Tag: lead author (page 1 of 4)

Your Smartphone Usage is Linked to Your Level of Depression

July 16, 2015 / / 0 Comments

April McCarthy, Prevent DiseaseYou can fake a smile, but your phone knows the truth. Depression can be detected from your smartphone sensor data by tracking the number of minutes you use the phone and your daily geographical locations, reports a Northwestern Medicine study.More and more smartphones are able to see what many of us cannot.The ongoing use of this communications technology, as compared to computer-based use such as email, is linked to increased psychological di [...]

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Rats try to rescue others in distress, suggesting they feel empathy

May 13, 2015 / / 0 Comments


Rats were even more likely to choose helping over getting a treat

Excerpt from cbc.ca

Calling someone a rat isn't a compliment about their character – but a new study suggests that maybe it should be.

Rats that see another rat struggling in a pool of water will open a door to rescue it, even if they could open a different door to get a chocolate treat instead.

Rats that knew what it was like to be wet and struggling in the pool were even quicker to help.
"Our findings suggest that rats can behave prosocially and that helper rats may be motivated by empathy-like feelings towards their distressed cage mate," Nobuya Sato, lead author of a study, said in a statement.

The study was published this week in the journal Animal Cognition.

Sato and his team at Kwansei Gakuin University in Japan designed experiments involving pairs of rat cage mates, either two males or two females.


'Helper rats may be motivated by empathy-like feelings,' suggests Nobuya Sato, a Kwansei Gakuin University in Japan research and lead author of a study released this week. (Andre Penner/Associated Press)


The two were placed in separate compartments separated by a transparent wall and door – one compartment that was dry and empty, and one filled with a deep pool of water and sheer walls that made it impossible to climb out. The door could be opened by the rat on the dry side, allowing the other rat to climb out of the pool.

Motivated by helping

Rats on the dry side of the cage were quick to open the door if they saw their cage mates struggling in the water, but not if the pool was empty or contained a stuffed toy rat. If no water was in either compartment, they also didn't open the door. That suggested that they were motivated by helping and not just opening the door for fun.

The researchers reversed the roles and found that rats were quicker to learn to open the door and rescue their cage mate if they had previously experienced a similar struggle in the pool.
"This modulation of learning by prior experience suggests that the helping behaviour observed in the present study might be based on empathy," they wrote.

In another experiment, rats in the dry compartment could choose between two different doors.
  • One that allowed them to rescue their cage mate from the pool.
  • Another that provided access to a chocolate cereal treat. 
More than half the time, rats chose to rescue the other rat first – especially if they were trained to open the door in a similar rescue scenario rather than being trained to open the door in order to access a food treat.

"These results suggest that for all rats, helping a distressed cage mate has a higher value than obtaining a food reward," the researchers wrote.

The results are similar to those in a previous experiment by different researchers, in which rats rescued other rats trapped in an acrylic tube. Still, there has some debate about whether this type of helping behaviour exists among animals other than primates such as monkeys and humans.

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Astronomers Giddy Over What They Call A Cosmic ‘Dinosaur Egg’ About To Hatch

May 9, 2015 / / 0 Comments



cosmic dinosaur egg
The Antennae galaxies, shown in visible light in a Hubble image (upper image), were studied with ALMA, revealing extensive clouds of molecular gas (center right image). One cloud (bottom image) is incredibly dense and massive, yet apparently star free, suggesting it is the first example of a prenatal globular cluster ever identified.


Excerpt from huffingtonpost.com

A dense cloud of gas 50 million light-years away has astronomers buzzing, and they're using all sorts of strange metaphors to get the rest of us to pay attention.

They've discovered what they think may be a globular cluster -- a big ball of up to one million stars -- on the verge of being born.

“This remarkable object looks like it was plucked straight out of the very early universe," Dr. Kelsey Johnson, an astronomer at the University of Virginia in Charlottesville and lead author on a paper about the research, said in a written statement. "To discover something that has all the characteristics of a globular cluster, yet has not begun making stars, is like finding a dinosaur egg that’s about to hatch.”

cosmic egg
ALMA image of dense cores of molecular gas in the Antennae galaxies. The round yellow object near the center may be the first prenatal example of a globular cluster ever identified. It is surrounded by a giant molecular cloud.


Johnson and her colleagues spotted the bizarre object, which they call the "Firecracker," using the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama desert in Chile. It's located inside a pair of interacting galaxies known to scientists as NGC 4038/NGC 4039, or The Antennae Galaxies.

The Firecracker has a mass that's 50 times that of our sun, and is under an enormous amount of pressure -- roughly 10,000 times greater than the average pressure in interstellar space. According to the researchers, this makes it a good candidate for collapsing into a globular cluster within the next million years.

What do other scientists make of the discovery? Dr. Alison Peck, ALMA scientist at the National Radio Astronomy Observatory, who was not involved in the new research, called it "important" and said she was "really excited to hear about these results."
She told The Huffington Post in an email:
"One of the things that we all yearn to understand is how our surroundings formed, how our galaxy and our solar system came to be. To do this, since we can’t actually watch things change over time, (it just takes too long), we need to find similar objects at different stages of development and compare them. What Dr. Johnson’s team have found here is an analog of an object that we look for in the very early universe, but they’ve found it so close by that we’ll be able to make extremely detailed observations and find out much more about the physical conditions in this exciting region."
The research is set to be published in the Astrophysical Journal. 

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Mercury’s Mysterious Magnetic Past Goes Back 4 Billion Years

May 9, 2015 / / 0 Comments

 Excerpt from sci-tech-today.com Examining rocks on Mercury's surface, scientists using data from NASA's Messenger spacecraft have revealed that the planet probably had a much stronger magnetic field nearly 4 billion years ago.  The fi...

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See Saturn moon’s ‘soda ocean’ shooting to surface in sheets

May 7, 2015 / / 0 Comments

 Excerpt from  cnet.comEnceladus may have a warm ocean beneath its icy surface, but it may also be shooting through that crust in big sheets, perhaps filled with sea monkeys.       We already know that Saturn's ...

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A super-hot super-Earth spotted 40 light-years away

May 5, 2015 / / 0 Comments

An artist's depiction of the exoplanet 55 Cancri E with its molten surface exposed on the left, and covered in gas and ash on the right. (NASA/JPL - Caltech/R.Hurt)Excerpt from latimes.comScientists have found an extreme planet where the atmospheric ...

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Our sun is five billion years younger than most other stars in our galaxy

April 9, 2015 / / 0 Comments






Excerpt from stgist.com



The sun, or the nearest star from Earth, was formed around 5 billion years after the Milky Way galaxy’s peak production of stars, a new research published in the Astrophysical Journal. 

Using multiple ground based, and space telescopes, including the Magellan Telescopes located at Las Campanas Observatory in South America, a new study was able to confirm that the closest star from us, the Sun, was formed after the so-called stellar “baby boom” of the Milky Way galaxy.

It’s like traveling back in time. Researchers from Texas A&M University in College Station, headed by astronomer Casey Papovich, were able to see the undepicted past of our own galaxy by observing similar regions located billions of light years away from us.

The “baby boom” happened around 10 billion years ago, the new study published in Astrophysical Journal revealed. At that time, the Milky Way galaxy was producing 30 times more stars than today. If so, then our solar system’s 4.6 billion years old Sun was formed more than 5 billion years after the production peak.

Sun’s late formation allowed the solar system we know today to produce planets with heavier elements. Scientists say elements heavier than hydrogen and helium became more abundant in “late to the game systems”, and the death of massive stars that were formed before the Sun had provided materials needed to form planets, including Earth and its complex life forms.

Scientists scanned through a collection of more than 24,000 galaxies, and took at least 2,000 snapshots of galaxies that closely resemble our own. The census has provided the most complete picture yet of how spiral galaxies similar to Milky Way form in the universe.

According to Mr. Papovich, the lead author of the study who also serves as an associate professor in the Department of Physics and Astronomy at A&M University in Texas, they know where to find traces by analyzing how galaxies like our own were formed.

Papovich said his team has provided a data that clearly show the rapid phase of growth around 9 to 10 billion years ago, or at least more than 5 billion years after our Sun formed. They also found the connection between the size of the galaxy, and the formation of stars.

Surprisingly, the robust collection of distant galaxies confirmed that stars formed inside the Milky Way, instead of forming in other smaller baby galaxies that later merged to join the system.

In separate studies, scientists were able to confirm that our own solar system is wetter than thought. Beyond Earth, celestial objects like Jupiter’s Galilean moons Europa and Ganymede, Saturn’s Enceladus, and even the dwarf planet Ceres in the asteroid belt, are hosting fluid slightly similar to Earth’s — and it is highly possible that the Sun’s late formation allowed this setup to exist.

Papovich who worked alongside Texas A&M postdoctoral researchers Vithal Tilvi and Ryan Quadri, were joined by at least two dozen astronomers from other countries. The research is published April 9th entitled “ZFOURGE/CANDELS: ON THE EVOLUTION OF M* GALAXY PROGENITORS FROM z = 3 TO 0.5*.” The research was funded by NASA

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Did natural selection make the Dutch the tallest people on the planet?

April 9, 2015 / / 0 Comments

Dutch national women's field hockey team



Excerpt from news.sciencemag.org
ByMartin Enserink

AMSTERDAM—Insecure about your height? You may want to avoid this tiny country by the North Sea, whose population has gained an impressive 20 centimeters in the past 150 years and is now officially the tallest on the planet. Scientists chalk up most of that increase to rising wealth, a rich diet, and good health care, but a new study suggests something else is going on as well: The Dutch growth spurt may be an example of human evolution in action.
The study, published online today in the Proceedings of the Royal Society B, shows that tall Dutch men on average have more children than their shorter counterparts, and that more of their children survive. That suggests genes that help make people tall are becoming more frequent among the Dutch, says behavioral biologist and lead author Gert Stulp of the London School of Hygiene & Tropical Medicine.

"This study drives home the message that the human population is still subject to natural selection," says Stephen Stearns, an evolutionary biologist at Yale University who wasn't involved in the study. "It strikes at the core of our understanding of human nature, and how malleable it is." It also confirms what Stearns knows from personal experience about the population in the northern Netherlands, where the study took place: "Boy, they are tall."

For many years, the U.S. population was the tallest in the world. In the 18th century, American men were 5 to 8 centimeters taller than those in the Netherlands. Today, Americans are the fattest, but they lost the race for height to northern Europeans—including Danes, Norwegians, Swedes, and Estonians—sometime in the 20th century.

Just how these peoples became so tall isn't clear, however. Genetics has an important effect on body height: Scientists have found at least 180 genes that influence how tall you become. Each one has only a small effect, but together, they may explain up to 80% of the variation in height within a population. Yet environmental factors play a huge role as well. The children of Japanese immigrants to Hawaii, for instance, grew much taller than their parents. Scientists assume that a diet rich in milk and meat played a major role.

The Dutch have become so much taller in such a short period that scientists chalk most of it up to their changing environment. As the Netherlands developed, it became one of the world's largest producers and consumers of cheese and milk. An increasingly egalitarian distribution of wealth and universal access to health care may also have helped.

Still, scientists wonder whether natural selection has played a role as well. For men, being tall is associated with better health, attractiveness to the opposite sex, a better education, and higher income—all of which could lead to more reproductive success, Stulp says.
Yet studies in the United States don't show this. Stulp's own research among Wisconsinites born between 1937 and 1940, for instance, showed that average-sized men had more children than shorter and taller men, and shorter women had more children than those of average height. Taken together, Stulp says, this suggests natural selection in the United States pulls in the opposite direction of environmental factors like diet, making people shorter instead of taller. That may explain why the growth in average American height has leveled off.

Stulp—who says his towering 2-meter frame did not influence his research interest—wondered if the same was true in his native country. To find out, he and his colleagues turned to a database tracking key life data for almost 100,000 people in the country's three northern provinces. The researchers included only people over 45 who were born in the Netherlands to Dutch-born parents. This way, they had a relatively accurate number of total children per subject (most people stop having children after 45) and they also avoided the effects of immigration.

In the remaining sample of 42,616 people, taller men had more children on average, despite the fact that they had their first child at a higher age. The effect was small—an extra 0.24 children at most for taller men—but highly significant. (Taller men also had a smaller chance of remaining childless, and a higher chance of having a partner.)  The same effect wasn't seen in women, who had the highest reproductive success when they were of average height.  The study suggests this may be because taller women had a smaller chance of finding a mate, while shorter women were at higher risk of losing a child.

Because tall men are likely to pass on the genes that made them tall, the outcome suggests that—in contrast to Americans—the Dutch population is evolving to become taller, Stulp says. "This is not what we've seen in other studies—that's what makes it exciting," says evolutionary biologist Simon Verhulst of the University of Groningen in the Netherlands, who was Stulp's Ph.D. adviser but wasn't involved in the current study. Verhulst points out that the team can't be certain that genes involved in height are actually becoming more frequent, however, as the authors acknowledge.

The study suggests that sexual selection is at work in the Dutch population, Stearns says: Dutch women may prefer taller men because they expect them to have more resources to invest in their children. But there are also other possibilities. It could be that taller men are more resistant to disease, Stearns says, or that they are more likely to divorce and start a second family. "It will be a difficult question to answer.”

Another question is why tall men in Holland are at a reproductive advantage but those in the United States are not. Stulp says he can only speculate. One reason may be that humans often choose a partner who's not much shorter or taller than they are themselves. Because shorter women in the United States have more children, tall men may do worse than those of average height because they're less likely to partner with a short woman.

In the end, Stearns says, the advantage of tall Dutchmen may be only temporary. Often in evolution, natural selection will favor one trend for a number of generations, followed by a stabilization or even a return to the opposite trend. In the United States, selection for height appears to have occurred several centuries ago, leading to taller men, and then it stopped. "Perhaps the Dutch caught up and actually overshot the American men," he says.

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Huge Alien Planet Bathes in the Light of Four Suns

April 5, 2015 / / 0 Comments



30 Ari with its newly discovered companion stars
Karen Teramura

Excerpt from nbcnews.com


Astronomers have spotted a fourth star in a planetary system called 30 Ari, bringing the number of known planet-harboring quadruple-sun systems to two. 

"Star systems come in myriad forms. There can be single stars, binary stars, triple stars, even quintuple star systems," study lead author Lewis Roberts, of NASA's Jet Propulsion Laboratory, said in a statement. "It's amazing the way nature puts these things together." 

30 Ari lies 136 light-years from the sun in the constellation Aries. Astronomers discovered a giant planet in the system in 2009; the world is about 10 times more massive than Jupiter and orbits its primary star every 335 days. There's also a pair of stars that lie approximately 1,670 astronomical units away. (One AU is the distance between Earth and the sun — about 93 million miles, or 150 million kilometers).

The newfound star circles its companion once every 80 years, at a distance of just 22 AU, but it does not appear to affect the exoplanet's orbit despite such proximity. This is a surprising result that will require further observations to understand, researchers said. 

To a hypothetical observer cruising through the giant planet's atmosphere, the sky would appear to host one small sun and two bright stars visible in daylight. With a large enough telescope, one of the bright stars could be resolved into a binary pair. 

The discovery marks just the second time a planet has been identified in a four-star system. The first four-star planet, PH1b or Kepler-64b, was spotted in 2012 by citizen scientists using publicly available data from NASA's Kepler mission. 

Planets with multiple suns have become less of a novelty in recent years, as astronomers have found a number of real worlds that resemble Tatooine, Luke Skywalker's home planet in the Star Wars films. 

The research was published online this month in the Astronomical Journal.

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Discovered: A ‘Treasure Chest’ of Ancient Galaxies

March 31, 2015 / / 0 Comments


full sky planck
The full visible sky as seen by the Planck space observatory. The band running through the middle corresponds to dust in our Milky Way galaxy. The black dots indicate the location of the proto-cluster candidates identified by Planck and subsequently observed by the Herschel space telescope. (Photo : ESA and the Planck Collaboration)


Excerpt from natureworldnews.com

Treasure seekers have found the haul of a lifetime, but it wasn't in some ancient temple or mysterious island. Instead, it was in the sky. Researcher using two of the European Space Agency's (ESA) impressive space telescopes have successfully identified what they are calling a "treasure chest" of ancient galaxy clusters, which could help explain how the Universe came to be the way it is today.

That's at least according to a study recently published (PDF) in the journal Astronomy and Astrophysics, which details how cosmologists used the ESA's Planck space observatory to identify the distant precursor galaxy clusters, and then poured over data from the Herschel telescope for a closer look.

"Finding so many intensely star-forming, dust galaxies in such concentrated groups was a huge surprise," Hervé Dole, lead author of the report from the Institut d'Astrophysique Spatiale in France, said in a statement. "We think this is a missing piece of cosmological structure formation."

So what does he mean by that? Let's turn back to the treasure chest metaphor for this one.  While Planck was the space observatory to dig up the chest, it was the Herschel data that allowed experts to look closely at each and every gold coin (galaxy cluster) inside. Now they are able to learn more about each coin's make, mint, and ultimately, its origins.

And that's a big step in better understanding the early Universe. Expects believe that it took a great deal of time after star and galaxies first sprung to life for them to assemble into large clusters. 

A summary of the 14 billion years out Universe has been in existence, as seen by the Plank space telescop. Light coming from some of the oldest parts of the Universe are just reaching the observatory now, allowing for experts to see the incredible uniformity of the early structure, compared to the chaotic beautify of star, galaxy, and cluster formation that crowd space today.
(Photo : ESA – C. Carreau) A summary of the 14 billion years out Universe has been in existence, as seen by the Plank space telescope. Light coming from some of the oldest parts of the Universe are just reaching the observatory now, allowing for experts to see the incredible uniformity of the early matter, compared to the chaotic beautify of star, galaxy, and cluster formation that crowds space today.
Once the clusters formed, their gravitational influence triggered the creation of new stars and galaxies. Dark matter - which is theorized to account for a great deal of each cluster's mass and influence - helped usher along the process of creating stars. But how these large clusters were ultimately assembled and grew is still a mystery.
That's why looking at some of the oldest 'coins' ever made - estimated to date back to up-to 11 billion light-years ago - could be exceptionally helpful.

"We still have a lot to learn about this new population," Dole said in an ESA release. "Hints of these kinds of objects had been found earlier in data from Herschel and other telescopes, but the all-sky capability of Planck revealed many more candidates for us to study."

"Even when we combined the powerful capabilities of Planck and Herschel, we were only scratching the surface of the phenomena taking place at this critical era in the history of our universe, when stars, galaxies and clusters seem to be forming simultaneously," 
added George Helou, director of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. "That's one of the reasons this finding is exciting. It shows us that there is so much more to be learned.

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Biologists fear DNA editing procedure can alter human DNA

March 20, 2015 / / 0 Comments




Excerpt from themarketbusiness.com

A group of biologists was alarmed with the use a new genome-editing technique to modify human DNA in a way that it can become hereditary.
The biologists worry that the new technique is so effective and easy to use that some physicians may push ahead with it before its safety can be weigh up. They also want the public to understand the ethical issues surrounding the technique, which could be used to cure genetic diseases, but also to enhance qualities like beauty or intelligence. The latter is a path that many ethicists believe should never be taken.

“You could exert control over human heredity with this technique, and that is why we are raising the issue,” said David Baltimore, a former president of the California Institute of Technology and a member of the group whose paper on the topic was published in the journal Science.

Ethicists have been concerned for decades about the dangers of altering the human germ line — meaning to make changes to human sperm, eggs or embryos that will last through the life of the individual and be passed on to future generations. Until now, these worries have been theoretical. But a technique invented in 2012 makes it possible to edit the genome precisely and with much greater ease. The technique has already been used to edit the genomes of mice, rats and monkeys, and few doubt that it would work the same way in people.

The new genome-editing technique holds the power to repair or enhance any human gene. “It raises the most fundamental of issues about how we are going to view our humanity in the future and whether we are going to take the dramatic step of modifying our own germline and in a sense take control of our genetic destiny, which raises enormous peril for humanity,” said George Daley, a stem cell expert at Boston Children’s Hospital and a member of the group.

The biologists writing in Science support continuing laboratory research with the technique, and few if any scientists believe it is ready for clinical use. Any such use is tightly regulated in the United States and Europe. American scientists, for instance, would have to present a plan to treat genetic diseases in the human germline to the Food and Drug Administration.

The paper’s authors, however, are concerned about countries that have less regulation in science. They urge that “scientists should avoid even attempting, in lax jurisdictions, germ line genome modification for clinical application in humans” until the full implications “are discussed among scientific and governmental organizations.”

Though such a moratorium would not be legally enforceable and might seem unlikely to exert global sway, there is a precedent. In 1975, scientists worldwide were asked to refrain from using a method for manipulating genes, the recombinant DNA technique, until rules had been established.

“We asked at that time that nobody do certain experiments, and in fact nobody did, to my knowledge,” said Baltimore, who was a member of the 1975 group. “So there is a moral authority you can assert from the U.S., and that is what we hope to do.”

Recombinant DNA was the first in a series of ever-improving steps for manipulating genetic material. The chief problem has always been one of accuracy, of editing the DNA at precisely the intended site, since any off-target change could be lethal. Two recent methods, known as zinc fingers and TAL effectors, came close to the goal of accurate genome editing, but both are hard to use. The new genome-editing approach was invented by Jennifer Doudna of the University of California, Berkeley, and Emmanuelle Charpentier of Umea University in Sweden.

Their method, known by the acronym Crispr-Cas9, co-opts the natural immune system with which bacteria remember the DNA of the viruses that attack them so they are ready the next time those same invaders appear. Researchers can simply prime the defense system with a guide sequence of their choice and it will then destroy the matching DNA sequence in any genome presented to it. Doudna is the lead author of the Science article calling for control of the technique and organized the meeting at which the statement was developed.

Though highly efficient, the technique occasionally cuts the genome at unintended sites. The issue of how much mistargeting could be tolerated in a clinical setting is one that Doudna’s group wants to see thoroughly explored before any human genome is edited.

Scientists also say that replacing a defective gene with a normal one may seem entirely harmless but perhaps would not be.
“We worry about people making changes without the knowledge of what those changes mean in terms of the overall genome,” Baltimore said. “I personally think we are just not smart enough — and won’t be for a very long time — to feel comfortable about the consequences of changing heredity, even in a single individual.”
Many ethicists have accepted the idea of gene therapy, changes that die with the patient, but draw a clear line at altering the germline, since these will extend to future generations. The British Parliament in February approved the transfer of mitochondria, small DNA-containing organelles, to human eggs whose own mitochondria are defective. But that technique is less far-reaching because no genes are edited.

There are two broad schools of thought on modifying the human germline, said R. Alta Charo, a bioethicist at the University of Wisconsin and a member of the Doudna group. One is pragmatic and seeks to balance benefit and risk. The other “sets up inherent limits on how much humankind should alter nature,” she said. 
Some Christian doctrines oppose the idea of playing God, whereas in Judaism and Islam there is the notion “that humankind is supposed to improve the world.” She described herself as more of a pragmatist, saying, “I would try to regulate such things rather than shut a new technology down at its beginning.”

Other scientists agree with the Doudna group’s message.
“It is very clear that people will try to do gene editing in humans,” said Rudolf Jaenisch, a stem cell biologist at the Whitehead Institute in Cambridge, Massachusetts, who was not a member of the Doudna group. “This paper calls for a moratorium on any clinical application, which I believe is the right thing to do.”
Writing in Nature last week, Edward Lanphier and other scientists involved in developing the rival zinc finger technique for genome editing also called for a moratorium on human germline modification, saying that use of current technologies would be “dangerous and ethically unacceptable.”

The International Society for Stem Cell Research said Thursday that it supported the proposed moratorium.

The Doudna group calls for public discussion but is also working to develop some more formal process, such as an international meeting convened by the National Academy of Sciences, to establish guidelines for human use of the genome-editing technique.

“We need some principled agreement that we want to enhance humans in this way or we don’t,” Jaenisch said. “You have to have this discussion because people are gearing up to do this.”

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The Moon’s History Is Surprisingly Complex, Chinese Rover Finds

March 16, 2015 / / 0 Comments




Excerpt from space.com


 The moon's past was livelier and more complex than scientists had thought, new results from China's first lunar rover suggest.

China's Yutu moon rover found evidence of at least nine distinct rock layers deep beneath its wheels, indicating that the area has been surprisingly geologically active over the past 3.3 billion years.
"Two things are most interesting," said Long Xiao, a researcher at the China University of Geosciences in Wuhan, who is the lead author of the study detailing the new findings. "One is [that] more volcanic events have been defined in the late volcanism history of the moon," Xiao told Space.com via email. 


"Another is the lunar mare [volcanic plain] area is not only composed of basaltic lavas, but also explosive eruption-formed pyroclastic rocks," Xiao added. "The latter finding may shed light on … the volatile contents in the lunar mantle." 


China's Yutu rover traveled about 374 feet (114 meters) on the moon in a zigzag fashion after touching down in December 2013



Yutu (whose name means "jade rabbit") is part of China's Chang'e 3 moon mission. Chang'e 3 delivered Yutu and a stationary lander to the lunar surface on Dec. 14, 2013 — the first soft touchdown on the moon since the Soviet Union's Luna 24 mission in 1976.
Yutu traveled 374 feet (114 meters) on the moon in a zigzag fashion before a glitch ended its travels in January 2014. 

The rover was equipped with cameras and three main scientific instruments — the Lunar Penetrating Radar (LPR), the Visible Near-Infrared Spectrometer (VNIS) and the Active Particle-Induced X-ray Spectrometer (APXS). The new study, which was published online today (March 12) in the journal Science, reports results from the camera and the LPR, which can probe about 1,300 feet (400 m) beneath the moon's surface.

Those data paint a detailed portrait of the Chang'e 3 landing site, which sits just 165 feet (50 m) away from a 1,475-foot-wide (450 m) crater known as C1. C1 was gouged out by a cosmic impact that occurred sometime between 80 million and 27 million years ago, the study authors said.

Yutu studied the ground it rolled over, characterized the craters it cruised past and investigated an oddly coarse-textured rock dubbed Loong, which measures about 13 feet long by 5 feet high (4 by 1.5 m). Overall, the rover's observations suggest that the composition of its landing site is quite different from that of the places visited by NASA's Apollo missions and the Soviet Union's Luna program.
While Yutu isn't beaming home any new data these days, the scientific community can expect to hear about more discoveries from the mission shortly, Xiao said.

"Unfortunately, Yutu encountered mechanical problems and has ended its mission," he told Space.com. "No more data will come. However, our report only provides the scientific results based on imagery and radar data. More results from NIS and APXS for composition study will come out soon."

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Scientists: Enceladus may have warm water ocean with ingredients for life

March 15, 2015 / / 0 Comments


Enceladus ocean
This artist's impression of the interior of Saturn's moon Enceladus shows that interactions between hot water and rock occur at the floor of the subsurface ocean -- the type of environment that might be friendly to life, scientists say. (NASA/JPL-Caltech)



Excerpt from latimes.com

Scientists say they’ve discovered evidence of a watery ocean with warm spots hiding beneath the surface of Saturn’s icy moon Enceladus. The findings, described in the journal Nature, are the first signs of hydrothermal activity on another world outside of Earth – and raise the chances that Enceladus has the potential to host microbial life.

Scientists have wondered about what lies within Enceladus at least since NASA’s Cassini spacecraft caught the moon spewing salty water vapor out from cracks in its frozen surface. Last year, a study of its gravitational field hinted at a 10-kilometer-thick regional ocean around the south pole lying under an ice crust some 30 to 40 kilometers deep.

Another hint also emerged about a decade ago, when Cassini discovered tiny dust particles escaping Saturn’s system that were nanometer-sized and rich in silicon.

“It’s a peculiar thing to find particles enriched with silicon,” said lead author Hsiang-Wen Hsu, a planetary scientist at the University of Colorado, Boulder. In Saturn’s moons and among its rings, water ice dominates, so these odd particles clearly stood out.

The scientists traced these particles’ origin to Saturn’s E-ring, which lies between the orbits of the moons Mimas and Titan and whose icy particles are known to come from Enceladus. So Hsu and colleagues studied the grains to understand what was going on inside the gas giant’s frigid satellite.   
Rather than coming in a range of sizes, these particles were all uniformly tiny – just a few nanometers across. Studying the spectra of these grains, the scientists found that they were made of silicon dioxide, or silica. That’s not common in space, but it’s easily found on Earth because it’s a product of water interacting with rock. 

Knowing how silica interacts in given conditions such as temperature, salinity and alkalinity, the scientists could work backward to determine what kind of environment creates these unusual particles.

A scientist could do the same thing with a cup of warm coffee, Hsu said.

“You put in the sugar and as the coffee gets cold, if you know the relation of the solubility of sugar as a function of temperature, you will know how hot your coffee was,” Hsu said. “And applying this to Enceladus’s ocean, we can derive a minimum [temperature] required to form these particles.”

The scientists then ran experiments in the lab to determine how such silica particles came to be. With the particles’ particular makeup and size distribution, they could only have formed under very specific circumstances, the study authors found, determining that the silica particles must have formed in water that had less than 4% salinity and that was slightly alkaline (with a pH of about 8.5 to 10.5) and at temperatures of at least 90 degrees Celsius (roughly 190 degrees Fahrenheit).

The heat was likely being generated in part by tidal forces as Saturn’s gravity kneads its icy moon. (The tidal forces are also probably what open the cracks in its surface that vent the water vapor into space.)
Somewhere inside the icy body, there was hydrothermal activity – salty warm water interacting with rocks. It’s the kind of environment that, on Earth, is very friendly to life.  

“It’s kind of obvious, the connection between hydrothermal interactions and finding life,” Hsu said. “These hydrothermal activities will provide the basic activities to sustain life: the water, the energy source and of course the nutrients that water can leach from the rocks.”

Enceladus, Hsu said, is now likely the “second-top object for astrobiology interest” – the first being Jupiter’s icy moon and fellow water-world, Europa.
This activity is in all likelihood going on right now, Hsu said – over time, these tiny grains should glom together into larger and larger particles, and because they haven’t yet, they must have been recently expelled from Enceladus, within the last few months or few years at most.

Gabriel Tobie of the University of Nantes in France, who was not involved in the research, compared the conditions that created these silica particles to a hydrothermal field in the Atlantic Ocean known as Lost City.

“Because it is relatively cold, Lost City has been posited as a potential analogue of hydrothermal systems in active icy moons. The current findings confirm this,” Tobie wrote in a commentary on the paper. “What is more, alkaline hydrothermal vents might have been the birthplace of the first living organisms on the early Earth, and so the discovery of similar environments on Enceladus opens fresh perspectives on the search for life elsewhere in the Solar System.”

However, Hsu pointed out, it’s not enough to have the right conditions for life – they have to have been around for long enough that life would have a fighting chance to emerge.

“The other factor that is also very important is the time.… For Enceladus, we don’t know how long this activity has been or how stable it is,” Hsu said. “And so that’s a big uncertainty here.”

One way to get at this question? Send another mission to Enceladus, Tobie said.

“Cassini will fly through the moon’s plume again later this year,” he wrote, “but only future missions that can undertake improved in situ investigations, and possibly even return samples to Earth, will be able to confirm Enceladus’ astrobiological potential and fully reveal the secrets of its hot springs. ”

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