вторник, 15 января 2019 г.

Building the Wall More powerful than abs of steel or brawny…

Building the Wall

More powerful than abs of steel or brawny biceps, your heart is the strongest muscle in your body. Its strength comes from the heart wall, which includes a layer of muscle, the myocardium and an inner lining, the endocardium. Wall integrity is essential for heart development and function, and how it’s maintained has been studied by researchers in zebrafish by focusing on a protein found in the endocardium, KLF2. Imaging the hearts of zebrafish mutants lacking KLF2 using confocal microscopy and 3D reconstructions revealed that myocardium cells were pushed outwards in mutants, as observed from the outside (left) and inside (right) of the heart. The team also found defects in signalling molecules in the mutants too, specifically with one called FGF. Blocking FGF signalling in normal hearts mimicked the defects seen in mutants, hinting at the inner workings of maintaining heart wall integrity.

Written by Lux Fatimathas

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X-ray pulse detected near event horizon as black hole devours star

On Nov. 22, 2014, astronomers spotted a rare event in the night sky: A supermassive black hole at the center of a galaxy, nearly 300 million light years from Earth, ripping apart a passing star. The event, known as a tidal disruption flare, for the black hole’s massive tidal pull that tears a star apart, created a burst of X-ray activity near the center of the galaxy. Since then, a host of observatories have trained their sights on the event, in hopes of learning more about how black holes feed.

X-ray pulse detected near event horizon as black hole devours star
This artist’s impression shows hot gas orbiting in a disk around a rapidly-spinning black hole. The elongated spot
depicts an X-ray-bright region in the disk, which allows the spin of the black hole to be estimated
[Credit: NASA/CXC/M. Weiss]

Now researchers at MIT and elsewhere have pored through data from multiple telescopes’ observations of the event, and discovered a curiously intense, stable, and periodic pulse, or signal, of X-rays, across all datasets. The signal appears to emanate from an area very close to the black hole’s event horizon — the point beyond which material is swallowed inescapably by the black hole. The signal appears to periodically brighten and fade every 131 seconds, and persists over at least 450 days.

The researchers believe that whatever is emitting the periodic signal must be orbiting the black hole, just outside the event horizon, near the Innermost Stable Circular Orbit, or ISCO — the smallest orbit in which a particle can safely travel around a black hole.

Given the signal’s stable proximity to the black hole, and the black hole’s mass, which researchers previously estimated to be about 1 million times that of the sun, the team has calculated that the black hole is spinning at about 50 percent the speed of light.

The findings, reported this week in the journal Science, are the first demonstration of a tidal disruption flare being used to estimate a black hole’s spin.

The study’s first author, Dheeraj Pasham, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research, says that most supermassive black holes are dormant and don’t usually emit much in the way of X-ray radiation. Only occasionally will they release a burst of activity, such as when stars get close enough for black holes to devour them. Now he says that, given the team’s results, such tidal disruption flares can be used to estimate the spin of supermassive black holes — a characteristic that has been, up until now, incredibly tricky to pin down.

“Events where black holes shred stars that come too close to them could help us map out the spins of several supermassive black holes that are dormant and otherwise hidden at the centers of galaxies,” Pasham says. “This could ultimately help us understand how galaxies evolved over cosmic time.”

Pasham’s co-authors include Ronald Remillard, Jeroen Homan, Deepto Chakrabarty, Frederick Baganoff, and James Steiner of MIT; Alessia Franchini at the University of Nevada; Chris Fragile of the College of Charleston; Nicholas Stone of Columbia University; Eric Coughlin of the University of California at Berkeley; and Nishanth Pasham, of Sunnyvale, California.

A real signal

Theoretical models of tidal disruption flares show that when a black hole shreds a star apart, some of that star’s material may stay outside the event horizon, circling, at least temporarily, in a stable orbit such as the ISCO, and giving off periodic flashes of X-rays before ultimately being fed by the black hole. The periodicity of the X-ray flashes thus encodes key information about the size of the ISCO, which itself is dictated by how fast the black hole is spinning.

Pasham and his colleagues thought that if they could see such regular flashes very close to a black hole that had undergone a recent tidal disruption event, these signals could give them an idea of how fast the black hole was spinning.

They focused their search on ASASSN-14li, the tidal disruption event that astronomers identified in November 2014, using the ground-based All-Sky Automated Survey for SuperNovae (ASASSN).

“This system is exciting because we think it’s a poster child for tidal disruption flares,” Pasham says. “This particular event seems to match many of the theoretical predictions.”

The team looked through archived datasets from three observatories that collected X-ray measurements of the event since its discovery: the European Space Agency’s XMM-Newton space observatory, and NASA’s space-based Chandra and Swift observatories. Pasham previously developed a computer code to detect periodic patterns in astrophysical data, though not for tidal disruption events specifically. He decided to apply his code to the three datasets for ASASSN-14li, to see if any common periodic patterns would rise to the surface.

What he observed was a surprisingly strong, stable, and periodic burst of X-ray radiation that appeared to come from very close to the edge of the black hole. The signal pulsed every 131 seconds, over 450 days, and was extremely intense — about 40 percent above the black hole’s average X-ray brightness.

“At first I didn’t believe it because the signal was so strong,” Pasham says. “But we saw it in all three telescopes. So in the end, the signal was real.”

Based on the properties of the signal, and the mass and size of the black hole, the team estimated that the black hole is spinning at least at 50 percent the speed of light.

“That’s not super fast — there are other black holes with spins estimated to be near 99 percent the speed of light,” Pasham says. “But this is the first time we’re able to use tidal disruption flares to constrain the spins of supermassive black holes.”

Illuminating the invisible

Once Pasham discovered the periodic signal, it was up to the theorists on the team to find an explanation for what may have generated it. The team came up with various scenarios, but the one that seems the most likely to generate such a strong, regular X-ray flare involves not just a black hole shredding a passing star, but also a smaller type of star, known as a white dwarf, orbiting close to the black hole.

Such a white dwarf may have been circling the supermassive black hole, at ISCO — the innermost stable circular orbit — for some time. Alone, it would not have been enough to emit any sort of detectable radiation. For all intents and purposes, the white dwarf would have been invisible to telescopes as it circled the relatively inactive, spinning black hole.

Sometime around Nov. 22, 2014, a second star passed close enough to the system that the black hole tore it apart in a tidal disruption flare that emitted an enormous amount of X-ray radiation, in the form of hot, shredded stellar material. As the black hole pulled this material inward, some of the stellar debris fell into the black hole, while some remained just outside, in the innermost stable orbit — the very same orbit in which the white dwarf circled. As the white dwarf came in contact with this hot stellar material, it likely dragged it along as a luminous overcoat of sorts, illuminating the white dwarf in an intense amount of X-rays each time it circled the black hole, every 131 seconds.

The scientists admit that such a scenario would be incredibly rare and would only last for several hundred years at most — a blink of an eye in cosmic scales. The chances of detecting such a scenario would be exceedingly slim.

“The problem with this scenario is that, if you have a black hole with a mass that’s 1 million times that of the sun, and a white dwarf is circling it, then at some point over just a few hundred years, the white dwarf will plunge into the black hole,” Pasham says. “We would’ve been extremely lucky to find such a system. But at least in terms of the properties of the system, this scenario seems to work.”

The results’ overarching significance is that they show it is possible to constrain the spin of a black hole, from tidal disruption events, according to Pasham. Going forward, he hopes to identify similar stable patterns in other star-shredding events, from black holes that reside further back in space and time.

“In the next decade, we hope to detect more of these events,” Pasham says. “Estimating spins of several black holes from the beginning of time to now would be valuable in terms of estimating whether there is a relationship between the spin and the age of black holes.”

Author: Jennifer Chu | Source: Massachusetts Institute of Technology [January 09, 2019]



Cosmic telescope zooms in on the beginning of time

Observations from Gemini Observatory identify a key fingerprint of an extremely distant quasar, allowing astronomers to sample light emitted from the dawn of time. Astronomers happened upon this deep glimpse into space and time thanks to an unremarkable foreground galaxy acting as a gravitational lens, which magnified the quasar’s ancient light. The Gemini observations provide critical pieces of the puzzle in confirming this object as the brightest appearing quasar so early in the history of the Universe, raising hopes that more sources like this will be found.

Cosmic telescope zooms in on the beginning of time
This is a Hubble Space Telescope image of a very distant quasar (at right) that has been brightened and split into three
images by the effects of the gravitational field of a foreground galaxy (left). The crosses mark the centers of each quasar
image. The quasar would have gone undetected if not for the power of gravitational lensing, which boosted its brightness
 by a factor of 50. The gravitational field of the foreground galaxy (seen at left) warps space like a funhouse mirror,
amplifying the quasar’s light. Shining with the brilliance of 600 trillion suns, the quasar is fueled by a supermassive black
hole at the heart of a young galaxy in the process of forming. The image shows the quasar as it looked 12.8 billion years ago
– only about 1 billion years after the big bang. The quasar appears red because its blue light has been absorbed by diffuse
gas in intergalactic space. By comparison, the foreground galaxy has bluer starlight light. The quasar, cataloged as
J043947.08+163415.7 (J0439+1634 for short), could hold the record of being the brightest in the early universe for some
 time, making it a unique object for follow-up studies [Credit: NASA, ESA, Xiaohui Fan (University of Arizona)]

Before the cosmos reached its billionth birthday, some of the very first cosmic light began a long journey through the expanding Universe. One particular beam of light, from an energetic source called a quasar, serendipitously passed near an intervening galaxy, whose gravity bent and magnified the quasar’s light and refocused it in our direction, allowing telescopes like Gemini North to probe the quasar in great detail.

“If it weren’t for this makeshift cosmic telescope, the quasar’s light would appear about 50 times dimmer,” said Xiaohui Fan of the University of Arizona who led the study. “This discovery demonstrates that strongly gravitationally lensed quasars do exist despite the fact that we’ve been looking for over 20 years and not found any others this far back in time.”

The Gemini observations provided key pieces of the puzzle by filling a critical hole in the data. The Gemini North telescope on Maunakea, Hawai’i, utilized the Gemini Near-InfraRed Spectrograph (GNIRS) to dissect a significant swath of the infrared part of the light’s spectrum. The Gemini data contained the tell-tale signature of magnesium which is critical for determining how far back in time we are looking. The Gemini observations also led to a determination of the mass of the black hole powering the quasar. “When we combined the Gemini data with observations from multiple observatories on Maunakea, the Hubble Space Telescope, and other observatories around the world, we were able to paint a complete picture of the quasar and the intervening galaxy,” said Feige Wang of the University of California, Santa Barbara, who is a member of the discovery team.

That picture reveals that the quasar is located extremely far back in time and space — shortly after what is known as the Epoch of Reionization — when the very first light emerged from the Big Bang. “This is one of the first sources to shine as the Universe emerged from the cosmic dark ages,” said Jinyi Yang of the University of Arizona, another member of the discovery team. “Prior to this, no stars, quasars, or galaxies had been formed, until objects like this appeared like candles in the dark.”

This artist’s impression shows how J043947.08+163415.7, a very distant quasar powered by a supermassive black hole, 

may look close up. This object is by far the brightest quasar yet discovered in the early Universe 

[Credit: ESA/Hubble, NASA, M. Kornmesser]

The foreground galaxy that enhances our view of the quasar is especially dim, which is extremely fortuitous. “If this galaxy were much brighter, we wouldn’t have been able to differentiate it from the quasar,” explained Fan, adding that this finding will change the way astronomers look for lensed quasars in the future and could significantly increase the number of lensed quasar discoveries. However, as Fan suggested, “We don’t expect to find many quasars brighter than this one in the whole observable Universe.”

The intense brilliance of the quasar, known as J0439+1634 (J0439+1634 for short), also suggests that it is fueled by a supermassive black hole at the heart of a young forming galaxy. The broad appearance of the magnesium fingerprint captured by Gemini also allowed astronomers to measure the mass of the quasar’s supermassive black hole at 700 million times that of the Sun. The supermassive black hole is most likely surrounded by a sizable flattened disk of dust and gas. This torus of matter — known as an accretion disk — most likely continually spirals inward to feed the black hole powerhouse.

Observations at submillimeter wavelengths with the James Clerk Maxwell Telescope on Maunakea suggest that the black hole is not only accreting gas but may be triggering star birth at a prodigious rate — which appears to be up to 10,000 stars per year; by comparison, our Milky Way Galaxy makes one star per year. However, because of the boosting effect of gravitational lensing, the actual rate of star formation could be much lower.

Quasars are extremely energetic sources powered by huge black holes thought to have resided in the very first galaxies to form in the Universe. Because of their brightness and distance, quasars provide a unique glimpse into the conditions in the early Universe. This quasar has a redshift of 6.51, which translates to a distance of 12.8 billion light years, and appears to shine with a combined light of about 600 trillion Suns, boosted by the gravitational lensing magnification. The foreground galaxy which bent the quasar’s light is about half that distance away, at a mere 6 billion light years from us.

Cosmic telescope zooms in on the beginning of time
The light from quasar J0439+1634, some 12.8 billion light years away, passes close to a faint galaxy that is about six billion
light years away. The gravity of this foreground galaxy warps the space around it, according Einstein’s theory of general
relativity. This bends the light like an optical lens, magnifies the quasar image by a factor of fifty, while at the same time split
the quasar image into three. Both the foreground galaxy and the multiply imaged quasar is captured by the high resolution
image of the Hubble SpaceTelescope. Ground-based telescopes, including the MMT, Keck, Gemini, LBT and JCMT, are used
 to observe this object in optical, infrared and sub-millimeter wavelengths to measure its distance, and to characterize its
central black hole and host galaxy [Credit: NASA, ESA, Xiaohui Fan (University of Arizona)]

Fan’s team selected J0439+1634 as a very distant quasar candidate based on optical data from several sources: the Panoramic Survey Telescope and Rapid Response System1 (Pan-STARRS1; operated by the University of Hawai’i’s Institute for Astronomy), the United Kingdom Infra-Red Telescope Hemisphere Survey (conducted on Maunakea, Hawai’i), and NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope archive.

The first follow-up spectroscopic observations, conducted at the Multi-Mirror Telescope in Arizona, confirmed the object as a high-redshift quasar. Subsequent observations with the Gemini North and Keck I telescopes in Hawai’i confirmed the MMT’s finding, and led to Gemini’s detection of the crucial magnesium fingerprint — the key to nailing down the quasar’s fantastic distance. However, the foreground lensing galaxy and the quasar appear so close that it is impossible to separate them with images taken from the ground due to blurring of the Earth’s atmosphere. It took the exquisitely sharp images by the Hubble Space Telescope to reveal that the quasar image is split into three components by a faint lensing galaxy.

The quasar is ripe for future scrutiny. Astronomers also plan to use the Atacama Large Millimeter/submillimeter Array, and eventually NASA’s James Webb Space Telescope, to look within 150 light-years of the black hole and directly detect the influence of the gravity from black hole on gas motion and star formation in its vicinity. Any future discoveries of very distant quasars like J0439+1634 will continue to teach astronomers about the chemical environment and the growth of massive black holes in our early Universe.

The findings are published in Astrophysical Journal Letters.

Source: Association of Universities for Research in Astronomy (AURA) [January 09, 2019]



First evidence of gigantic remains from star explosions

Astrophysicists have found the first ever evidence of gigantic remains being formed from repeated explosions on the surface of a dead star in the Andromeda Galaxy, 2.5 million light years from Earth. The remains or “super-remnant” measures almost 400 light years across. For comparison, it takes just 8 minutes for light from the Sun to reach us.

First evidence of gigantic remains from star explosions
A composite image of Liverpool Telescope data (bottom left) and Hubble Space Telescope data (top right) of the nova
 super-remnant. M31N 2008-12a is in the centre [Credit: Matt Darnley, Liverpool John Moores University]

A white dwarf is the dead core of a star. When it is paired with a companion star in a binary system, it can potentially produce a nova explosion. If the conditions are right, the white dwarf can pull gas from its companion star and when enough material builds up on the surface of the white dwarf, it triggers a thermonuclear explosion or “nova,” shining a million times brighter than our Sun and initially moving at up to 10,000 km per second.

Astrophysicists including Dr Steven Williams from Lancaster University in the UK examined the nova M31N 2008-12a in the Andromeda Galaxy, one of our nearest neighbours.

They used Hubble Space Telescope imaging, accompanied by spectroscopy from telescopes on Earth, to help uncover the nature of a gigantic super-remnant surrounding the nova. This is the first time such a huge remnant has been associated with a nova, and their research appears in Nature.

Dr Williams worked on Liverpool Telescope observations of the nova as well as helping to interpret the results.

He said: “This result is significant, as it is the first such remnant that has been found around a nova. This nova also has the most frequent explosions of any we know — once a year. The most frequent in our own Galaxy in only once every 10 years.

“It also has potential links to Type Ia supernovae, as this is how we would expect a nova system to behave when it is nearly massive enough to explode as a supernova.”

A Type Ia supernova is caused when the entire white dwarf is blown apart when it reaches a critical upper mass, rather than an explosion on its surface as in the case of the nova in this work. Type Ia supernovae are relatively rare. We have not observed one in our own Galaxy since Kepler’s supernova of 1604, named after the famous astronomer Johannes Kepler, who observed it shortly after it exploded and for the following year.

The team simulated how such a nova can create a vast, evacuated cavity around the star, by continually sweeping up the surrounding medium within a shell at the edge of a growing super-remnant.

The models show that the super-remnant — larger than almost all known remnants of supernova explosions — is consistent with being built up by frequent nova eruptions over millions of years.

Dr Matt Darnley from Liverpool John Moores University in the UK, who led the work, said: “Studying M31N 2008-12a and its super-remnant could help us to understand how some white dwarfs grow to their critical upper mass and how they actually explode as a Type Ia Supernova once they get there. Type Ia supernovae are critical tools used to work out how the universe expands and grows.”

Source: Lancaster University [January 09, 2019]



Astronomers map ‘light echoes’ of newly discovered black hole

A team of astronomers led by Erin Kara, the Neil Gehrels Prize Postdoctoral Fellow in the University of Maryland’s Department of Astronomy, has charted the environment surrounding a relatively small, “stellar mass” black hole that is 10 times the mass of the sun. The observations provide the clearest picture to date of how these small black holes consume matter and emit energy.

Astronomers map 'light echoes' of newly discovered black hole
The Neil Gehrels Swift Observatory took this image of MAXI J1820+070 on March 11, 2018,
using its X-Ray Telescope [Credit: NASA/Swift]

The research results was presented on January 9, 2019 at a press conference at the 233rd Meeting of the American Astronomical Society in Seattle, Washington. A research paper was also published in the journal Nature.

Using NASA’s Neutron star Interior Composition Explorer (NICER) payload aboard the International Space Station, the team detected X-ray light from the recently discovered black hole, called MAXI J1820+070 (J1820 for short), as it consumed material from a companion star. Waves of X-rays formed “light echoes” that reflected off the swirling gas near the black hole and revealed changes in the environment’s size and shape.

“NICER has allowed us to measure light echoes closer to a stellar-mass black hole than ever before,” said Kara, the lead author of the research paper, who is also a Hubble Fellow with a co-appointment at NASA’s Goddard Space Flight Center and the Joint Space-Science Institute. “Previously, these light echoes off the inner accretion disk were only seen in supermassive black holes, which are millions to billions of solar masses and undergo changes slowly. Stellar black holes like J1820 have much lower masses and evolve much faster, so we can see changes play out on human time scales.”

J1820 is located about 10,000 light-years from Earth, in the direction of the constellation Leo. The black hole’s companion star was identified in a survey by the European Space Agency’s (ESA) Gaia mission, which allowed researchers to estimate its distance from Earth. Astronomers were unaware of the black hole’s presence until March 11, 2018, when an outburst was spotted by the Japanese Aerospace and Exploration Agency’s Monitor of All-sky X-ray Image (MAXI), also aboard the space station.

In just a few days, J1820 went from a totally unknown black hole to one of the brightest sources in the X-ray sky. NICER moved quickly to capture this dramatic transition and continues to follow the fading tail of the eruption.

“NICER was designed to be sensitive enough to study faint, incredibly dense objects called neutron stars,” said Zaven Arzoumanian, NICER science lead and an astrophysicist at NASA Goddard. “We’re pleased at how useful it’s also proven in studying these very X-ray-bright stellar mass black holes.”

Astronomers map 'light echoes' of newly discovered black hole
This animation shows waves of X-rays from the black hole MAXI J1820+070’s corona (blue) echoing off the accretion
disk (orange). Measuring these echoes allows astronomers to map the black hole’s corona and disk, similar to the
 way oceanographers use sonar to chart the ocean floor [Credit: NASA’s Goddard Space Flight Center]

A black hole can siphon gas from a nearby companion star and into a ring of material called an accretion disk. Gravitational and magnetic forces heat the disk to millions of degrees Celsius, making it hot enough to produce X-rays at the inner parts of the disk, near the black hole. Outbursts occur when an instability in the disk causes a flood of gas to suddenly rush inward toward the black hole, like a gaseous avalanche. Astronomers do not yet understand what causes these disk instabilities.

Above the disk is the corona, a region of subatomic particles heated to 1 billion degrees Celsius that glows in higher-energy X-rays. Many mysteries remain about the origin and evolution of a black hole’s corona. Some theories suggest the structure could represent an early form of the high-speed particle jets these types of systems often emit.

Astrophysicists want to better understand how the inner edge of a black hole’s accretion disk–and the corona above it–change in size and shape as a black hole consumes material from a companion star. If scientists can understand how and why these changes occur in stellar-mass black holes over a period of weeks, they could gain new insights into how supermassive black holes evolve over millions of years and how they affect the galaxies where they reside.

One method used to chart such changes is called X-ray reverberation mapping, which uses X-ray reflections in much the same way sonar uses sound waves to map undersea terrain. Some X-rays from the corona travel straight toward us, while others light up the disk and reflect back at different energies and angles.

X-ray reverberation mapping of supermassive black holes has shown that the inner edge of the accretion disk is very close to a black hole’s event horizon– the point beyond which no matter or energy can escape. The corona is also compact, lying closer to the black hole rather than over much of the accretion disk.

Previous observations of X-ray echoes from stellar mass black holes suggested the inner edge of the accretion disk could be quite distant–up to hundreds of times the size of the event horizon. However, J1820 behaved more like its supermassive cousins.

As they examined NICER’s observations of J1820, Kara’s team saw a decrease in the delay, or lag time, between the initial flare of X-rays coming directly from the corona and the flare’s echo off of the disk. This indicated that the X-rays traveled over shorter and shorter distances before they were reflected. From 10,000 light-years away, the researchers estimated that the corona contracted vertically from roughly 100 miles to about 10 miles. To put this in perspective, it would be like seeing something the size of a blueberry shrink to the size of a poppy seed from the distance between Earth and Pluto.

“This is the first time that we’ve seen this kind of evidence that it’s the corona shrinking during this particular phase of outburst evolution,” said co-author Jack Steiner, an astrophysicist at the Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research in Cambridge. “The corona is still pretty mysterious, and we still have a loose understanding of what it is. But we now have evidence that the thing that’s evolving in the system is the structure of the corona itself.”

To confirm that the decrease in lag time was due to a change in the corona and not the accretion disk, the researchers used a signal called the iron K line, which is created when X-rays from the corona collide with iron atoms in the disk, causing them to fluoresce.

According to Einstein’s theory of relativity, time runs slower in strong gravitational fields and at high velocities. When the iron atoms closest to the black hole are bombarded by light from the core of the corona, the wavelengths of the X-rays they emit get stretched because time is moving slower for them than for the observer.

Kara’s team discovered that J1820’s stretched iron K line remained constant, which means the inner edge of the disk remained close to the black hole–similar to a supermassive black hole. If the decreased lag time was caused by the inner edge of the disk moving even further inward, then the iron K line would have become even more stretched.

These observations give scientists new insights into how material funnels into a black hole and how energy is released in this process.

“NICER’s observations of J1820 have taught us something new about stellar-mass black holes and about how we might use them as analogs for studying supermassive black holes and their effects on galaxy formation,” said co-author Philip Uttley, an astrophysicist at the University of Amsterdam. “We’ve seen four similar events in NICER’s first year, and it’s remarkable. It feels like we’re on the edge of a huge breakthrough in X-ray astronomy.”

Source: University of Maryland [January 09, 2019]



Thousands of stars turning into crystals

The first direct evidence of white dwarf stars solidifying into crystals has been discovered by astronomers at the University of Warwick, and our skies are filled with them.

Thousands of stars turning into crystals
White dwarf star in the process of solidifying [Credit: University of Warwick/Mark Garlick]

Observations have revealed that dead remnants of stars like our Sun, called white dwarfs, have a core of solid oxygen and carbon due to a phase transition during their lifecycle similar to water turning into ice but at much higher temperatures. This could make them potentially billions of years older than previously thought.

The discovery, led by Dr Pier-Emmanuel Tremblay from the University of Warwick’s Department of Physics, has been published in Nature and is largely based on observations taken with the European Space Agency’s Gaia satellite.

White dwarf stars are some of the oldest stellar objects in the universe. They are incredibly useful to astronomers as their predictable lifecycle allows them to be used as cosmic clocks to estimate the age of groups of neighboring stars to a high degree of accuracy. They are the remaining cores of red giants after these huge stars have died and shed their outer layers and are constantly cooling as they release their stored up heat over the course of billions of years.

The astronomers selected 15,000 white dwarf candidates within around 300 light years of Earth from observations made by the Gaia satellite and analysed data on the stars’ luminosities and colours.

They identified a pile-up, an excess in the number of stars at specific colours and luminosities that do not correspond to any single mass or age. When compared to evolutionary models of stars, the pile-up strongly coincides to the phase in their development in which latent heat is predicted to be released in large amounts, resulting in a slowing down of their cooling process. It is estimated that in some cases these stars have slowed down their aging by as much as 2 billion years, or 15 percent of the age of our galaxy.

Dr Tremblay said: “This is the first direct evidence that white dwarfs crystallise, or transition from liquid to solid. It was predicted fifty years ago that we should observe a pile-up in the number of white dwarfs at certain luminosities and colours due to crystallisation and only now this has been observed.

“All white dwarfs will crystallise at some point in their evolution, although more massive white dwarfs go through the process sooner. This means that billions of white dwarfs in our galaxy have already completed the process and are essentially crystal spheres in the sky. The Sun itself will become a crystal white dwarf in about 10 billion years.”

Crystallisation is the process of a material becoming a solid state, in which its atoms form an ordered structure. Under the extreme pressures in white dwarf cores, atoms are packed so densely that their electrons become unbound, leaving a conducting electron gas governed by quantum physics, and positively charged nuclei in a fluid form. When the core cools down to about 10 million degrees, enough energy has been released that the fluid begins to solidify, forming a metallic core at its heart with a mantle enhanced in carbon.

Dr Tremblay adds: “Not only do we have evidence of heat release upon solidification, but considerably more energy release is needed to explain the observations. We believe this is due to the oxygen crystallising first and then sinking to the core, a process similar to sedimentation on a river bed on Earth. This will push the carbon upwards, and that separation will release gravitational energy.

“We’ve made a large step forward in getting accurate ages for these cooler white dwarfs and therefore old stars of the Milky Way. Much of the credit for this discovery is down to the Gaia observations. Thanks to the precise measurements that it is capable of, we have understood the interior of white dwarfs in a way that we never expected. Before Gaia we had 100-200 white dwarfs with precise distances and luminosities — and now we have 200,000. This experiment on ultra-dense matter is something that simply cannot be performed in any laboratory on Earth.”

Source: University of Warwick [January 09, 2019]



Scientists hit on the protein and lipid composition of the Siberian mammoth bone

Scientists from Skoltech and Moscow Institute of Physics and Technology (MIPT) studied the protein and lipid composition of a mammoth bone found near the Yana River in northeastern Siberia. Their study is one of the few pioneering endeavors in paleolipidomics — a frontier research area that comes to complement paleogenomics and paleoproteomics. The results of their study were published in the European Journal of Mass Spectrometry.

Scientists hit on the protein and lipid composition of the Siberian mammoth bone
This is a slider [Credit: @tsarcyanide/MIPT Press Office]

Scientists worldwide took interest in the molecular composition of the remains of extinct creatures several decades ago. Advanced methods of genetic analysis have made it possible to study DNA extracted from fossilized bones, giving rise to a whole new trend in science, paleogenetics, that has helped crack a lot of evolutionary mysteries. Nevertheless, genetics alone is hardly enough to get a full picture of the animals that inhabited the Earth long before humans.

In living organisms, the protein and fat composition is nearly as essential as DNA. This is why at some point paleogenomics was joined by paleoproteomics that studies ancient proteins. The lipid molecules, most of which are extremely unstable and could not be preserved for millions of years, were largely disregarded. However, some lipids experienced oxidative stress and turned into fossils that can be studied and may provide valuable insights into what our ancestors ate, what ailments they suffered from and how well-developed their nervous system was.

Relying on both paleoproteomics and paleolipidomics and applying advanced liquid chromatography and mass spectrometry methods, the scientists from Skoltech and MIPT identified 98 proteins and 73 lipids in the bones of the Siberian mammoth and compared their findings to the bone analysis results for the modern African elephant.

“We found collagen that forms the core of the bone tissue along with other protein varieties, such as albumin, lumican, osteoglycine, and alpha-2-HS-glycoprotein, that regulate various processes in the body. As for lipids, it transpired that very few can last that long. We found only triglycerides but no phosphatidylcholines or sphingomyelins,” said Yury Kostyukevich, the author of the study and senior research scientist at MIPT and Skoltech.

“We applied our experience in the mass spectrometry analysis of various biological samples to analyze fossilized bones in an attempt to expand the horizons of mass spectrometry in various fields of science. Proteomic and lipidomic approaches based on mass spectrometry proved to be remarkably effective in biomedical research and may also prove useful to archaeologists and paleontologists,” explained Professor Eugene Nikolaev.

Proteins are known to serve as markers of various diseases. Some studies show that analyzing fossilized human remains can help determine the diseases humans suffered from. It is not quite clear though what information the bone tissue lipids can provide. In their recent study, the scientists set out to find out which lipids can survive in fossilized remains for tens of thousands of years. According to the Skoltech and MIPT Professor Evgeny Nikolaev, future research will help to answer this question.

Source: Moscow Institute of Physics and Technology [January 09, 2019]



Russia lost control of its space radio telescope Spekt-R

ROSCOSMOS – Spekt-R Mission logo.

Jan. 15, 2019

Russia is no longer able to communicate with its only radio telescope in orbit, called Spekt-R.

Russia has lost control of its only space radio telescope, Spektr-R. It works to restore communication with the machine, announced Monday the Russian Space Agency Roscosmos, which has experienced a series of failures in recent years.

Spektr-R or RadioAstron

The giant telescope – Spektr-R or RadioAstron – no longer responds to the instructions of its control center on Earth since Thursday, said Roscosmos, who recently experienced the failure of launching a Soyuz rocket with two men on board. A new attempt to regain control Monday night has failed, according to Russian news agencies quoting a Roscomos official.

An American observatory, however, has received signals from the aircraft, which means that its aircraft systems operate autonomously, said the Russian space agency. The Spektr-R telescope – nicknamed the “Russian Hubble”, in reference to the US Space Telescope – was launched in 2011 to observe black holes, neutron stars and magnetic fields. With Earth-based observatories and a ten-meter antenna, it is one of the largest telescopes in the world.

Another telescope

A new attempt to make contact with the device will take place, according to Roscosmos, the previous ones remained without result. “You can not bury a satellite that is undoubtedly still alive,” the project director Yuri Kovalev said in an email to AFP, refusing to say that the telescope was definitely lost. It’s like asking for a comment on the state of health of a patient at a time when doctors are fighting to save him, “he added.

The Spektr-R telescope was supposed to remain in service only until 2014, but its mission had been extended. According to experts, this project had been an important success for the Russian space program. Russia plans to launch this year another telescope, Spektr-RG, whose mission will be to “complete the map of the world,” according to Roscosmos.

In October, the Soyuz rocket that was to bring two astronauts, a Russian and an American, to the orbital station, failed. The two men returned to Earth safe and sound after the automatic ejection of their capsule.

Related article:

Soyuz MS-10 – Emergency landing after a failure

Roscosmos: https://www.roscosmos.ru/

Images, Text, Credits: ATS/ROSCOSMOS/RIANOVOSTI/Orbiter.ch Aerospace/Roland Berga.

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HiPOD 14 Jan 2019: The Source of Dunes in Chasma BorealeThis…

HiPOD 14 Jan 2019: The Source of Dunes in Chasma Boreale

This image shows dunes during the summer, when they were free from the seasonal layer of carbon dioxide ice that covers the region for much of the year. These dunes, which are near the head of the largest trough in the North Polar cap (called Chasma Boreale), were formed by strong winds blowing down the canyon toward its mouth.

ID: ESP_018963_2650
Date: 13 August 2010
Altitude: 319 km

NASA/JPL/University of Arizona

Malachite | #Geology #GeologyPage #Mineral Locality: Star of…

Malachite | #Geology #GeologyPage #Mineral

Locality: Star of the Congo Mine, Lubumbashi, Katanga, Democratic Republic of the Congo

Size: 4.1 × 3 × 2.2 cm

Largest Crystal: 1.20cm

Photo Copyright © Thames Valley Minerals /e-rocks. com

Geology Page



Sannur Cave, Beni Suef, Egypt | #Geology #GeologyPage…

Sannur Cave, Beni Suef, Egypt | #Geology #GeologyPage #Egypt

Sannur Cave Protectorate is located in the Beni-Suef governorate of Egypt and lies at 70 km southeast of the city of Beni Suef and 200 km from Cairo. The place has many geographical formations of stalactites and stalagmites as well.

Read more & More Photos: http://www.geologypage.com/2016/04/sannur-cave-beni-suef-egypt.html

Geology Page



Dioptase | #Geology #GeologyPage #Mineral Locality: Omaue Mine,…

Dioptase | #Geology #GeologyPage #Mineral

Locality: Omaue Mine, Kaokoveld Plateau, Kunene Region, Namibia

Size: 1.5 × 3.5 × 1.8 cm

Photo Copyright © eShop-minerals /e-rocks. com

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Double Star System Flips Planet-Forming Disk into Pole Position

View of the double star system and surrounding disc.

Copyright and credit: University of Warwick/Mark Garlick

View from the surface of an orbiting planet.

Copyright and credit: University of Warwick/Mark Garlick

Cambridge, MA – New research that included astronomers Luca Matra and David J. Wilner of the Center for Astrophysics | Harvard & Smithsonian has found the first confirmed example of a double star system that has flipped its surrounding disc to a position that leaps over the orbital plane of those stars. The international team of astronomers used the Atacama Large Millimeter/sub-millimeter Array (ALMA) to obtain high-resolution images of the Asteroid belt-sized disc.

The overall system presents the unusual sight of a thick hoop of gas and dust circling at right angles to the binary star orbit. Until now this setup only existed in theorists’ minds, but the ALMA observation proves that polar discs of this type exist, and may even be relatively common.

The new research is published today (14 January 2019) by Royal Society University Research Fellow Dr. Grant M. Kennedy of the University of Warwick’s Department of Physics and Centre for Exoplanets and Habitability in Nature Astronomy in a paper entitled “A circumbinary protoplanetary disc in a polar configuration.”

Dr. Grant M. Kennedy of the University of Warwick said:

“Discs rich in gas and dust are seen around nearly all young stars, and we know that at least a third of the ones orbiting single stars form planets. Some of these planets end up being misaligned with the spin of the star, so we’ve been wondering whether a similar thing might be possible for circumbinary planets. A quirk of the dynamics means that a so-called polar misalignment should be possible, but until now we had no evidence of misaligned discs in which these planets might form.”

Dr. Kennedy and his fellow researchers used ALMA to pin down the orientation of the ring of gas and dust in the system. The orbit of the binary was previously known, from observations that quantified how the stars move in relation to each other. By combining these two pieces of information they were able to establish that the dust ring was consistent with a perfectly polar orbit. This means that while the stellar orbits orbit each other in one plane, like two horses going around on a carousel, the disc surrounds these stars at right angles to their orbits, like a giant ferris wheel with the carousel at the centre.

Dr. Grant M. Kennedy of the University of Warwick added:

“Perhaps the most exciting thing about this discovery is that the disc shows some of the same signatures that we attribute to dust growth in discs around single stars. We take this to mean planet formation can at least get started in these polar circumbinary discs. If the rest of the planet formation process can happen, there might be a whole population of misaligned circumbinary planets that we have yet to discover, and things like weird seasonal variations to consider.”

If there were a planet or planetoid present at the inner edge of the dust ring, the ring itself would appear from the surface as a broad band rising almost perpendicularly from the horizon. The polar configuration means that the stars would appear to move in and out of the disc plane, giving objects two shadows at times. Seasons on planets in such systems would also be different. On Earth they vary throughout the year as we orbit the Sun. A polar circumbinary planet would have seasons that also vary as different latitudes receive more or less illumination throughout the binary orbit.

The full research team for this paper also included: Dr. Grant M. Kennedy of the University of Warwick’s Department of Physics and Centre for Exoplanets and Habitability as lead author and; Stefano Facchini of the Max-Planck-Institut fur Extraterrestrische Physik; Julien Milli of the European Southern Observatory (ESO); Olja Panic of the School of Physics & Astronomy, University of Leeds; Daniel Price of Monash University’s Centre for Astrophysics (MoCA) and School of Physics and Astronomy; and Mark C. Wyatt, and Ben M. Yelverton of the Institute of Astronomy, University of Cambridge. This press release was first prepared by the University of Warwick.

Headquartered in Cambridge, Mass., the Center for Astrophysics | Harvard & Smithsonian (CfA) is a collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

For more information, contact:

Tyler Jump
Public Affairs
Center for Astrophysics | Harvard & Smithsonian
+1 617-495-7462

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2019 January 15 The Heart and Soul Nebulas Image Credit &…

2019 January 15

The Heart and Soul Nebulas
Image Credit & Copyright: Mario Zauner

Explanation: Is the heart and soul of our Galaxy located in Cassiopeia? Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found. The Heart Nebula, officially dubbed IC 1805 and visible in the featured image on the bottom right, has a shape reminiscent of a classical heart symbol. The Soul Nebula is officially designated IC 1871 and is visible on the upper left. Both nebulas shine brightly in the red light of energized hydrogen. Also shown in this three-color montage is light emitted from sulfur, shown in yellow, and oxygen, shown in blue. Several young open clusters of stars are visible near the nebula centers. Light takes about 6,000 years to reach us from these nebulas, which together span roughly 300 light years. Studies of stars and clusters like those found in the Heart and Soul Nebulas have focused on how massive stars form and how they affect their environment.

∞ Source: apod.nasa.gov/apod/ap190115.html

Geoscientists reconstruct ‘eye-opening’ 900-year Northeastern…

Geoscientists reconstruct ‘eye-opening’ 900-year Northeastern U.S. climate record http://www.geologypage.com/2019/01/geoscientists-reconstruct-eye-opening-900-year-northeastern-u-s-climate-record.html

Chang’e-4 Probe & Rover Takes Color Photos on Moon’s Far Side

CLEP – China Lunar Exploration Program logo.

Jan. 14, 2019

China’s Chang’e-4 probe took color photos on the lunar surface after it successfully made the first ever soft-landing on the far side of the moon.

The China National Space Administration (CNSA) Friday released the 360-degree panoramic photos taken by a camera installed on the top of the lander (see related article: Unpublished 360° picture of the hidden side of the Moon, link bellow).

Chang’e-4 probe

The images were sent back via the relay satellite Queqiao, which was operating around the second Lagrangian point of the earth-moon system, about 455,000 km from the earth, where it can see both the earth and the moon’s far side.

Scientists have made a preliminary analysis on the terrains and landform surrounding the probe according to the color pictures.

Chang’e-4 probe touched down on the Von Karman Crater in the South Pole-Aitken Basin in the morning of Jan. 3, and the lunar rover Yutu-2 drove onto the lunar surface late that night.

Lunar rover Yutu-2

Then the rover took a “nap” as the solar radiation raised the temperature on the lunar surface to over 100 degrees centigrade. It restarted to work on the moon.

The lander, the rover and the relay satellite are in good condition, said CNSA.

Related article & links:

Unpublished 360° picture of the hidden side of the Moon

China’s Yutu-2 rover Enters Standby Mode for ‘Noon Nap’ as Chang’e 4 Tests Continue

“Small step for the rover, big step for China”

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

For more information about China National Space Administration (CNSA), visit: http://www.cnsa.gov.cn/

Images, Text, Credits: CASC/CNSA/CLEP.

Greetings, Orbiter.ch Archive link

Aging Faster in Space to Age Better on Earth

ISS – International Space Station logo.

Jan. 14, 2019

A new investigation heading to the International Space Station will provide space-flown samples to scientists from academia, industry and government agencies, who have agreed to share their data and results in an online database that is open to the public. Rodent Research-8 (RR-8) examines the physiology of aging and the effect of age on disease progression using groups of young and old mice flown in space and kept on Earth.

“The objective is to expose the mice to microgravity and track physiological changes,” said Michael S. Roberts, deputy chief scientist at the U.S. National Laboratory, a sponsor of the investigation. “Tissue samples from space-flown animals are extremely valuable to biomedical research and opportunities to use the space station are limited to a few missions each year. This investigation was conceived primarily to provide the biomedical research community on Earth with tissues from mice exposed to microgravity.” Scientists receiving tissue samples include investigators at Stanford University, University of Southern California, University of Kansas, Virginia Commonwealth University, Northwestern University, Biogen, KBRwyle, LaunchPad Medical LLC, the U.S. Air Force and the NASA Gene Lab program, a science collaboration initiative at NASA Ames Research Center.

Image above: David Saint-Jacques, of the Canadian Space Agency, completes the Bone Densitometer calibration in support of the Rodent Research-8 investigation. Image Credit: NASA.

Previous research has shown that spending time in space causes bone density loss, immune dysfunction, cardiovascular issues such as stiffening of arteries, and loss of skeletal muscle mass and strength in both humans and rodent models. These changes resemble aging in people age on Earth, but happen more quickly. That makes spaceflight an opportunity to study – and perhaps lessen – the effects of aging.

“There is something about being in space for an extended period of time, more than several weeks,” said Roberts. “A lot of the experiments with rodents on the space station have looked at the effects of microgravity, but microgravity may not be the sole cause. Exposure to the space environment also involves radiation, stress, and other factors that affect health. It could be some combination of all of them. Part of this experiment is validating that general aging response in the mice.”

The investigation keeps a group of young mice (10-16 weeks old) and another group of older mice (30-52 weeks old) on the space station for different periods of time – approximately 30 and 60 days – to make it possible to examine that accelerated aging process more closely. Researchers also plan to observe the activity levels of the different groups, expecting the younger mice to be more active than the older ones. Activity, or exercise, is known to affect the rate of bone and muscle loss in mice just as it does in humans. The mice, provided by Taconic Biosciences, are all from a genetically identical strain.

Image above: NASA astronaut Anne Mcclain working within a Mouse Habitat Unit. ISS Research is really phenomenal; every day we get to play a part in learning about our universe, our Earth, and the creatures that live on it. Getting to do science on the ceiling? Well, now that’s just cool!” she tweeted. Image Credit: NASA.

“We are trying to get down to the molecular basis for what is happening,” Roberts said. “To use mice or other organisms as models for studying humans, we need to understand whether the effects of space exposure have the same causes and outcomes as conditions in humans on Earth. We want to see if the same things happen in mice and whether the rate of change is affected by the age of the mouse at exposure.”

Better understanding of changes to the body that occur in spaceflight can contribute to developing countermeasures and therapies that protect the health of astronauts and help people with age-related conditions and diseases on Earth.

While this investigation focuses on the effect of age on the changes induced by space, future investigations could compare males versus females or different genetic strains of mice, or the effects of varying their habitat on the space station.

RR8 makes use of the Life Sciences Glovebox (LSG), a sealed workbench-type environment for life science and technology investigations on the space station. Its larger size allows two crew members to work in the LSG simultaneously.

This investigation is sponsored by the International Space Station U.S. National Laboratory and New York-based Taconic Biosciences.

Related links:

Rodent Research-8 (RR-8): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7713

U.S. National Laboratory: http://www.iss-casis.org/

Life Sciences Glovebox (LSG): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7676

NASA Gene Lab program: https://www.nasa.gov/genelab

Taconic Biosciences: https://www.taconic.com/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Michael Johnson/JSC/International Space Station Program Science Office/Melissa Gaskill.

Greetings, Orbiter.chArchive link

Space Station Science Highlights: Week of January 7, 2019

ISS – Expedition 58 Mission patch.

Jan. 14, 2019

The three Expedition 58 crew members aboard the International Space Station have finished packing the SpaceX Dragon cargo craft with science experiments and hardware. The vehicle splashed down on on Sunday, Jan. 13.

Image above: The SpaceX Dragon cargo craft is pictured attached to the International Space Station’s Harmony module as the orbital complex orbited 261 miles above the Indian Ocean southwest of the continent of Africa. The Canadarm2 robotic arm vertically splits the frame prior to grappling the spacecraft ahead of planned departure activities. Image Credit: NASA.

In addition to packing the Dragon and preparing for its departure, the crew conducted science in the areas of protein crystal growth, human health, biotechnology and more. Here’s a look at some of the science conducted this week aboard the orbiting lab:

Investigation studies space-grown crystals for protection against radiation

In the near future, crews will embark on multi-month missions to the Moon, and eventually Mars and beyond. All incredible adventures, however, have their hazards, and a major one for crews on long-duration spaceflights is the space radiation they will be exposed to during their missions.

Perfect Crystals is a study to learn more about an antioxidant protein, manganese superoxide dismutase, that protects the body from the effects of radiation and some harmful chemicals. The space station’s microgravity environment allows researchers to grow more perfectly ordered crystals of the proteins. These crystals are brought back to Earth and studied in detail to learn more about how the manganese superoxide dismutase works. Understanding how this protein functions may aid researchers in developing techniques to reduce the threat of radiation exposure to astronauts as well as prevent and treat some kinds of cancers on Earth.

Animation above: NASA astronaut Anne McClain and David Saint-Jacques of the Canadian Space Agency prepare coldbags to be packed for return on to the SpaceX-16 Dragon. Image Credit: NASA.

Last week a crew member packed two samples for return on the SpaceX Dragon vehicle. The remaining unit will stay on board the station until its return on SpaceX 18.

ICE Cubes facility undergoes reconfiguration

The International Commercial Experiment, or ICE Cubes Facility, combines a sliding framework permanently installed in the space station’s Columbus module with “plug-and-play” Experiment Cubes. The easy-to-install-and-remove Experiment Cubes come in different sizes and often can be built with commercial off-the-shelf components, significantly reducing the cost and time to develop experiments.

Animation above: Crew members terminated the two Group Activation Packs (GAPS) and placed them in to the Space Automated Bioproduct Laboratory (SABL) facility. NALCO Biofilms examines biofilms on Earth and in space and monitors the rate of corrosion caused by microorganisms. Animation Credit: NASA.

The system supports research in a wide range of disciplines, from pharmaceutical development to experiments on stem cells, radiation, and microbiology, fluid sciences and more. It provides the opportunity to conduct testing and validation of space technologies and processes in a true space environment. Because ICE Cubes can accommodate free-floating experiments in the Columbus module, it can even be used to test guidance, navigation and docking equipment. The system also can support education experiments and demonstrations to inspire future generations of scientists and explorers.

Last week, the crew shuffled the cubes around, removing Cube #1 and installing Cube #2.

Changes in crew members hearts and vessels tracked

As humans get older, arteries stiffen, causing an increase in blood pressure and elevating the risk for cardiovascular disease. It has been observed that some crew members returning from the space station have much stiffer arteries than when they went into space. The Cardiac and Vessel Structure and Function with Long-Duration Space Flight and Recovery (Vascular Echo) investigation examines changes in crew members’ blood vessels and heart, while in space and upon their return home, following them through their recovery. The results could provide insight into potential countermeasures to help maintain crew member health, and quality of life for those on Earth.

International Space Station (ISS). Image Credit: NASA

Last week, crew members performed blood pressure measurements and took historical documentation photos to track changes in blood vessels and the heart.

Other work was performed on these investigations:

– CASIS PCG 16 evaluates growth of LRRK2 protein crystals in microgravity. LRRK2 is implicated in Parkinson’s disease, but crystals of the protein grown on Earth are too small and compact to study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7855

– Rodent Research-8 (RR-8) examines the physiology of aging and the effect of age on disease progression using groups of young and old mice flown in space and kept on Earth: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7713

– MISSE-10 hosts a suite of eight NASA investigations aboard the Materials International Space Station Flight Facility (MISSE-FF): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7929

– STaARS Bioscience-4 examines how oligodendrocyte progenitor cells (OPCs) react to microgravity, specifically the rate at which the cells proliferate and differentiate in the microgravity environment: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7503

– CASIS PCG-11 produces acetylcholinesterase crystals, a neurotransmitter enzyme, enabling the development of better antidotes to fatal organophosphate nerve agents, which act by inhibiting acetylcholinesterase in the nervous system: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7631

– Micro-14 studies C. albicans to define mechanisms that lead to cellular adaptation responses to the spaceflight environment: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7642

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

SpaceX Dragon: https://www.nasa.gov/mission_pages/station/structure/launch/spacex.html

Perfect Crystals: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7617

ICE Cubes Facility: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7607

Vascular Echo: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1664

Spot the Station: https://spotthestation.nasa.gov/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Animations (mentioned), Text, Credits: NASA/Michael Johnson/Vic Cooley, Lead Increment Scientist Expeditions 57/58.

Best regards, Orbiter.chArchive link

Deep low-frequency earthquakes indicate migration of magmatic…

Deep low-frequency earthquakes indicate migration of magmatic fluids beneath Laacher See Volcano http://www.geologypage.com/2019/01/deep-low-frequency-earthquakes-indicate-migration-of-magmatic-fluids-beneath-laacher-see-volcano.html

Medical scanner helps to unlock the mysteries of a giant…

Medical scanner helps to unlock the mysteries of a giant prehistoric marine reptile http://www.geologypage.com/2019/01/medical-scanner-helps-to-unlock-the-mysteries-of-a-giant-prehistoric-marine-reptile.html

Reconstruction of trilobite ancestral range in the southern…

Reconstruction of trilobite ancestral range in the southern hemisphere http://www.geologypage.com/2019/01/reconstruction-of-trilobite-ancestral-range-in-the-southern-hemisphere.html

How to predict when a volcano will erupt…

How to predict when a volcano will erupt http://www.geologypage.com/2019/01/how-to-predict-when-a-volcano-will-erupt.html

Bismuth Crystal “Artificially grown bismuth crystal”…

Bismuth Crystal “Artificially grown bismuth crystal” http://www.geologypage.com/2019/01/bismuth-crystal-artificially-grown-bismuth-crystal.html

Sampling Hot Molten Lava…

Sampling Hot Molten Lava http://www.geologypage.com/2019/01/sampling-hot-molten-lava.html

Feeding Fat A thriving network of blood vessels feeds…

Feeding Fat

A thriving network of blood vessels feeds nutrients and oxygen to our hungry tissues. A process called angiogenesis weaves wriggly vessels like these – called capillaries – deep into our growing tissues. These capillaries formed inside a mouse’s fat or adipose tissue, one of the only tissues that changes size and shape later in life, requiring new vessels to form. In obese fat tissue, though, angiogenesis is often blocked – researchers found high levels of a protein called FOXO1 in cells lining these stunted blood vessels. By reducing FOXO1, researchers kick-started angiogenesis – a surge in vessel building that not only made the mouse’s fat healthier, but also requires a lot of energy, mopping up excess blood sugar and reducing weight gain in the process. The next challenge is to design treatments to carefully control FOXO1 in human cells in the hope of lowering the risk of cardiovascular disease and diabetes.

Today marks the start of National Obesity Awareness Week

Written by John Ankers

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    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...