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Thursday, October 31, 2013

Surprise! Most People Can See In Total Darkness

Find a space with total darkness and slowly move your hand from side to side in front of your face. What do you see?

If the answer is a shadowy shape moving past, you are probably not imagining things. With the help of computerized eye trackers, a new cognitive science study finds that at least 50 percent of people can see the movement of their own hand even in the absence of all light.



"Seeing in total darkness? According to the current understanding of natural vision, that just doesn't happen," says Duje Tadin, a professor of brain and cognitive sciences at the University of Rochester who led the investigation. "But this research shows that our own movements transmit sensory signals that also can create real visual perceptions in the brain, even in the complete absence of optical input."

Through five separate experiments involving 129 individuals, the authors found that this eerie ability to see our hand in the dark suggests that our brain combines information from different senses to create our perceptions. The ability also "underscores that what we normally perceive of as sight is really as much a function of our brains as our eyes," says first author Kevin Dieter, a post-doctoral fellow in psychology at Vanderbilt University.

The study seems to confirm anecdotal reports that spelunkers in lightless caves often are able to see their hands. In other words, the "spelunker illusion," as one blogger dubbed it, is likely not an illusion after all.



For most people, this ability to see self-motion in darkness probably is learned, the authors conclude. "We get such reliable exposure to the sight of our own hand moving that our brains learn to predict the expected moving image even without actual visual input," says Dieter.

Tadin, Dieter, and their team from the University of Rochester and Vanderbilt University reported their findings online October 30 in Psychological Science, the flagship journal of the Association for Psychological Science.

Although seeing one's hand move in the dark may seem simple, the experimental challenge in this study was to measure objectively a perception that is, at its core, subjective. That hurdle at first stumped Tadin and his postdoctoral advisor at Vanderbilt Randolph Blake after they initially stumbled upon the puzzling observation in 2005. "While the phenomenon looked real to us, how could we determine if other people were really seeing their own moving hand rather than just telling us what they thought we wanted to hear?" asks Blake, the Centennial Professor of Psychology at Vanderbilt and a co-author on the paper.

Years later, Dieter, at the time a doctoral student working in Tadin's Rochester lab, helped devise several experiments to probe the sight-without-light mystery. For starters, the researchers set up false expectations. In one scenario, they led subjects to expect to see "motion under low lighting conditions" with blindfolds that appeared to have tiny holes in them. In a second set up, the same participants had similar blindfolds without the "holes" and were led to believe they would see nothing. In both set ups, the blindfolds were, in fact, equally effective at blocking out all light. A third experiment consisted of the experimenter waving his hand in front of the blindfolded subject. Ultimately, participants were fitted with a computerized eye tracker in total darkness to confirm whether self-reported perceptions of movement lined up with objective measures.

In addition to testing typical subjects, the team also recruited people who experience a blending of their senses in daily life. Known as synesthetes, these individuals may, for example, see colors when they hear music or even taste sounds. This study focused on grapheme-color synesthetes, individuals who always see numbers or letters in specific colors.

Study participant Lindsay Bronnenkant demonstrates a task used in a new study on vision and movement.

Credit: Rochester University

The researchers enlisted individuals from Rochester, Nashville, Fenton, Michigan, and Seoul, South Korea, but, in a lucky coincidence, one synesthete could not have been closer. At the time, Lindsay Bronnenkant was working as a lab technician for co-author David Knill, a professor of brain and cognitive sciences at Rochester.

"As a child, I just assumed that everybody associated colors with letters," says the 2010 Rochester graduate who majored in brain and cognitive sciences. For Bronnenkant, "A is always yellow, but Y is an oranger yellow." B is navy, C burnt orange, and so on. She thought of these associations as normal, "like when you smell apple pie and you think of grandma." She doesn't remember a time when she did not see numbers and letters in color, but she does wonder if the particular colors she associates with numbers derived from the billiard balls her family had growing up. When she donned the blindfold and waved her hand in the experiment, "what I saw was a blur. It was very dim, but it was almost like I was looking at a light source."

Bronnenkant was not atypical in that respect. Across all types of participants, about half detected the motion of their own hand and they did so consistently, despite the expectations created with the faux holes. And very few subjects saw motion when the experimenter waved his hand, underscoring the importance of self-motion in this visual experience. As measured by the eye tracker, subjects who reported seeing motion were also able to smoothly track the motion of their hand in darkness more accurately than those who reported no visual sensation—46 percent versus 20 percent of the time.

Reports of the strength of visual images varied widely among participants, but synesthetes were strikingly better at not just seeing movement, but also experiencing clear visual form. As an extreme example in the eye tracking experiment, one synesthete exhibited near perfect smooth eye movement—95 percent accuracy—as she followed her hand in darkness. In other words, she could track her hand in total darkness as well as if the lights were on.

"You can't just imagine a target and get smooth eye movement," explains Knill. "If there is no moving target, your eye movements will be noticeably jerky."

The link with synesthesia suggests that our human ability to see self-motion is based on neural connections between the senses, says Knill. "We know that sensory cross talk underlies synesthesia. But seeing color with numbers is probably just the tip of the iceberg; synesthesia may involve many areas of atypical brain processing."

Does that mean that most humans are preprogrammed to see themselves in the dark? Not likely, says Tadin. "Innate or experience? I'm pretty sure it's experience," he concludes. "Our brains are remarkably good at finding such reliable patterns. The brain is there to pick up patterns—visual, auditory, thinking, movement. And this is one association that is so highly repeatable that it is logical our brains picked up on it and exploited it."

Whether hardwired or learned, Bronnenkant finds the cross talk between her senses a potent reminder of the underlying interconnectivity of nature. "It's almost a spiritual thing," she says. "Sometimes, yeah, I think to myself, 'I just got this sense from a billiard ball,' but other times I think that being able to cross modalities actually reflects how unified the world is. We think of math and chemistry and art as different fields, but really they are facets of the same world; they are just ways of looking at the world through different lenses."


Contacts and sources:
Bo Hu
Rochester University

Bo Hu, a postdoctoral student at Rochester, also contributed to this study. The research was funded by the following grants: NIH R01- EY019295 (to D.T.), R01-EY017939 (to D.K.), World Class University program through the Korea Science and Engineering Foundation funded by the Ministry of Education, Science and Technology (R31-10089 to R.B.), NIH P30-EY001319, P30

40 Billion Exploding Stars

Most of the universe's heavy elements, including the iron central to life itself, formed early in cosmic history and spread throughout the universe, according to a new study of the Perseus Galaxy Cluster using Japan's Suzaku satellite.

Between 2009 and 2011, researchers from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), jointly run by Stanford University and the Department of Energy's SLAC National Accelerator Laboratory in California, used Suzaku's unique capabilities to map the distribution of iron throughout the Perseus Galaxy Cluster.

What they found is remarkable: Across the cluster, which spans more than 11 million light-years of space, the concentration of X-ray-emitting iron is essentially uniform in all directions.

"This tells us that the iron -- and by extension other heavy elements -- already was widely dispersed throughout the universe when the cluster began to form," said KIPAC astrophysicist Norbert Werner, the study's lead researcher. "We conclude that any explanation of how this happened demands lead roles for supernova explosions and active black holes." 

The universe underwent a turbulent youth 10 to 12 billion years ago, as shown in this illustration. Stars formed at very high rates, but many of these newborn stars died quickly in supernova explosions that produced the chemical elements beyond helium - the building blocks of later stars, planets and life. In the same period, supermassive black holes in the centers of galaxies devoured large amounts of the gas around them, producing strong jets and outflows. The combined energy from numerous supernova explosions and black hole jets created powerful "winds" that blew these elements out of the galaxies, into intergalactic space.

Credit: Akihiro Ikeshita

The most profligate iron producers are type Ia supernovae, which occur either when white dwarf stars merge or otherwise acquire so much mass that they become unstable and explode. According to the Suzaku observations, the total amount of iron contained in the gas filling the cluster amounts to 50 billion times the mass of our sun, with about 60 percent of that found in the cluster's outer half.

The team estimates that at least 40 billion type Ia supernovae contributed to the chemical "seeding" of the space that later became the Perseus Galaxy Cluster.

Making the iron is one thing, while distributing it evenly throughout the region where the cluster formed is quite another. The researchers suggest that everything came together during one specific period of cosmic history.

Between about 10 and 12 billion years ago, the universe was forming stars as fast as it ever has. Abundant supernovae accompany periods of intense star formation, and the rapid-fire explosions drove galaxy-scale outflows. At the same time, supermassive black holes at the centers of galaxies were at their most active, rapidly accreting gas and releasing large amounts of energy, some of which drove powerful jets. Together, these galactic "winds" blew the chemical products of supernovae out of their host galaxies and into the wider cosmos.

Sometime later, in the regions of space with the largest matter densities, galaxy clusters formed, scooping up and mixing together the cosmic debris from regions millions of light-years across.

"If our scenario is correct, then essentially all galaxy clusters with masses similar to the Perseus Cluster should show similar iron concentrations and smooth distributions far from the center," said co-author Ondrej Urban, also at KIPAC.

Suzaku explored faint X-ray emission from hot gas throughout the Perseus Galaxy Cluster. The satellite recorded image strips along eight different directions, shown here in false color, for a total exposure exceeding 11.5 days. Bluer colors indicate fainter X-ray emission. The dashed circle marks the cluster's effective boundary, where new gas is now entering, and is 2.7 degrees wide.

Credit: NASA/ISAS/DSS/O. Urban al., MNRAS

Galaxy clusters contain hundreds to thousands of galaxies, as well as enormous quantities of diffuse gas and dark matter, bound together by their collective gravitational pull.

New gas entering the cluster falls toward its center, eventually moving fast enough to generate shock waves that heat the infalling gas. In the Perseus Cluster, gas temperatures reach as high as 180 million degrees Fahrenheit (100 million C), so hot that the atoms are almost completely stripped of their electrons and emit X-rays.

Young stars, exploding supernovae, and voraciously feeding black holes produced powerful winds 10 to 12 billion years ago. The spoon in this illustration represents the outflows that lifted heavy elements from young galaxies and mixed it with the intergalactic gas.

Credit: Akihiro Ikeshita

The Perseus Galaxy Cluster, which is located about 250 million light-years away and named for its host constellation, is the brightest extended X-ray source beyond our own galaxy, and the brightest and closest cluster for which Suzaku has attempted to map outlying gas.

The team used Suzaku's X-ray telescopes to make 84 observations of the Perseus Cluster, resulting in radial maps along eight different directions. Thanks to the sensitivity of the spacecraft's instruments, the researchers could measure the iron distribution of faint gas in the cluster's outermost reaches, where new gas continues to fall into it.

The findings will be published in the Oct. 31 issue of the journal Nature.

Suzaku (Japanese for "red bird of the south") was launched as Astro-E2 on July 10, 2005, and renamed in orbit. The observatory was developed by the Japan Aerospace Exploration Agency's Institute of Space and Astronautical Science in collaboration with NASA and other Japanese and U.S. institutions. NASA Goddard supplied Suzaku's X-ray telescopes and data-processing software and continues to operate a facility that supports U.S. astronomers who use the spacecraft.


Contacts and sources:  
Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

Wednesday, October 30, 2013

4th X-Flare In A Week: Sun Continues to Emit Solar Flares

The sun emitted a significant solar flare – its fourth X-class flare since Oct. 23, 2013 -- peaking at 5:54 p.m. on Oct. 29, 2013. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. 

X2.3 flare from 22:00 UT October 29. Blended SDO AIA 304 and 193 wavelengths.
Image Credit: NASA/SDO

This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.

The sun emitted a significant solar flare – its fourth X-class flare since Oct. 23, 2013 -- peaking at 5:54 p.m. on Oct. 29, 2013. NASA's Solar Dynamics Observatory captured the flare in this image, which shows light in wavelengths of both 304 and193 Angstroms.
Image Credit: NASA/SDO

To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

This flare is classified as an X2.3 class flare. "X-class" denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.

Image Credit: NASA/SDO

Increased numbers of flares are quite common at the moment, since the sun's normal 11-year activity cycle is ramping up toward solar maximum conditions. Humans have tracked this solar cycle continuously since it was discovered in 1843, and it is normal for there to be many flares a day during the sun's peak activity.

After emitting its first significant solar flares since June 2013 earlier in the week, the sun continued to produce mid-level and significant solar flares on Oct. 27 and Oct. 28, 2013.

X2.3 flare from 22:00 UT October 29. Blended SDO AIA 131 and 171 wavelengths.
 
Image Credit: NASA/SDO

Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel.

One of the larger flares was classified as an X1.0 flare, which peaked at 10:03 p.m. EDT on Oct. 27. "X-class" denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc. In the past, X-class flares of this intensity have caused degradation or blackouts of radio communications for about an hour.

Another large flare was classified as an M5.1 flare, which peaked at 12: 41 a.m. EDT on Oct. 28. Between Oct. 23, and the morning of Oct 28, there were three X-class flares and more than 15 additional M-class flares.

X2.3 flare from 22:00 UT October 29. Blended SDO AIA 171 and 131 wavelengths. Cropped.
 
Image Credit: NASA/SDO

Increased numbers of flares are quite common at the moment, since the sun is headed toward solar maximum conditions as part of its normal 11-year activity cycle. Humans have tracked this solar cycle continuously since it was discovered in 1843, and it is normal for there to be many flares a day during the sun's peak activity.

The recent solar flare activity has also been accompanied by several coronal mass ejections or CMEs, another solar phenomenon that can send billions of tons of particles into space that can reach Earth one to three days later. These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.

Updates will be provided as needed.

Doomed Mystery Planet Baffling Astronomers

Kepler-78b is a planet that shouldn't exist. This scorching lava world circles its star every eight and a half hours at a distance of less than one million miles - one of the tightest known orbits. According to current theories of planet formation, it couldn't have formed so close to its star, nor could it have moved there.

Credit: Harvard-Smithsonian Center for Astrophysics

"This planet is a complete mystery," says astronomer David Latham of the Harvard-Smithsonian Center for Astrophysics (CfA). "We don't know how it formed or how it got to where it is today. What we do know is that it's not going to last forever."

"Kepler-78b is going to end up in the star very soon, astronomically speaking," agrees CfA astronomer Dimitar Sasselov.


Credit: Harvard-Smithsonian Center for Astrophysics

Not only is Kepler-78b a mystery world, it is the first known Earth-sized planet with an Earth-like density. Kepler-78b is about 20 percent larger than the Earth, with a diameter of 9,200 miles, and weighs almost twice as much. As a result it has a density similar to Earth's, which suggests an Earth-like composition of iron and rock.

The tight orbit of Kepler-78b poses a challenge to theorists. When this planetary system was forming, the young star was larger than it is now. As a result, the current orbit of Kepler-78b would have been inside the swollen star.

"It couldn't have formed in place because you can't form a planet inside a star. It couldn't have formed further out and migrated inward, because it would have migrated all the way into the star. This planet is an enigma," explains Sasselov.

Credit: Harvard-Smithsonian Center for Astrophysics

According to Latham, Kepler-78b is a member of a new class of planets recently identified in data from NASA's Kepler spacecraft. These newfound worlds all orbit their stars with periods of less than 12 hours. They're also small, about the size of Earth. Kepler-78b is the first planet in the new class to have its mass measured.

"Kepler-78b is the poster child for this new class of planets," notes Latham.

The team studied Kepler-78b using a newly commissioned, high-precision spectrograph known as HARPS-North, at the Roque de los Muchachos Observatory on La Palma. They coordinated their work with a second, independent team using the HIRES spectrograph at the Keck Observatory. The teams' measurements agreed with each other, increasing their confidence in the result.

Kepler-78b is a doomed world. Gravitational tides will draw it even closer to its star. Eventually it will move so close that the star's gravity will rip the world apart. Theorists predict that Kepler-78b will vanish within three billion years.

Interestingly, our solar system could have held a planet like Kepler-78b. If it had, the planet would have been destroyed long ago leaving no signs for astronomers today.

Kepler-78b orbits a Sun-like G-type star located 400 light-years from Earth in the constellation Cygnus.


Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.


Contacts and sources:
David A. Aguilar
Director of Public Affairs
Harvard-Smithsonian Center for Astrophysics

Banned Books: Should You Or Shouldn't You Let Your Child Read Them?

1902, the Omaha Public Library banned Mark Twain’s critically acclaimed novel Huckleberry Finnfrom its bookshelves. In response, the author sent the library a brief letter that included the following excerpt:

“I am tearfully afraid this noise is doing much harm. It has started a number of hitherto spotless people to reading Huck Finn out of a natural human curiosity to learn what this all about — people whose morals will go to wreck and ruin now.”

Credit: Full Time Nanny

Twain’s satirical take on the issue notwithstanding, the subject of banned books continues to be a hot topic today, particularly among parents. Most parents want their children to receive a broad, rounded education that equips them for the diverse challenges of life in the modern world, but some are concerned that their kids may be unduly influenced by a book’s language, theme or subject matter. While parents may argue that they have the right to decide what their children read, it can also be argued that banning books restricts the rights of other parents to make the same determination. Whatever perspective a parent takes on the subject of banned books, it’s important to explore the facts fully before engaging in an open conversation with children about the topic.

The Difference Between Challenged Books and Banned Books

A book challenge isn’t just a person or group voicing an objection to a book. It’s a formal, written complaint that attempts to remove the work from a school’s curriculum or library, effectively banning the book. Around half of the challenges that are made each year are initiated by parents. Library patrons, school administrators, government bodies and special interest groups also routinely file book challenges.

Between 2000 and 2009, more than 5,000 books were reported as challenged in the nation’s libraries and schools, according to the American Library Association (ALA). The actual number of challenges is likely much higher. The ALA estimates that around 80% of all challenges go unreported.

Although the majority of challenges do not result in an outright ban, those that do can have profound and far-reaching effects. In 2012, the Arizona state legislature passed a law that effectively banned ethnic studies from being taught in schools. As a result, the Tucson Unified School District was required toremove multiple book titles from the curriculum, including Shakespeare’s The Tempest. The play was determined to contain themes of “race, ethnicity and oppression” that are not allowed under the new law.

Why Are Books Challenged?

Those who seek to ban books from public and private libraries and educational institutions are motivated by a number of factors. Most concerns fall into four categories: family values, religion, political views and minority rights. The most common reasons cited over that last decade include:

• Sexually Explicit Material. More than 30% of challenges referred to content of a sexual nature. Even a passing reference to nudity in a book can spark challenges. In a challenge to remove the Maurice Sendak children’s book In the Night Kitchen from a Minnesota institution, a drawing of a boy with no clothes was cited as “the foundation for future use of pornography.”

• Offensive Language. Some people object to children being exposed to any type of offensive language. However, while the use of vulgar, racist or misogynistic words in everyday life is generally regarded as inappropriate, their usage in literature can put them in a context that helps explain to children why they are considered distasteful.

• Excess Violence. Few parents want their children exposed to gratuitous violence, but even books that use allegory to condemn the use of violence have been challenged. Books designed to help children recognize and address domestic violence come under scrutiny as well.

• Religious Viewpoint. Some people challenge books that they feel undermine the validity of their religious faith. Whether it’s a Harry Potter book targeted for “satanic” or “ungodly” content or books that question the belief in God, books challenged for religious reasons are among the most controversial.

Should Your Children Read Banned Books?

Ultimately, decisions about which banned or challenged books are suitable for a particular child should be left to parents and guardians. Because children mature at different rates of development, a book that’s appropriate for one eight-year-old child may be unsuitable for another. Knowing when to begin a conversation about banned books can be difficult. Once children become aware about the subject, however, their curiosity may lead them to read books that parents may not approve. A frank discussion about why books are challenged and/or banned may be enough to quell their interest.

Choosing Appropriate Books for Children

One of the most effective ways for parents to learn which books are appropriate for their children is to take regular family trips to the local library. Nothing instills a love of learning in a child more than a parent that exhibits the same interest. The opportunity to compare and contrast books teaches children analytical skills that make them less susceptible to content that some parents fear might have a negative influence over them. When a child wants to read a book that the parents deem inappropriate, parents may find it useful to use the situation as an opportunity to share their personal views and family values.

Children will naturally gravitate toward library reading sections intended for their age groups, avoiding sections that they feel might be above their reading level. A librarian can suggest age-appropriate titles. Parents can seek guidance from children’s book reviews as well. Storing the library books on a central shelf in the home gives parents a way to track the child’s reading material.

Although children have the right to seek out books that interest and inform them, parents are ultimately responsible for their kids’ well-being. It is a parent’s right to guide their children’s reading choices without negating the rights of other parents to make their own decisions


Contacts and sources:
Hannah Anderson
Full Time Nanny

Tuesday, October 29, 2013

Holy Grail Of Science: The Origin Of Life Presented - It Rained From The Skies And Started In The Bowels Of Hell

Sankar Chatterjee presents what he calls the "Holy Grail of science" to Geological Society of America. 

It has baffled humans for millennia: how did life begin on planet Earth? Now, new research from a Texas Tech University paleontologist suggests it may have rained from the skies and started in the bowels of hell.

Sankar Chatterjee, Horn Professor of Geosciences and curator of paleontology at the Museum of Texas Tech University believes he has found the answer by connecting theories on chemical evolution with evidence related to our planet’s early geology.

Meteorite bombardment left large craters that contained water and chemical building blocks for life, which ultimately led to the first organisms.  
Bombardment
Credit: Texas Tech University

“This is bigger than finding any dinosaur,” Chatterjee said. “This is what we’ve all searched for – the Holy Grail of science.”

Thanks to regular and heavy comet and meteorite bombardment of Earth’s surface during its formative years 4 billion years ago, the large craters left behind not only contained water and the basic chemical building blocks for life, but also became the perfect crucible to concentrate and cook these chemicals to create the first simple organisms.

He will present his findings Oct. 30 during the 125th Anniversary Annual Meeting of the Geological Society of America in Denver.

As well as discovering how ancient animals flew, Chatterjee discovered the Shiva Meteorite Crater, which was created by a 25-mile-wide meteorite that struck off the coast of India. This research concluded this giant meteorite wreaked havoc simultaneously with the Chicxulub meteorite strike near Mexico, finishing the dinosaurs 65 million years ago.

Ironically, Chatterjee’s latest research suggests meteorites can be givers of life as well as takers. He said that meteor and comet strikes likely brought the ingredients and created the right conditions for life on our planet. By studying three sites containing the world’s oldest fossils, he believes he knows how the first single-celled organisms formed in hydrothermal crater basins.

“When the Earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms,” Chatterjee said. “It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life – the ancestors to all living things.”

Recipe for Living

As the basins filled, volcanically driven geothermal vents heated the water and created convection. The result was constant water movement, creating a thick primordial soup.

Credit: Texas Tech University

“For may years, the debate on the origins of life centered on the chemical evolution of living cells from organic molecules by natural processes. Chatterjee said life began in four steps of increasing complexity – cosmic, geological, chemical and biological.

In the cosmic stage, a still-forming Earth and our solar system took a daily pounding from rocky asteroids and icy comets between 4.1 to 3.8 billion years ago. Plate tectonics, wind and water have hidden evidence of this early onslaught on our planet, but ancient craters on the surfaces of Mars, Venus, Mercury and our moon show just how heavy the meteorite showers once were.

Larger meteorites that created impact basins of about 350 miles in diameter inadvertently became the perfect crucibles, he said. These meteorites also punched through the Earth’s crust, creating volcanically driven geothermal vents. Also, they brought the basic building blocks of life that could be concentrated and polymerized in the crater basins.

After studying the environments of the oldest fossil-containing rocks on Earth in Greenland, Australia and South Africa, Chatterjee said these could be remnants of ancient craters and may be the very spots where life began in deep, dark and hot environments.

Because of Earth’s perfect proximity to the sun, the comets that crashed here melted into water and filled these basins with water and more ingredients. This gave rise to the geological stage. As these basins filled, geothermal venting heated the water and created convection, causing the water to move constantly and create a thick primordial soup.

“The geological stage provides special dark, hot, and isolated environments of the crater basins with the hydrothermal vent systems that served as incubators for life,” he said. “Segregation and concentration of organic molecules by convective currents took place here, something like the kinds we find on the ocean floor, but still very different. It was a bizarre and isolated world that would seem like a vision of hell with the foul smells of hydrogen sulfide, methane, nitric oxide and steam that provided life-sustaining energy.”

Then began the chemical stage, Chatterjee said. The heat churning the water inside the craters mixed chemicals together and caused simple compounds to grow into larger, more complex ones.

Eventually, the first life forms left the confines of the crater and ventured into the newly formed oceans.
Credit:  Texas Tech University

Protecting Important Information

Most likely, pores and crevices on the crater basins acted as scaffolds for concentrations of simple RNA and protein molecules, he said. Unlike a popular theory that believes RNA came first and proteins followed, Chatterjee believes RNA and proteins emerged simultaneously and were encapsulated and protected from the environment.

“The dual origin of the ‘RNA/protein’ world is more plausible in the vent environments than the popular ‘RNA world,’” he said. “RNA molecules are very unstable. In vent environments, they would decompose quickly. Some catalysts, such as simple proteins, were necessary for primitive RNA to replicate and metabolize. On the other hand, amino acids, from which proteins are made, are easier to make than RNA components.”

The question remains how loose RNA and protein material floating in this soup protected itself in a membrane. Chatterjee believes University of California professor David Deamer’s hypothesis that membranous material existed in the primordial soup. Deamer isolated fatty acid vesicles from the Murchison meteorite that fell in 1969 in Australia. The cosmic fatty bubbles extracted from the meteorite mimic cell membranes.

“Meteorites brought this fatty lipid material to early Earth,” Chatterjee said. “This fatty lipid material floated on top of the water surface of crater basins but moved to the bottom by convection currents. At some point in this process during the course of millions of years, this fatty membrane could have encapsulated simple RNA and proteins together like a soap bubble. The RNA and protein molecules begin interacting and communicating. Eventually RNA gave way to DNA – a much more stable compound – and with the development of the genetic code, the first cells divided.”

Sankar Chatterjee is the curator of paleontology at the Museum of Texas Tech and a Horn professor in the Department of Geosciences in the College of Arts and Sciences. -
Chatterjee
Credit:  Texas Tech University

The final stage – the biological stage – represents the origin of replicating cells as they began to store, process and transmit genetic information to their daughter cells, Chatterjee said. Infinite combinations took place, and countless numbers must have failed to function before the secret of replication was broken and the proper selection occurred.

“These self-sustaining first cells were capable of Darwinian evolution,” he said. “The emergence of the first cells on the early Earth was the culmination of a long history of prior chemical, geological and cosmic processes.”

Chatterjee also believes that modern RNA-viruses and protein-rich prions that cause deadly diseases probably represent the evolutionary legacy of primitive RNA and protein molecules. They may be the oldest cellular particles that predated the first cellular life. Once cellular life evolved, RNA-viruses and prions became redundant, but survived as parasites on the living cells.

The problem with theories on the origins of life is that they don’t propose any experiments that lead to the emergence of cells, Chatterjee said. However, he suggested an experiment to recreate the ancient prebiotic world and support or refute his theory.

“If future experiments with membrane-bound RNA viruses and prions result in the creation of a synthetic protocell, it may reflect the plausible pathways for the emergence of life on early Earth,” he said.

Contacts and sources:
Written by John Davis

The Monsters That Killed The Giant Oar Fish Found

Dissecting a small sampling of tissue from an 18-foot oarfish late last week, UC Santa Barbara parasitologists discovered the elusive California sea monster hosted its own little monsters inside.

On October 13, 2013 The crew of sailing school vessel Tole Mour and Catalina Island Marine Institute instructors hold an 18-foot-long oarfish that was found in the waters of Toyon Bay on Santa Catalina Island, Calif.
Credit: Catalina Island Marine Institute

"Our findings say that these are actually majorly parasitized fish," said Armand Kuris, professor of zoology in the UCSB Department of Ecology, Evolution and Marine Biology, of the late night dissection last Thursday.

Part of the team that dissected an 18-foot oarfish l to r: Armand Kuris, professor of zoology, and graduate student researchers Sara Weinstein and John McLaughlin. Weinstein holds a 15 cm larval tapeworm found in the fish's intestine.

Credit: Sonia Fernandez

The oarfish carcass was found on October 13 by a Catalina Island snorkeler. Because the oarfish lives in such deep, dark and mysterious waters, and doesn't take bait, said Kuris, the creature is a rare find, especially for parasitologists.

The small white threadlike organism is a nematode, or roundworm, found in the sample of oarfish tissue dissected by the researchers.

Credit: Sonia Fernandez

"Oarfish wash ashore, one every few years," said Kuris, adding that finding such a fish that hasn't rotted or been eaten by other organisms, and is found in a place where scientists can get a hold of the carcass is "the result of many uncommon events." There are only two papers on oarfish parasites, he said.

Also known as the "king of herrings," and "ribbonfish," the oarfish (Regalecus glesne) is thought to be the world's largest bony fish, reaching over 30 feet long, giving rise to its sea serpent reputation. However, because it lives in deep waters (from 650-1000 feet), relatively little is known about the creature.


UCSB Scientists Find Parasites in Giant Oarfish from UC Santa Barbara on Vimeo.

With the help of UCSB research biologist and ichthyologist Milton Love, the group was able to obtain a small sample of tissues –– gills, intestine, stomach, spleen and gallbladder –– for dissection. The results of their examination not only revealed more parasites than previously documented, but also clues into the ecology and habitat of the deep-water fish.

"In this little piece of intestine that we had, we found quite a few of these rather large larval tapeworms. One of them was about 15 cm (6 inches) long," said Kuris. They found a couple dozen specimens of two species in the small segment, along with two juvenile roundworms. And, unexpectedly, grad student Sara Weinstein found the hooked proboscis of an adult spiny-headed worm embedded in the intestine as well.

The life cycle stage in which these parasites were found is important, explained Kuris, because such parasites live out their life cycles in different hosts. The larval tapeworms, which hadn't yet developed their telltale segments, for instance, will stay in their larval stage indefinitely until the oarfish gets eaten by a shark, whereupon they resume their maturation inside the shark. The spiny-headed worm, on the other hand, was an adult, indicating that the oarfish ate the organism –– probably krill or some deep-water crustacean –– that hosted its juvenile form.


Credit: Catalina Island Marine Institute

"These (findings) tell you about what the natural enemies of the oarfish are," said Kuris. The species it feeds on also indicate where the elusive oarfish is likely to live or hunt for food.

The next step for the researchers is to send parasite specimens away for further identification, and possibly even molecular analysis of the DNA. Despite the fact that they had only a small portion of the total fish, the researchers were able to come away with a huge amount of information.

"This thing had all sorts of stuff in it, even when we had almost no actual tissue to work with," Kuris said.

The dissection was also performed by researcher Ryan Hechinger, grad students John McLaughlin and Alejandra Jaramillo, and undergraduates Maggie Espinoza, Gabriella Dunn and technician Jake Ashford.



Contacts and sources:
Sonia Fernandez
University of California Santa Barbara 

Three Space Ghosts: Spooky Structures Seen In Newly Released NASA Releases Images

In the spirit of Halloween, scientists are releasing a trio of stellar ghosts caught in infrared light by NASA's Spitzer Space Telescope. All three spooky structures, called planetary nebulas, are in fact material ejected from dying stars. As death beckoned, the stars' wispy bits and pieces were blown into outer space.

Death Beckons Three Aging Stars: This trio of ghostly images from NASA's Spitzer Space Telescope shows the disembodied remains of dying stars called planetary nebulas. Planetary nebulas are a late stage in a sun-like star's life, when its outer layers have sloughed off and are lit up by ultraviolet light from the central star. They come in a variety of shapes, as indicated by these three spooky structures.
This trio of ghostly images from NASA's Spitzer Space Telescope shows the disembodied remains of dying stars called planetary nebulas
Image Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA
In all of the images, infrared light at wavelengths of 3.6 microns is rendered in blue, 4.5 microns in green, and 8.0 microns in red.

"Some might call the images haunting," said Joseph Hora of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., principal investigator of the Spitzer observing program. "We look to the pictures for a sense of the history of the stars’ mass loss, and to learn how they evolved over time."

All stars about the mass of our sun will die similarly ethereal deaths. As sun-like stars grow old, billions of years after their inception, they run out of fuel in their cores and puff up into red, giant stars, aptly named "red giants." The stars eventually cast off their outer layers, which expand away from the star. When ultraviolet light from the core of a dying star energizes the ejected layers, the billowy material glows, bringing their beautiful shapes to light.

These objects in their final death throes, the planetary nebulas, were named erroneously after their resemblance to planets by William Herschel in 1785. They come in an array of shapes, as illustrated by the three highlighted here in infrared images from Spitzer. The ghostly material will linger for only a few thousand years before ultimately fading into the dark night.

Exposed Cranium Nebula

The brain-like orb called PMR 1 has been nicknamed the "Exposed Cranium" nebula by Spitzer scientists. This planetary nebula, located roughly 5,000 light-years away in the Vela constellation, is host to a hot, massive dying star that is rapidly disintegrating, losing its mass.

The nebula's insides, which appear mushy and red in this view, are made up primarily of ionized gas, while the outer green shell is cooler, consisting of glowing hydrogen molecules.

Ghost of Jupiter Nebula

The Ghost of Jupiter, also known as NGC 3242, is located roughly 1,400 light-years away in the constellation Hydra. Spitzer's infrared view shows off the cooler outer halo of the dying star, colored here in red. 

Also evident are concentric rings around the object, the result of material being tossed out periodically during the star's fitful death.

Little Dumbbell Nebula

This planetary nebula, known as NGC 650, or the Little Dumbbell, is about 2,500 light-years from Earth in the Perseus constellation. Unlike the other spherical nebulas, it has a bipolar or butterfly shape due to a "waist," or disk, of thick material, running from lower left to upper right. 

Fast winds blow material away from the star, above and below this dusty disk. The ghoulish green and red clouds are from glowing hydrogen molecules. The green area is hotter than the red.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu andhttp://www.nasa.gov/spitzer .


Contacts and sources:
Whitney Clavin  
Jet Propulsion Laboratory, Pasadena, Calif.

New Sea Creature Unknown To Science Is Swimming Off Northern Australia: Humpback Dolphin Species Just Discovered

A species of humpback dolphin previously unknown to science is swimming in the waters off northern Australia, according to a team of researchers working for the Wildlife Conservation Society, the American Museum of Natural History, and numerous other groups that contributed to the study.

Two individual animals from an as-of-yet unnamed species of humpback dolphin are shown in the waters off northern Australia.

Credit: Photo credit: Guido Parra

To determine the number of distinct species in the family of humpback dolphins (animals named for a peculiar hump just below the dorsal fin), the research team examined the evolutionary history of this family of marine mammals using both physical features and genetic data. While the Atlantic humpback dolphin is a recognized species, this work provides the best evidence to date to split the Indo-Pacific humpback dolphin into three species, one of which is completely new to science.

A new as-of-yet unnamed species of humpback dolphin is shown off the coast of northern Australia.

Credit: Photo credit: Guido Parra

"Based on the findings of our combined morphological and genetic analyses, we can suggest that the humpback dolphin genus includes at least four member species," said Dr. Martin Mendez, Assistant Director of WCS's Latin America and the Caribbean Program and lead author of the study. "This discovery helps our understanding of the evolutionary history of this group and informs conservation policies to help safeguard each of the species."

The authors propose recognition of at least four species in the humpback dolphin family: the Atlantic humpback dolphin (Sousa teuszii), which occurs in the eastern Atlantic off West Africa; the Indo-Pacific humpback dolphin (Sousa plumbea), which ranges from the central to the western Indian Ocean; another species of Indo-Pacific humpback dolphin (Sousa chinensis), which inhabits the eastern Indian and western Pacific Oceans; and a fourth Sousaspecies found off northern Australia yet to be named (the formal adjustment of the naming and number of species occurs through a separate and complementary process based on these findings).

"New information about distinct species across the entire range of humpback dolphins will increase the number of recognized species, and provides the needed scientific evidence for management decisions aimed at protecting their unique genetic diversity and associated important habitats," said Dr. Howard Rosenbaum, Director of WCS's Ocean Giants Program and senior author on the paper.

Two dolphins from the as-of-yet unnamed species of humpback dolphin are shown off northern Australia. The discovery will help conservationists and decision makers to formulate new policies to safeguard these marine mammals.

Credit: Photo credit: Guido Parra

Working to bring taxonomic clarity to a widespread yet poorly known group of dolphins, the authors assembled a large collection of physical data gathered mostly from beached dolphins and museum specimens. Specifically, the team examined features from 180 skulls covering most of the distribution area of the group in order to compare morphological characters across this region.

The researchers also collected 235 tissue samples from animals in the same areas, stretching from the eastern Atlantic to the western Pacific Oceans, analyzing both mitochondrial and nuclear DNA for significant variations between populations.


Contacts and sources:

Canyon Of Fire On The Sun 200,000 Miles Long

A magnetic filament of solar material erupted on the sun in late September, breaking the quiet conditions in a spectacular fashion. The 200,000 mile long filament ripped through the sun's atmosphere, the corona, leaving behind what looks like a canyon of fire.
 
Credit:  Goddard Space Flight Center

 The glowing canyon traces the channel where magnetic fields held the filament aloft before the explosion. Visualizers at NASA's Goddard Space Flight Center in Greenbelt, Md. combined two days of satellite data to create a short movie of this gigantic event on the sun.

In reality, the sun is not made of fire, but of something called plasma: particles so hot that their electrons have boiled off, creating a charged gas that is interwoven with magnetic fields.

These images were captured on Sept. 29-30, 2013, by NASA's Solar Dynamics Observatory, or SDO, which constantly observes the sun in a variety of wavelengths.

Different wavelengths help capture different aspect of events in the corona. The red images shown in the movie help highlight plasma at temperatures of 90,000° F and are good for observing filaments as they form and erupt. 

The yellow images, showing temperatures at 1,000,000° F, are useful for observing material coursing along the sun's magnetic field lines, seen in the movie as an arcade of loops across the area of the eruption. The browner images at the beginning of the movie show material at temperatures of 1,800,000° F, and it is here where the canyon of fire imagery is most obvious.

Credit:  Goddard Space Flight Center

By comparing this with the other colors, one sees that the two swirling ribbons moving farther away from each other are, in fact, the footprints of the giant magnetic field loops, which are growing and expanding as the filament pulls them upward.


Contacts and sources:
 NASA's Goddard Space Flight Center 

New Remains Of Neanderthals Found In The Cova Negra Xativa

A team of archaeologists, led by Professor of Prehistory at the University of Valencia Valentín Villaverde, has found three new fossil remains of Neanderthals in the Middle Palaeolithic site of Cova Negra Xativa during archaeological excavations has developed over this month. In particular, work has enabled the discovery of a fragment of wall of an adult, child cranial fragment and child premolar.

Credit:  University of Valencia 

The results of the recent campaign were presented this morning at the University of Valencia by the Vice Chancellor for Research and Science Policy, Pedro Carrasco, Professor Valentín Villaverde, and the local archaeologist Xativa, Angel Velasco. Also attended by the mayor of the capital of La Costera, Alfonso Rus. Carrasco has highlighted the research work of Villaverde as a benchmark of the University of Valencia for its strength, its leadership to raise funds for research and the relevance of their results. "The Prometheus project we present today is also one of the most important and especially remarkable because it comes from the field of humanities," stressed the Vice Chancellor.

The three new Neanderthal fossils were found "in the upper sedimentary package, which includes levels corresponding to the top of the sequence documented at the site," explains the researcher. Consequently, "the chronology is not accurate, however, it is possible to correlate it with other remains found in excavations of the fifties of the last century and some of the remains discovered in the campaigns of the eighties. Its morphology is unambiguous and clearly refers to the upper Pleistocene Neanderthal populations "he says.

Handling of Skulls: by rituals and cannibalism

Villaverde is important to note that the two brands have cranial remains found on its outer face. "In a case appear nibbling produced by an animal and the other were probably made using a cutting tool, which could be related to the manipulation of the skull, whether by ritualistic cannibalism or for" argues. "This kind of manipulations have been documented in numerous fields Neanderthal remains in the Iberian Peninsula and France," says the project manager.

Valentín Villaverde fossil material ensures that the Cova Negra "up one of the richest collections of human remains Neanderthals in the Iberian Peninsula, with twenty-five pieces, and presents the peculiarity that the high number of documented infant remains." So far, the set consists of a minimum of seven individuals, two of whom are adults, one a teenager and four are children. In fact, this site is the third in the Iberian peninsula with an increased number of individuals identified after Sidrón Cave of Asturias and one of the highlights of Europe and the Middle East.

The researchers conducted a detailed study of the near future remains to determine if any of them can find the existence of new individuals. However, and ensure that the three new pieces "constitute a finding of first order for the knowledge of the characteristics of Neanderthal populations in southern Europe, and cranial fragments are preserved in an excellent state on their faces intracranial" in Villaverde words. The paleontological study of the parts, as in the past, will be led by Professor of the Universidad Complutense de Madrid Juan Luis Arsuaga.

The campaigns of the University of Valencia in the Middle Palaeolithic site of Xativa of 1981-1991, under the direction of Valentin Villaverde, and allowed to find twelve Neanderthal fossils. Previously, he had found two more during the campaigns led by G. Vines in the years 1928-1933 and eight along the excavations led by F. Jorda between 1950 and 1957.

The Prometheus 'Beyond History'

The excavation of the University of Valencia in the Cova Negra is integrated into the framework of the research project 'Beyond History: origin Palaeolithic settlement and consolidation of Valencia' (PROMETEOII/2013/016), funded by the Department d'Educació Culture i Esport of the Generalitat Valenciana, whose principal investigator is Professor of the Department of Prehistory Prehistory Archaeology Valentín Villaverde i. 

In addition, the project involved Prehistoric Research Service of the Provincial Government and the City Council of Valencia Xativa. In fact, the municipal archaeologist capital of La Costera, Angel Velasco, recent work has coordinated the excavations, which has had the collaboration of students and graduates of the University of Valencia and Alicante, as well as members of the Polytechnic University of Valencia.

The Valentín Villaverde research work focuses on various aspects of ancient prehistory: the Middle Palaeolithic, Upper Palaeolithic and prehistoric art. He is director of excavations at the sites of Cova Negra Xativa, the Cova de les Cendres of Teulada-Moraira, the Bubo Ratlla of Elche, the wrap Chelva Gorge and Cave Anton de Mula, as well as the tracing papers and documents in paintings and engravings Coats of Cova de les Meravelles of Gandia, the Cova dels Cavalls (Tírig), Coves of Jumping (Coves of Vinromà), Vicent Abric (Thousands), the Cingle of Remigia Mola (Ares del Maestre), Cova Remigia (Ares del Maestre), Abric of Twill (Alcoy), Abric Centelles (Albocāsser) and the Xivana Abric (Alfarb).

Villaverde is a member of the Scientific Committee of the National Research Center on Human Evolution (CENIEH) and several international scientific committees and scientific committees of several journals in prehistoric archeology. He also directed the Master in Archaeology and PhD program in Mediterranean Prehistory and Archaeology of the University of Valencia.

More information

Contatsand sources: 
RUVID Association
University of Valencia

Why School Lunches Could Be Adding To The Obesity Epidemic And What You Can Do To Help

As your child walks in from school, takes off his backpack and slumps on the couch, obviously exhausted from a full day of school, you may wonder why his energy has vanished. Ask him what he had for lunch in the school cafeteria, and you may find your answer.

From pizza and French fries to fruit dripping with rich corn syrup and canned, processed vegetables, your child’s food choices may be less than desirable to a health-conscious parent. It’s no wonder your child’s energy is gone and his clothes keep getting tighter.

Credit: eNanny Source

Many parents are finding that school lunches could be adding to the childhood obesity epidemic. Luckily, there is something you can do to help.

What’s For Lunch?

“The problem with many school lunches, or meals rather, is that they are highly processed,” says Elizabeth Prebish, registered dietitian for Organic Life, provider of healthy lunches in Chicago, Illinois. “Many school lunches include processed meats, fried foods and high amounts of sugars or carbohydrates.”

With restricted budgets to feed large quantities of mouths, typical food service companies use conventional meats that contain hormones, antibiotics and steroids – all things small children do not need, says Prebish.

In addition to lunch, it’s possible your child is filling up on sweets as well. The school lunch system provides many opportunities for sweets, including offering ice cream and bakery items, not to mention chocolate milk. “Having these items as daily options is definitely a contribution to the obesity epidemic,” says Prebish. “These processed sugars are addictive, leaving children craving the same foods not only in school but when they are home as well.”

Snack Time

From Halloween and fall festivals to school picnics and class parties, a celebration with food is a common occurrence in the classroom. Beyond the gorging of party cookies and cakes, some nutrition experts believe that even healthier snacks scheduled into the daily classroom schedule can contribute to childhood obesity.

“The number one way in which schools contribute to childhood obesity is by scripting snacks into the daily schedule,” says Adrienne Hew, nutrition specialist and founder of NutritionHeretic.com. “Children who are well fed do not need snacks – having snacks scripted into the schedule drives them to want to eat even when they are not hungry.”

The idea of incorporating snacks into the school day derived from a practice used for diabetics that uses small meals throughout the day to help keep blood sugar steady, says Hew. “However, the snacks that are offered to children would kill a diabetic – crackers, cookies, Cheerios and juice,” she says.

Cooking Up Change

In order to prompt change, parents need to offer solutions and suggestions to school districts and school board members. Offering a viable solution that is realistic with decreased school budgets is key.

“I would love to see schools engage with the community by going to local farmers or food co-ops and cutting cheap or free deals to absorb their leftover produce or produce that isn’t perfect for selling at the stand but can still be salvaged for making soups, stews and salads,” says Hew.

Another inexpensive option would be to recruit culinary students to complete internships in the schools as apprenticing or head chefs under the supervision of the person who normally is in charge of budgeting, suggests Hew. This economically-appealing option would give interns the opportunity to practice their skills, prepare healthy, innovative meals for school lunches and afford the district with a cost-effective option.

Parents can also advocate for a food service system that offers more natural products, says Prebish. “If this is not an option, work with your food service provider to determine more healthful substitutions that the children will also enjoy,” she says. “Try for more natural, and even organic, products wherever possible.”

In addition to working with food service systems, make yourself known at school board meetings. Parents can work to improve lunch selections by speaking to the board, the community and fellow parents. At each meeting try to provide a suggestion for healthier options, such as replacing meat-based burgers with veggie burgers.

According to Dr. Timothy Radak, faculty member in the Public Health program at Walden University, veggie burgers typically have one-third the amount of fat, no cholesterol and are similar in regards to the amount of protein as meat-based burgers.

Suggest cost-saving, evidence-based ideas to show the benefits to the district’s bottom line and the overall health of each student on campus. Schools could also reduce or eliminate some foods with health risks, such as red meat, processed foods or sugary drinks, says Radak. “Use the cost savings to provide more fresh fruits, vegetables and low fat, nutritious meal options.”

More importantly, educate your child about food, healthy eating habits and smart options for lunch. It is possible that when given the option, he may toss out the pizza and French fries for the veggie burger.


Contacts and sources:
Nancy Parker

Saturday, October 26, 2013

Coldest Place In The Universe Found

Astronomers believe they have found the coldest place in the Universe. 

At a cosmologically crisp one degree Kelvin (minus 458 degrees Fahrenheit), the Boomerang Nebula is the coldest known object in the Universe – colder, in fact, than the faint afterglow of the Big Bang, which is the natural background temperature of space, according to Charles Blue of the National Radio Astronomy Observatory.

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have taken a new look at this intriguing object to learn more about its frigid properties and to determine its true shape, which has an eerily ghost-like appearance.

The Boomerang Nebula reveals its true shape with ALMA. The background blue structure, as seen in visible light (HST), shows a classic double-lobe shape with a very narrow central region. ALMA’s ability to see the cold molecular gas reveals the nebula’s more elongated shape, in red. 
Credit: Bill Saxton; NRAO/AUI/NSF;

As originally observed with ground-based telescopes, this nebula appeared lopsided, which is how it got its name. Later observations with the Hubble Space Telescope revealed a bow-tie-like structure. The new ALMA data, however, reveal that the Hubble image tells only part of the story, and the twin lobes seen in that image may actually be a trick of the light as seen at visible wavelengths.

“This ultra-cold object is extremely intriguing and we’re learning much more about its true nature with ALMA,” said Raghvendra Sahai, a researcher and principal scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, and lead author of a paper published in theAstrophysical Journal. “What seemed like a double lobe, or ‘boomerang’ shape, from Earth-based optical telescopes, is actually a much broader structure that is expanding rapidly into space.”

The Boomerang Nebula, located about 5,000 light-years away in the constellation Centaurus, is a relatively young example of an object known as a planetary nebula. Planetary nebulae, contrary to their name, are actually the end-of-life phases of stars like our Sun that have sloughed off their outer layers. What remains at their centers are white dwarf stars, which emit intense ultraviolet radiation that causes the gas in the nebulae to glow and emit light in brilliant colors.

The Boomerang is a pre-planetary nebula, representing the stage in a star's life immediately preceding the planetary nebula phase, when the central star is not yet hot enough to emit enough ultraviolet radiation to produce the characteristic glow. At this stage, the nebula is seen by starlight reflecting off its dust grains.

The outflow of gas from this particular star is expanding rapidly and cooling itself in the process. This is similar in principle to the way refrigerators use expanding gas to produce cold temperatures. The researchers were able to take the temperature of the gas in the nebula by seeing how it absorbed the cosmic microwave background radiation, which has a very uniform temperature of 2.8 degrees Kelvin (minus 455 degrees Fahrenheit).

“When astronomers looked at this object in 2003 with Hubble, they saw a very classic ‘hourglass’ shape,” commented Sahai. “Many planetary nebulae have this same double-lobe appearance, which is the result of streams of high-speed gas being jettisoned from the star. The jets then excavate holes in a surrounding cloud of gas that was ejected by the star even earlier in its lifetime as a red giant.”

View of Boomerang Nebula from Hubble Space Telescope
Credit: Hubble Space Telescope

Observations with single-dish millimeter wavelength telescopes, however, did not detect the narrow waist seen by Hubble. Instead, they found a more uniform and nearly spherical outflow of material.

ALMA’s unprecedented resolution allowed the researchers to reconcile this discrepancy. By observing the distribution of carbon monoxide molecules, which glow brightly at millimeter wavelengths, the astronomers were able to detect the double-lobe structure that is seen in the Hubble image, but only in the inner regions of the nebula. Further out, they actually observed a more elongated cloud of cold gas that is roughly round.

The researchers also discovered a dense lane of millimeter-sized dust grains surrounding the star, which explains why this outer cloud has an hourglass shape in visible light. The dust grains have created a mask that shades a portion of the central star and allows its light to leak out only in narrow but opposite directions into the cloud, giving it an hourglass appearance.

“This is important for the understanding of how stars die and become planetary nebulae,” said Sahai. “Using ALMA, we were quite literally and figuratively able to shed new light on the death throes of a Sun-like star.”

ALMA’s 12-meter and 7-meter diameter antennas are the most precise ever made. In the gusty winds and fluctuating temperatures of the high-altitude desert, they can maintain perfect parabolic shapes to within a fraction of the thickness of a human hair on the entire surface. Such accuracy, which must be better than one-tenth of the shortest wavelength ALMA is able to observe (300 micrometers), is critical to properly detecting very faint radiation. 
Credit: ALMA (ESO/NAOJ/NRAO), C. Padilla 

The new research also indicated that the outer fringes of the nebula are beginning to warm, even though they are still slightly colder than the cosmic microwave background. This warming may be due to the photoelectric effect -- an effect first proposed by Einstein in which light is absorbed by solid material, which then re-emits electrons.

Additional authors on this paper include Wouter Vlemmings, Chalmers University of Technology, Onsala, Sweden; Patrick Huggins, New York University, New York; Lars-Ake Nyman, Joint ALMA Observatory, Santiago de Chile; and Yiannis Gonidakis, CSIRO, Australia Telescope National Facility.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement byAssociated Universities, Inc.

Thursday, October 24, 2013

Gold Grows In Trees In Australia, Leaves Rich In Little Gold Nuggest

Eucalyptus trees in the Kalgoorlie region of Western Australia are drawing up gold particles from the earth via their root system and depositing it their leaves and branches.

Eucalyptus leaf showing traces of gold.

Credit: CSIRO

Scientists from CSIRO made the discovery and have published their findings in the journal Nature Communications.

"The eucalypt acts as a hydraulic pump – its roots extend tens of metres into the ground and draw up water containing the gold. As the gold is likely to be toxic to the plant, it’s moved to the leaves and branches where it can be released or shed to the ground," CSIRO geochemist Dr Mel Lintern said.



The discovery is unlikely to start an old-time gold rush – the "nuggets" are about one-fifth the diameter of a human hair. However, it could provide a golden opportunity for mineral exploration, as the leaves or soil underneath the trees could indicate gold ore deposits buried up to tens of metres underground and under sediments that are up to 60 million years old.

"The leaves could be used in combination with other tools as a more cost effective and environmentally friendly exploration technique," Dr Lintern said.

"By sampling and analysing vegetation for traces of minerals, we may get an idea of what’s happening below the surface without the need to drill. It’s a more targeted way of searching for minerals that reduces costs and impact on the environment.

Gum leaf samples showing traces of manganese.
Credit: CSIRO

"Eucalyptus trees are so common that this technique could be widely applied across Australia. It could also be used to find other metals such as zinc and copper."

Using CSIRO’s Maia detector for x-ray elemental imaging at the Australian Synchrotron, the research team was able to locate and see the gold in the leaves. The Synchrotron produced images depicting the gold, which would otherwise have been untraceable.

"Our advanced x-ray imaging enabled the researchers to examine the leaves and produce clear images of the traces of gold and other metals, nestled within their structure," principal scientist at the Australian Synchrotron Dr David Paterson said.

Eucalyptus leaves showing traces of different minerals
Credit: CSIRO 

"Before enthusiasts rush to prospect this gold from the trees or even the leaf litter, you need to know that these are tiny nuggets, which are about one-fifth the diameter of a human hair and generally invisible by other techniques and equipment."

CSIRO research using natural materials, such as calcrete and laterite in soils, for mineral exploration has led to many successful ore deposit discoveries in regional Australia. The outcomes of the research provide a direct boost to the national economy.

Access the full paper at Nature Communications [external link]
Contacts and sources:
Emily Lehmann
CSIRO Australia

The Deepest Look Into The Universe Ever

NASA's Hubble, Spitzer and Chandra space telescopes are teaming up to look deeper into the universe than ever before. With a boost from natural "zoom lenses" found in space, they should be able to uncover galaxies that are as much as 100 times fainter than what these three great observatories typically can see.


Credit: NASA, ESA, and Z. Levay (STScI/AURA)

In an ambitious collaborative program called The Frontier Fields, astronomers will make observations over the next three years of six massive galaxy clusters, exploiting a natural phenomenon known as gravitational lensing, to learn not only what is inside the clusters but also what is beyond them. The clusters are among the most massive assemblages of matter known, and their gravitational fields can be used to brighten and magnify more distant galaxies so they can be observed.

"The Frontier Fields program is exactly what NASA's great observatories were designed to do; working together to unravel the mysteries of the Universe" said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington. "Each observatory collects images using different wavelengths of light with the result that we get a much deeper understanding of the underlying physics of these celestial objects."

MACS J1149.5+2223

Credit: Credit: NASA, ESA, and M. Postman (STScI), and the CLASH team

The first object they will view is Abell 2744, commonly known as Pandora's Cluster. The giant galaxy cluster appears to be the result of a simultaneous pile-up of at least four separate, smaller galaxy clusters that took place over a span of 350 million years.

Astronomers anticipate these observations will reveal populations of galaxies that existed when the universe was only a few hundred million years old, but have not been seen before.

"The idea is to use nature's natural telescopes in combination with the great observatories to look much deeper than before and find the most distant and faint galaxies we can possibly see," said Jennifer Lotz, a principal investigator with the Space Telescope Science Institute (STScI) in Baltimore, Md.

Data from the Hubble and Spitzer space telescopes will be combined to measure the galaxies' distances and masses more accurately than either observatory could measure alone, demonstrating their synergy for such studies.

MACS J0717.5+3745
Credit: NASA, ESA, and H. Ebeling (University of Hawaii)

"We want to understand when and how the first stars and galaxies formed in the universe, and each great observatory gives us a different piece of the puzzle," said Peter Capak, the Spitzer principal investigator for the Frontier Fields program. "Hubble tells you which galaxies to look at and how many stars are being born in those systems. Spitzer tells you how old the galaxy is and how many stars have formed."

The Chandra X-ray Observatory also will peer deep into the star fields. It will image the clusters at X-ray wavelengths to help determine their mass and measure their gravitational lensing power, and identify background galaxies hosting supermassive black holes.

MACS J0416.1-2403

Credit: NASA, ESA, and M. Postman (STScI), and the CLASH team

High-resolution Hubble data from the Frontier Fields program will be used to trace the distribution of dark matter within the six massive foreground clusters. Accounting for the bulk of the universe's mass, dark matter is the underlying invisible scaffolding attached to galaxies.

Abell 2744
Credit: NASA, ESA, and R. Dupke (Eureka Scientific, Inc.), et al.

Hubble and Spitzer have studied other deep fields with great success. The Frontier Fields researchers anticipate a challenge because the distortion and magnification caused by the gravitational lensing phenomenon will make it difficult for them to understand the true properties of the background galaxies.


Contact and sources"
NASA
Hubble Space Telescope

Photo: Oldest Galaxy Yet Found, Formed 700 Million Years After The Big Bang

University of California, Riverside astronomers Bahram Mobasher and Naveen Reddy are members of a team that has discovered the most distant galaxy ever found. The galaxy is seen as it was just 700 million years after the Big Bang, when the universe was only about 5 percent of its current age of 13.8 billion years.

This is an artist's rendition of the newly discovered most distant galaxy z8_GND_5296. The galaxy looks red in the actual Hubble Space Telescope image because the collective blue light from stars get shifted toward redder colors due to the expansion of the universe and its large distance from Earth.
Credit: V. Tilvi, S.L. Finkelstein, C. Papovich, NASA, ESA, A. Aloisi, The Hubble Heritage, HST, STScI, and AURA.

In collaboration with astronomers at the University of Texas at Austin, Texas A & M University, and the National Optical Astronomy Observatories, Mobasher and Reddy identified a very distant galaxy candidate using deep optical and infrared images taken by the Hubble Space Telescope. Follow-up observations of this galaxy by the Keck Telescope in Hawai'i confirmed its distance.

In searching for distant galaxies, the team selected several candidates, based on their colors, from the approximately 100,000 galaxies identified in the Hubble Space Telescope images taken as a part of the CANDELS survey, the largest project ever performed by the Hubble Space Telescope, with a total allocated time of roughly 900 hours. However, using colors to sort galaxies is tricky because some nearby objects can masquerade as distant galaxies.

This image from the Hubble Space Telescope CANDELS survey highlights the most distant galaxy in the universe with a measured distance, dubbed z8_GND_5296. The galaxy's red color alerted astronomers that it was likely extremely far away and, thus, seen at an early time after the Big Bang. A team of astronomers including Steven Finkelstein of the University of Texas at Austin and Vithal Tilvi of Texas A&M University measured the exact distance using the Keck I telescope with the new MOSFIRE spectrograph. They found that this galaxy is seen at about 700 million years after the Big Bang, when the universe was just 5% of its current age of 13.8 billion years.
Credit: V. Tilvi, Texas A&M University; S.L. Finkelstein, University of Texas at Austin; C. Papovich, Texas A&M University; CANDELS Team and Hubble Space Telescope/NASA

The paper's lead author is Steven Finkelstein, an assistant professor at the University of Texas at Austin and 2011 Hubble Fellow who previously was a postdoctoral research associate at Texas A&M under the mentorship of Texas A&M astrophysicist Casey Papovich, who is second author as well as current mentor to Tilvi. Ten other international institutions collaborated on the effort, from California to Massachusetts and Italy to Israel.

The galaxy, known by its catalog name z8_GND_5296, fascinated the researchers. Whereas our home, the Milky Way, creates about one or two Sun-like stars every year or so, this newly discovered galaxy forms around 300 a year and was observed by the researchers as it was 13 billion years ago. That's the time it took for the galaxy's light to travel to Earth. Just how mind-boggling is that? A single light year, which is the distance light travels in a year, is nearly six trillion miles. Because the universe has been expanding the whole time, the researchers estimate the galaxy's present distance to be roughly 30 billion light years away.

"Because of its distance we get a glimpse of conditions when the universe was only about 700 million years old — only 5 percent of its current age of 13.8 billion years," said Papovich, an associate professor in the Department of Physics and Astronomy and a member of the George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy since 2008.

Papovich notes that researchers are able to accurately gauge the distances of galaxies by measuring a feature from the ubiquitous element hydrogen called the Lyman alpha transition, which emits brightly in distant galaxies. It's detected in nearly all galaxies that are seen from a time more than one billion years from the Big Bang, but getting closer than that, the hydrogen emission line, for some reason, becomes increasingly difficult to see.

"We were thrilled to see this galaxy," Finkelstein said. "And then our next thought was, 'Why did we not see anything else? We're using the best instrument on the best telescope with the best galaxy sample. We had the best weather — it was gorgeous. And still, we only saw this emission line from one of our sample of 43 observed galaxies, when we expected to see around six. What's going on?'"

The researchers suspect they may have zeroed in on the era when the universe made its transition from an opaque state in which most of the hydrogen is neutral to a translucent state in which most of the hydrogen is ionized. So it's not necessarily that the distant galaxies aren't there. It could be that they're hidden from detection behind a wall of neutral hydrogen fog, which blocks the hydrogen emission signal.

Tilvi notes this is one of two major changes in the fundamental essence of the universe since its beginning — the other being a transition from a plasma state to a neutral state. He is leading the effort on a follow-up paper that will use a sophisticated statistical analysis to explore that transition further.

Therefore, to measure the distance to these galaxies in a definitive way, astronomers use spectroscopy -- specifically, how much the wavelength of a galaxy's light has shifted towards the red-end of the spectrum as it travels from the galaxy to Earth, due to the expansion of the universe. This phenomenon is called "redshift." Since the expansion velocity (redshift) and distances of galaxies are proportional, the redshift gives astronomers a measure of the distance to galaxies.

"What makes this galaxy unique, compared to other such discoveries, is the spectroscopic confirmation of its distance," said Mobasher, a professor of physics and observational astronomy.

Mobasher explained that because light travels at about 186,000 miles per second, when we look at distant objects, we see them as they appeared in the past. The more distant we push these observations, the farther into the past we can see.

"By observing a galaxy that far back in time, we can study the earliest formation of galaxies," he said. "By comparing properties of galaxies at different distances, we can explore the evolution of galaxies throughout the age of the universe."

The discovery was made possible by a new instrument, MOSFIRE, commissioned on the Keck Telescope. Not only is the instrument extremely sensitive, but it is designed to detect infrared light -- a region of the spectrum to where the wavelength of light emitted from distant galaxies is shifted -- and could target multiple objects at a time. It was the latter feature that allowed the researchers to observe 43 galaxy candidates in only two nights at Keck, and obtain higher quality observations than previous studies.

By performing spectroscopy on these objects, researchers are able to accurately gauge the distances of galaxies by measuring a feature from the ubiquitous element hydrogen called the Lyman alpha transition. It is detected in most galaxies that are seen from a time more than one billion years from the Big Bang, but as astronomers probe earlier in time, the hydrogen emission line, for some reason, becomes increasingly difficult to see.

Of the 43 galaxies observed with MOSFIRE, the research team detected this Lyman alpha feature from only one galaxy, z8-GND-5296, shifted to a redshift of 7.5. The researchers suspect they may have zeroed in on the era when the universe made its transition from an opaque state in which most of the hydrogen is neutral to a translucent state in which most of the hydrogen is ionized (called the Era of Re-ionization).

"The difficulty of detecting the hydrogen emission line does not mean that the galaxies are absent," said Reddy, an assistant professor of astronomy. "It could be that they are hidden from detection behind a wall of neutral hydrogen."

The team's observations showed that z8-GND-5296 is forming stars extremely rapidly -- producing each year ~300 times the mass of our sun. By comparison, the Milky Way forms only two to three stars per year. The new distance record-holder lies in the same part of the sky as the previous record-holder (redshift 7.2), which also happens to have a very high rate of star-formation.

"So we're learning something about the distant universe," said Steven Finkelstein at the University of Texas at Austin, who led the project. "There are way more regions of very high star formation than we previously thought. There must be a decent number of them if we happen to find two in the same area of the sky."

"With the construction and commissioning of larger ground-based telescopes -- the Thirty Meter Telescope in Hawai'i and Giant Magellan Telescope in Chile -- and the 6.5 meter James Webb Space Telescope in space, by the end of this decade we should expect to find many more such galaxies at even larger distances, allowing us to witness the process of galaxy formation as it happens," Mobasher said.

"It's exciting to know we're the first people in the world to see this," said Vithal Tilvi, a Texas A&M postdoctoral research associate and co-author of the paper, set to be available online at http://dx.doi.org/10.1038/nature12657 after Oct. 24. "It raises interesting questions about the origins and the evolution of the universe."

Contacts and sources:
Iqbal Pittalwala
University of California - Riverside

Vimal Patel
Texas A&M University