Hubble Captures a Collection of Ancient Stars

The NASA/ESA Hubble Space Telescope has produced a beautiful image of the globular cluster Messier 56 (also known as M 56 or NGC 6779), which is located about 33,000 light years away from Earth in the constellation of Lyra (The Lyre). The cluster is composed of a large number of stars, tightly bound to each other by gravity.

However, this was not known when Charles Messier first observed it in January 1779. He described Messier 56 as "a nebula without stars," like most globular clusters that he discovered -- his telescope was not powerful enough to individually resolve any of the stars visible here, making it look like a fuzzy ball through his telescope's eyepiece. We clearly see from Hubble's image how the development of technology over the years has helped our understanding of astronomical objects.

Astronomers typically infer important properties of globular clusters by looking at the light of their constituent stars. But they have to be very careful when they observe objects like Messier 56, which is located close to the Galactic plane. This region is crowded by "field-stars," in other words, stars in the Milky Way that happen to lie in the same direction but do not belong to the cluster. These objects can contaminate the light, and hence undermine the conclusions reached by astronomers.

A tool often used by scientists for studying stellar clusters is the color-magnitude (or Hertzsprung-Russell) diagram. This chart compares the brightness and color of stars -- which in turn, tells scientists the surface temperature of a star.

By comparing high quality observations taken with the Hubble Space Telescope with results from the standard theory of stellar evolution, astronomers can characterize the properties of a cluster. In the case of Messier 56, this includes its age, which at 13 billion years is approximately three times the age of the Sun. Furthermore, they have also been able to study the chemical composition of Messier 56. The cluster has relatively few elements heavier than hydrogen and helium, typically a sign of stars that were born early in the Universe's history, before many of the elements in existence today were formed in significant quantities.

Astronomers have found that the majority of clusters with this type of chemical makeup lie along a plane in the Milky Way's halo. This suggests that such clusters were captured from a satellite galaxy, rather than being the oldest members of the Milky Way's globular cluster system as had been previously thought.

This image consists of visible and near-infrared exposures from Hubble's Advanced Camera for Surveys. The field of view is approximately 3.3 by 3.3 arcminutes.

Read more at Science Daily

Neil Armstrong, First Human to Walk on Moon, Dies at 82

Neil Armstrong has died at the age of 82.

As reported by the Associated Press, Armstrong died following “complications resulting from cardiovascular procedures,” according to a statement from his family.

Armstrong was the commander of Apollo 11. On July 20, 1969, together with fellow astronaut Buzz Aldrin, he landed the mission’s Lunar Module on the surface of the moon, and six hours later, he climbed down the ladder of the spacecraft, becoming the first human to walk on another world.

He retired from NASA 41 years ago today, just over two years after his historic mission with Aldrin and Michael Collins, who orbited the moon as the Lunar Module descended to the surface.

Armstrong was born in Wapakoneta, Ohio and first soloed an airplane just a few weeks after his sixteenth birthday. Before being selected as an astronaut, Armstrong was a naval aviator flying F9F Panther fighter jets in the Korean War. After the War, he became a research pilot for the National Advisory Committee for Aeronautics, the predecessor of NASA. While a research pilot, he flew the rocket powered Bell X-1B and the North American X-15 along with a wide variety of jet and propeller aircraft.

During his time in the X-15 program, now under NASA, Armstrong demonstrated his engineering skills working on the hypersonic aircraft’s flight control system as well as the relatively primitive simulator used to develop flight profiles of the first winged aircraft to fly into space.

At the same time, Armstrong was working on the X-15 program, he also worked on the X-20 Dynasoar project, part of the Air Force’s ‘Man in Space Soonest’ program. The veteran test pilot flew a modified Douglas F5D fighter jet (now on display at the Neil Amrstrong Museum in Wapakoneta) on a series of flights to develop launch abort procedures that were to be used for the winged X-20 spacecraft.

Armstrong joined the astronaut core as part of the “new nine” and first flew on Gemini 8. In 1968, the now space flight veteran was selected as commander of Apollo 11, the first mission slated to land on the moon.

After retiring from NASA, Armstrong went on to be a professor of aerospace engineering and served on the board of various companies.

From Wired Science

Bigger Creatures Live Longer, Travel Farther for a Reason

A long-standing mystery in biology about the longer lifespans of bigger creatures may be explained by the application of a physical law called the Constructal Law.

What this law proposes is that anything that flows -- a river, bloodstream or highway network -- will evolve toward the same basic configuration out of a need to be more efficient. And, as it turns out, that same basic law applies to all bodies in motion, be they animals or tanker trucks, says Adrian Bejan, the J.A. Jones Professor of mechanical engineering at Duke and father of the Constructal Law.

In his latest theory paper, appearing Aug. 24 in the journal Nature Scientific Reports, Bejan argues that there is a universal tendency for larger things, animate and inanimate, to live longer and to travel further.

He starts his argument with an examination of the well-known observation in biology that larger animals tend to live longer. Bejan wanted to see if this general rule might apply to inanimate systems as well and proceeded to mathematically analyze the relationship in rivers, jets of air and vehicles.

He found, as a general rule, that bigger rivers are older and that larger jets of air, such as atmospheric jet streams, last longer. By his calculations, larger vehicles should also last longer, but hard evidence of that is lacking, he says, and there are outliers of course, like Subaru Justys with 300,000 miles.

By being larger and lasting longer, all of these systems also travel farther, he says.

If you look at a moving vehicle or animal simply as a mass in motion, that is, something flowing, "the spreading of the mass of vehicles and animals is completely analogous to the flow of water in river channels," Bejan says. "It is the same design."

Interestingly, if the body size and lifespan of known species of animals are plotted on a curve, it falls on a slope of about ¼. And then, following a different line of inquiry, if you plot the frequency of breathing to body size, that is a slope of - ¼.

When combined, these two insights about animal body size work out to a constant for the number of breaths per lifetime, Bejan says. This gives most creatures about the same number of breaths in their lifetime, but the larger, slower-breathing animals use their breaths up over a longer span of time. "So bigger means a longer lifespan," he said. "I was looking at this enigma about body size and longevity from a point of view that hadn't occurred to biologists," Bejan said.

The Constructal Law governs how big an engine a truck needs and how big a heart a whale needs. "There's no difference between a vehicle and an animal," Bejan said. "Being larger means two things, not one: you live longer and you travel farther."

Read more at Science Daily

Most Mutations Come from Dad

Humans inherit more than three times as many mutations from their fathers as from their mothers, and mutation rates increase with the father's age but not the mother's, researchers have found in the largest study of human genetic mutations to date.

The study, based on the DNA of around 85,000 Icelanders, also calculates the rate of human mutation at high resolution, providing estimates of when human ancestors diverged from nonhuman primates. It is one of two papers published this week by the journal Nature Genetics as well as one published at Nature that shed dramatic new light on human evolution.

"Most mutations come from dad," said David Reich, professor of genetics at Harvard Medical School and a co-leader of the study. In addition to finding 3.3 paternal germline mutations for each maternal mutation, the study also found that the mutation rate in fathers doubles from age 20 to 58 but that there is no association with age in mothers -- a finding that may shed light on conditions, such as autism, that correlate with the father's age.

The study's first author is James Sun, a graduate student in Reich's lab who worked with researchers from deCODE Genetics, a biopharma company based in Reykjavik, Iceland, to analyze about 2,500 short sequences of DNA taken from 85,289 Icelanders in 24,832 father-mother-child trios. The sequences, called microsatellites, vary in the number of times that they repeat, and are known to mutate at a higher rate than average places in the genome.

Reich's team identified 2,058 mutational changes, yielding a rate of mutation that suggests human and chimpanzee ancestral populations diverged between 3.7 million and 6.6 million years ago.

A second team, also based at deCODE Genetics (but not involving HMS researchers), published a paper this week in Nature on a large-scale direct estimate of the rate of single nucleotide substitutions in human genomes (a different type of mutation process), and came to largely consistent findings.

The finding complicates theories drawn from the fossil evidence. The upper bound, 6.6 million years, is less than the published date of Sahelanthropus tchadensis, a fossil that has been interpreted to be a human ancestor since the separation of chimpanzees, but is dated to around 7 million years old. The new study suggests that this fossil may be incorrectly interpreted.

Great Heights

A second study led by HMS researchers, also published in Nature Genetics this week, adds to the picture of human evolution, describing a newly observable form of recent genetic adaptation.

The team led by Joel Hirschhorn, Concordia Professor of Pediatrics and professor of genetics at Boston Children's Hospital and HMS, first asked why closely-related populations can have noticeably different average heights. David Reich also contributed to this study.

They examined genome-wide association data and found that average differences in height across Europe are partly due to genetic factors. They then showed that these genetic differences are the result of an evolutionary process that acts on variation in many genes at once. This type of evolution had been proposed to exist but had not previously been detected in humans.

Although recent human evolution is difficult to observe directly, some of its impact can be inferred by studying the human genome. In recent years, genetic studies have uncovered many examples where recent evolution has left a distinctive signature on the human genome. The clearest "footprints" of evolution have been seen in regions of DNA surrounding mutations that occurred fairly recently (typically in the last several thousand years) and confer an advantageous trait, such as resistance to malaria. Hirschhorn's team observed, for the first time in humans, a different signature of recent evolution: widespread small but consistent changes at many different places in the genome, all affecting the same trait, adult height.

"This paper offers the first proof and clear example of a new kind of human evolution for a specific trait," said Hirschhorn, who is also a senior associate member of the Broad Institute. "We provide a demonstration of how humans have been able to adapt rapidly without needing to wait for new mutations to happen, by drawing instead on the existing genetic diversity within the human population."

Average heights can differ between populations, even populations that are genetically very similar, which suggests that human height might have been evolving differently across these populations. Hirschhorn's team studied variants in the genome that are known to have small but consistent effects on height: people inheriting the "tall" version of these variants are known to be slightly taller on average than people inheriting the "short" versions of the same variants.

The researchers discovered that, in northern Europe, the "tall" versions of these variants are consistently a little more common than they are in southern Europe. The combined effects of the "tall" versions being more common can partly explain why northern Europeans are on average taller than southern Europeans. The researchers then showed that these slight differences have arisen as a result of evolution acting at many variants, and acting differently in northern than in southern Europe.

Read more at Science Daily

Grave of Richard III May Be Under Parking Lot

King Richard III of England had the honor of being memorialized in a William Shakespeare play after his death in battle in 1485. Now, modern-day archaeologists are on the hunt for the medieval king's physical resting place.

The University of Leicester, Leicester City Council and the Richard III Society have joined forces to search for the grave of Richard III, thought to be under a parking lot for city council offices. The team will use ground-penetrating radar to search for the ideal spots to dig.

"This archaeological work offers a golden opportunity to learn more about medieval Leicester as well as about Richard III's last resting place -- and, if he is found, to re-inter his remains with proper solemnity in Leicester Cathedral," Philippa Langley, a Richard III Society member, said in a statement.

Richard III was King of England from 1483 to 1485. He died during the Battle of Bosworth Field during the War of the Roses, an English civil war between the House of Lancaster and the House of York. Richard III was the last English king to die in battle. Shakespeare penned "Richard III," a play about the tragic king, approximately 100 years later.

Regardless of his Shakespeare claim to fame, the king was talked about for his own right. "Richard III is a charismatic figure who attracts tremendous interest, partly because he has been so much maligned in past centuries, and partly because he occupies a pivotal place in English history," Langley said.

"The continuing interest in Richard means that many fables have grown up around his grave." Langley said, adding that some far-fetched tales include that the bones were thrown into the river Soar.

"Other fables, equally discredited, claimed that his coffin was used as a horse-trough," Langley said.

After his death, the king was stripped and brought to Leicester, where he was buried in the church of the Franciscan Friary, known as the Greyfriars. The location of Greyfriars was eventually lost to history.

"The big question for us is determining the whereabouts of the church on the site and also where in the church the body was buried," University of Leicester archaeologist Richard Buckley said in a statement. "Although in many ways finding the remains of the king is a long-shot, it is a challenge we shall undertake enthusiastically. There is certainly potential for the discovery of burials within the area, based on previous discoveries and the postulated position of the church."

Read more at Discovery News

Animals Are as With It as Humans, Scientists Say

An international group of prominent scientists has signed The Cambridge Declaration on Consciousness in which they are proclaiming their support for the idea that animals are conscious and aware to the degree that humans are -- a list of animals that includes all mammals, birds, and even the octopus. But will this make us stop treating these animals in totally inhumane ways?

While it might not sound like much for scientists to declare that many nonhuman animals possess conscious states, it's the open acknowledgement that's the big news here. The body of scientific evidence is increasingly showing that most animals are conscious in the same way that we are, and it's no longer something we can ignore.

 What's also very interesting about the declaration is the group's acknowledgement that consciousness can emerge in those animals that are very much unlike humans, including those that evolved along different evolutionary tracks, namely birds and some encephalopods.

"The absence of a neocortex does not appear to preclude an organism from experiencing affective states," they write. "Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors."

Consequently, say the signatories, the scientific evidence is increasingly indicating that humans are not unique in possessing the neurological substrates that generate consciousness.

 The group consists of cognitive scientists, neuropharmacologists, neurophysiologists, neuroanatomists, and computational neuroscientists -- all of whom were attending the Francis Crick Memorial Conference on Consciousness in Human and Non-Human Animals. The declaration was signed in the presence of Stephen Hawking, and included such signatories as Christof Koch, David Edelman, Edward Boyden, Philip Low, Irene Pepperberg, and many more.

The declaration made the following observations:

• The field of Consciousness research is rapidly evolving. Abundant new techniques and strategies for human and non-human animal research have been developed. Consequently, more data is becoming readily available, and this calls for a periodic reevaluation of previously held preconceptions in this field. Studies of non-human animals have shown that homologous brain circuits correlated with conscious experience and perception can be selectively facilitated and disrupted to assess whether they are in fact necessary for those experiences. Moreover, in humans, new non-invasive techniques are readily available to survey the correlates of consciousness.
   
• The neural substrates of emotions do not appear to be confined to cortical structures. In fact, subcortical neural networks aroused during affective states in humans are also critically important for generating emotional behaviors in animals. Artificial arousal of the same brain regions generates corresponding behavior and feeling states in both humans and non-human animals. Wherever in the brain one evokes instinctual emotional behaviors in non-human animals, many of the ensuing behaviors are consistent with experienced feeling states, including those internal states that are rewarding and punishing. Deep brain stimulation of these systems in humans can also generate similar affective states. Systems associated with affect are concentrated in subcortical regions where neural homologies abound. Young human and nonhuman animals without neocortices retain these brain-mind functions. Furthermore, neural circuits supporting behavioral/electrophysiological states of attentiveness, sleep and decision making appear to have arisen in evolution as early as the invertebrate radiation, being evident in insects and cephalopod mollusks (e.g., octopus).

Read more at Discovery News

Spacetime: A Smoother Brew Than We Knew

Spacetime may be less like beer and more like sipping whiskey. Or so an intergalactic photo finish would suggest.

Physicist Robert Nemiroff of Michigan Technological University reached this heady conclusion after studying the tracings of three photons of differing wavelengths that were recorded by NASA's Fermi Gamma-ray Space Telescope in May 2009.

The photons originated about 7 billion light years away from Earth in one of three pulses from a gamma-ray burst. They arrived at the orbiting telescope just one millisecond apart, in a virtual tie.

Gamma-ray bursts are short-lived bursts of gamma-ray photons, the most energetic form of light. They can originate far across the universe, and astronomers believe many are caused by giant stars collapsing, often billions of years before Earth was formed.

"Gamma-ray bursts can tell us some very interesting things about the universe," Nemiroff said. In this case, those three photons recorded by the Fermi telescope suggest that spacetime may not be not as bubbly as some scientists think.

Some theories of quantum gravity say that the universe is not smooth but foamy -- made of fundamental units called Planck lengths that are less than a trillionth of a trillionth the diameter of a hydrogen atom. Planck lengths are so small that there's no way to detect them, except via photons like those that make up gamma-ray bursts.

Here's why. The wavelengths of these photons are some of the shortest distances known to science -- so short they should interact with the even smaller Planck length. And if they interact, the photons should be dispersed -- scattered -- on their trek through Planck length-pixelated spacetime.

In particular, they should disperse in different ways if their wavelengths differ, just as a ping pong ball and a softball might take alternate paths down a gravely hillside.

You wouldn't notice the scattering over short distances, but across billions of light years, the Planck lengths should disperse the light. And three photons from the same gamma-ray burst should not have crashed through the Fermi telescope at the same moment.

Read more at Science Daily

More Exoplanets Discovered: 41 New Transiting Planets in Kepler Field of View

Two newly submitted studies verify 41 new transiting planets in 20 star systems. These results may increase the number of Kepler's confirmed planets by more than 50 percent: to 116 planets hosted in 67 systems, over half of which contain more than one planet.

The papers are currently under scientific peer-review.

Nineteen of the newly validated planetary systems have two closely spaced transiting planets and one system has three. Five of the systems are common to both of these independent studies.

The planets range from Earth-size to more than seven times the radius of Earth, but generally orbit so close to their parent stars that they are hot, inhospitable worlds.

The planets were confirmed by analyzing Transit Timing Variations (TTVs). In closely packed systems, the gravitational pull of the planets causes the acceleration or deceleration of a planet along its orbit. These "tugs" cause the orbital period of each planet to change from one orbit to the next. TTV demonstrates that two transiting planet candidates are in the same system and that their masses are planetary in nature.

"These systems, with their large gravitational interactions, give us important clues about how planetary systems form and evolve," said lead researcher Jason Steffen, the Brinson postdoctoral fellow at Fermilab Center for Particle Astrophysics in Batavia, Ill. "This information helps us understand how our own solar system fits into the population of all planetary systems."

The two research teams used data from NASA's Kepler space telescope, which measures dips in the brightness of more than 150,000 stars, to search for transiting planets.

"The sheer volume of planet candidates being identified by Kepler is inspiring teams to look at the planet confirmation and characterization process differently. This TTV confirmation technique can be applied to large numbers of systems relatively quickly and with little or no follow-up observations from the ground," said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center, Moffett Field, Calif. "Perhaps the bottleneck between identifying planet candidates and confirming them just got a little wider."

Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Read more at Science Daily

Gibbons on Helium Trill Like Opera Singers

Gibbons effortlessly use the same techniques as professional opera singers when calling out to other animals, scientists found by listening to the squeaky songs of one of the apes on helium.

The Japanese study provides evidence for an unusual physiological similarity between gibbons and humans.

"The complexity of human speech is unique among primates as it requires varied soft sounds made by the rapid movements of vocal tracts," lead researcher Takeshi Nishimura, from the Primate Research Institute at Kyoto University, said in a statement. "Our speech was thought to have evolved through specific modifications in our vocal anatomy. However, we've shown how the gibbons' distinctive song uses the same vocal mechanics as soprano singers, revealing a fundamental similarity with humans."

Nishimura's team analyzed 20 melodious and loud calls of a captive white-handed gibbon (Hylobates lar) in a normal atmosphere, followed by 37 calls in an environment infused with helium.

Sucking in helium from a balloon gives humans a squeaky, high-pitch-sounding voice, because the gas, which is less dense than air, pushes the resonance frequencies of the vocal tract upwards, but doesn't change the sound at its source. An analysis of the gibbon's squeaky songs suggested that the same is true for these apes. Like humans, the origin of the sound of a gibbon's call, which occurs in the larynx, is separate from the vocal tools used to modify it, the research showed.



What's more, the analysis demonstrated gibbons have expert control over the tuning of their vocal cords and tract when singing -- an ability that is important to the subtleties of human speech and is mastered by soprano singers.

Read more at Discovery News

Vaporizing Planets in the Name of Science

One sure-fire way to grab an audience's attention is to vaporize a planet, amirite? We saw the destruction of Vulcan in Star Trek, the end of Krypton in the Christopher Reeves-era Superman, while the Death Star vaporized Alderaan in Star Wars: A New Hope.

As for Hitchhikers Guide to the Galaxy, Douglas Adams went all in, vaporizing the Earth right off the bat, all because an alien race known as the Vogons want to make way for a hyperspatial express route, leaving poor Arthur to roam about the Milky Way in his bathrobe.

But can you really vaporize a planet? According to the latest computer simulations by a couple of planetary scientists in St. Louis, you betcha! As outlined in their new paper in The Astrophysical Journal, Bruce Fegley and his colleagues (Katharina Lodders and Laura Schaefer) mathematically constructed a couple of model "Super-Earths" and put them through a series of atmospheric simulations.

The object wasn't really to study how to destroy the Earth. Fegley et al were trying to learn more about the kinds of atmospheres most likely to be found on Super-Earths -- i.e., exoplanets with masses that are more than that of Earth but less than that of Neptune, while still being rocky in nature, instead of, say, a gas giant.

Having detailed knowledge of likely chemical compositions could help astronomers who hunt for such planets find them. And one way of gaining that knowledge is to build computer models of Super-Earths and vaporize them.

Most exoplanets within that size range that have been found are gaseous in nature, because they orbit so close to their host stars that any rocky stuff gets melted. (How Stuff Works has an excellent summary of the various techniques astronomers use to hunt for exoplanets.)

For instance, using photometry, astronomers can detect an exoplanet as it transits the host star, because of predictable periodic dimming of a star's brightness as the planet momentarily blocks its light. Astronomers can also determine the chemical composition of said planet's atmosphere because the star's light gets filtered through that atmosphere -- think of it as stellar spectroscopy.

This, in turn, provides clues as to the planet's density, because the gases in the atmosphere likely came about because of vaporized rock. So it would be nice to have tidy simulated models to compare with the measured spectra of actual exoplanets.

One model Super-Earth had a continental crust just like our Earth, dominated by granite, while the other simulated Earth's composition before its crust formed, when it was mostly bulk silicate. (Water is the key ingredient in getting Earth today from that precursor Earth. Without it, our planet's crust would more closely resemble Venus.)

Then they plugged in the likely surface temperatures of observed Super-Earths, ranging from between 270 to 1700 degrees Celsius, just to see what would happen to the atmosphere. "The vapor pressure of the liquid rock increases as you heat it, just as the vapor pressure of water increases as you bring a pot to boil," Fegley explained via press release. "Ultimately this puts all the constituents of rick into the atmosphere."

Read more at Discovery News