Life on Mars? Nakhla Martian meteorite reveals mineral-rich structure

A new ovoid structure discovered in the Nakhla Martian meteorite is made of nanocrystalline iron-rich clay, contains a variety of minerals, and shows evidence of undergoing a past shock event from impact, with resulting melting of the permafrost and mixing of surface and subsurface fluids.

Based on the results of a broad range of analytical studies to determine the origin of this new structure, scientists present the competing hypotheses for how this ovoid formed, point to the most likely conclusion, and discuss how these findings impact the field of astrobiology in a fascinating article published in Astrobiology.

In the article, "A Conspicuous Clay Ovoid in Nakhla: Evidence for Subsurface Hydrothermal Alteration on Mars with Implications for Astrobiology," Elias Chatzitheodoridis, National Technical University of Athens, Greece, and Sarah Haigh and Ian Lyon, the University of Manchester, UK, describe the use of tools including electron microscopy, x-ray, and spectroscopy to analyze the ovoid structure.

While the authors do not believe the formation of this structure involved biological materials, that is a possible hypothesis, and they note that evidence exists supporting the presence of niche environments in the Martian subsurface that could support life.

"This study illustrates the importance of correlating different types of datasets when attempting to discern whether something in rock is a biosignature indicative of life," says Sherry L. Cady, PhD, Editor-in-Chief of Astrobiology and Chief Scientist at the Pacific Northwest National Laboratory.

"Though the authors couldn't prove definitively that the object of focus was evidence of life, their research strategy revealed a significant amount of information about the potential for life to inhabit the subsurface of Mars."

NASA's 3-D Study of Comets Reveals Chemical Factory at Work

This rotating 3-D map shows how HNC molecules (made of hydrogen, carbon and nitrogen) are released from the nucleus of comet Lemmon and then spread evenly throughout the atmosphere, or coma. 

Similar maps revealed that HNC and formaldehyde are produced in the coma, rather than the comet's nucleus. 

Image courtesy Brian Kent /NRAO /AUI /NSF.

A NASA-led team of scientists has created detailed 3-D maps of the atmospheres surrounding comets, identifying several gases and mapping their spread at the highest resolution ever achieved.

"We achieved truly first-of-a-kind mapping of important molecules that help us understand the nature of comets," said Martin Cordiner, a researcher working in the Goddard Center for Astrobiology at NASA's Goddard Space Flight Center in Greenbelt, Maryland. Cordiner led the international team of researchers.

Almost unheard of for comet studies, the 3-D perspective provides deeper insight into which materials are shed from the nucleus of the comet and which are produced within the atmosphere, or coma.

This helped the team nail down the sources of two key organic, or carbon-containing, molecules.

The observations were conducted in 2013 on comets Lemmon and ISON using the Atacama Large Millimeter/submillimeter Array (ALMA), a network of high-precision antennas in Chile. These comets are the first to be studied with ALMA.

The ALMA observations combine a high-resolution 2-D image of a comet's gases with a detailed spectrum at each point.

From these spectra, researchers can identify the molecules present at every point and determine their velocities (speed plus direction) along the line-of-sight; this information provides the third dimension - the depth of the coma.

"So, not only does ALMA let us identify individual molecular species in the coma, it also gives us the ability to map their locations with great sensitivity," said Anthony Remijan, a scientist with the National Radio Astronomy Observatory, one of the organizations that operates ALMA, and a co-author of the study.

The researchers reported results for three molecular species, focusing primarily on two whose sources have been difficult to discern (except in comet Halley).

The 3-D maps indicated whether each molecule was flowing outward evenly in all directions or coming off in jets or in clumps.

In each comet, the team found that two species - formaldehyde and HNC (made of one hydrogen, one nitrogen and one carbon) - were produced in the coma.

For formaldehyde, this confirmed what researchers already suspected, but the new maps contained enough detail to resolve clumps of the material moving into different regions of the coma day-by-day and even hour-by-hour.

For HNC, the maps settled a long-standing question about the material's source. Initially, HNC was thought to be pristine interstellar material coming from the nucleus of a comet, whereas later work suggested other possible sources.

The new study provided the first proof that HNC is produced during the breakdown of large molecules or organic dust in the coma.

"Understanding organic dust is important, because such materials are more resistant to destruction during atmospheric entry, and some could have been delivered intact to early Earth, thereby fueling the emergence of life," said Michael Mumma, Director of the Goddard Center for Astrobiology, and a co-author on the study.

"These observations open a new window on this poorly known component of cometary organics."

Hubble Study in spiral Galaxy M83 reveals new super-powered small black hole, MQ1

Nearby spiral galaxy M83 and the MQ1 system with jets, as seen by the Hubble Space Telescope. 

The blue circle marks the position of the MQ1 system in the galaxy (shown inset). 

Image courtesy M83 - NASA, ESA and the Hubble Heritage Team (WFC3/UVIS, STScI-PRC14-04a).MQ1 inset - W. P. Blair (Johns Hopkins University) and R. Soria (ICRAR-Curtin).

A team of Australian and American astronomers have been studying nearby galaxy M83 and have found a new superpowered small black hole, named MQ1, the first object of its kind to be studied in this much detail.

Astronomers have found a few compact objects that are as powerful as MQ1, but have not been able to work out the size of the black hole contained within them until now.

The team observed the MQ1 system with multiple telescopes and discovered that it is a standard-sized small black hole, rather than a slightly bigger version that was theorised to account for all its power.

Curtin University senior research fellow Dr Roberto Soria, who is part of the International Centre for Radio Astronomy Research (ICRAR) and led the team investigating MQ1, said it was important to understand how stars were formed, how they evolved and how they died, within a spiral shaped galaxy like M83.

"MQ1 is classed as a microquasar - a black hole surrounded by a bubble of hot gas, which is heated by two jets just outside the black hole, powerfully shooting out energy in opposite directions, acting like cosmic sandblasters pushing out on the surrounding gas," Dr Soria said.

"The significance of the huge jet power measured for MQ1 goes beyond this particular galaxy: it helps astronomers understand and quantify the strong effect that black hole jets have on the surrounding gas, which gets heated and swept away.

"This must have been a significant factor in the early stages of galaxy evolution, 12 billion years ago, because we have evidence that powerful black holes like MQ1, which are rare today, were much more common at the time."

"By studying microquasars such as MQ1, we get a glimpse of how the early universe evolved, how fast quasars grew and how much energy black holes provided to their environment."

As a comparison, the most powerful microquasar in our galaxy, known as SS433, is about 10 times less powerful than MQ1.

Although the black hole in MQ1 is only about 100 kilometres wide, the MQ1 structure, as identified by the Hubble Space Telescope, is much bigger than our Solar System, as the jets around it extend about 20 light years from either side of the black hole.

Black holes vary in size and are classed as either stellar mass (less than about 70 times the mass of our Sun) or supermassive (millions of times the mass of our Sun, like the giant black hole that is located in the middle of the Milky Way).

MQ1 is a stellar mass black hole and was likely formed when a star died, collapsing to leave behind a compact mass.

Moon rocks reveal surprising meteorite history

SHRIMP-2 Curtin University

Associate Prof Nemchin's discovery challenges the long-held view that there was a single spike in huge meteorite impacts 3.9 billion years ago. 

Credit: Curtin University

Alexander Nemchin, a WA geologist, analyzing lunar rock samples collected during the Apollo missions has uncovered evidence of a huge meteorite strike 4.2 billion years ago.

Curtin University Associate Professor Alexander Nemchin made the discovery when he dated a section of rock from the Moon that melted in heat of the meteorite impact.

The object that hit the Moon was probably tens of kilometers across and would have left a crater several hundred kilometers wide.

Associate Prof Nemchin says the strike happened at least 300 million years before the youngest known lunar impact basins and his discovery challenges the long-held view that there was a single spike in huge impacts 3.9 billion years ago.

He says this period of intense meteorite bombardment, which would have affected both the Moon and the Earth, was previously thought to be a one-off event.

"A few years ago we started to see evidence that it's probably not quite the case," Nemchin says.

"It's possible that there are some impacts not related to this 3.9 [billion years] spike … there are some that happened much earlier.

"It has implications for a number of things including how life evolved on Earth."

Nemchin analysed the moon rock using SHRIMP, an ion probe instrument, at Curtin University, which allows researchers to determine the age of tiny amounts of rock by examining the atoms that make up the sample.

He was able to borrow the rock, which was collected from the rim of North Ray crater during the Apollo 16 mission, because of NASA's relatively open approach to the use of moon rocks for scientific research.

"All you need is to have record of doing scientific research, you need to demonstrate that you've got a way to keep the samples safe and you know how to work with small, rare samples," Nemchin says.

"It's really very open in many ways."

Nemchin says currently the best explanation for any increase in meteorite impacts throughout the Solar System 3.9 billion years ago is that some planets were thought to be displaced from their normal orbits at that time.

He says the movement of Jupiter and Saturn, with their huge mass, destabilised Neptune and sent smaller asteroids and comets "randomly flying around" in the Solar System.

"Of course when they go all over the place they start hitting all the other planets," Nemchin says.

SMA reveals giant star cluster in the making

This image from the Smithsonian's Submillimeter Array maps the projected density of molecular gas in the central 30 light years of W49A. 

Brighter colours mark denser regions. 

The brightest region at the image center is less than three light-years across, yet it contains about 50,000 suns' worth of molecular gas. 

Credit: Roberto Galván-Madrid (ESO), Hauyu Baobab Liu (ASIAA, Taiwan), Tzu-Cheng Peng (ESO)

W49A might be one of the best-kept secrets in our galaxy.

This star-forming region shines 100 times brighter than the Orion nebula, but is so obscured by dust that very little visible or infrared light escapes.

The Smithsonian's Submillimeter Array (SMA) has peered through the dusty fog to provide the first clear view of this stellar nursery. The SMA revealed an active site of star formation being fed by streamers of infalling gas.

"We were amazed by all the features we saw in the SMA images," says lead author Roberto Galván-Madrid, who conducted this research at the Harvard-Smithsonian Center for Astrophysics (CfA) and the European Southern Observatory (ESO).

W49A is located about 36,000 light-years from Earth, on the opposite side of the Milky Way.

It represents a nearby example of the sort of vigorous star formation seen in so-called "starburst" galaxies, where stars form 100 times faster than in our galaxy.

The heart of W49A holds a giant yet surprisingly compact star cluster. About 100,000 stars already exist within a space only 10 light-years on a side.

In contrast, fewer than 10 stars lie within 10 light-years of our Sun. In a few million years, the giant star cluster in W49A will be almost as crowded as a globular cluster.

The SMA also revealed an intricate network of filaments feeding gas into the center, much like tributaries feed water into mighty rivers on Earth.

Being denser than average will help the W49A star cluster to survive. Most star clusters in the galactic disk dissolve rapidly, migrating away from each other under the influence of gravitational tides.

This is why none of the Sun's sibling stars remain nearby. Since it is so compact, the cluster in W49A might remain intact for billions of years.

The Submillimeter Array mapped the molecular gas within W49A in exquisite detail.

It showed that central 30 light-years of W49A is several hundred times denser than the average molecular cloud in the Milky Way.

In total, the nebula contains about 1 million suns' worth of gas, mostly molecular hydrogen.

NASA WISE reveals the Milky Way's ancient brown dwarf population

A brown dwarf from the thick-disk or halo is shown. 

Although astronomers observe these objects as they pass near to the solar system, they spend much of their time away from the busiest part of the Galaxy, and the Milky Way's disk can be seen in the background. 

Credit: John Pinfield

A team of astronomers led by Dr David Pinfield at the University of Hertfordshire have discovered two of the oldest brown dwarfs in the Galaxy.

These ancient objects are moving at speeds of 100-200 kilometres per second, much faster than normal stars and other brown dwarfs and are thought to have formed when the Galaxy was very young, more than 10 billion years ago.

Intriguingly the scientists believe they could be part of a vast and previously unseen population of objects. The researchers publish their results in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society.

Brown dwarfs are star-like objects but are much less massive (with less than 7% of the Sun's mass), and do not generate internal heat through nuclear fusion like stars.

Because of this brown dwarfs simply cool and fade with time and very old brown dwarfs become very cool indeed - the new discoveries have temperatures of 250-600 degrees Celsius, much cooler than stars (in comparison the Sun has a surface temperature of 5600 degrees Celsius).

Pinfield's team identified the new objects in the survey made by the Wide-field Infrared Survey Explorer (WISE), a NASA observatory that scanned the mid-infrared sky from orbit in 2010 and 2011.

The object names are WISE 0013+0634 and WISE 0833+0052, and they lie in the Pisces and Hydra constellations respectively.

Additional measurements confirming the nature of the objects came from large ground-based telescopes (Magellan, Gemini, VISTA and UKIRT).

The infrared sky is full of faint red sources, including reddened stars, faint background galaxies (large distances from our own Milky Way) and nebulous gas and dust.

Identifying cool brown dwarfs in amongst this messy mixture is akin to finding needles in a haystack. But Pinfield's team developed a new method that takes advantage of the way in which WISE scans the sky multiple times.

This allowed them to identify cool brown dwarfs that were fainter than other searches had revealed.

The team of scientists then studied the infrared light emitted from these objects, which are unusual compared to typical slower moving brown dwarfs.

The spectral signatures of their light reflects their ancient atmospheres, which are almost entirely made up of hydrogen rather than having the more abundant heavier elements seen in younger stars.

Pinfield comments on their venerable ages and high speeds, "Unlike in other walks of life, the Galaxy's oldest members move much faster than its younger population".

More information: "A deep WISE search for very late type objects and the discovery of two halo/thick-disk T dwarfs: WISE 0013+0634 and WISE 0833+0052", D. J. Pinfield et al, Monthly Notices of the Royal Astronomical Society, in press. A pre-publication version of the paper is available on arXiv: arxiv.org/abs/1308.0495

ALMA reveals ghostly shape of 'coldest place in the universe'

The Boomerang Nebula, called the "coldest place in the Universe," reveals its true shape with ALMA. 

The background blue structure, as seen in visible light with the Hubble Space Telescope, shows a classic double-lobe shape with a very narrow central region. 

ALMA's resolution and ability to see the cold molecular gas reveals the nebula's more elongated shape, as seen in red. 

Credit: Bill Saxton; NRAO/AUI/NSF; NASA/Hubble; Raghvendra Sahai

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

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

As originally observed with ground-based telescopes, this nebula appeared lopsided, which is how it got its name.

Later observations with the Hubble Space Telescope revealed a bow-tie-like structure. The new ALMA data, however, reveal that the Hubble image tells only part of the story, and the twin lobes seen in that image may actually be a trick of the light as seen at visible wavelengths.

Raghvendra Sahai

"This ultra-cold object is extremely intriguing and we're learning much more about its true nature with ALMA," said Raghvendra Sahai, a researcher and principal scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of a paper published in the Astrophysical Journal.

"What seemed like a double lobe, or 'boomerang' shape, from Earth-based optical telescopes, is actually a much broader structure that is expanding rapidly into space."

The Boomerang Nebula, located about 5,000 light-years away in the constellation Centaurus, is a relatively young example of an object known as a planetary nebula.

Planetary nebulae, contrary to their name, are actually the end-of-life phases of stars like our Sun that have sloughed off their outer layers.

What remains at their centers are white dwarf stars, which emit intense ultraviolet radiation that causes the gas in the nebulae to glow and emit light in brilliant colours.

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

The outflow of gas from this particular star is expanding rapidly and cooling itself in the process. This is similar in principle to the way refrigerators use expanding gas to produce cold temperatures.

The researchers were able to take the temperature of the gas in the nebula by seeing how it absorbed the cosmic microwave background radiation, which has a very uniform temperature of 2.8 degrees Kelvin (minus 455 degrees Fahrenheit).

"When astronomers looked at this object in 2003 with Hubble, they saw a very classic 'hourglass' shape," commented Sahai.

"Many planetary nebulae have this same double-lobe appearance, which is the result of streams of high-speed gas being jettisoned from the star. The jets then excavate holes in a surrounding cloud of gas that was ejected by the star even earlier in its lifetime as a red giant."

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

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

New Star's 'Snow Line' Reveals Clues About Planet Formation

Astronomers have identified the point where carbon monoxide (CO) freezes in the disk around a sunlike star — information that could help them understand how planets form.

A team of international scientists has calculated the CO "snow line" for a star called TW Hydrae, determining that the gas solidifies at about the distance of the orbit of Neptune, where it could help feed the formation of the outer edges of the system.

"The CO snow line is interesting, not only because CO is abundant in the disks, but its snow line is the most accessible to direct observations due to its low freeze-out temperature — it's farther away from the star," said principal investigator Chunhua Qi of the Harvard-Smithsonian Center for Astrophysics.

"It could mark the starting point where smaller icy bodies, like comets, and dwarf planets, like Pluto, would begin to form."

Volatiles like carbon monoxide freeze at a range of temperatures, and each can have its own impact on the growth of orbiting bodies.

The location of the snow lines for volatiles can affect planetary formation. 

Recent research has indicated the water snow line, shown here, lies farther out than previously suspected.

Credit: NASA, ESA, and A. Feild (STScI)

Tracer ions
Stars form when a disk of dust and gas collapses in on itself due to gravity. The remaining material continues to orbit the newly formed object in a disk of material.

As dust and gas particles pass through the disk, scientists say, they come together to form larger and larger clumps that can eventually grow into planets. Frozen volatiles help this process along.

"The snow line provides more sticky solid grains, and enhances the planet formation efficiency and grain growth," Qi told reporters.

But determining the location of these grains can be a challenge. Emission from volatiles along the outside of the disk can make it difficult for scientists to image the telltale signs of frozen compounds.

To locate the region of the disk where CO freezes, Qi and his team utilized a new technique. Using the Atacama Large Millimeter Array (ALMA) in Chile, they searched for the ion diazenylium (N2H+), rather than the hard-to-find carbon monoxide, around TW Hydrae, which lies 176 light-years from Earth.

"N2H+ is easily destroyed in the presence of CO gas, and is abundant where CO has frozen out," Qi said.

The new technique should be helpful for studying the CO snow lines of other stars, which will provide more insight into how outer solar-system objects form.

"As long as the disk is gas-rich, so that there should be enough N2H+, we can use this ion to image the CO snow line," Qi said.

NASA Hi-C Rocket-launched camera reveals highways and sparkles in the solar atmosphere

An image of an active, magnetically complicated region of the Sun captured by the new Hi-C instrument. 

It shows plasma in the outer solar atmosphere at a temperature of 1-2 million degrees Celsius. 

The inset box at bottom left shows 'sparkle' features that are releasing vast amounts of energy into the corona. 

The box at top right shows a close-up of part of a solar filament where 'blobs' of solar plasma flow along thread-like 'highway' structures. 

Credit: NASA MSFC and UCLan 

Using an innovative new camera on board a sounding rocket, an international team of scientists have captured the sharpest images yet of the Sun's outer atmosphere.

The team discovered fast-track 'highways' and intriguing 'sparkles' that may help answer a long-standing solar mystery.

Prof. Robert Walsh of the University of Central Lancashire (UCLan) will present the new results on Monday 1 July at the RAS National Astronomy Meeting in St Andrews, Scotland.

With partners in the United States and Russia, the UCLan team used a sounding rocket to launch the NASA High Resolution Coronal Imager (Hi-C) from the White Sands Missile Range in New Mexico, USA.

During its short flight, the Hi-C team obtained images of the solar atmosphere (the solar corona) five times sharper than anything seen before and acquired data at a rate of about one image every five seconds.



The ultra-high resolution images captured by NASA's Hi-C instrument (High-resolution Coronal Imager) have uncovered an amazing amount of detail within the hot outer atmosphere of the Sun (the corona). 

Movie top right: "blobs" of electrified gas (plasma) racing along magnetic highways at strands with material moving along them at up to 80 km/s. 

Movie bottom left: solar "sparkles" switching off and on in under 30 seconds, releasing energy into the solar corona.

The new camera observed the Sun in extreme ultraviolet light and focused on a large, magnetically-active sunspot region. Images from Hi-C reveal a number of new features in the corona, including 'blobs' of gas ricocheting along 'highways' and bright dots that switch on and off rapidly which the group call 'sparkles'.

In the new images, small clumps of electrified gas (plasma) at a temperature of about one million degrees Celsius are seen racing along highways shaped by the Sun's magnetic field.

These blobs travel at around 80 km per second (the equivalent of 235 times the speed of sound on Earth), fast enough to travel the distance from Glasgow to London in 7 seconds.

The highways are 450 km across, roughly the length of Ireland from north to south.

These 'sparkles' typically last around 25 seconds, are about 680 km across (the size of the UK) and release at least 1024 (one million million million million) Joules of energy in each event or around 10,000 times the annual energy consumption of the population of the UK (based on information from the UK Department of Energy and Climate Change).

The sparkles are thus a clear signal that enormous amounts of energy are being added into the corona and may then be released violently to heat the plasma.

Solar physicist Professor Robert Walsh, UCLan's University Director of Research, added: "I'm incredibly proud of the work of my colleagues in developing Hi-C.

The camera is effectively a microscope that lets us view small scale events on the Sun in unprecedented detail.

For the first time we can unpick the detailed nature of the solar corona, helping us to predict when outbursts from this region might head towards the Earth."

NASA Marshall heliophysicist Dr Jonathan Cirtain, principal investigator for the Hi-C mission said: "Our team developed an exceptional instrument capable of revolutionary image resolution of the solar atmosphere.

We took advantage of the high level of solar activity to focus in on an active sunspot and obtained these remarkable pictures."

ESO VLT Reveals Dust ring around Supermassive black hole in NGC 3783

This artist’s impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus (The Centaur). 

New observations using the Very Large Telescope Interferometer at ESO’s Paranal Observatory in Chile have revealed not only the torus of hot dust around the black hole but also a wind of cool material in the polar regions.

Credit: ESO/M. Kornmesser

ESO's Very Large Telescope Interferometer has gathered the most detailed observations ever of the dust around the huge black hole at the centre of an active galaxy.

Rather than finding all of the glowing dust in a doughnut-shaped torus around the black hole, as expected, the astronomers find that much of it is located above and below the torus.

These observations show that dust is being pushed away from the black hole as a cool wind - a surprising finding that challenges current theories and tells us how supermassive black holes evolve and interact with their surroundings.

Over the last twenty years, astronomers have found that almost all galaxies have a huge black hole at their centre.

Some of these black holes are growing by drawing in matter from their surroundings, creating in the process the most energetic objects in the Universe: active galactic nuclei (AGN).

The central regions of these brilliant powerhouses are ringed by doughnuts of cosmic dust dragged from the surrounding space, similar to how water forms a small whirlpool around the plughole of a sink.

It was thought that most of the strong infrared radiation coming from AGN originated in these doughnuts.

But new observations of a nearby active galaxy called NGC 3783, harnessing the power of the Very Large Telescope Interferometer (VLTI) at ESO's Paranal Observatory in Chile, have given a team of astronomers a surprise.

Although the hot dust - at some 700 to 1000 degrees Celsius - is indeed in a torus as expected, they found huge amounts of cooler dust above and below this main torus.

As Sebastian Honig (University of California Santa Barbara, USA and Christian-Albrechts-Universitat zu Kiel, Germany), lead author of the paper presenting the new results, explains, "This is the first time we've been able to combine detailed mid-infrared observations of the cool, room-temperature dust around an AGN with similarly detailed observations of the very hot dust. This also represents the largest set of infrared interferometry for an AGN published yet."

The newly-discovered dust forms a cool wind streaming outwards from the black hole. This wind must play an important role in the complex relationship between the black hole and its environment.

The black hole feeds its insatiable appetite from the surrounding material, but the intense radiation this produces also seems to be blowing the material away.

It is still unclear how these two processes work together and allow supermassive black holes to grow and evolve within galaxies, but the presence of a dusty wind adds a new piece to this picture.

More Information: ESO Research Paper

Hubble Image: Reveals very bright South America Galaxy

Credit: ESA/Hubble & NASA

The contorted object captured by Hubble in this picture is IRAS 22491-1808, also known as the South America Galaxy. 

It is an ultra-luminous infrared galaxy (ULIRG) that emits a huge amount of light at infrared wavelengths. 

The reason for this intense infrared emission lies in an episode of strong star formation activity, which was set off by a collision between two interacting galaxies.

In this image, the twisted shape hides a number of features. 

In the central region, which is very complex and disturbed, scientists have been able to distinguish two nuclei, remains of the two different galaxies that are currently colliding to form a new one. 

IRAS 22491-1808 is among the most luminous of these types of galaxies, and is considered to be mid-way through its merging stage.

The center of this appealing object also shows several intense star-forming knots which, as seen in the picture, actually outshine the nuclei in optical wavelengths. 

To pick out the two merging nuclei in IRAS 22491-1808, scientists have had to observe it in infrared wavelengths, where they are more distinct.

Other traces of the galactic collision are the three very noticeable tails in the image—two linear and one circular. 

The tail extending towards the bottom of the image from the main body exhibits a red clump of star formation at its base.

NASA ASTER Image: Infrared Light Reveals Tornado's Path

On May 20, 2013, central Oklahoma was devastated by a EF-5 tornado, the most severe on the enhanced Fujita scale. 

The Newcastle-Moore tornado killed at least 24 people, injured 377, and affected nearly 33,000 in some way. 

Early estimates suggest that more then $2 billion in damage was done to public and private property; at least 13,000 structures were destroyed or damaged. 

It was the deadliest tornado in the United States since an EF-5 event killed 158 people in Joplin, Missouri, in 2011.

On June 2, 2013, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite observed the scar of that tornado on the Oklahoma landscape. 

In this false-colour image, infrared, red, and green wavelengths of light have been combined to better distinguish between water, vegetation, bare ground, and human developments. 

Water is blue. Buildings and paved surfaces are blue-gray. Vegetation is red. The tornado track appears as a beige stripe running west to east across this image; the colour reveals the lack of vegetation in the wake of the storm.

According to the National Weather Service, the tornado was on the ground for 39 minutes, ripping across 17 miles (27 kilometers) from 4.4 miles west of Newcastle to 4.8 miles east of Moore, Oklahoma. 

At its peak, the funnel cloud was 1.3 miles (2.1 kilometers) wide and wind speeds reached 210 miles (340 km) per hour.

Image Credit: NASA Earth Observatory

Gas cloud reveals Black Holes near centre of Milky Way galaxy

Colour composite image of Centaurus A, revealing the lobes and jets emanating from the active galaxy’s central black hole. 

Composite images: ESO/WFI (Optical); MPIfR/ESO/APEX/A.Weiss et al. (Submillimetre); NASA/CXC/CfA/R.Kraft et al. (X-ray)

A team of researchers from Columbia University has published a paper in Physical Review Letters in which they suggest that the movement of gas cloud G2 near the center of our galaxy may reveal previously hidden small black holes.

They note also that observation of G2's movement might lead to direct evidence of the existence of intermediate size black holes.

G2, a massive cloud of gasses three times the size of Pluto's orbit (but just 3 times the mass of Earth) was discovered moving through our galaxy two years ago by researchers at the Max Planck Institute.

After noting its projected path, the researchers at Columbia have found that it will likely pass through a region of space that is thought to harbor as many as 20,000 small black holes (a single massive black hole is believed to exist at the center of our galaxy.)

They suggest that researchers here on Earth might be able to actually see the interaction between the gas cloud and any black holes that are encountered.

As the gas cloud comes near a black hole, they believe some of the gas will begin to spiral as it's pulled in by its gravity.

That, they say, should cause a lot of heat to be expelled and x-ray light to be emitted—enough to be observable using x-ray telescopes.

They go so far as to estimate that researchers might be able to see evidence of as many as 16 interactions.

More exciting to some in the field, is the possibility that the movement of G2 through our galaxy may give direct evidence of what are known as intermediate sized black holes—believed by some to be several times the mass of our sun.

To date, their existence is purely theoretical. If G2 comes across one, and interacts with it, the event could prove that they really do exist.

They, like the many small black holes in the universe, are believed to reside near the center of the galaxy, which is where G2 is heading.

The researchers estimate it will reach the best position for study this September, giving researchers plenty of time to prepare.

One unknown attribute of G2 could throw a wrench into the project however—the density of the gas cloud is not yet known.

If it's not dense enough, any interactions with a black hole may not create enough light to be seen from Earth.

More information: Gas Cloud G2 Can Illuminate the Black Hole Population Near the Galactic Center, Phys. Rev. Lett. 110, 221102 (2013) prl.aps.org/abstract/PRL/v110/i22/e221102

Abstract
Galactic nuclei are expected to be densely populated with stellar- and intermediate-mass black holes.

Exploring this population will have important consequences for the observation prospects of gravitational waves as well as understanding galactic evolution.

The gas cloud G2 currently approaching Sgr A* provides an unprecedented opportunity to probe the black hole and neutron star population of the Galactic nucleus.

We examine the possibility of a G2-cloud–black-hole encounter and its detectability with current x-ray satellites, such as Chandra and NuSTAR.

We find that multiple encounters are likely to occur close to the pericenter, which may be detectable upon favorable circumstances.

This opportunity provides an additional important science case for leading x-ray observatories to closely follow G2 on its way to the nucleus.

South Africa's New Radio Telescope SKA Reveals Giant Outbursts from Binary Star System

An artist's impression of the Circinus X-1 system showing the binary (double) star system. 

Two stars orbit each other every 16.5 days in an elliptical orbit. 

The small white sphere is the neutron star - an extremely dense and compact remnant of an exploded star, only about 20 km in diameter. 

The red sphere is an ordinary star - the companion star in this system. 

When the two stars are at their closest, the neutron star pulls material from its companion star. 

An accretion disk (the blue disk) forms around the neutron star, containing the matter that is sucked from the ordinary star. 

Powerful jets of material (the orange rays) then blast out from the neutron star at close to the speed of light, causing powerful flares in radio frequencies. 

Credit: Image courtesy of University of Southampton /SKA South Africa

An international team of astronomers have reported the first scientific results from the Karoo Array Telescope (KAT-7) in South Africa, the pathfinder radio telescope for the $3 billion global Square Kilometre Array (SKA) project.

The results appear in the latest issue of the international astronomical journal Monthly Notices of the Royal Astronomical Society (MNRAS).

Using the seven-dish KAT-7 telescope and the 26 m radio telescope at the Hartebeesthoek Radio Astronomy Observatory (HartRAO), astronomers have observed a neutron star system known as Circinus X-1 as it fires energetic matter from its core into the surrounding system in extensive, compact `jets' that flare brightly, details of which are visible only in radio waves.

Journal Reference: 
R. P. Armstrong, R.P. Fender, G.D. Nicolson, S. Ratcliffe, M. Linares, J.Horrell, L. Richter, M. P. E. Schurch, M. Coriat, P. Woudt, J. Jonas, R. Booth, B. Fanaroff. A return to strong radio flaring by Circinus X-1 observed with the Karoo Array Telescope test array KAT-7. Monthly Notices of the Royal Astronomical Society, 2013

NASA Mars HiRISE: Camera reveals Two hundred impacts each year

This image shows one of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA's Mars Reconnaissance Orbiter since 2006. 

Credit: NASA /JPL-Caltech /MSSS /UA

Scientists using images from NASA's Mars Reconnaissance Orbiter, or MRO, have estimated that the planet is bombarded by more than 200 small asteroids or bits of comets per year forming craters at least 12.8 feet (3.9 meters) across.

Researchers have identified 248 new impact sites on parts of the Martian surface in the past decade, using images from the spacecraft to determine when the craters appeared.

The 200-per-year planet-wide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.

The University of Arizona's High Resolution Imaging Science Experiment, or HiRISE camera, took pictures of the fresh craters at sites where before and after images had been taken.

This combination provided a new way to make direct measurements of the impact rate on Mars and will lead to better age estimates of recent features on Mars, some of which may have been the result of climate change.

"It's exciting to find these new craters right after they form," said Ingrid Daubar of the UA, lead author of the paper published online this month by the journal Icarus.

"It reminds you Mars is an active planet, and we can study processes that are happening today."

These asteroids or comet fragments typically are no more than 3 to 6 feet (1 to 2 meters) in diameter.

Space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere.

MRO has been examining Mars with six instruments since 2006. Daubar is an imaging targeting specialist who has been on the HiRISE uplink operation s team from the very beginning.

She is also a graduate student in the UA's department of planetary science and plans on graduating with her doctorate in spring 2014.

Leslie Tamppari

"There are five of us who help plan the images that HiRISE will take over a two-week cycle," she explained.

"We work with science team members across the world to understand their science goals, help select the image targets and compile the commands for the spacecraft and the camera."

"The longevity of this mission is providing wonderful opportunities for investigating changes on Mars," said MRO Deputy Project Scientist Leslie Tamppari of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

ESA ESO APEX Telescope Reveals Spectacular 'Fiery Ribbon' in Orion Nebula

This dramatic new image of cosmic clouds in the constellation of Orion reveals what seems to be a fiery ribbon in the sky. 

The orange glow represents faint light coming from grains of cold interstellar dust, at wavelengths too long for human eyes to see. 

CREDIT: ESO/Digitized Sky Survey 2

APEX telescope in Chile has captured stunning new photos of a cosmic ribbon shimmering in the Orion nebula more than 1,000 light-years from Earth.

The new images — released by the European Southern Observatory (ESO) today (May 15) — show what scientists described as a "fiery ribbon" of red gas and dust shining in the constellation Orion's belt.

The ribbon is a small part of a huge star-forming region of the universe.

ESO scientists used the APEX telescope in Chile to craft a video tour of the clouds of dust that combine to create new stars.

"The large bright cloud in the upper right of the image is the well-known Orion Nebula, also called Messier 42," ESO officials wrote in a news release.

"It is readily visible to the naked eye as the slightly fuzzy middle 'star' in the sword of Orion. The Orion Nebula is the brightest part of a huge stellar nursery where new stars are being born, and is the closest site of massive star formation to Earth."



Although the clouds of dust and gas in the red-tinted image might look as if they're burning hot, they are actually freezing cold.

ESO's APEX telescope in Chile took the photo in wavelengths invisible to the human eye. In this image, the hottest object glow blue while the coolest have an orange tint.

Cosmic Flash may reveal Birth of a Black Hole

A computer-generated image of the light distortions created by a black hole. Credit: Alain Riazuelo, IAP/UPMC/CNRS

When a massive star exhausts its fuel, it collapses under its own gravity and produces a black hole, an object so dense that not even light can escape its gravitational grip.

According to a new analysis by an astrophysicist at the California Institute of Technology (Caltech), just before the black hole forms, the dying star may generate a distinct burst of light that will allow astronomers to witness the birth of a new black hole for the first time.

Tony Piro

Tony Piro, a postdoctoral scholar at Caltech, describes this signature light burst in a paper published in the May 1 issue of the Astrophysical Journal Letters.

While some dying stars that result in black holes explode as gamma-ray bursts, which are among the most energetic phenomena in the universe, those cases are rare, requiring exotic circumstances, Piro explains.

"We don't think most run-of-the-mill black holes are created that way." In most cases, according to one hypothesis, a dying star produces a black hole without a bang or a flash: the star would seemingly vanish from the sky—an event dubbed an unnova. "You don't see a burst," he says. "You see a disappearance."

But, Piro hypothesizes, that may not be the case. "Maybe they're not as boring as we thought," he says.

According to well-established theory, when a massive star dies, its core collapses under its own weight. As it collapses, the protons and electrons that make up the core merge and produce neutrons.

For a few seconds—before it ultimately collapses into a black hole—the core becomes an extremely dense object called a neutron star, which is as dense as the sun would be if squeezed into a sphere with a radius of about 10 kilometers (roughly 6 miles).

This collapsing process also creates neutrinos, which are particles that zip through almost all matter at nearly the speed of light.

As the neutrinos stream out from the core, they carry away a lot of energy—representing about a tenth of the sun's mass (since energy and mass are equivalent, per E = mc2).

According to a little-known paper written in 1980 by Dmitry Nadezhin of the Alikhanov Institute for Theoretical and Experimental Physics in Russia, this rapid loss of mass means that the gravitational strength of the dying star's core would abruptly drop.

When that happens, the outer gaseous layers—mainly hydrogen—still surrounding the core would rush outward, generating a shock wave that would hurtle through the outer layers at about 1,000 kilometers per second (more than 2 million miles per hour).

Stan Woosley

Using computer simulations, two astronomers at UC Santa Cruz, Elizabeth Lovegrove and Stan Woosley, recently found that when the shock wave strikes the outer surface of the gaseous layers, it would heat the gas at the surface, producing a glow that would shine for about a year—a potentially promising signal of a black-hole birth.

Although about a million times brighter than the sun, this glow would be relatively dim compared to other stars.

"It would be hard to see, even in galaxies that are relatively close to us," says Piro.

But now Piro says he has found a more promising signal. In his new study, he examines in more detail what might happen at the moment when the shock wave hits the star's surface, and he calculates that the impact itself would make a flash 10 to 100 times brighter than the glow predicted by Lovegrove and Woosley.

"That flash is going to be very bright, and it gives us the best chance for actually observing that this event occurred," Piro explains. "This is what you really want to look for."

Such a flash would be dim compared to exploding stars called supernovae, for example, but it would be luminous enough to be detectable in nearby galaxies, he says.

The flash, which would shine for 3 to 10 days before fading, would be very bright in optical wavelengths—and at its very brightest in ultraviolet wavelengths.

Piro estimates that astronomers should be able to see one of these events per year on average. Surveys that watch the skies for flashes of light like supernovae—surveys such as the Palomar Transient Factory (PTF), led by Caltech—are well suited to discover these unique events, he says.

The intermediate Palomar Transient Factory (iPTF), which improves on the PTF and just began surveying in February, may be able to find a couple of these events per year.

Neither survey has observed any black-hole flashes as of yet, says Piro, but that does not rule out their existence. "Eventually we're going to start getting worried if we don't find these things." But for now, he says, his expectations are perfectly sound.

Novel analysis method reveals more about the enigmatic Quasar

The interaction of a supermassive black hole and a disk of accreting matter, called a quasar, can be seen at the center of a faraway galaxy in this artist's concept. 

It consists of a dusty, doughnut-shaped cloud of gas and dust that feeds a central supermassive black hole. 

As the black hole feeds, the gas and dust heat up and spray out different kinds of light, as illustrated by the white rays. 

In the nearly six decades since quasars were discovered, the list of these energetic galaxies powered by supermassive black holes has grown to more than 100,000 – enough examples to reveal important information about the quasar population as a whole.

But attempts to conduct a celestial census of these powerful objects have been limited by a fundamental problem: Although quasars are bright, they also span billions of light years in distance from Earth. Just as with stars in an urban sky, the closest quasars can be seen even if they are dim, while the oldest and most distant ones can be seen only if they are bright.

This means astrophysicists have to study a sample with big differences among individual members, including distance, age, brightness and type of radiation emitted.

Astrophysicists with the Kavli Institute for Particle Astrophysics and Cosmology, a joint SLAC-Stanford institute, found a way to reach past these limitations: They improved an algorithm that homes in on important commonalities of a population of objects while taking into account the limitations and biases for observations made in multiple types of electromagnetic radiation, such as optical light or radio waves – two of the most important wavelengths for studying quasars.

In the process they shed new light on a contentious question: Are there two types of quasars, with one "louder" in radio than the other, or is there just one type with emissions that vary widely across the electromagnetic spectrum?

A recent paper in The Astrophysical Journal details how the team, including KIPAC scientist Jack Singal, KIPAC member and Stanford professor Vahe Petrosian and KIPAC alumnus Lukasz Stawarz, improved upon an algorithm developed more than a decade ago by Petrosian and Bradley Efron, a respected statistics professor at Stanford.

After validating their algorithm with a small sample, the team turned it loose on the largest sample of quasars yet available: the Sloan Digital Sky Survey (SDSS) Data Release 7 catalog, which has optical-light measurements for more than 100,000 quasars, plus data from the FIRST radio survey, which has more than 400,000 celestial radio sources, to achieve a huge combined sample of radio and optical quasars for analysis.

The team found that quasars have, on average, grown steadily dimmer in both radio and optical light over the history of the universe, but have dimmed more in radio than in optical – dramatically so.

This analysis also supports the "one quasar population" model, and both that and the greater dimming in radio relative to optical light are sure to spark controversy.

Regardless, the work represents what the authors consider to be the most rigorous analysis yet of the evolution of quasars in both radio and optical emissions.

According to Singal, the technique is also useful for studying any population of objects that can be found at widely varying distances – for example, blazars or gamma-ray bursts.

More information: iopscience.iop.org/0004-637X/764/1/43

Atomic Fountain reveals 'Gravitational Red Shift'

Atomic fountain reveals 'gravitational red shift' - New Scientist

YOUR watch runs a tiny bit faster at the top of Everest, where Earth's gravity is slightly weaker, than it does at sea level.

This difference is dubbed the "gravitational red shift" (GRS) and is one of the trickiest predictions of general relativity to measure because the effect is so small.

Now the accuracy of measurement has been improved by a factor of 10,000. Holger Müller at the University of California, Berkeley, decided to reanalyse a decade-old experiment.

In the 1990s, a team led by Nobel laureate Steven Chu made an "atomic fountain" of caesium atoms, launching them 30 centimetres into the air.

A pulse of laser light struck the atoms as they neared their zenith, which kicked them into a two-state quantum superposition. One of the states was given extra momentum, causing it to rise to a slightly higher altitude than the other state before falling.

Müller realised the atoms and their very rapid oscillations could be treated as tiny "clocks" and so could be used to measure GRS. The team compared the difference between the two states and discovered that the state that climbed slightly higher had oscillated ever-so-slightly faster than the lower state.

With an accuracy of 7 parts in a billion, this measurement is 10,000 times as accurate as the previous one (Nature, DOI: 10.1038/nature08776).

NASA MARS: Stranded Rover Spirit reveals interesting discovery

A topographic map of Spirit's surroundings at Troy. Spirit is straddling the edge of a small crater. Sulfate materials are located in the crater (from the middle of the rover and extending to the left).

The topo map was generated from stereo images taken by Spirit's navigation camera when it was approaching the area in April 7, 2009.

Welcome to "Troy" - Mars style. NASA's robotic rover Spirit is bogged down on the Red Planet in a place the rover team named after the ancient city of Troy. So why aren't scientists lamenting?

"The rover's spinning wheels have broken through a crust, and we've found something supremely interesting in the disturbed soil," says Ray Arvidson of the Washington University in St. Louis.

Spirit, like its twin rover Opportunity, has roamed the Red Planet for nearly 6 years. During that time, the rover has had some close calls and come out fighting from each. In fact, it's been driving backwards since one of its wheels jammed in 2006. From the beginning, the rovers' motto has been "follow the water."

Both rovers have been searching Mars for minerals formed in the presence of H2O. Mars appears dry today, but minerals can provide clues that water was once there.

"It's been easy for Opportunity to find such minerals," explains Arvidson. "Opportunity landed in an ancient lake bed. Spirit has had to work much harder. Spirit landed in basaltic plains formed by lava flows chewed up by repeated meteoroid impacts. There's been little evidence of anything that was ever very wet."

But when Spirit reached an area of Mars called the "Columbia Hills," the whole complexion of the mission changed. "Spirit came across iron hydroxide, a mineral that forms in the presence of water. That alerted us to the change. We started coming across more and more rocks formed in the presence of water." Then Spirit got stuck in a patch of loose soil on the edge of a small crater. Heavy sigh. Stuck again.

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