Biggest Full Moon of 2012 Occurs This Week

Skywatchers take note: The biggest full moon of the year is due to arrive this weekend.

The moon will officially become full Saturday (May 5) at 11:35 p.m. EDT. And because this month's full moon coincides with the moon's perigee — its closest approach to Earth — it will also be the year's biggest.

The moon will swing in 221,802 miles (356,955 kilometers) from our planet, offering skywatchers a spectacular view of an extra-big, extra-bright moon, nicknamed a supermoon.

And not only does the moon's perigee coincide with full moon this month, but this perigee will be the nearest to Earth of any this year, as the distance of the moon's close approach varies by about 3 percent, according to meteorologist Joe Rao, SPACE.com's skywatching columnist. This happens because the moon's orbit is not perfectly circular.

This month's full moon is due to be about 16 percent brighter than average. In contrast, later this year on Nov. 28, the full moon will coincide with apogee, the moon's farthest approach, offering a particularly small and dim full moon.

Though the unusual appearance of this month's full moon may be surprising to some, there's no reason for alarm, scientists warn. The slight distance difference isn't enough to cause any earthquakes or extreme tidal effects, experts say.

However, the normal tides around the world will be particularly high and low. At perigee, the moon will exert about 42 percent more tidal force than it will during its next apogee two weeks later, Rao said.

The last supermoon occurred in March 2011.

Read more at Discovery News

Thieving Stars Snatch Orphan Planets

Our galaxy is thought to be teeming with billions of "nomad" planets. These worlds are interstellar orphans, with no stellar parent to call home. Some were likely gravitationally flung from their parent star at an early age, while others may have evolved on their lonesome, clumping from small clouds of interstellar gas and dust.

If there are so many orphaned worlds drifting alone, how often might they be snatched by the gravitational tug of a star that happens to be drifting in the same direction?

Surprisingly, say astronomers from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and Peking University in China, it may happen more often than astrophysicists ever dreamed.

"Stars trade planets just like baseball teams trade players," said CfA's Hagai Perets in an April 17 press release.

In a Feb. 24 Discovery News article, space correspondent Irene Klotz detailed research based on the microlensing of nomad planets and the estimate that there may be as many as 100,000 of these interstellar orphans per star in our galaxy.

Perets' research is based on the assumption that there is only one nomad planet per star in a simulated young star cluster.

From this low estimate, Perets and collaborator Thijs Kouwenhoven (Peking University) found that 3-6 percent of the stars in their simulated cluster captured a nomad planet at some point in time. Naturally, the bigger the star, the greater its gravity, and therefore the bigger the chance a nomad planet may be snatched.

Although it may sound as if Perets and Kouwenhoven are being overly conservative with their estimate of nomad planets (especially in light of the 100,000 planets per star estimate), they deliberately focused on a young cluster of stars, which, by their nature, would be closely packed. Also, there would be fewer nomad worlds in these early years. As clusters of stars grow older, they spread out, greatly reducing the density of stars. It's for this reason that most of the "planet snatching" would happen in the very early history of star cluster evolution -- despite there being fewer nomad worlds.

During the cluster's formative years, gravitational interactions between the stars and the inevitable dynamical chaos within young star systems would cause planets to be slingshotted from their stable orbits. Then, as they travel through interstellar space, having been evicted from their orbital homes, neighboring stars traveling in the same direction may pull the nomads into new orbits.

Read more at Discovery News

Yellowstone 'Super-Eruption' Less Super, More Frequent Than Thought

The Yellowstone "super-volcano" is a little less super -- but more active -- than previously thought.

Researchers at Washington State University and the Scottish Universities Environmental Research Centre say the biggest Yellowstone eruption, which created the 2 million year old Huckleberry Ridge deposit, was actually two different eruptions at least 6,000 years apart.

Their results paint a new picture of a more active volcano than previously thought and can help recalibrate the likelihood of another big eruption in the future. Before the researchers split the one eruption into two, it was the fourth largest known to science.

"The Yellowstone volcano's previous behavior is the best guide of what it will do in the future," says Ben Ellis, co-author and post-doctoral researcher at Washington State University's School of the Environment. "This research suggests explosive volcanism from Yellowstone is more frequent than previously thought."

The new ages for each Huckleberry Ridge eruption reduce the volume of the first event to 2,200 cubic kilometers, roughly 12 percent less than previously thought. A second eruption of 290 cubic kilometers took place more than 6,000 years later.

That first eruption still deserves to be called "super," as it is one of the largest known to have occurred on Earth and darkened the skies with ash from southern California to the Mississippi River. By comparison, the 1980 eruption of Mount St. Helens produced 1 cubic kilometer of ash. The larger blast of Oregon's Mount Mazama 6,850 years ago produced 116 cubic kilometers of ash.

The study, funded by the National Science Foundation and published in the June issue of the Quaternary Geochronology, used high-precision argon isotope dating to make the new calculations. The radioactive decay rate from potassium 40 to argon 40 serves as a "rock clock" for dating samples and has a precision of .2 percent. Darren Mark, co-author and a post-doctoral research fellow at the SUERC, recently helped fine tune the technique and improve it by 1.2 percent -- a small-sounding difference that can become huge across geologic time.

"Improved precision for greater temporal resolution is not just about adding another decimal place to a number, says Mark. "It's far more exciting. It's like getting a sharper lens on a camera. It allows us to see the world more clearly."

Read more at Science Daily

Highly Religious People Are Less Motivated by Compassion Than Are Non-Believers

"Love thy neighbor" is preached from many a pulpit. But new research from the University of California, Berkeley, suggests that the highly religious are less motivated by compassion when helping a stranger than are atheists, agnostics and less religious people.

In three experiments, social scientists found that compassion consistently drove less religious people to be more generous. For highly religious people, however, compassion was largely unrelated to how generous they were, according to the findings which are published in the most recent online issue of the journal Social Psychological and Personality Science.

The results challenge a widespread assumption that acts of generosity and charity are largely driven by feelings of empathy and compassion, researchers said. In the study, the link between compassion and generosity was found to be stronger for those who identified as being non-religious or less religious.

"Overall, we find that for less religious people, the strength of their emotional connection to another person is critical to whether they will help that person or not," said UC Berkeley social psychologist Robb Willer, a co-author of the study. "The more religious, on the other hand, may ground their generosity less in emotion, and more in other factors such as doctrine, a communal identity, or reputational concerns."

Compassion is defined in the study as an emotion felt when people see the suffering of others which then motivates them to help, often at a personal risk or cost.

While the study examined the link between religion, compassion and generosity, it did not directly examine the reasons for why highly religious people are less compelled by compassion to help others. However, researchers hypothesize that deeply religious people may be more strongly guided by a sense of moral obligation than their more non-religious counterparts.

"We hypothesized that religion would change how compassion impacts generous behavior," said study lead author Laura Saslow, who conducted the research as a doctoral student at UC Berkeley.

Saslow, who is now a postdoctoral scholar at UC San Francisco, said she was inspired to examine this question after an altruistic, nonreligious friend lamented that he had only donated to earthquake recovery efforts in Haiti after watching an emotionally stirring video of a woman being saved from the rubble, not because of a logical understanding that help was needed.

"I was interested to find that this experience -- an atheist being strongly influenced by his emotions to show generosity to strangers -- was replicated in three large, systematic studies," Saslow said.

In the first experiment, researchers analyzed data from a 2004 national survey of more than 1,300 American adults. Those who agreed with such statements as "When I see someone being taken advantage of, I feel kind of protective towards them" were also more inclined to show generosity in random acts of kindness, such as loaning out belongings and offering a seat on a crowded bus or train, researchers found.

When they looked into how much compassion motivated participants to be charitable in such ways as giving money or food to a homeless person, non-believers and those who rated low in religiosity came out ahead: "These findings indicate that although compassion is associated with pro-sociality among both less religious and more religious individuals, this relationship is particularly robust for less religious individuals," the study found.

In the second experiment, 101 American adults watched one of two brief videos, a neutral video or a heartrending one, which showed portraits of children afflicted by poverty. Next, they were each given 10 "lab dollars" and directed to give any amount of that money to a stranger. The least religious participants appeared to be motivated by the emotionally charged video to give more of their money to a stranger.

"The compassion-inducing video had a big effect on their generosity," Willer said. "But it did not significantly change the generosity of more religious participants."

In the final experiment, more than 200 college students were asked to report how compassionate they felt at that moment. They then played "economic trust games" in which they were given money to share -- or not -- with a stranger. In one round, they were told that another person playing the game had given a portion of their money to them, and that they were free to reward them by giving back some of the money, which had since doubled in amount.

Those who scored low on the religiosity scale, and high on momentary compassion, were more inclined to share their winnings with strangers than other participants in the study.

"Overall, this research suggests that although less religious people tend to be less trusted in the U.S., when feeling compassionate, they may actually be more inclined to help their fellow citizens than more religious people," Willer said.

Read more at Science Daily

Why Bigger Animals Aren't Always Faster

New research in the journal Physiological and Biochemical Zoology shows why bigger isn't always better when it comes to sprinting speed.

"Typically, bigger animals tend to run faster than smaller animals, because they have longer legs," said Christofer J. Clemente of Harvard University, who led the research. "But this only works up to a point. The fastest land animal is neither the biggest nor the smallest, but something in between. Think about the size of an elephant, a mouse and a cheetah."

Clemente and his team studied monitor lizards to show that that the same principle applies within species as well as across species, and to identify why this is the case. Because adult monitor lizards vary substantially in size, they are an ideal species for testing how size affects speed. The researchers timed and photographed monitors ranging from two to 12 pounds, as sprinted across a 45-foot track.

The researchers found that the midsize lizards were fastest-and they discovered why.

Using high-speed cameras and markers placed at key spots on the lizards' bodies, the researchers created computer models comparing characteristics of the lizards' running strides.

"We then looked at how the mechanics of the stride changed with body size, and we found that the changes in the stride were consistent with the changes in speed," Clemente said. "Above a certain size, lizards were changing the way they ran, perhaps due to a decreased ability of the bones and muscles to support a larger body mass."

Testing this phenomenon within a single species helps clear up questions about why the biggest animals aren't the fastest. Large animals tend to be closely related evolutionarily. So it's hard to tell whether slower speeds are due to biomechanical issues stemming from size, or from any number of other factors stemming from a shared evolutionary history.

Looking at individuals within a species rather than making cross-species comparisons helps to eliminate this phylogenetic bias. The results bolster the hypothesis that large size creates biomechanical constraints.

Read more at Science Daily

Dirty Books Reveal Medieval Reading Habits

Dirty pages of century old books have revealed the fears, desires and humanity of medieval Europeans, suggesting that they were as self-interested and afraid of illness as people are today.

Kathryn Rudy, lecturer in the School of Art History at the University of St Andrews, analyzed a number of 15th and early 16th century European prayer books to reconstruct the reading habits of people who lived in medieval times.

The book turned out to be a kind of forensic analysis of what interested people of the time. She soon realized that the darkness of thumbed pages correlated to the intensity of their use and handling. The dirtiest pages were most likely also the most read, while relatively clean pages were probably neglected.

Using a densitometer, a machine that measures the darkness of a reflecting surface, Rudy was able to intepret how a reader handled a book, which sections were the most popular and which were ignored.

"Although it is often difficult to study the habits, private rituals and emotional states of people, this new technique can let us into the minds of people from the past," Rudy said.

The densitometer spiked at a manuscript dedicated to St. Sebastian, who was often prayed to for protection against the plague.

According to Rudy, the result shows that the reader was terrified of the plague and repeated the prayer in a bid to ward off the disease.

Similarly, pages which contained prayers for personal salvation were much more soiled and worn than those asking for other people's redemption.

"Religion was inseparable from physical health, time management, and interpersonal relationships in medieval times. In the century before printing, people ordered tens of thousands of prayer books -- sometimes quite beautifully illuminated ones -- even though they might cost as much as a house," Rudy said.

Treasured and read several times a day at key prayer times, those religious book appear to have produced some "side effects" -- they put the reader to sleep.

Read more at Discovery News

Hubble Images Searchlight Beams from a Preplanetary Nebula

The NASA/ESA Hubble Space Telescope has been at the cutting edge of research into what happens to stars like our sun at the ends of their lives. One stage that stars pass through as they run out of nuclear fuel is called the preplanetary or protoplanetary nebula stage. A new Hubble image of the Egg Nebula shows one of the best views to date of this brief but dramatic phase in a star's life.

The preplanetary nebula phase is a short period in the cycle of stellar evolution, and has nothing to do with planets. Over a few thousand years, the hot remains of the aging star in the center of the nebula heat it up, excite the gas, and make it glow as a subsequent planetary nebula. The short lifespan of preplanetary nebulae means there are relatively few of them in existence at any one time. Moreover, they are very dim, requiring powerful telescopes to be seen. This combination of rarity and faintness means they were only discovered comparatively recently. The Egg Nebula, the first to be discovered, was first spotted less than 40 years ago, and many aspects of this class of object remain shrouded in mystery.

At the center of this image, and hidden in a thick cloud of dust, is the nebula's central star. While we can't see the star directly, four searchlight beams of light coming from it shine out through the nebula. It is thought that ring-shaped holes in the thick cocoon of dust, carved by jets coming from the star, let the beams of light emerge through the otherwise opaque cloud. The precise mechanism by which stellar jets produce these holes is not known for certain, but one possible explanation is that a binary star system, rather than a single star, exists at the center of the nebula.

The onion-like layered structure of the more diffuse cloud surrounding the central cocoon is caused by periodic bursts of material being ejected from the dying star. The bursts typically occur every few hundred years.

Read more at Science Daily

DNA Fingerprinting Enters 21st Century

As any crime show buff can tell you, DNA evidence identifies a victim's remains, fingers the guilty, and sets the innocent free. But in reality, the processing of forensic DNA evidence takes much longer than a 60-minute primetime slot.

To create a victim or perpetrator's DNA profile, the U.S. Federal Bureau of Investigation (FBI) scans a DNA sample for at least 13 short tandem repeats (STRs). STRs are collections of repeated two to six nucleotide-long sequences, such as CTGCTGCTG, which are scattered around the genome. Because the number of repeats in STRs can mutate quickly, each person's set of these genetic markers is different from every other person's, making STRs ideal for creating a unique DNA fingerprint.

The FBI first introduced their STR identification system in 1998, when STRs were the darling of the genetics community. However, other identifying genomic markers were soon discovered and gained in popularity. Around the same time, high throughput sequencing allowed researchers to process vast amounts of DNA, but using methods that were ineffectual in repeated DNA, including STRs. STRs were mostly forgotten by geneticists, and innovations to study them stalled.

Now Whitehead Institute researchers have pulled STR identification into the 21st Century by creating lobSTR, a three-step system that accurately and simultaneously profiles more than100,000 STRs from a human genome sequence in one day -- a feat that previous systems could never complete. The lobSTR algorithm is described in the May issue of Genome Research.

"lobSTR found that in one human genome, 55% of the STRs are polymorphic, they showed some difference, which is very surprising," says Whitehead Fellow Yaniv Erlich. "Usually DNA's polymorphism rate is very low because most DNA is identical between two people. With this tool, we provide access to tens of thousands of quickly changing markers that you couldn't get before, and those can be used in medical genetics, population genetics, and forensics."

To create a DNA fingerprint, lobSTR first scans an entire genome to identify all STRs and what nucleotide pattern is repeated within those stretches of DNA. Then, lobSTR notes the non-repeating sequences flanking either end of the STRs. These sequences anchor each STR's location within the genome and determine the number of repeats at the STRs. Finally, lobSTR removes any "noise" to produce an accurate description of the STRs' configuration.

According to Melissa Gymrek, who is the first author of the Genome Research paper, lobSTR's ability to accurately and efficiently describe thousands of STRs in one genome has opened up many new research opportunities.

Read more at Science Daily

Newest Wildlife Tracking Tool: Leeches?

Leeches may be a wildlife biologist's new best friend when in the field.

A team of Danish and British researchers has found that DNA (deoxyribonucleic acid, the genetic code for life) in the blood consumed by leeches can be used to confirm the presence of mammals, particularly shy, hard-to-find or rare ones.

This provides a cheap, simple alternative to traditional tracking tools, from sensor-equipped cameras to hair and feces collection. And, unlike the elusive mammals researchers are often seeking, the leeches come to humans in the hopes of a good meal.

First, researchers tested 20 medical leeches that had eaten goat blood from the Copenhagen Zoo. The leeches contained traces of goat DNA for more than four months after their blood meal, they found. That genetic signature would allow researchers to identify the mammals a leech had come into contact with.

Next, they tested the technique in the field, by catching leeches in a Vietnamese rain forest. Of 25 leeches tested, 21 contained traces of DNA from local mammals, including an Annamite striped rabbit, which has not been seen in the area since its discovery in 1996.

Read more at Discovery News

Older People Hold Stronger Belief in God

Across the world, people have varying levels of belief (and disbelief) in God, with some nations being more devout than others. But new research reveals one constant across parts of the globe: As people age, their belief in God seems to increase.

The new study is based on data collected as part of the General Social Survey by researchers at the National Opinion Research Center (NORC) at the University of Chicago.

The researchers looked at data from 30 countries where surveys, taken at two or more time points between 1991 and 2008, asked residents about their belief in God. Participants answered three main "belief" questions, including their level of belief (from strong to atheistic), their changing beliefs over their lifetime and their attitude toward the notion that God is concerned with their personal lives.

Age seemed to be a big factor in belief. Belief in God was highest among older adults, with 43 percent of those 68 and older saying they are certain that God exists, compared with 23 percent of those 27 and younger, averaged across the countries surveyed.

"Looking at differences among age groups, the largest increases in belief in God most often occur among those 58 years of age and older," Smith said in a statement, referring to the change in belief between the 58 to 67 age group and those 68 and older. "This suggests that belief in God is especially likely to increase among the oldest groups, perhaps in response to the increasing anticipation of mortality."

Atheism ranged from 52 percent in the former East Germany to less than 1 percent in the Philippines; a largely opposite pattern was found for strong belief in God, with 84 percent of Philippine residents indicating such and 8 percent of those in East Germany saying they were certain God existed. The lowest "strong belief" in God came from Japan, where the level was 4 percent.

Overall, countries dominated by Catholic societies, like the Philippines, showed the strongest belief in God. The United States stood out for its high belief in God among developed countries. At the other end of the religion spectrum, atheism seemed to have the strongest hold in northwest European countries such as Scandinavia and those of the former Eastern Bloc, excluding Poland.

Support for the concept that God is concerned with people in a personal way ranged from 8 percent in the former East Germany to 82 percent in the Philippines. About 68 percent of individuals in the United States held that personal view of God.

Over the study period, just five of the countries showed a consistent growth in their belief in God: West Germany, Israel, Japan, Russia and Slovenia. Meanwhile, 16 countries showed a consistent decline in belief: Australia, Austria, East Germany, Great Britain, Ireland, the Netherlands, New Zealand, Northern Ireland, Norway and Poland. Some countries showed a mixed pattern, with some measures moving toward belief and others away.

Read more at Discovery News