Tag: computer (page 4 of 11)

Rosetta spacecraft raises new questions about comet’s origin

January 23, 2015 / / 0 Comments

Excerpt from news.asiaone.com CAPE CANAVERAL, US - Scientists using Europe's comet-orbiting Rosetta spacecraft have discovered that the complicated ancient body is coated with surprisingly simple organic molecules and surrounded by a changing clou...

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Google Chairman Eric Schmidt: "The Internet Will Disappear"

January 23, 2015 / / 0 Comments


 


Excerpt from hollywoodreporter.com

Google executive chairman Eric Schmidt on Thursday predicted the end of the Internet as we know it.

At the end of a panel at the World Economic Forum in Davos, Switzerland, where his comments were webcast, he was asked for his prediction on the future of the web. “I will answer very simply that the Internet will disappear,” Schmidt said.

“There will be so many IP addresses…so many devices, sensors, things that you are wearing, things that you are interacting with that you won’t even sense it,” he explained. “It will be part of your presence all the time. Imagine you walk into a room, and the room is dynamic. And with your permission and all of that, you are interacting with the things going on in the room.”

Concluded Schmidt: “A highly personalized, highly interactive and very, very interesting world emerges.”

The panel, entitled The Future of the Digital Economy, also featured Facebook COO Sheryl Sandberg and others.
Earlier in the debate, Schmidt discussed the issue of market dominance. The European Union has been looking at Google’s search market dominance in a long-running antitrust case, and the European parliament late last year even called for a breakup.
“You now see so many strong tech platforms coming, and you are seeing a reordering and a future reordering of dominance or leaders or whatever term you want to use because of the rise of the apps on the smartphone,” Schmidt said Thursday. “All bets are off at this point as to what the smartphone app infrastructure is going to look like” as a “whole new set” of players emerges to power smartphones, which are nothing but super-computers, the Google chairman argued. “I view that as a completely open market at this point.”

Asked about his recent trip to North Korea, Schmidt said the country has many Internet connections through data phones, but there is no roaming and web usage is “heavily supervised.” Schmidt said “it’s very much surveillance of use,” which he said was not good for the country and others.

Sandberg and Schmidt lauded the Internet as an important way to give more people in the world a voice. Currently, only 40 percent of people have Internet access, the Facebook COO said, adding that any growth in reach helps extend people’s voice and increase economic opportunity. “I’m a huge optimist,” she said about her outlook for the industry. “Imagine what we can do” once the world gets to 50 percent, 60 percent and more in terms of Internet penetration.
She cited women as being among the beneficiaries, saying the Internet narrows divides.

Schmidt similarly said that broadband can address governance issues, information needs, personal issues, women empowerment needs and education issues. “The Internet is the greatest empowerment of citizens … in many years,” he said. “Suddenly citizens have a voice, they can be heard.”
During another technology panel at the World Economic Forum on Thursday, Yahoo CEO Marissa Mayer, Liberty Global CEO Mike Fries and others answered questions on the need to regulate privacy standards on the Internet and for tech companies following the Snowden case, the Sony hack and the like.

Mayer said that the personalized Internet “is a better Internet,” emphasizing: “We don’t sell your personal data … We don’t transfer your personal data to third parties.” She said users own their data and need to have control, adding that people give up data to the government for tax assessment, social services and other purposes.
Fries said Liberty Global subscribers view billions of hours of content and generate billions of clicks, but added that “today we do nothing.” He explained: “We generate zero revenue from all of that information.” But he acknowledged that big data was big business for a lot of people.

Both executives said transparency was important to make sure users know privacy standards and the like.

Gunther Oettinger, a conservative German politician serving as the European Union’s commissioner for digital economy and society, said on the panel that “we need a convincing global understanding, we need a UN agency for data protection and security.” Asked what form that “understanding” should have, he said he was looking for “clear, pragmatic, market-based regulation.” Explained Oettinger: “It’s a public-private partnership.”

Fries said such a solution was likely not to happen in the near term, given the size of the EU. “I think it is going to take several years,” he said, adding that some countries’ parliaments would likely take a stab at it.

But he warned that a joint solution would make more sense. “We don’t want Germany to have its own Internet,” Fries said. “Some countries may build their own Internets” and “balkanize” the web, he warned.

Mayer said on the issue of regulation: “I like Tim’s idea better of the beneficent marketplace.” She spoke of fellow panelist and computer specialist Tim Berners-Lee, known as the inventor of the World Wide Web.

Asked how Yahoo stores and handles client records, she said the online giant “changed the way we store and communicate data” after Snowden and also changed encryptions between data centers. And the company protects users through encryption methods, she added. Mayer said that trust and confidence of Yahoo users has rebounded since.

Mayer was also asked what happens if a government asks for a user’s data, a question that has new significance after the recent terrorist attacks in Paris, which have led some to call for increased surveillance powers of the Internet for governments. Mayer said Yahoo always assesses if such a request is reasonable. “We have a very good track record for standing up to what’s not reasonable,” she said.

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Spacecraft found on Mars – and it’s ours

January 21, 2015 / / 0 Comments




Computer image of the Beagle 2


Excerpt from skyandtelescope.com
By Kelly Beatty  


On December 25, 2003, a British-built lander dropped to the Martian surface and disappeared without a trace. Now we know what happened to it.  It's hard to overstate how valuable the main camera aboard the Mars Reconnaissance Orbiter has been. The craft's High-Resolution Imaging Science Experiment, or HiRISE, uses a 20-inch (0.5-m) f/24 telescope to record details on the Martian surface as small as 0.3 m (about 10 inches). 

Beagle 2 seen from orbit by HiRISE
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014. NASA / JPL / Univ. of Arizona / Univ. of Leicester - See more at: http://www.skyandtelescope.com/astronomy-news/beagle-2-lander-found-on-mars-01192015/#sthash.5KSZ8V6W.dpuf


Primarily it's a powerful tool for studying Martian geology at the smallest scales, and NASA scientists sometimes use it to track the progress (and even the arrivals) of their rovers. Beagle 2 on Mars  The clamshell-like Beagle 2 lander weighed just 30 kg, but it was well equipped to study Martian rocks and dust — and even to search for life. Beagle 2 consortium  But the HiRISE team has also been on a years-long quest to find the remains of Beagle 2, a small lander that had hitchhiked to the Red Planet with the European Space Agency's Mars Express orbiter. It descended to the Martian surface on Christmas Day in 2003 and was never heard from again. Space aficionados have debated its fate ever since. Did parachute failure lead to a crash landing? Did strong surface winds flip the saucer-shaped craft upside down? Did the Martians take it hostage?  Now, thanks to HiRISE, we know more of the story.  
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014. NASA / JPL / Univ. of Arizona / Univ. of Leicester 


Images taken in February 2013 and June 2014 of the landing area in Isidis Planitia showed promising blips near the edge of each frame. A follow-up color view, acquired on December 15th and released three days ago, show a bright spot consistent with Beagle 2. The fully-opened lander would have been less than 2 m (6½ feet) across, so the craft is only barely resolved. Apparently the spacecraft made it to the surface intact, opened its clamshell cover, and had partially deployed its four petal-shaped solar-cell panels before something went awry. Beagle 2 seen from orbit by HiRISE  

One encouraging clue is that the bright reflection changes position slightly from image to image, consistent with sunlight reflecting off different lander panels. Two other unusual spots a few hundred meters away appears to be the lander's parachute and part of the cover that served as a shield during the 5½-km-per-second atmospheric descent...


On December 25, 2003, a British-built lander dropped to the Martian surface and disappeared without a trace. Now we know what happened to it.
It's hard to overstate how valuable the main camera aboard the Mars Reconnaissance Orbiter has been. The craft's High-Resolution Imaging Science Experiment, or HiRISE, uses a 20-inch (0.5-m) f/24 telescope to record details on the Martian surface as small as 0.3 m (about 10 inches). Primarily it's a powerful tool for studying Martian geology at the smallest scales, and NASA scientists sometimes use it to track the progress (and even the arrivals) of their rovers.
Beagle 2 on Mars
The clamshell-like Beagle 2 lander weighed just 30 kg, but it was well equipped to study Martian rocks and dust — and even to search for life.
Beagle 2 consortium
But the HiRISE team has also been on a years-long quest to find the remains of Beagle 2, a small lander that had hitchhiked to the Red Planet with the European Space Agency's Mars Express orbiter. It descended to the Martian surface on Christmas Day in 2003 and was never heard from again. Space aficionados have debated its fate ever since. Did parachute failure lead to a crash landing? Did strong surface winds flip the saucer-shaped craft upside down? Did the Martians take it hostage?
Now, thanks to HiRISE, we know more of the story. Images taken in February 2013 and June 2014 of the landing area in Isidis Planitia showed promising blips near the edge of each frame. A follow-up color view, acquired on December 15th and released three days ago, show a bright spot consistent with Beagle 2. The fully-opened lander would have been less than 2 m (6½ feet) across, so the craft is only barely resolved. Apparently the spacecraft made it to the surface intact, opened its clamshell cover, and had partially deployed its four petal-shaped solar-cell panels before something went awry.
Beagle 2 seen from orbit by HiRISE
An overhead view of Beagle 2's landing site on Isidis Planitia shows a bright reflection from the long-lost spacecraft. Apparently it landed safely on December 25, 2003, and had begun to operate when it failed. NASA's Mars Reconnaissance Orbiter recorded this image on December 15, 2014.
NASA / JPL / Univ. of Arizona / Univ. of Leicester
One encouraging clue is that the bright reflection changes position slightly from image to image, consistent with sunlight reflecting off different lander panels. Two other unusual spots a few hundred meters away appears to be the lander's parachute and part of the cover that served as a shield during the 5½-km-per-second atmospheric descent.
The initial images didn't just show up. They'd been requested and searched by Michael Croon of Trier, Germany, who'd served on the Mars Express operations team. Croon had asked for specific camera targeting through a program called HiWish, through which anyone can submit suggestions for HiRISE images. Read more about this fascinating sleuthing story.
"Not knowing what happened to Beagle 2 remained a nagging worry," comments Rudolf Schmidt in an ESA press release about the find. "Understanding now that Beagle 2 made it all the way down to the surface is excellent news." Schmidt served as the Mars Express project manager at the time.
Built by a consortium of organizations, Beagle 2 was the United Kingdom's first interplanetary spacecraft. The 32-kg (73-pound) lander carried six instruments to study geochemical characteristics of the Martian surface and to test for the presence of life using assays of carbon isotopes. It was named for HMS Beagle, the ship that carried a crew of 73 (including Charles Darwin) on an epic voyage of discovery in 1831–36.
- See more at: http://www.skyandtelescope.com/astronomy-news/beagle-2-lander-found-on-mars-01192015/#sthash.5KSZ8V6W.dpuf

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Meteorite is ‘hard drive’ from space ~ Researchers decode ancient recordings from asteroid ~ BBC

January 21, 2015 / / 0 Comments


Pallasite meteorite
The Esquel meteorite consists of gem-quality crystals embedded in metal.



Excert from bbc.com

Researchers have decoded ancient recordings from fragments of an asteroid dating back billions of years to the start of the Solar System. 

They found tiny "space magnets" in meteorites which retain a memory of the birth and death of the asteroid's core.
Like the data recorded on the surface of a computer hard drive, the magnetic signals written in the space rock reveal how Earth's own metallic core and magnetic field may one day die.

The work appears in Nature journal.

Using a giant X-ray microscope, called a synchrotron, the team was able to read the signals that formed more than four-and-a-half billion years ago, soon after the birth of the Solar System.

“Start Quote

It's like a cosmic archaeological mission”
Dr James Bryson University of Cambridge
The meteorites are pieces of a parent asteroid that originally came from asteroid belt, between Mars and Jupiter.
They represents the left-over fragments of a planet that failed to form. The magnetic recording within it traps a signal of the precise moments when an iron-rich core formed in the asteroid as well as when it froze, killing its magnetic field.
The new picture of metallic core solidification in the asteroid provide clues about the magnetic field and iron-rich core of Earth.
Core values "Ideas about how the Earth's core evolved through [our planet's] history are really changing at the moment," lead researcher Dr Richard Harrison, from the University of Cambridge, told BBC News.
"We believe that Earth's magnetic field is linked to core solidification. Earth's solid inner core may have started to form at very interesting time in terms of the evolution of life on Earth.
"By studying an asteroid we get to see this in fast forward. We can see the start of core solidification in the magnetic records as well as its end, and start to think about how these processes work on Earth."

Magnetic fieldThe Earth's magnetic field will likely die off when the core completely freezes
The meteorites studied by the team originally fell to Earth in Argentina, and are composed of gem-quality crystals enclosed in a metallic matrix of iron and nickel. 

Tiny particles, smaller than one thousandth the width of a human hair, trapped within the metal have retained the magnetic signature of the parent asteroid from its birth in the early Solar System.

"We're taking ancient magnetic field measurements in nano-scale materials to the highest ever resolution in order to piece together the magnetic history of asteroids - it's like a cosmic archaeological mission," said Dr James Bryson, the paper's lead author. 

"Since asteroids are much smaller than Earth, they cooled much more quickly, so these processes occur on a shorter timescales, enabling us to study the whole process of core solidification."

Prof Wyn William, from the University of Edinburgh, who was not involved in the study, commented: "To be able to get a time stamp on these recordings, to get a cooling rate and the time of solidification, is fantastic. It's a very nice piece of work."

The key to the long-lived stability of the recording is the atomic-scale structure of the iron-nickel particles that grew slowly in the asteroid core and survived in the meteorites. 

Making a final comment on the results, Dr Harrison said: "In our meteorites we've been able to capture both the beginning and end of core freezing, which will help us understand how these processes affected the Earth in the past and provide a possible glimpse of what might happen in the future." 

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Using X-rays, scientists read 2,000 year old scrolls charred by Mount Vesuvius

January 20, 2015 / / 0 Comments


Mount Vesuvius today



By Amina Khan 
Excerpt from latimes.com

Talk about reading between the lines! Scientists wielding X-rays say they can, for the first time, read words inside the charred, rolled-up scrolls that survived the catastrophic eruption of Mt. Vesuvius nearly two millenniums ago.
Testing the scroll
Researchers Daniel Delattre, left, and Emmanuel Brun observe the scroll before X-ray phase contrast imaging begins. (J. Delattre)
The findings, described in the journal Nature Communications, give hope to researchers who have until now been unable to read these delicate scrolls without serious risk of destroying them.
The scrolls come from a library in Herculaneum, one of several Roman towns that, along with Pompeii, was destroyed when Mt. Vesuvius erupted in AD 79. This library, a small room in a large villa, held hundreds of handwritten papyrus scrolls that had been carbonized from a furnace-like blast of 608-degree-Fahrenheit gas produced by the volcano.

“This rich book collection, consisting principally of Epicurean philosophical texts, is a unique cultural treasure, as it is the only ancient library to survive together with its books,” the study authors wrote. “The texts preserved in these papyri, now mainly stored in the Officina dei Papiri in the National Library of Naples, had been unknown to scholars before the discovery of the Herculaneum library, since they had not been copied and recopied in late Antiquity, the middle ages and Renaissance.”
So researchers have tried every which way to read these rare and valuable scrolls, which could open a singular window into a lost literary past. The problem is, these scrolls are so delicate that it’s nearly impossible to unroll them without harming them. That hasn’t kept other researchers from trying, however – sometimes successfully, and sometimes not.

“Different opening techniques, all less effective, have been tried over the years until the so-called ‘Oslo method’ was applied in the 1980s on two Herculaneum scrolls now in Paris with problematic results, since the method required the rolls to be picked apart into small pieces,” the study authors wrote. (Yikes.)

Any further attempts to physically open these scrolls were called off since then, they said, “because an excessive percentage of these ancient texts was irretrievably lost by the application of such methods.”
This is where a technique like X-ray computed tomography, which could penetrate the rolled scrolls, would come in handy. The problem is, the ancient writers used ink made of carbon pulled from smoke residue. And because the papyrus had been carbonized from the blazing heat, both paper and ink are made of roughly the same stuff. Because the soot-based ink and baked paper have about the same density, until now it’s been practically impossible to tell ink and paper apart.

But a team led by Vito Mocella of the Institute for Microelectronics and Microsystems in Naples, Italy, realized they could use a different technique called X-ray phase-contrast tomography. Unlike the standard X-ray CT scans, X-ray phase-contrast tomography examines phase shifts in the X-ray light as it passes through different structures.
Using the technique, the scientists were able to make out a few words and letters from two scrolls, one of them still rolled.

Reading these scrolls is difficult; computer reconstructions of the rolled scroll reveal that the blast of volcanic material so damaged its once-perfect whorls that its cross section looks like a half-melted tree-ring pattern. The paper inside has been thoroughly warped, and some of the letters on the paper probably distorted almost beyond recognition.
Nonetheless, the researchers were able to read a number of words and letters, which were about 2 to 3 millimeters in size. On an unrolled fragment of a scroll called “PHerc.Paris. 1,” they were able to make up the words for “would fall” and “would say.” In the twisted, distorted layers of the rolled-up papyrus called “PHerc.Paris. 4,” they could pick out individual letters: alpha, nu, eta, epsilon and others.

The letters in “PHerc.Paris. 4” are also written in a distinctive style with certain decorative flourishes that seemed very similar to a scroll called “PHerc. 1471,” which holds a text written by the Epicurean philosopher Philodemus. The researchers think they were written in the second quarter of the first century BC.


Ultimately, the researchers wrote, this work was a proofof concept to give other researchers a safe and reliable way to explore ancient philosophical works that were until now off-limits to them.

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New data that fundamental physics constants underlie life-enabling universe

January 19, 2015 / / 0 Comments

Excerpt from spacedaily.com For nearly half a century, theoretical physicists have made a series of discoveries that certain constants in fundamental physics seem extraordinarily fine-tuned to allow for the emergence of a life-enabling universe.Thi...

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Three Earth-like planets sighted around nearby star

January 17, 2015 / / 0 Comments

This artistic impression shows NASA's planet-hunting Kepler spacecraft operating in a new mission profile called K2. By analyzing data captured by the Kepler spacecraft, a UA-led team of researchers has discovered three new Earth-size planets orbiti...

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The Best Bet for Alien Life May Be in Planetary Systems Very Different From Ours

January 16, 2015 / / 0 Comments




Excerpt from wired.com


In the hunt for extraterrestrial life, scientists started by searching for a world orbiting a star just like the sun. After all, the steady warmth of that glowing yellow ball in the sky makes life on Earth possible.

But as astronomers continue to discover thousands of planets, they’re realizing that if (or when) we find signs of extraterrestrial life, chances are good that those aliens will orbit a star quite different from the sun—one that’s redder, cooler, and at a fraction of the sun’s size and mass. So in the quest for otherworldly life, many astronomers have set their sights on these small stars, known as red dwarfs or M dwarfs.

At first, planet-hunting astronomers didn’t care so much about M dwarfs. After the first planet outside the solar system was discovered in 1995, scientists began hunting for a true Earth twin: a rocky planet like Earth with an orbit like ours around a sun-like star. Indeed, the search for that kind of system drove astronomers through most of the 2000s, says astronomer Phil Muirhead of Boston University.

But then astronomers realized that it might be technically easier to find planets around M dwarfs. Detecting another planet is really hard, and scientists rely on two main methods. In the first, they look for a drop in a star’s brightness when a planet passes in front of it. In the second, astronomers measure the slight wobble of a star, caused by the gentle gravitational tug of an orbiting planet. With both of these techniques, the signal is stronger and easier to detect for a planet orbiting an M dwarf. A planet around an M dwarf also orbits more frequently, increasing the chances that astronomers will spot it.

M dwarfs got a big boost from the Kepler space telescope, which launched in 2008. By staring at small patch of the sky, the telescope searches for suddenly dimming stars when a planet passes in front of them. In doing so, the spacecraft discovered a glut of planets—more than 1,000 at the latest count—it found a lot of planets around M dwarfs. “Kepler changed everything,” Muirhead said. Because M-dwarf systems are easier to find, the bounty of such planets is at least partly due to a selection effect. But, as Muirhead points out, Kepler is also designed to find Earth-sized planets around sun-like stars, and the numbers so far suggest that M-dwarfs may offer the best odds for finding life.

“By sheer luck you would be more likely to find a potentially habitable planet around an M dwarf than a star like the sun,” said astronomer Courtney Dressing of Harvard. She led an analysis to estimate how many Earth-sized planets—which she defined as those with radii ranging from one to one-and-a-half times Earth’s radius—orbit M dwarfs in the habitable zone, the region around the star where liquid water can exist on the planet’s surface. According to her latest calculations, one in four M dwarfs hosts such a planet.

That’s higher than the estimated number of Earth-sized planets around a sun-like star, she says. For example, an analysis by astronomer Erik Petigura of UC Berkeley suggests that fewer than 10 percent of sun-like stars have a planet with a radius between one and two times that of Earth’s.

This illustration shows Kepler-186f, the first rocky planet found in a star's habitable zone. Its star is an M dwarf.
This illustration shows Kepler-186f, the first rocky planet found in a star’s habitable zone. Its star is an M dwarf. NASA Ames/SETI Institute/JPL-Caltech


M dwarfs have another thing going for them. They’re the most common star in the galaxy, comprising an estimated 75 percent of the Milky Way’s hundreds of billions of stars. If Dressing’s estimates are right, then our galaxy could be teeming with 100 billion Earth-sized planets in their stars’ habitable zones.

To be sure, these estimates have lots of limitations. They depend on what you mean by the habitable zone, which isn’t well defined. Generally, the habitable zone is where it’s not too hot or too cold for liquid water to exist. But there are countless considerations, such as how well a planet’s atmosphere can retain water. With a more generous definition that widens the habitable zone, Petigura’s numbers for Earth-sized planets around a sun-like star go up to 22 percent or more. Likewise, Dressing’s numbers could also go up.
Astronomers were initially skeptical of M-dwarf systems because they thought a planet couldn’t be habitable near this kind of star. For one, M dwarfs are more active, especially during within the first billion years of its life. They may bombard a planet with life-killing ultraviolet radiation. They can spew powerful stellar flares that would strip a planet of its atmosphere.

And because a planet will tend to orbit close to an M dwarf, the star’s gravity can alter the planet’s rotation around its axis. When such a planet is tidally locked, as such a scenario is called, part of the planet may see eternal daylight while another part sees eternal night. The bright side would be fried while the dark side would freeze—hardly a hospitable situation for life.

But none of these are settled issues, and some studies suggest they may not be as big of a problem as previously thought, says astronomer Aomawa Shields of UCLA. For example, habitability may depend on specific types and frequency of flares, which aren’t well understood yet. Computer models have also shown that an atmosphere can help distribute heat, preventing the dark side of a planet from freezing over.

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Chondrules Were Byproducts of Violent Planetary Process

January 16, 2015 / / 0 Comments


 Chondrules were Byproducts of Violent Planetary Process



Excerpt from perfscience.com

For long, meteors that crashed on earth were considered to be remnants of the early solar system. The meteors are usually found studded with chondrules, tiny, glass, spherical grains.  It was considered that chondrules were early kernels of terrestrial planets.

But researchers at MIT and Purdue University have a new revelation to make. They have found that chondrules might not have played a fundamental role in the formation of planets.  The researchers based their findings on computer simulations and concluded that chondrules are by-products of planetary process and not the building blocks. The team found that planetary bodies as big as moon already existed before chondrules came on the scene. 

The researchers think that chondrules were most probably formed by the collision of moon-sized planter embryos. Brandon Johnson from MIT’s Department of Earth, Atmospheric and Planetary Sciences said, “This tells us that meteorites aren’t actually representative of the material that formed planets — they’re these smaller fractions of material that are the byproduct of planet formation”.  Johnson affirmed that the study findings have also unveiled that the early solar system was more violent than they have expected. The research team said that they have also modeled all the different types of impact that might have taken place in the early solar system.
For long, meteors that crashed on earth were considered to be remnants of the early solar system. The meteors are usually found studded with chondrules, tiny, glass, spherical grains.
It was considered that chondrules were early kernels of terrestrial planets. But researchers at MIT and Purdue University have a new revelation to make. They have found that chondrules might not have played a fundamental role in the formation of planets.
The researchers based their findings on computer simulations and concluded that chondrules are by-products of planetary process and not the building blocks. The team found that planetary bodies as big as moon already existed before chondrules came on the scene.
The researchers think that chondrules were most probably formed by the collision of moon-sized planter embryos. Brandon Johnson from MIT’s Department of Earth, Atmospheric and Planetary Sciences said, “This tells us that meteorites aren’t actually representative of the material that formed planets — they’re these smaller fractions of material that are the byproduct of planet formation”.
Johnson affirmed that the study findings have also unveiled that the early solar system was more violent than they have expected. The research team said that they have also modeled all the different types of impact that might have taken place in the early solar system.
- See more at: http://perfscience.com/content/2141073-chondrules-were-byproducts-violent-planetary-process#sthash.4XzOzvJT.dpuf
For long, meteors that crashed on earth were considered to be remnants of the early solar system. The meteors are usually found studded with chondrules, tiny, glass, spherical grains.
It was considered that chondrules were early kernels of terrestrial planets. But researchers at MIT and Purdue University have a new revelation to make. They have found that chondrules might not have played a fundamental role in the formation of planets.
The researchers based their findings on computer simulations and concluded that chondrules are by-products of planetary process and not the building blocks. The team found that planetary bodies as big as moon already existed before chondrules came on the scene.
The researchers think that chondrules were most probably formed by the collision of moon-sized planter embryos. Brandon Johnson from MIT’s Department of Earth, Atmospheric and Planetary Sciences said, “This tells us that meteorites aren’t actually representative of the material that formed planets — they’re these smaller fractions of material that are the byproduct of planet formation”.
Johnson affirmed that the study findings have also unveiled that the early solar system was more violent than they have expected. The research team said that they have also modeled all the different types of impact that might have taken place in the early solar system.
- See more at: http://perfscience.com/content/2141073-chondrules-were-byproducts-violent-planetary-process#sthash.4XzOzvJT.dpuf

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Meteorites may have been given too much credit for ‘building’ our Solar System

January 15, 2015 / / 0 Comments





Excerpt from thespacereporter.com


Meteorites might not have had as much of an impact as early planet formation as we thought.The space rocks are commonly considered to be the building blocks of planets, but a new study by MIT and Purdue scientists suggests that the rocks are merely a byproduct of planet formation, not a crucial part in the process.

According to the study, meteorites are what was cast off when other proto-planetary bodies collided in the early days of the Solar System. The new theory, which was determined using computer simulations of collisions in the early Solar System, counteracts the theory that meteorites’ chondrules (small grains of molten droplets on their surface) are remnants of collisions with gas and dust that eventually formed planets.

“This tells us that meteorites aren’t actually representative of the material that formed planets – they’re these smaller fractions of material that are the byproduct of planet formation,” says Brandon Johnson of MIT’s Earth, Atmospheric and Planetary Sciences department. “But it also tells us the early solar system was more violent than we expected: You had these massive sprays of molten material getting ejected out from these really big impacts. It’s an extreme process.”

The collision models showed that bodies the size of the Moon formed well before meteorites would have formed chondrules, suggesting that the meteorites were not involved in building planets in the previously accepted manner.

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‘Super-Earths’ May Have Stable Oceans That Are Key For Alien Life

January 14, 2015 / / 0 Comments

Excerpt from huffingtonpost.comNASA's Kepler space telescope celebrated its 1,000th exoplanet discovery earlier this month, an impressive milestone in the search for life on other worlds. Now astronomers are homing in on those exoplanets that may ...

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New EAGLE Simulation Shows Galaxies as They Really Are ~ Video

January 13, 2015 / / 0 Comments


The EAGLE simulation of the universe generates a more accurate picture of galaxies than any simulation of this size before it.



Excerpt from space.com

Galaxies come in all different shapes and sizes, and a massive new simulation of the universe has captured that galactic variety with more accuracy than any simulation before it, according to a new study.

Using a simulation called EAGLE (Evolution and Assembly of GaLaxies and their Environments), researchers from multiple institutes in Europe have cooked up a dazzling simulation of the universe that contains tens of thousands of galaxies.



A sample of the new simulation can be seen in the video above. It shows the evolution of the universe in a region 25 megaparsecs cubed (about 81 million light years).



"This is really a staggering success, I think it's fair to say," Rob Crain from Liverpool John Moores University and a member of the group that built EAGLE, told Space.com. The researchers are part of a collaboration called the Virgo Consortium for Cosmological Supercomputer Simulations. "Go to our previous generation of simulations, and the galaxies all look like big spherical blobs. Now they form disks and bars and irregular galaxies and different types of ellipticals."

A computer simulation is like a recipe for the universe. Scientists have to start with a list of ingredients and instructions — which actually means a description of the physics that underlie the current universe. While many simulations can recreate the major cosmic ingredients (like stars and galaxies), the subtleties are harder to achieve (like the shape, mass and distribution of those stars and galaxies).

The bottom right corner of the screen shows the time after the Big Bang (denoted by "t"). In the early universe, matter is dispersed and hazy, but gradually coalesces into a sort of web, with long strands of material connecting nodes where galaxies are clustered. At 1:06, the simulation starts again from the beginning and shows the three major components of the model: dark matter (labeled as CDM), gas (the red globs are gas clouds where stars are often born), and stars. The full EAGLE simulation contains an area 100 megaparsecs cubed.

One goal of the EAGLE group was to produce a simulation large enough that it contained all types of galaxies seen in the universe. This allows the researchers to find out if the physics they programmed into EAGLE are accurate for all galaxies, and if they produce the correct number of galaxies in the universe.




Schaye said the picture of the universe created by the EAGLE simulation "is not perfect, but for astronomers the level of agreement is very impressive. It seems we have the main ingredients in place."

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Theoretical physics: The origins of space and time

January 7, 2015 / / 0 Comments


Excerpt from nature.com
By Zeeya Merali


Many researchers believe that physics will not be complete until it can explain not just the behaviour of space and time, but where these entities come from.

“Imagine waking up one day and realizing that you actually live inside a computer game,” says Mark Van Raamsdonk, describing what sounds like a pitch for a science-fiction film. But for Van Raamsdonk, a physicist at the University of British Columbia in Vancouver, Canada, this scenario is a way to think about reality. If it is true, he says, “everything around us — the whole three-dimensional physical world — is an illusion born from information encoded elsewhere, on a two-dimensional chip”. That would make our Universe, with its three spatial dimensions, a kind of hologram, projected from a substrate that exists only in lower dimensions.

This 'holographic principle' is strange even by the usual standards of theoretical physics. But Van Raamsdonk is one of a small band of researchers who think that the usual ideas are not yet strange enough. If nothing else, they say, neither of the two great pillars of modern physics — general relativity, which describes gravity as a curvature of space and time, and quantum mechanics, which governs the atomic realm — gives any account for the existence of space and time. Neither does string theory, which describes elementary threads of energy.

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Zeeya Merali discusses some of the theories that are trying to explain the origins of space and time.


Van Raamsdonk and his colleagues are convinced that physics will not be complete until it can explain how space and time emerge from something more fundamental — a project that will require concepts at least as audacious as holography. They argue that such a radical reconceptualization of reality is the only way to explain what happens when the infinitely dense 'singularity' at the core of a black hole distorts the fabric of space-time beyond all recognition, or how researchers can unify atomic-level quantum theory and planet-level general relativity — a project that has resisted theorists' efforts for generations.

“All our experiences tell us we shouldn't have two dramatically different conceptions of reality — there must be one huge overarching theory,” says Abhay Ashtekar, a physicist at Pennsylvania State University in University Park.

Finding that one huge theory is a daunting challenge. Here, Nature explores some promising lines of attack — as well as some of the emerging ideas about how to test these concepts...

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