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Mon, 27 Feb 2017
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Science & Technology


Red dwarf flares jeopardize habitability of planet Proxima b

The habitability of planets orbiting young red dwarf stars is threatened by frequent stellar eruptions that likely deplete atmospheric oxygen levels, according to new NASA research.

The findings, published in the Astrophysical Journal Letters, concern 'habitable zones', the region around a star where conditions could potentially allow life-sustaining liquid water.

The research has implications for the recently-discovered Proxima b planet in the "habitable zone" of red dwarf, Proxima Centauri. Proxima b, which is 1.3 times the size of Earth, was previously found to be the planet most likely to harbor life.


Stargazer's triple treat: Eclipse, comet, full moon all coming Friday night

Skywatchers will enjoy a rare space triple-header Friday night and early Saturday morning: A "penumbra" lunar eclipse during the full "snow" moon — and the flyby of a comet.
© NASA/USA Today
Here's a look at what you will see if you set your eyes to the night sky:

Eye 1

Anonymous no more: Google's new AI system unscrambles pixelated faces

© Google
On the left, 8x8 images; in the middle, the images generated by Google; and on the right, the original 32x32 faces.
Company reveals technology capable of increasing picture resolution 16-fold, effectively restoring lost data - but results still an educated guess

Google's neural networks have achieved the dream of CSI viewers everywhere: the company has revealed a new AI system capable of "enhancing" an eight-pixel square image, increasing the resolution 16-fold and effectively restoring lost data.

The neural network could be used to increase the resolution of blurred or pixelated faces, in a way previously thought impossible; a similar system was demonstrated for enhancing images of bedrooms, again creating a 32x32 pixel image from an 8x8 one.

Google's researchers describe the neural network as "hallucinating" the extra information. The system was trained by being shown innumerable images of faces, so that it learns typical facial features. A second portion of the system, meanwhile, focuses on comparing 8x8 pixel images with all the possible 32x32 pixel images they could be shrunken versions of.

Blue Planet

Genetic study of North Americans suggests we are even more diverse than we thought

© Getty
As individuals, our DNA offers insight into things like our personalities, our health and where we come from. But taken together, all those individual portraits can add up to paint a detailed history of humankind.

A study published this week in Nature Communications led by the DNA testing company Ancestry.com presents exactly this kind of bird's eye view. Last month, Ancestry surpassed 3 million customers in its DNA databases. That's an awful lot of DNA, and now the company has set its sites on figuring out exactly what it might learn from all of it.

In the new study, Ancestry's scientists set out to build a picture of how North America's population moved across the country over the past few hundred years. Using genotype data from over 700,000 individuals who have purchased the company's DNA kits, scientists created a network of genetically-identified relationships and then used network analysis techniques to identify clusters of individuals.


The reasons why, once we start worrying, some of us just can't stop

A certain amount of worrying is a normal part of life, especially these days with barely a moment passing without some disconcerting headline landing in your news feed. But for some people, their worrying reaches pathological levels. They just can't stop wondering "What if ...?". It becomes distressing and feels out of control. In the formal jargon, they would likely be diagnosed with Generalised Anxiety Disorder, but excessive worrying is also a part of other conditions like panic disorder. There are many factors that contribute to anxiety problems in general, but a new review in Biological Psychology homes in on the cognitive and emotional factors that specifically contribute to prolonged bouts of worry. Its take-home points make an interesting read for anyone who considers themselves a worrier, and for therapists, the review highlights some approaches to help anxious clients get a hold of their excessive worrying.

The review authors, Graham Davey and Frances Meeten at the University of Sussex and the Institute of Psychiatry, Psychology and Neuroscience, explain that what gets many pathological worriers worrying in the first place is that they seem to be highly vigilant to any sources of threat and danger, and if there's any ambiguity about whether a situation is threatening or not, they will tend to interpret it as being dangerous. If they haven't yet heard from their daughter today, for instance, the problem worrier will not only notice this fact, they will also contemplate that it's because she's in trouble, rather than simply busy.


Longest ever personality study finds no correlation between measures taken at age 14 and age 77

Imagine you've reached the fine age of 77 and you hear news of a school reunion. You're going to have the chance to meet up with several of your former classmates who you haven't seen since you were fourteen-years-old. They'll look a lot different, of course, but what about their personality? Will they be broadly the same as they were back then?

Past research that's looked at trait changes from adolescence to mid-life has shown there tends to be a moderate amount of stability, so too research that's looked at changes from mid-life into old age. Put these two sets of data together and you might expect to see at least some personality stability across an entire lifespan. Your classmates probably won't have changed completely.

Comment: Childhood Personality Can Predict Important Outcomes in Emerging Adulthood


7500-year-old solar event recorded in tree rings

© Nagoya University
Figure: Picture of the bristlecone pine forest in California, the United States where the bristlecone pine sample for this study used to live (taken by Prof. A.J.T. Jull). In this forest, there are many living old trees exceed 1000 years old. Harsh environments make bristlecone pines very dense and long lives.
An international team led by researchers at Nagoya University, along with US and Swiss colleagues, has identified a new type of solar event and dated it to the year 5480 BC; they did this by measuring carbon-14 levels in tree rings, which reflect the effects of cosmic radiation on the atmosphere at the time. They have also proposed causes of this event, thereby extending knowledge of how the sun behaves.

When the activity of the sun changes, it has direct effects on the earth. For example, when the sun is relatively inactive, the amount of a type of carbon called carbon-14 increases in the earth's atmosphere. Because carbon in the air is absorbed by trees, carbon-14 levels in tree rings actually reflect solar activity and unusual solar events in the past. The team took advantage of such a phenomenon by analyzing a specimen from a bristlecone pine tree, a species that can live for thousands of years, to look back deep into the history of the sun.

"We measured the 14C levels in the pine sample at three different laboratories in Japan, the US, and Switzerland, to ensure the reliability of our results," A. J. Timothy Jull of the University of Arizona says. "We found a change in 14C that was more abrupt than any found previously, except for cosmic ray events in AD 775 and AD 994, and our use of annual data rather than data for each decade allowed us to pinpoint exactly when this occurred."


Cause of noises made by meteors found

© Spalding et. al./Scientific Reports
Bright, flaring meteors are sometimes accompanied by faint noises. What's strange about these popping, sizzling, rustling, and hissing sounds are that they reportedly occur almost instantly to earthly onlookers. This makes little sense, as meteors are as far as sixty miles away from viewers on the ground, so any sound they make should take several minutes be heard. What's going on? Do meteors somehow defy the laws of physics?

Researcher Richard Spalding and several of his colleagues at Sandia National Laboratories recently set out to study this strange phenomenon, and in a study just published to the journal Scientific Reports, they announce that the sounds are likely created through light.

Meteor fireballs sometimes pulse with light many times brighter than the full Moon, and these blasts can briefly heat the surfaces of objects many miles away. Such sudden temperature changes can actually create sound.

"We suggest that each pulse of light can heat the surfaces of natural dielectric transducers," Spalding and his colleagues write. "The surfaces rapidly warm and conduct heat into the nearby air, generating pressure waves. A succession of light-pulse-produced pressure waves can then manifest as sound to a nearby observer."


New study reports massive Mars volcano erupted for 2 billion years

An aerial view of Olympus Mons, the largest volcano in the solar system. The image was taken by the Viking 1 Orbiter.
An unusual meteorite found in Algeria in 2012 has given scientists information about volcanic activity on Mars, and it's not like anything we've ever seen on Earth.

Analysis of the 6.9-ounce meteorite, labeled Northwest Africa (NWA) 7635 by an international team of scientists, has helped determine that sometime in its 4.5 billion-year history, Mars had a single volcano that erupted continuously for more than 2 billion years.

"We've never seen anything like that on Earth," says Marc Caffee, professor of physics and astronomy at Purdue University and a member of the research team.

The research was published this week in the journal Science Advances.

So far, more than 100 meteorites in collections around the world have been identified as Martian meteorites. "Even though we've never had astronauts walk on Mars, we still have pieces of the Martian surface to study, thanks to these meteorites," Caffee says.

Most Martian meteorites are found either in Antarctica or North Africa. "Between Antarctica and other deserts we add more than 1,000 meteorites per year, but only a few of those are interesting, including those originating from Mars and the moon," Caffee says. "The standard ones are sent to the Smithsonian, but the unusual ones are sent to NASA and the community of scientists is informed in case they want to request samples."


Black hole's feeding frenzy is breaking records

© CXC/M. Weiss; X-ray: NASA/CXC/UNH/D. Lin et al, Optical: CFHT
Artist illustration depicting the record breaking "tidal disruption event" (TDE). The red shows hotter material that falls toward the black hole and generates a distinct X-ray flare. The blue shows a wind blowing from the in-falling material.
A giant black hole ripped apart a nearby star and then continued to feed off its remains for close to a decade, according to research led by the University of New Hampshire. This black hole meal is more than 10 times longer than any other previous episode of a star's death.

"We have witnessed a star's spectacular and prolonged demise," said Dacheng Lin, a research scientist at UNH's Space Science Center and the study's lead author. "Dozens of these so-called tidal disruption events have been detected since the 1990s, but none that remained bright for nearly as long as this one."

Using data from a trio of orbiting X-ray telescopes, NASA's Chandra X-ray Observatory and Swift Satellite as well as ESA's XMM-Newton, researchers found evidence of a massive "tidal disruption event" (TDE). Tidal forces, due to the intense gravity from the black hole, can destroy an object -- such as a star -- that wanders too close. During a TDE, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole. As it travels inward, and is ingested by the black hole, the material heats up to millions of degrees and generates a distinct X-ray flare.