars.

Scientists have previously been unable to explain how these depressions formed, but believed that the depressions may have been created by a process known as sublimation, where ice changes directly from its solid state into a gas without becoming liquid water. The loss of ice would have created cavities between the soil particles, which would have caused the ground to collapse into a depression.

In the new study, the researchers analysed the depressions and discovered a series of small sinuous channels that connected them together. The researchers say these channels could only be formed by running water, and not by ice turning directly into gas.

The scientists were able to lend further weight to their conclusions by comparing the Mars images to images of thermokarst landscapes that are found on Earth today, in places such as Siberia and Alaska. Thermokarst landscapes are areas where permafrost is melting, creating lakes that are interconnected by the same type of drainage channels found on Mars.

The team believe the melting ice would have created lakes and that a rise in water levels may have caused some of the lakes to burst their banks, which enabled water to carve a pathway through the frozen ground from the higher lakes and drain into the lower lying lakes, creating permanent channels between them.

Professor Jan-Peter Muller, Mullard Space Science Laboratory, Department of Space Climate Physics at University College London, was responsible for mapping the 3D shape of the surface of Mars. He adds:

"We can now model the 3D shape of Mars' surface down to sub-metre resolution, at least as good as any commercial satellite orbiting the Earth. This allows us to test our hypotheses in a much more rigorous manner than ever before."

The researchers determined the age of the lakes by counting crater impacts, a method originally developed by NASA scientists to determine the age of geological features on the moon. More craters around a geological feature indicate that an area is older than a region with fewer meteorite impacts. In the study, the scientists counted more than 35,000 crater impacts in the region around the lakes, and determined that the lakes formed approximately three billion years ago. The scientists are unsure how long the warm and wet periods lasted during the Hesperian epoch or how long the lakes sustained liquid water in them.

The researchers say their study may have implications for astrobiologists who are looking for evidence of life on Mars. The team say these lake beds indicate regions on the planet where it could have been warm and wet, potentially creating habitats that may have once been suitable for microbial life. The team say these areas may be good targets for future robotic missions.

Bureau Report

Five exoplanets identified by Kepler space telescope

Five new exoplanets -- earth-size planets in the habitable zone of sun-like stars -- have been discovered by NASA scientists.

The five planets -- Kepler 4b, 5b, 6b, 7b and 8b -- named after Kepler space telescope which identified them, vary in size from that of a Neptune to larger than Jupiter, the US space agency reported on its website.

The planets are also called "hot Jupiters" because of their high masses extreme temperatures ranging from 2,200 to 3,000 degrees Fahrenheit.

The temperatures are too high for life to exist on these planets, the agency said.

"These observations contribute to our understanding of how planetary systems form and evolve from the gas and dust disks that give rise to both the stars and their planets," said William Borucki of NASA's Ames Research Center in California.

The planets, whose stars are hotter and larger than our Sun, have an orbiting period ranging from 3.3 to 4.9 days.

Jon Morse, director of the Astrophysics Division at NASA said, "We expected Jupiter-size planets in short orbits to be the first planets Kepler could detect.

The mission, which is expected to continue until at least November 2012, will search for planets as small as Earth, including those that orbit stars in a warm habitable zone where liquid water could exist on the surface of the planet.

"It's only a matter of time before more Kepler observations lead to smaller planets with longer period orbits, coming closer and closer to the discovery of the first Earth analog," Morse said.

"Today's discoveries are a significant contribution to that goal. The Kepler observations will tell us whether there are many stars with planets that could harbour life, or whether we might be alone in our galaxy," Borucki said.

The Kepler mission was launched last year from Florida. It continuously and simultaneously observes more than 1,50,000 stars and has already measured hundreds of possible planet signatures that are being analysed.

The existence of five exoplanets was confirmed by the ground-based observatories.

The discoveries were announced yesterday by the members of the Kepler science team during a news briefing at the American Astronomical Society meeting in Washington.

PTI

Swiss glaciers melting slower now than in 1940s!

Contrary to popular perception that glaciers are melting faster the world over due to global warming, a new study says that Swiss glaciers were melting even faster in the 1940s when temperatures were lower.

Significantly, ETH Zurich researchers attribute the melting of glaciers in the 1940s to a lower level of aerosol - a suspension of fine solid particles or liquid droplets in a gas - pollution in the atmosphere.

The increase in winter snow and melting glaciers in summer have been measured at heights of 3,000 metres, on the Clariden Firn, the Great Aletsch glacier and the Silvretta glacier, without interruption for almost 100 years.

Matthias Huss used this unique range of measurements to examine how climate change in the last century affected the glaciers, as part of his doctoral dissertation.

His work was supervised by Martin Funk, professor in glaciology at the Laboratory for Hydraulics, Hydrology and Glaciology ('VAW') ETH Zurich, who co-authored the study.

The research team took into account the solar radiation measured on the earth's surface in Davos since 1934.

They arrived at their findings by calculating the daily melt rates with the aid of climate data and a temperature index model, based on the half-yearly measurements on the glaciers since 1914.

These results were then compared with the long-term measurements of solar radiation in Davos, says a release of ETH Zurich.

Studies over the past two decades have shown that solar radiation varies substantially due to aerosols and clouds, and this is assumed to influence climate fluctuations.

The new study was published in Geophysical Research Letters.

IANS