Within two months, a new record for most distant galaxy: Nasa

Subodh Varma, TNN Nov 16, 2012, 02.49PM IST

NEW DELHI: The record for the most distant galaxy from Earth has been broken just two months after it was set. What appeared as a tiny blob to Nasa scientists turned out to be a small infant galaxy 13.3 billion light years away, Nasa said in a statement yesterday. Since the Universe itself is 13.7 billion years old, this means that the newly discovered galaxy was just 420 million years old when the light that scientists saw, left it. So, it also becomes the oldest known galaxy. Currently, it is known as MACS0647-JD.

The previous record was set in September this year when the same team discovered a galaxy 13.2 billion light years away. It was 490 million old.

Scientists are now able to discover these uber-distant objects by combining the power of Nasa's Hubble and Spitzer space telescopes and one of nature's own natural "zoom lenses" in space. Light from very distant objects gets magnified by the gravity of massive galaxies that happen to be in its way. This effect is called "gravitational lensing".

This find is the latest discovery from a program called Cluster Lensing And Supernova Survey with Hubble (CLASH), an international group led by Marc Postman of the Space Telescope Science Institute in Baltimore.

Along the way, 8 billion years into its journey, light from MACS0647-JD took a detour along multiple paths around the massive galaxy cluster MACS J0647+7015. Without the cluster's magnification powers, astronomers would not have seen this remote galaxy. Because of gravitational lensing, the CLASH research team was able to observe three magnified images of MACS0647-JD with the Hubble telescope.

"This cluster does what no man-made telescope can do," said Postman. "Without the magnification, it would require a Herculean effort to observe this galaxy."

The newly discovered most distant galaxy is so small it may be in the first steps of forming a larger galaxy, Nasa said. Analysis shows the galaxy is less than 600 light-years wide. Based on observations of somewhat closer galaxies, astronomers estimate that a typical galaxy of a similar age should be about 2,000 light-years wide. For comparison, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

"This object may be one of many building blocks of a galaxy," said the study's lead author, Dan Coe of the Space Telescope Science Institute. "Over the next 13 billion years, it may have dozens, hundreds or even thousands of merging events with other galaxies and galaxy fragments."

Coe and his collaborators spent months systematically ruling out these other alternative explanations for the object's identity, including red stars, brown dwarfs and red (old or dusty) galaxies at intermediate distances from Earth. They concluded that a very distant galaxy was the correct explanation.

The new galaxy may be too far away for any current telescope to confirm the distance based on spectroscopy, which spreads out an object's light into thousands of colors, Nasa said. Nevertheless, Coe is confident the fledgling galaxy is the new distance champion based on its unique colors and the research team's extensive analysis.

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Man began spear-hunting 200,000 years earlier than believed

LONDON: Man began hunting with stone-tipped spears half a million years ago — 200,000 years earlier than previously thought, according to a new study.

Scientists have discovered our ancestors began hunting with stone-tipped spears 500,000 years ago — with the help of a special crossbow and a dead springbok, the Daily Mail reported.

Until recently, it was thought attaching a stone tip to a spear — known as 'hafting' — started about 300,000 years ago.

However, by comparing the wear visible on 500,000-year-old stone points found in South Africa with modern experimental points fired by a specially calibrated crossbow at a springbok carcass, scientists proved they had been used as spear tips for hunting.

'Hafting' was an important technological advance that made it possible to handle or throw sharp points with much more power and control.

Lead author Jayne Wilkins from the department of anthropology at the University of Toronto in Canada, said the research suggested stone-tipped spears could have been in use before the divergence of early humans and Neanderthals.

"This changes the way we think about early human adaptations and capacities before the origin of our own species," she said.

"Although both Neanderthals and humans used stone-tipped spears, this is the first evidence that the technology originated prior to or near the divergence of these two species," she added.

Attaching stone points to spears was an important advance in hunting weaponry for early humans. Hafted tools require more effort and planning to manufacture, but a sharp stone point on the end of a spear can increase its killing power.

The new study — which examined stone points from the South African archaeological site of Kathu Pan 1 — shows that they were also used in the early middle pleistocene, a period associated with Homo heidelbergensis, the last common ancestor of Neanderthals, and modern humans.

Wilkins and colleagues from Arizona State University and the University of Cape Town, compared the ancient stone points to experimental points which they hafted to wooden dowels using Acacia resin and sinew before thrusting them into a springbok with a mounted crossbow.

The stone points exhibit certain types of breaks that occur more commonly when they are used to tip spears compared to other uses.

"The archaeological points have damage that is very similar to replica spear points used in our spearing experiment," Wilkins said.

This type of damage is not easily created through other processes, she added.

The findings were published in the journal Science.

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After a month, Curiosity set to hit the road again

LOS ANGELES: After playing in the sand, the Curiosity rover is poised to trek across the Martian landscape in search of a rock to drill into , scientists reported.
The six-wheel rover has been parked for more than a month at a sand dune where it has been busy scooping up soil, sniffing the atmosphere and measuring radiation levels on the surface. Its next task is to zero in on a rock and that requires driving to a new location.

Mission deputy scientist Ashwin Vasavada expected Curiosity to be on the move in the "next few days" . "It's the bedrock which really gives you the story of ancient Mars," said Vasavada of the Nasa Jet Propulsion Laboratory, which manages the $2.5 billion mission. "The soil is a little harder to interpret because we don't know how old it is or where it came from."

The car-size rover touched down in Gale Crater, an ancient depression near the Martian equator, in August on a two-year mission to probe whether the landing site once had conditions capable of supporting microbial life. Armed with a high-tech suite of instruments, it's the most sophisticated spacecraft to ever land on the red planet.

During the first three months, a weather station aboard Curiosity detected brief drops in air pressure , a sign of whirlwinds in the region. "These events are starting to occur more and more often," said Manuel de la Torre Juarez of Nasa JPL. "We expect to see more in the future."

Previous rovers have spotted and even recorded dust devils dancing across the Martian terrain , but scientists said Curiosity has not yet seen evidence that the swirling winds have lifted dust.

Curiosity's ultimate destination is a 5km-high mountain rising from the center of the crater floor that's rich in mineral deposits. Scientists had hoped to drive to the base before the end of the year, but that doesn't look likely after the extended stay at its current spot.

Google has updated its coverage of Mars with high resolution images from a Nasa satellite orbiting the planet, as part of their freely downloadable Google Earth app. The Google Earth app has showed Mars since 2009, but up until now most areas of the red planet could only be seen in low-resolution .

Google Mars updated large amounts of the planet's surface with images from the Context Camera (CTX) on Nasa's Mars Reconnaissance Orbiter, with a resolution of around 20ft per pixel, the Daily Mail reported.

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Mars rover Curiosity set to hit the road again

LOS ANGELES: After playing in the sand, the Curiosity rover is poised to trek across the Martian landscape in search of a rock to drill into, scientists reported Thursday.

The six-wheel rover has been parked for more than a month at a sand dune where it has been busy scooping up soil, sniffing the atmosphere and measuring radiation levels on the surface. Its next task is to zero in on a rock and that requires driving to a new location.

Mission deputy scientist Ashwin Vasavada expected Curiosity to be on the move in the ``next few days.''

``It's the bedrock which really gives you the story of ancient Mars,'' said Vasavada of the NASA Jet Propulsion Laboratory, which manages the $2.5 billion mission. ``The soil is a little harder to interpret because we don't know how old it is or where it came from.''

The car-size rover touched down in Gale Crater, an ancient depression near the Martian equator, in August on a two-year mission to probe whether the landing site once had conditions capable of supporting microbial life. Armed with a high-tech suite of instruments, it's the most sophisticated spacecraft to ever land on the red planet.

During the first three months, a weather station aboard Curiosity detected brief drops in air pressure, a sign of whirlwinds in the region.

``These events are starting to occur more and more often,'' said Manuel de la Torre Juarez of NASA JPL. ``We expect to see more in the future.''

Previous rovers have spotted and even recorded dust devils dancing across the Martian terrain, but scientists said Curiosity has not yet seen evidence that the swirling winds have lifted dust.

Curiosity's ultimate destination is a 3-mile-high (5-kilometer-high) mountain rising from the center of the crater floor that's rich in mineral deposits. Scientists had hoped to drive to the base before the end of the year, but that doesn't look likely after the extended stay at its current spot.

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Within two months, a new record for most distant galaxy

NEW DELHI: The record for the most distant galaxy from Earth has been broken just two months after it was set. What appeared as a tiny blob to Nasa scientists turned out to be a small infant galaxy 13.3 billion light years away, Nasa said in a statement yesterday. Since the Universe itself is 13.7 billion years old, this means that the newly discovered galaxy was just 420 million years old when the light that scientists saw, left it. So, it also becomes the oldest known galaxy. Currently, it is known as MACS0647-JD.

The previous record was set in September this year when the same team discovered a galaxy 13.2 billion light years away. It was 490 million old.

Scientists are now able to discover these uber-distant objects by combining the power of Nasa's Hubble and Spitzer space telescopes and one of nature's own natural "zoom lenses" in space. Light from very distant objects gets magnified by the gravity of massive galaxies that happen to be in its way. This effect is called "gravitational lensing".

This find is the latest discovery from a program called Cluster Lensing And Supernova Survey with Hubble (CLASH), an international group led by Marc Postman of the Space Telescope Science Institute in Baltimore.

Along the way, 8 billion years into its journey, light from MACS0647-JD took a detour along multiple paths around the massive galaxy cluster MACS J0647+7015. Without the cluster's magnification powers, astronomers would not have seen this remote galaxy. Because of gravitational lensing, the CLASH research team was able to observe three magnified images of MACS0647-JD with the Hubble telescope.

"This cluster does what no man-made telescope can do," said Postman. "Without the magnification, it would require a Herculean effort to observe this galaxy."

The newly discovered most distant galaxy is so small it may be in the first steps of forming a larger galaxy, Nasa said. Analysis shows the galaxy is less than 600 light-years wide. Based on observations of somewhat closer galaxies, astronomers estimate that a typical galaxy of a similar age should be about 2,000 light-years wide. For comparison, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

"This object may be one of many building blocks of a galaxy," said the study's lead author, Dan Coe of the Space Telescope Science Institute. "Over the next 13 billion years, it may have dozens, hundreds or even thousands of merging events with other galaxies and galaxy fragments."

Coe and his collaborators spent months systematically ruling out these other alternative explanations for the object's identity, including red stars, brown dwarfs and red (old or dusty) galaxies at intermediate distances from Earth. They concluded that a very distant galaxy was the correct explanation.

The new galaxy may be too far away for any current telescope to confirm the distance based on spectroscopy, which spreads out an object's light into thousands of colors, Nasa said. Nevertheless, Coe is confident the fledgling galaxy is the new distance champion based on its unique colors and the research team's extensive analysis.

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Within two months, a new record for most distant galaxy: Nasa

NEW DELHI: The record for the most distant galaxy from Earth has been broken just two months after it was set. What appeared as a tiny blob to Nasa scientists turned out to be a small infant galaxy 13.3 billion light years away, Nasa said in a statement yesterday. Since the Universe itself is 13.7 billion years old, this means that the newly discovered galaxy was just 420 million years old when the light that scientists saw, left it. So, it also becomes the oldest known galaxy. Currently, it is known as MACS0647-JD.

The previous record was set in September this year when the same team discovered a galaxy 13.2 billion light years away. It was 490 million old.

Scientists are now able to discover these uber-distant objects by combining the power of Nasa's Hubble and Spitzer space telescopes and one of nature's own natural "zoom lenses" in space. Light from very distant objects gets magnified by the gravity of massive galaxies that happen to be in its way. This effect is called "gravitational lensing".

This find is the latest discovery from a program called Cluster Lensing And Supernova Survey with Hubble (CLASH), an international group led by Marc Postman of the Space Telescope Science Institute in Baltimore.

Along the way, 8 billion years into its journey, light from MACS0647-JD took a detour along multiple paths around the massive galaxy cluster MACS J0647+7015. Without the cluster's magnification powers, astronomers would not have seen this remote galaxy. Because of gravitational lensing, the CLASH research team was able to observe three magnified images of MACS0647-JD with the Hubble telescope.

"This cluster does what no man-made telescope can do," said Postman. "Without the magnification, it would require a Herculean effort to observe this galaxy."

The newly discovered most distant galaxy is so small it may be in the first steps of forming a larger galaxy, Nasa said. Analysis shows the galaxy is less than 600 light-years wide. Based on observations of somewhat closer galaxies, astronomers estimate that a typical galaxy of a similar age should be about 2,000 light-years wide. For comparison, the Large Magellanic Cloud, a dwarf galaxy companion to the Milky Way, is 14,000 light-years wide. Our Milky Way is 150,000 light-years across.

"This object may be one of many building blocks of a galaxy," said the study's lead author, Dan Coe of the Space Telescope Science Institute. "Over the next 13 billion years, it may have dozens, hundreds or even thousands of merging events with other galaxies and galaxy fragments."

Coe and his collaborators spent months systematically ruling out these other alternative explanations for the object's identity, including red stars, brown dwarfs and red (old or dusty) galaxies at intermediate distances from Earth. They concluded that a very distant galaxy was the correct explanation.

The new galaxy may be too far away for any current telescope to confirm the distance based on spectroscopy, which spreads out an object's light into thousands of colors, Nasa said. Nevertheless, Coe is confident the fledgling galaxy is the new distance champion based on its unique colors and the research team's extensive analysis.

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'Early humans ate grass like a cow'

LONDON: Early humans who roamed the African savanna three-and-a-half million years ago had a diet more like a cow than a great ape - comprising of grass and sedges, a new Oxford study has found.

Researchers found that Australopithecus bahrelghazali chomped its way through rushes and grasses rather than soft fruits preferred by its chimpanzee cousins, thanks to its powerful jaws and big grinding teeth.

The study shows the ancestral human diet diverged from that of the apes much sooner than previously thought, the 'Daily Mail' reported. Experts analysed the amount of carbon in teeth from A bahrelghazali specimens dug up from a fossil site in Chad with the help of a laser that freed carbon from the enamel. This showed the creature's diet would have been rich in C4 plants such as grasses and sedges.

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Well-preserved tree fossils from Jurassic age found in Chhattisgarh

RAIPUR: In a discovery that might excite geologists the world over, researchers of the State Forest Research and Training Institute (SFRTI) in Chhattisgarh have said that they have discovered tree fossils that date back about 250 million years - or the Jurassic age. The discovery could be a precursor to more such findings in the Sarguja region, known for its rich fossil reserves.

SFRTI director K C Yadav said that this was the first discovery of tree fossils in Chhattisgarh of international significance. Evidence suggests that the fossils, dating to the lower Gondwana time scale, were discovered on the north side of the Tamor Pingla wildlife sanctuary, in north Sarguja forest division.

During the exploration, scientists discovered an 18ft fossil stump of a tree measuring 10ft in diameter in a well-preserved state, along with six other large sections. They also found the fossil stump of another tree, which was 43ft long and 6ft in diameter, by the roadside in the forest.

Yadav said that the fossils are likely to be of the Glossopteris and Araucaria species. As fossils of different types and sizes are present in abundance in the entire area, the principal chief conservator of wildlife and biodiversity, Ram Prakash, asked SFRTI to survey the area and prepare a plan for developing a fossil park of national level for the protection of these fossils.

"It will not only help researchers but also laymen to learn more about tree fossils," he said, adding that he has also approved Rs 4 lakh for the first phase of conservation of the area. Explaining the magnitude of the discovery, Yadav said, "They are the oldest tree fossils found in India so far. Scientists from the Birbal Sahni Institute of Paleobotany (BSIP), Lucknow have also confirmed this."

R C Mehrotra, a scientist at BSIP, said, "We have taken samples of the fossils for examination, but a preliminary assessment suggests that they are the oldest fossils. After a month, we will give a report about the species of the trees."

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New gene triples risk for Alzheimer's disease

Scientists have identified a new gene variant that seems to strongly raise the risk for Alzheimer's disease, giving a fresh target for research into treatments for the mind-robbing disorder.

The problem gene is not common - less than 1 percent of people are thought to have it - but it roughly triples the chances of developing Alzheimer's compared to people with the normal version of the gene. It also seems to harm memory and thinking in older people without dementia.

The main reason scientists are excited by the discovery is what this gene does, and how that might reveal what causes Alzheimer's and ways to prevent it. The gene helps the immune system control inflammation in the brain and clear junk such as the sticky deposits that are the hallmark of the disease. Mutations in the gene may impair these tasks, so treatments to restore the gene's function and quell inflammation may help.

"It points us to potential therapeutics in a more precise way than we've seen in the past," said Dr. William Thies, chief medical and scientific officer of the Alzheimer's Association, which had no role in the research. Years down the road, this discovery will likely be seen as very important, he predicted.

It is described in a study by an international group published online Wednesday by the New England Journal of Medicine.

About 35 million people worldwide have dementia, and Alzheimer's is the most common type. In the U.S., about 5 million have Alzheimer's. Medicines such as Aricept and Namenda just temporarily ease symptoms. There is no known cure.

Until now, only one gene - ApoE - has been found to have a big impact on Alzheimer's risk. About 17 percent of the population has at least one copy of the problem version of this gene but nearly half of all people with Alzheimer's do. Other genes that have been tied to the disease raise risk only a little, or cause the less common type of Alzheimer's that develops earlier in life, before age 60.

The new gene, TREM2, already has been tied to a couple other forms of dementia. Researchers led by deCODE Genetics Inc. of Iceland honed in on a version of it they identified through mapping the entire genetic code of more than 2,200 Icelanders.

Further tests on 3,550 Alzheimer's patients and more than 110,000 people without dementia in several countries, including the United States, found that the gene variant was more common in Alzheimer's patients.

"It's a very strong effect," raising the risk of Alzheimer's by three to four times - about the same amount as the problem version of the ApoE gene does, said Dr. Allan Levey, director of an Alzheimer's program at Emory University, one of the academic centers participating in the research.

Researchers also tested more than 1,200 people over age 85 who did not have Alzheimer's disease and found that those with the variant TREM2 gene had lower mental function scores than those without it. This adds evidence the gene variant is important in cognition, even short of causing Alzheimer's.

"It's another piece in the puzzle. It suggests the immune system is important in Alzheimer's disease," said Andrew Singleton, a geneticist with the National Institute on Aging, which helped pay for the study.

One prominent scientist not involved in the study - Dr. Rudolph Tanzi, a Harvard Medical School geneticist and director of an Alzheimer's research program at Massachusetts General Hospital - called the work exciting, but added a caveat.

"I would like to see more evidence that this is Alzheimer's" rather than one of the other dementias already tied to the gene, Tanzi said. Autopsy or brain imaging tests can show whether the cases attributed to the gene variant are truly Alzheimer's or misdiagnosed, he said.

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Space junk to rise with carbon dioxide level

PARIS: A build-up of carbon dioxide in the upper levels of Earth's atmosphere risks causing a faster accumulation of man-made space junk and resulting in more collisions, scientists said on Sunday. While it causes warming on Earth, carbon dioxide conversely cools down the atmosphere and contracts its outermost layer, the thermosphere, where many satellites including the International Space Station (ISS) operate, said a study published in the journal Nature Geoscience.

A contracted thermosphere, in turn, reduces atmospheric "drag" on satellites — a similar force to that experienced when holding one's hand out the window of a moving car.

This "drag" is what causes satellite orbits to change, drawing them closer to Earth, which means that orbiters like the ISS have to boost themselves back on course with onboard engines.

"The observed carbon dioxide increase is expected to gradually result in a cooler, more contracted upper atmosphere and a consequent reduction in the atmospheric drag experienced by satellites," said a statement from the Naval Research Laboratory, which took part in the study. Commenting on the paper, space expert Hugh Lewis said a cooler troposphere will extend the lifetime of space junk — staying farther out for longer instead of burning up in the lower layers of the atmosphere, closer to Earth.

"Consequently, space junk will accumulate at a faster rate and we will see more collisions between space objects as a result," he said.

"We will also see many more 'near-misses ' and these have an important effect on spacecraft operators." Lewis said there would be no increased risk for us on Earth as the rate at which satellites re-enter would be reduced. "However, we would see some effects on services provided from space if an important satellite was destroyed by a collision..., " he said. On the positive side, satellites would no longer need to boost themselves back into orbit quite as often, meaning they can carry less fuel.

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