Tuesday, 15 October 2013

'Diamond rain' falls on Saturn and Jupiter

14 October 2013 Last updated at 11:04 GMT

By James MorganScience reporter, BBC News
Diamond rain could be "the most common precipitation in the Solar System" the authors say


Diamonds big enough to be worn by Hollywood film stars could be raining down on Saturn and Jupiter, US scientists have calculated.

New atmospheric data for the gas giants indicates that carbon is abundant in its dazzling crystal form, they say.

Lightning storms turn methane into soot (carbon) which as it falls hardens into chunks of graphite and then diamond.

These diamond "hail stones" eventually melt into a liquid sea in the planets' hot cores, they told a conference.
Continue reading the main story
“Start Quote


People ask me - how can you really tell? It all boils down to the chemistry. And we think we're pretty certain”Dr Kevin BainesUniversity of Wisconsin-Madison

The biggest diamonds would likely be about a centimetre in diameter - "big enough to put on a ring, although of course they would be uncut," says Dr Kevin Baines, of the University of Wisconsin-Madison and Nasa's Jet Propulsion Laboratory.

He added they would be of a size that the late film actress Elizabeth Taylor would have been "proud to wear".

"The bottom line is that 1,000 tonnes of diamonds a year are being created on Saturn.

"People ask me - how can you really tell? Because there's no way you can go and observe it.

"It all boils down to the chemistry. And we think we're pretty certain."

Thunderstorm alleys

Baines presented his unpublished findings at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Denver, Colorado, alongside his co-author Mona Delitsky, from California Speciality Engineering.
Gigantic storms on Saturn create black clouds of soot - which hardens into diamonds as it falls

Uranus and Neptune have long been thought to harbour gemstones. But Saturn and Jupiter were not thought to have suitable atmospheres.

Baines and Delitsky analysed the latest temperature and pressure predictions for the planets' interiors, as well as new data on how carbon behaves in different conditions.

They concluded that stable crystals of diamond will "hail down over a huge region" of Saturn in particular.

"It all begins in the upper atmosphere, in the thunderstorm alleys, where lightning turns methane into soot," said Baines.

"As the soot falls, the pressure on it increases. And after about 1,000 miles it turns to graphite - the sheet-like form of carbon you find in pencils."

By a depth of 6,000km, these chunks of falling graphite toughen into diamonds - strong and unreactive.

These continue to fall for another 30,000km - "about two-and-a-half Earth-spans" says Baines.

"Once you get down to those extreme depths, the pressure and temperature is so hellish, there's no way the diamonds could remain solid.

"It's very uncertain what happens to carbon down there."

One possibility is that a "sea" of liquid carbon could form.

"Diamonds aren't forever on Saturn and Jupiter. But they are on Uranus and Neptune, which are colder at their cores," says Baines.

'Rough diamond'

The findings are yet to be peer reviewed, but other planetary experts contacted by BBC News said the possibility of diamond rain "cannot be dismissed".

"The idea that there is a depth range within the atmospheres of Jupiter and (even more so) Saturn within which carbon would be stable as diamond does seem sensible," says Prof Raymond Jeanloz, one of the team who first predicted diamonds on Uranus and Neptune.

"And given the large sizes of these planets, the amount of carbon (therefore diamond) that may be present is hardly negligible."

However Dr Nadine Nettelmann, of the University of California, Santa Cruz, said further work was needed to understand whether carbon can form diamonds in an atmosphere which is rich in hydrogen and helium - such as Saturn's.
The planet 55 Cancri e may not be so precious after all, a new study suggests

"Baines and Delitsky considered the data for pure carbon, instead of a carbon-hydrogen-helium mixture," she explained.

"We cannot exclude the proposed scenario (diamond rain on Saturn and Jupiter) but we simply have no data on mixtures in the planets. So we do not know if diamond formation occurs at all."

Meanwhile, an exoplanet that was believed to consist largely of diamond may not be so precious after all, according to new research.

The so-called "diamond planet" 55 Cancri e orbits a star 40 light-years from our Solar System.

A study in 2010 suggested it was a rocky world with a surface of graphite surrounding a thick layer of diamond, instead of water and granite like Earth.

But new research to be published in the Astrophysical Journal, calls this conclusion in question, making it unlikely any space probe sent to sample the planet's innards would dig up anything sparkling.

Carbon, the element diamonds are made of, now appears to be less abundant in relation to oxygen in the planet's host star - and by extension, perhaps the planet.

"Based on what we know at this point, 55 Cancri e is more of a 'diamond in the rough'," said author Johanna Teske, of the University of Arizona.


THIS is science: CYBORG MONKEYS with PROSTHETIC ARMS

No, it's not the long awaited cyborg monkey butler
By Lewis Page, 15th October 2013


Exciting news on various important science and tech beats today, as we learn that boffins have achieved breakthroughs in the allied fields of brain-chipped monkeys, robotics and cybernetics. To wit, they have been working out how to equip monkeys wielding robot arms with a sense of touch.

Rather than monkey, robot, or monkey-robot cyborg combination butler-Terminators, however, this research is aimed at making robot arms for human beings work better. This research is funded by our old friends at the US military bonkers-boffinry bureau DARPA, hoping to deliver better replacement limbs for American troops injured in the Wars on Stuff.


“If you really want to create an arm that can actually be used dexterously without the enormous amount of concentration it takes without sensory feedback, you need to restore the somatosensory feedback," explains Sliman Bensmaia, Chicago uni prof.

Bansmaia and his colleagues set to work on this using experimental monkeys. A Chicago uni statement describes the research:


The researchers performed a series of experiments with rhesus macaques that were trained to respond to stimulation of the hand. In one setting, they were gently poked on the hand with a physical probe at varying levels of pressure. In a second setting, some of the animals had electrodes implanted into the area of the brain that responds to touch. These animals were given electrical pulses to simulate the sensation of touch, and their hands were hidden so they wouldn’t see that they weren’t actually being touched.

Using data from the animals’ responses to each type of stimulus, the researchers were able to create a function, or equation, that described the requisite electrical pulse to go with each physical poke of the hand. Then, they repeated the experiments with a prosthetic hand that was wired to the brain implants. They touched the prosthetic hand with the physical probe, which in turn sent electrical signals to the brain.


It seems that, poke-wise, the monkeys didn't distinguish between fleshy and robotic hand stimulus. In Bensmaia's view, this means we're well on our way to artificial arms with a sense of touch.

“This is the first time as far as I know where an animal or organism actually perceives a tactile stimulus through an artificial transducer,” says the prof. “It’s an engineering milestone."

Human trials are anticipated within the next year, apparently, though we here on theReg brainplug desk would note that electrodes inside the human skull seem unlikely to become a widespread solution. Human trials may well take place, but inserting electrodes for the purpose would be most unusual: normally such trials are done with people who have already had to have electrodes inserted for other reasons.

Still, there may be ways around the need for risky, dangerous brain plugs. And so we may yet see better prosthetic arms – even if not the long desired monkey butlers – reasonably soon.

Bensmaia and his colleagues' research can be read here courtesy of theProceedings of the National Academy of Sciences. ®

Saturday, 10 August 2013

Resurrected protein's clue to origins of life

8 August 2013 Last updated at 16:19 GMT

By Simon RedfernReporter, BBC News
The earliest life would have survived at more than 100 C


New reconstructions of ancient proteins have provided clues to the habitat and origins of life on Earth.

The resurrected protein is thought to have existed almost four billion years ago in single-celled organisms linked to the earliest ancestor of all life.

The protein survives in the extreme environments of high acidity and temperature expected on early Earth and, intriguingly, also Mars.

Spanish and US scientists reported their study in the journal Structure.


“Maybe we have resurrected Martian proteins. Maybe the last universal common ancestor formed on Mars and transferred to Earth”
Professor Jose Sanchez-RuizGranada University

Gene sequences in a protein called thioredoxin, taken from a wide variety of modern organisms, were analysed and placed in an evolutionary context - locating them on a molecular-scale tree of life - to chart their progression from their primordial forms.

First, computer analysis was used to determine how modern genetic sequences developed from original codes, so the ancient DNA sequences in the protein from as far back as four billion years ago could be determined.Ancestral code

They then used modern bacteria to convert the ancient gene sequences into a chemically active protein that could be measured to determine its molecular structure and the properties of the ancient protein.

The thioredoxin protein is an enzyme which can break sulphur bonds in other molecules and has a number of metabolic functions in cells. It is shared by almost all life on Earth, from the simplest bacteria to complex animals including humans, indicating that the ultimate single-celled ancestor of all life on Earth would also have had the gene.

Prof Eric Gaucher of Georgia Tech, US, helped with the ancestral gene sequence reconstruction and commented: "A gene can become deactivated by as few as one or two mutations.

"If our ancestral sequences were incorrectly inferred by having a single mistake, that could have led to a dead gene. Instead, our approach created biochemically active proteins that fold up into three dimensional structures that look like modern protein structures, thus validating our approach."
Protein folding has survived billions of years

The group used molecular clocks to date the evolutionary branches back in time and linked them to geological changes in Earth's environment.

Changes in the protein's length appeared to occur in fits and starts, with its helix structure suddenly lengthening at the point that cells started to develop a nucleus (the transition from prokaryote to eukaryote), paving the way for higher life.

The results suggest that biological systems might evolve at the molecular level in discrete jumps rather than along continuous pathways, as has been suggested from studies of the evolution of species.Hell on Earth

The group studied how well the ancient thioredoxin coped with heat, and found that it survived temperatures of more than 110 C, as well as being stable in acidic environments.

"We have looked at a number of gene families now, and for all of them, we find the most ancient proteins are the most thermally stable. From this, we conclude that ancient life lived in a hot environment," Prof Gaucher told the BBC.

The early Earth was a hostile environment for life. It was hellish, and the first geological eon on Earth is termed the "Hadean" after Hades, the ancient Greek god of the underworld. Before four billion years ago it is thought that Earth suffered heavy bombardment from meteorites. It is likely that any atmosphere that survived was hot and possibly acidic four billion years ago.

The ancient protein's properties indicate that it may have been adapted to that environment. It shares features with "extremophiles" - bacteria found today in extreme environments like hot springs and even at depth within Earth's crustal rocks.

It may be that the only life that survived that heavy bombardment were the forms that could cope with high temperatures and energies, like this ancient protein.Alien resurrection?

Another intriguing possibility, although not discussed in this study. is that the ancient protein came to Earth having formed at an earlier time on another planet.

In particular, recent evidence from Nasa's Curiosity rover suggests that Mars may well have been a more conducive place for life to develop than Earth during the first 500 million years of the Solar System, before four billion years ago.

Many Martian meteorites have landed on Earth, with our planet acting like a local gravitational vacuum cleaner.

"Four billion years ago Mars was a much a safer place than Earth. Maybe we have resurrected Martian proteins. Maybe the last universal common ancestor (the first life) formed on Mars and transferred to Earth," commented Prof Sanchez-Ruiz.


Thursday, 8 August 2013

If We Landed on Europa, What Would We Want to Know?


This artist's concept shows a simulated view from the surface of Jupiter's moon Europa. Europa's potentially rough, icy surface, tinged with reddish areas that scientists hope to learn more about, can be seen in the foreground. The giant planet Jupiter looms over the horizon. Image credit: NASA/JPL-Caltech

August 07, 2013

Most of what scientists know of Jupiter's moon Europa they have gleaned from a dozen or so close flybys from NASA's Voyager 2 spacecraft in 1979 and NASA's Galileo spacecraft in the mid-to-late 1990s. Even in these fleeting, paparazzi-like encounters, scientists have seen a fractured, ice-covered world with tantalizing signs of a liquid water ocean under its surface. Such an environment could potentially be a hospitable home for microbial life. But what if we got to land on Europa's surface and conduct something along the lines of a more in-depth interview? What would scientists ask? A new study in the journal Astrobiology authored by a NASA-appointed science definition team lays out their consensus on the most important questions to address.

"If one day humans send a robotic lander to the surface of Europa, we need to know what to look for and what tools it should carry," said Robert Pappalardo, the study's lead author, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "There is still a lot of preparation that is needed before we could land on Europa, but studies like these will help us focus on the technologies required to get us there, and on the data needed to help us scout out possible landing locations. Europa is the most likely place in our solar system beyond Earth to have life today, and a landed mission would be the best way to search for signs of life."

The paper was authored by scientists from a number of other NASA centers and universities, including the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.; University of Colorado, Boulder; University of Texas, Austin; and the NASA Goddard Space Flight Center, Greenbelt, Md. The team found the most important questions clustered around composition: what makes up the reddish "freckles" and reddish cracks that stain the icy surface? What kind of chemistry is occurring there? Are there organic molecules, which are among the building blocks of life?

Additional priorities involved improving our images of Europa - getting a look around at features on a human scale to provide context for the compositional measurements. Also among the top priorities were questions related to geological activity and the presence of liquid water: how active is the surface? How much rumbling is there from the periodic gravitational squeezes from its planetary host, the giant planet Jupiter? What do these detections tell us about the characteristics of liquid water below the icy surface?

"Landing on the surface of Europa would be a key step in the astrobiological investigation of that world," said Chris McKay, a senior editor of the journal Astrobiology, who is based at NASA Ames Research Center, Moffett Field, Calif. "This paper outlines the science that could be done on such a lander. The hope would be that surface materials, possibly near the linear crack features, include biomarkers carried up from the ocean."

This work was conducted with Europa study funds from NASA's Science Mission Directorate, Washington, D.C. JPL is a division of the California Institute of Technology, Pasadena.



Giant Maya Carvings Found in Guatemala











See more photos from the website: 

Big Discovery

Photograph courtesy Francisco Estrada-Belli

Archaeologist Anya Shetler cleans an inscription below an ancient stucco frieze recently unearthed in the buried Maya city of Holmul in the Peten region of Guatemala. Sunlight from a tunnel entrance highlights the carved legs of a ruler sitting atop the head of a Maya mountain spirit.

The enormous frieze—which measures 26 feet by nearly 7 feet (8 meters by 2 meters)—depicts human figures in a mythological setting, suggesting these may be deified rulers. It was discovered in July in the buried foundations of a rectangular pyramid in Holmul.



Maya archaeologist Francisco Estrada-Belli and his team were excavating a tunnel left open by looters when they happened upon the frieze. "The looters had come close to it, but they hadn't seen it," Estrada-Belli said.

According to Estrada-Belli, the frieze is one of the best preserved examples of its kind. "It's 95 percent preserved. There's only one corner that's not well preserved because it's too close to the surface, but the rest of it isn't missing any parts," said Estrada-Belli, who is affiliated with Tulane University, Boston University, and the American Museum of Natural History and who is also a National Geographic Explorer. His excavations at Holmul were supported by the National Geographic Society/Waitt Grants Program.

Maya archaeologist Marcello Canuto agreed, calling the frieze "amazingly and beautifully preserved."

"We often dream of finding things this well preserved, and Francisco did it," said Canuto, who is the director of the Middle American Research Institute at Tulane University in New Orleans; he was not involved in the project.

For example, despite being mostly faded away now, traces of red, blue, green, and yellow paint are still visible on the frieze.

"It gives you an idea of how intricate and ornate these sites that we are excavating must have been during their apogee," Canuto said. "These sites must have been a feast for the eyes when they were inhabited."



David Stuart, a Maya hieroglyph expert at the University of Texas at Austin, pointed out that archaeologists think most large Maya temples were probably decorated with similar sorts of designs.



"But not all temples were so carefully buried and preserved like this," said Stuart, who did not participate in the project. "Also, each temple facade was slightly different and therefore unique in terms of its detail and message." (Explore an interactive map of key Maya sites.)



Caught Between Two Great Powers

The section of the temple at Holmul where the frieze was found dates back to about 590 A.D., which corresponds to the Maya classical era, a period defined by the power struggles between two major Maya dynasties: Tikal and Kaanul.

The two kingdoms competed with one another for resources and for control of other, smaller Maya city-states. Until now, however, it had been unclear which dynasty Holmul owed its allegiance to, but an inscription on the newly discovered frieze reveals that the temple was commissioned by Ajwosaj, ruler of a neighboring city-state called Naranjo, which archaeologists know from other discoveries was a vassal city of the Kaanul kingdom.

"We now know that Holmul was under the influence of the Kaanul dynasty," Canuto said.

In 2012, Canuto's team found and deciphered a series of hieroglyphically inscribed panels at another Maya city of a similar size to Holmul, called La Corona, which was also under the patronage of the Kaanul kingdom.

Recent discoveries at sites like La Corona and Holmul are helping reveal how these sites, despite being relatively small compared with some of their neighbors, were important players on the region's larger geopolitical stage.



"We're now beginning to appreciate how all these hierarchical levels of sites were involved in a larger political game that put them on [the side of either Tikal or Kaanul]," Canuto explained. (See "Why the Maya Fell.")

All About Location

Why was Holmul—a minor city that was home to only 10,000 to 20,000 people—so important to the Tikal and Kaanul dynasties?

Previous work by Estrada-Belli suggests Holmul occupied a strategic position for both kingdoms. The city lay along the best east-west route between the Tikal dynasty's capital city, also called Tikal, and the coast. It also lay along a north-south route between the Kaanul capital city of Dzibanche and the Guatemalan highlands that did not pass through Tikal territory.

The Guatemalan highlands contained precious resources such as basalt, obsidian, and jade that were coveted by both kingdoms.

"A [Maya] king without jade was no king at all," Canuto said.

By controlling Holmul in the east and La Corona in the west, the Kaanul dynasty was able to effectively access these riches without going through the capital city of its rival.

(See video of a Maya mural and calendar uncovered by National Geographic grantee Bill Saturno in Guatemala.)

Staying Put for Now

The frieze still lies buried in Holmul where it was initially discovered because it is too big to move, said lead archaeologist Estrada-Belli.

"We're going to try to preserve it and create a stable environment around it so people can eventually visit it," he said.



"We're very concerned about its present condition, so we had to re-bury the entrance tunnel to keep the humidity and climate around it stable."

—Ker Than


Tuesday, 6 August 2013

Thick Ice Sheet Covering Mars May Explain Mysterious Double-Layered Ejecta Craters

By Charles Poladianon August 05 2013 4:25 PM



Double-Layered Ejecta Craters may be the result of a thick layer of ice once covering mars. NASA

Researchers believe a mysterious type of crater was created as a result of mars having a thick sheet of ice covering its surface. Ejected material from the impact would later return to the surface, slide downward on the ice and create a secondary later at the bottom of the impact site.

According to geologists from Brown University, double-layered ejecta (DLE) craters were produced as a result of a sheet of ice covering the surface of mars. DLE craters have an impact site, a first layer of ejected debris and a smaller second layer of debris. The second layer may have been formed as ejected debris at the top of the crater rim slid off a sheet of ice that may have been 50 meters thick.

The DLE craters were first observed from data collected by NASA’s Viking missions in the 1970’s. While there was no explanation for these types of craters, the geologists believe, based on recent research indicating a period of mars’ history where ice was present, an object crashing into a layer of ice would have produced results similar to a DLE crater.

The new study of DLE craters was led by James W. Head, professor of geological science, and David Kutai Weiss, a graduate student at the university, and will be published in the journal Geophysical Research Letters. According to Head, in mars’ past the climate was cool enough to have ice present at the same location where DLE craters are located. “During these times, ice from the polar caps is redistributed into the mid-latitudes of mars as a layer about 50 meters thick, in the same place that we see that the DLEs have formed,” said Head in astatement.

As the geologists explain, the hypothesis of a sheet of ice causing a landslide of ejected material would explain several features of DLE craters. The inner layer of these craters have ridges flowing outward from the crater rim, called radial striations, that are commonly found in landslides that occur on glaciers on Earth.

Other DLE crater data supported the landslide on ice theory. According to Head, a steep crater rim was needed and larger craters, 25 kilometers, approximately 15 miles, or more in diameter, would not have a steep enough crater rim. Based on 600 known DLE craters, all of them were less than 25 kilometers in diameter. DLE craters did not have secondary impact areas, a trait common in other craters, and the researchers believe a sheet of ice could have protected mars’ surface from large chunks of ejected debris.

Understanding how DLE craters formed creates a clearer picture of mars’ history. “It could tell us a lot about the history of the martian climate on a global scale,” said Weiss.


Thursday, 1 August 2013

NASA’s Spitzer Space Telescope Observes A Stellar System That Has Its Own 'Hula Hoop' Dust Disk

By Charles Poladian
on August 01 2013 8:27 AM


NASA’s Spitzer Space Telescope discovered a stellar system in its infancy and observed some rather interesting phenomena. Of the three young stars that make up the system, two of them have a leftover dust disk surrounding them that resembles a "hula hoop."



An artist's representation of the YLW 16A stellar system. NASA/JPL-Caltech

The stellar system, YLW 16A, is located in the Rho Ophiuchi cloud complex, a star-forming region consisting of dense gas and dust, 407 light-years from earth. The dust disk is at a tilt due to the gravitational pull of the third star in the system.


The system goes through bright and dim periods, resembling a blink, every 93 days, NASA says. As the two stars orbit one another, they eventually appear above the dust disk, creating a period of brightness but will eventually be obscured by the surrounding dust. The observations of YLW 16A were made by NASA’s Spitzer Telescope in infrared light. Other observations came from the Two Micron All-Sky, or 2MASS, Survey at the Infrared Processing and Analysis Center at the California Institute of Technology and the European Southern Observatory’s Very Large Telescope in Chile.

Blinking stellar systems similar to YLW 16A were believed to be relatively rare but recent observations indicate these systems may be more common. NASA notes the discovery of four other blinking stellar systems. Lead author Peter Plavchan, from the NASA Exoplanet Science Institute and IPEC at Caltech, said, “These blinking systems offer natural probes of the binary and circumbinary planet formation process.” Binary planets are those that orbit a single star while circumbinary planets orbit two stars. Plavchan’s research will be published in the journal Astronomy & Astrophysics.

The dust disk surrounding the stars will eventually be the fuel for the formation of other stars and planets to form a new solar system, NASA says. Future observations of blinking stellar systems could provide new insight on planet formations as well as the dust and other material that make up the disks.


Tuesday, 30 July 2013

Spacecraft sees giant 'hole' in sun

By Megan GannonPublished July 29, 2013
Space.com




The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun’s north pole on July 18, 2013, at 9:06 a.m. EDT. (ESA&NASA/SOHO)


A space telescope aimed at the sun has spotted a gigantic hole in the solar atmosphere — a dark spot that covers nearly a quarter of our closest star, spewing solar material and gas into space.

The so-called coronal hole over the sun's north pole came into view between July 13 and 18 and was observed by the Solar and Heliospheric Observatory, or SOHO. NASA released a video of the sun hole as seen by the SOHO spacecraft, showing the region as a vast dark spot surrounded by solar activity.

Coronal holes are darker, cooler regions of the sun's atmosphere, or corona, containing little solar material. In these gaps, magnetic field lines whip out into the solar wind rather than looping back to the sun's surface. Coronal holes can affect space weather, as they send solar particles streaming off the sun about three times faster than the slower wind unleashed elsewhere from the sun's atmosphere, according to a description from NASA.

"While it’s unclear what causes coronal holes, they correlate to areas on the sun where magnetic fields soar up and away, failing to loop back down to the surface, as they do elsewhere," NASA's Karen Fox at the agency's Goddard Space Flight Center in Greenbelt, Md., explained in an image description.

These holes are not uncommon, but their frequency changes with the solar activity cycle. The sun is currently reaching its 11-year peak in activity, known as the solar maximum. Around the time of this peak, the sun's poles switch their magnetism. The number of coronal holes typically decreases leading up to the switch.

After the reversal, new coronal holes appear near the poles. Then as the sun approaches the solar minimum again, the holes creep closer to the equator, growing in both size and number, according to NASA.

The $1.27-billion SOHO satellite was launched in 1995 and is flying a joint mission between NASA and the European Space Agency (ESA). It watches solar activity from an orbit about the Lagrange Point 1, a gravitationally stable spot between Earth and the sun that is about 932,000 miles from our planet.




Read more: http://www.foxnews.com/science/2013/07/29/spacecraft-sees-giant-hole-in-sun/#ixzz2aXYd3Q86

How Giant Black Holes Spin: New Twist Revealed

by Mike Wall, SPACE.com Senior Writer | July 29, 2013 07:01pm ET



An artist’s impression of a supermassive black hole at the centre surrounded by matter flowing onto the black hole in what is termed an accretion disk. Also shown is an outflowing jet of energetic particles, believed to be powered by the black hole's spin.




A newly discovered way to determine the spin of monster black holes could help shed light on the evolution of these bizarre objects and the galaxies they anchor.

Astronomers watched as a black hole that sits at the core of a spiral galaxy 500 million light-years from Earth gobbled up gas and dust from its surrounding accretion disk. They were able to measure the distance between the inner edge of the disk and the black hole, which, in turn, allowed them to estimate the black hole's spin.

“If a black hole is spinning, it drags space and time with it, and that drags the accretion disk, containing the black hole's food, closer towards it," study lead author Chris Done, of the University of Durham in the United Kingdom, said in a statement. "This makes the black hole spin faster — a bit like an ice skater doing a pirouette." [Gallery: Black Holes of the Universe]


WATCH THE VIDEO HERE


Researchers said the technique could help astronomers address broad questions about galactic evolution, which is intimately tied to the growth and activity of the supermassive black holes that lurk at the heart of most, if not all, galaxies.

"Understanding this connection between stars in a galaxy and the growth of a black hole, and vice versa, is the key to understanding how galaxies form throughout cosmic time," Done said.

Done and her colleagues used the European Space Agency's XMM-Newton satellite to study the distant supermassive black hole, which contains as much mass as 10 million suns.

This black hole blasts out prodigious amounts of energy as it feeds on the material in its accretion disk. XMM-Newton observed this output in optical, ultraviolet and X-ray wavelengths, enabling the astronomers to measure how far the disk sits from the black hole.

Astronomers have calculated the spin of supermassive black holes before. In February, for example, a different research team determined the rotation rate of the black hole at the center of a spiral galaxy called NGC 1365. That group inferred the spin speed by measuring the distortion of high-energy light emitted by iron atoms in the accretion disk.


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It's tough to describe black-hole spin rates because they don't really translate into familiar terms, such as miles per hour. For example, the NGC 1365 team, which used observations by XMM-Newton and NASA's NuStar spacecraft, found the black hole's rotation rate to be 84 percent of the maximum allowed by Einstein's theory of general relativity.

In the new study, Done and her team estimated that the black hole found 500 million light-years away — which is powering a superluminous "active galactic nucleus" known as PG1244+026 — has a relatively low spin rate.

"This contrasts with the recent X-ray determinations of (close to) maximal black hole spin in other [similar galaxies] based on relativistic smearing of the iron profile," the researchers wrote in the study, which was published online today (July 29) in the journal Monthly Notices of the Royal Astronomical Society.

"Better high-energy data are required in order to determine whether this new method gives a spin estimate which is consistent with that derived from the iron line, or whether it instead reveals a lack of understanding of disc continuum emission and/or of disc reflection," the team wrote.


NASA spots eclipsing planet in X-rays for first time

Chandra’s X-rays also detected a faint red companion to the main star in HD 189733.



Photo credit: NASA



Science Recorder | Stephanie Verkoeyen | Tuesday, July 30, 2013



Planets outside our solar system, commonly referred to as exoplanets, were discovered almost 20 years ago. Now, for the first time, X-ray observations have detected an exoplanet passing in front of its parent star.

The advantageous alignment occurred in the HD 189733 system, 63 light-years from Earth. As the planet transited its star, both NASA’s Chandra X-ray Observatory and the European Space Agency’s XMM Newton Observatory observed a dip in X-ray intensity.

Katja Poppenhaeger of Harvard led the study, which is to be published in The Astrophysical Journal next month. According to Poppenhaeger, thousands of planets have been detected in optical light, but being able to study one in X-rays reveals new information about its properties.

The planet, known as HD 189733b, is similar in size to Jupiter, but is in very close orbit around its star, a condition referred to as a “hot Jupiter.” HD 189733b is the closest hot Jupiter to Earth, making it a prime target for astronomers. NASA’s Kepler space telescope has been used to study it at optical wavelengths, while NASA’s Hubble Space Telescope has confirmed it is blue in color.

In this new study, clues have been revealed regarding the size of the planet’s atmosphere. During the transits, the spacecraft observed a decrease in light. X-ray light experienced a decrease three times greater than did optical light, which suggests that there may be extended layers of the planet’s atmosphere transparent to optical light, but opaque to X-rays.

“However, we need more data to confirm this idea,” said co-author Jurgen Schmitt.

Researchers are also learning how the planet and the star can affect one another. For a decade, astronomers have known that ultraviolet and X-ray radiation has been evaporating the atmosphere of HD 189733b over time, losing an estimated 100 million to 600 million kilograms of mass per second.

The planet’s extended atmosphere has made it a larger target for high-energy radiation, with its atmosphere thinning about 25 percent to 65 percent faster than if the atmosphere were smaller.

Chandra’s X-rays also detected a faint red companion to the main star in HD 189733. Though likely formed at the same time, the main star appears to be at least 3 billion years younger than its companion due to a higher rotation. The main star also has displayed higher levels of magnetic activity, and is about 30 times brighter in X-rays than its companion.

This unusual activity may result from having a big planet as a companion, according to Poppenhaeger. The hot Jupiter may be keeping the star’s rotation and magnetic activity high as a result of tidal forces, making it behave like a much younger star.

Earlier this month, it was announced that HD 189733b is a true blue planet.

“We saw the light becoming less bright in the blue but not in the green or red. Light was missing in the blue but not in the red when it was hidden,” said Frederic Pont of the University of Exeter. “This means that the object that disappeared was blue.”

Not only is HD 189733b a blue planet, it may rain glass on this alien world.



Read more: http://www.sciencerecorder.com/news/nasa-spots-eclipsing-planet-in-x-rays-for-first-time/#ixzz2aXWpAfDm

Testing the Future: Astronaut in Space Remote-Controls Robot in California

BY ADAM MANN
07.30.13
6:30 AM




NASA's K-10 rover maneuvers around the Roverscape, a pebbly field at the Ames Research Center full of obstacles such as boulders, fake rocks, and steep slopes.



MOUNTAIN VIEW, California – On a pebbled field built next to a parking lot, a small rover scoots forward and expels a long sheet of polyimide plastic from its backside, the third film the probe has deployed. The sheets are arranged in a Y-shaped formation that simulates a radio antenna on the moon.

No one is around to direct the seemingly autonomous robot. But the entire operation is being remote-controlled by Italian astronaut Luca Parmitano, who is flying 400 kilometers overhead in the International Space Station.

This is the second in a series of tests at NASA’s Ames Research Center aimed at taking the next giant leap in humans and robots working together. A technology known as telerobotics may one day allow astronauts to stay in orbit while guiding robots in real time on the surface of another planet. It will let humans explore new places, including perhaps unreachable locations such as the boiling valleys of Venus or the icy oceans of Europa, while lowering the risk to their lives. With a human mind in the loop, the robots will be able to make much quicker decisions and overcome obstacles to range farther than ever before.

“This is a glimpse of the future of space exploration,” said astronomer Jack Burns of the University of Colorado, during the test on July 26.

During the test at Ames, NASA’s K-10 rover is outfitted with an array of sensors. The 1.4-meter-tall robot has several cameras and an overhead LIDAR scanner to build a 3-D map of its environment, and a sophisticated suite of software to help it get around. Parmitano isn’t driving the probe with a joystick up there. He punches instructions on a laptop, telling the robot to go from point A to point B, and K-10 figures out the best path to avoid obstacles and lay down the radio antenna.

In Burns’ vision, within 10 years, astronauts in orbit around the moon could be deploying a much larger version of this radio telescope on the lunar far side. With such an instrument, astronomers could glimpse some of the earliest periods in our universe’s history, when the first stars and galaxies formed. Currently, both ground- and space-based telescopes experience too much radio noise from human technology and the Earth’s ionosphere to get a clear picture of this era. Because the moon acts as a giant shield, the lunar far side is the only place in the inner solar system quiet enough to see this cosmic dawn. Telerobotics would allow NASA to build a radio telescope on the moon for cheaper than it might otherwise.

NASA is currently building a new generation of enormous rockets, the Space Launch System, which could eventually dwarf the Saturn V that launched Apollo astronauts to the moon. By 2021, it may be ready to carry its first crew beyond low-Earth orbit. Burns wants that first mission to go to the far side of the moon, a place humans have hardly explored, set up a 50 to 100 meter radio antenna, and conduct important geological investigations of the moon’s South Pole Aiken Basin, one of the largest impact craters in the solar system.

In trying to convince NASA to seamlessly bring together human and robotic exploration, Burns has a partner in crime: engineer Terry Fong, leader of the agency’s telerobotics group and a self-professed robot geek at heart.

In an ideal telerobotics situation, human operators control a probe on another planet in real time. For the Curiosity rover, currently on Mars, NASA engineers have to send a complex set of instructions to the robot each morning and wait patiently while it executes them. Because it takes light between seven and 20 minutes to travel between Earth and Mars, any problems or change in commands take a very long time to work out and the rover does everything at an extremely slow pace. Furthermore, a large team of engineers is required at mission control to monitor and instruct the robot.

“With this test, it’s the complete opposite,” said Fong. “We have a single operator” who can make changes on the fly and react to unexpected situations with the creativity and problem-solving skills of the human mind.

From his perch on the space station, Parmitano controlled the robot with a Lenovo Thinkpad laptop showing an up-to-the-minute 3-D model of the area around the K-10. Contradicting the idea that everything in space exploration is always state-of-the-art, Fong mentioned the laptop was running Windows XP. But like a good app developer, Fong and his team want to ensure their control system is user friendly. Parmitano only saw the interface he was using to drive the K-10 two hours before the test began, yet he was able to move the robot deftly and accomplish all the required goals fairly quickly.

Fong hopes to develop telerobotics protocols for more than just space exploration. As some Silicon Valley bosses are finding out, it’s easier to send a robot surrogate into the office for you when you’re far away. The remote-controlled robot can navigate the halls and interact with employees.

“It’s the same sorts of obstacles that you have to get around in an office or on another planet,” Fong said.

There are many more situations on Earth where you could send a robot to more safely do what is now a man’s job. One day, advanced human-controlled probes could go exploring deep underground or at the bottom of the ocean, assess and fix damage after a Fukushima-type disaster, operate search-and-rescue when a building collapses, or perform emergency surgery on a battlefield.


Sunday, 28 July 2013

Scientists discover what’s killing the bees and it’s worse than you thought


By Todd Woody @greenwombat July 24, 2013

Outlawing a type of insecticides is not a panacea. AP Photo/Ben Margot



As we’ve written before, the mysterious mass die-off of honey bees that pollinate $30 billion worth of crops in the US has so decimated America’s apis melliferapopulation that one bad winter could leave fields fallow. Now, a new study has pinpointed some of the probable causes of bee deaths and the rather scary results show that averting beemageddon will be much more difficult than previously thought.

Scientists had struggled to find the trigger for so-called Colony Collapse Disorder (CCD) that has wiped out an estimated 10 million beehives, worth $2 billion, over the past six years. Suspects have included pesticides, disease-bearing parasites and poor nutrition. But in a first-of-its-kind study published today in the journal PLOS ONE, scientists at the University of Maryland and the US Department of Agriculture have identified a witch’s brew of pesticides and fungicides contaminating pollen that bees collect to feed their hives. The findings break new ground on why large numbers of bees are dying though they do not identify the specific cause of CCD, where an entire beehive dies at once.

When researchers collected pollen from hives on the east coast pollinating cranberry, watermelon and other crops and fed it to healthy bees, those bees showed a significant decline in their ability to resist infection by a parasite calledNosema ceranae. The parasite has been implicated in Colony Collapse Disorder though scientists took pains to point out that their findings do not directly link the pesticides to CCD. The pollen was contaminated on average with nine different pesticides and fungicides though scientists discovered 21 agricultural chemicals in one sample. Scientists identified eight ag chemicals associated with increased risk of infection by the parasite.

Most disturbing, bees that ate pollen contaminated with fungicides were three times as likely to be infected by the parasite. Widely used, fungicides had been thought to be harmless for bees as they’re designed to kill fungus, not insects, on crops like apples.

“There’s growing evidence that fungicides may be affecting the bees on their own and I think what it highlights is a need to reassess how we label these agricultural chemicals,” Dennis vanEngelsdorp, the study’s lead author, told Quartz.

Labels on pesticides warn farmers not to spray when pollinating bees are in the vicinity but such precautions have not applied to fungicides.

Bee populations are so low in the US that it now takes 60% of the country’s surviving colonies just to pollinate one California crop, almonds. And that’s not just a west coast problem—California supplies 80% of the world’s almonds, a market worth $4 billion.

In recent years, a class of chemicals called neonicotinoids has been linked to bee deaths and in April regulators banned the use of the pesticide for two years in Europe where bee populations have also plummeted. But vanEngelsdorp, an assistant research scientist at the University of Maryland, says the new study shows that the interaction of multiple pesticides is affecting bee health.

“The pesticide issue in itself is much more complex than we have led to be believe,” he says. “It’s a lot more complicated than just one product, which means of course the solution does not lie in just banning one class of product.”

The study found another complication in efforts to save the bees: US honey bees, which are descendants of European bees, do not bring home pollen from native North American crops but collect bee chow from nearby weeds and wildflowers. That pollen, however, was also contaminated with pesticides even though those plants were not the target of spraying.

“It’s not clear whether the pesticides are drifting over to those plants but we need take a new look at agricultural spraying practices,” says vanEngelsdorp.