среда, 18 июля 2018 г.

Aping Monkey Hearts Heart failure is the leading cause of…

Aping Monkey Hearts

Heart failure is the leading cause of death across the world – saving patients usually involves spotting and treating issues like heart disease early, or a race for emergency care later on. Here is a breakthrough – human embryonic stem cells turned into new cardiomyocytes, cells that repair heart tissue before permanent damage takes hold. Following a heart attack, the muscle of this macaque monkey heart is riddled with holes – scar tissue (blue) quickly fills the gaps left in the damaged heart wall (red), gradually weakening the heart towards complete failure. But an injection of around 750 million human cardiomyocytes (green) integrate into the monkey muscle – over the next few weeks they peel back the scar tissue, repairing the heart. Researchers believe that similar injections will become routine following human heart attacks, backed up by careful monitoring as new heart cells begin to heal our most precious organ.

Written by John Ankers

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Spinning-top asteroids, from Rosetta to Hayabusa2 – and maybe Hera

ESA – European Space Agency patch.

18 July 2018

As Japan’s Hayabusa2 drew closer to its target Ryugu asteroid, a strange new planetoid came into view – but one with a somewhat familiar shape. This distinct ‘spinning top’ asteroid class has been seen repeatedly in recent years, and might give a foretaste of things to come for ESA’s proposed Hera mission.

Asteroid Ryugu

Hayabusa2 is currently just 20 km away from the 900-m wide asteroid. The view from its navigation camera reveals a spinning body with an enlarged ridge of material around its equator – a bulge suggesting Ryugu may once have been spinning much faster.

As ESA’s space scientist Michael Küppers followed Hayabusa2’s approach he recalled Europe’s own asteroid first encounter, just under a decade ago on 5 September 2008, when Rosetta performed a flyby of the Šteins asteroid en route to its final destination, comet 67P/Churyumov-Gerasimenko.

Šteins Asteroid

“At 6 km across, Šteins was much larger, but had a similar diamond shape,” says Michael. “Personally I wasn’t surprised to see this again with Ryugu, because it has turned up with many smaller asteroids in recent years.

“The thinking is this shape is due to asteroids being set spinning rapidly, and the resulting centrifugal force moving material away from the poles and towards the equator. As for what causes such a spin, this probably comes down to the so-called ‘YORP’ effect.”

Approaching Ryugu

The Yarkovsky–O’Keefe–Radzievskii–Paddack effect, named after four different researchers who worked on asteroids, is triggered by the warming of asteroids by sunlight. The asteroids re-radiate this energy as heat, which gives rise to a tiny amount of thrust. Eventually Newton’s Third Law – ‘every action has an equal and opposite reaction’ – exerts itself. And due to their irregular shapes, some parts of asteroids generate more thrust than others, leading to a turning force like wind past a windmill.

“The resulting centrifugal force could continue to the point that material is actually thrown out into space,” adds Michael, “leading to the creation of the binary or multiple asteroid systems that make up 15% of all asteroids so far discovered. Some might also crumble apart altogether. For larger asteroids YORP is less likely to influence shape, as their ratio between mass and surface area is much higher.”

Simulation of asteroid spin creating binary asteroids

Today Michael is serving as project scientist on ESA’s Hera mission study, planned as humankind’s first mission to a binary asteroid system if approved at next year’s ESA Council meeting at ministerial level. His role is to work with external scientists to come up with mission requirements, and make early plans for operations and data analysis.

Hera’s target is the Didymos system, with a 780 m main body orbited by a smaller 160 m ‘Didymoon’. NASA’s DART spacecraft will impact this smaller body in 2022 to measurably shift its orbit, ahead of Hera’s arrival in 2026 – the two missions combining in an audacious, full-scale planetary defence test.

Asteroid collision

“The larger ‘Didymain’ body is a similar size to Ryugu,” says Michael, “but our radar-based shape model is quite crude, and we can’t tell for sure if it is similarly spinning-top shaped. If so, then this might explain the origin of Didymoon. There have been examples of runaway binaries, where an asteroid’s companion has been lost in some way. So it is possible that Ryugu might have been a binary at some point in the past.”

Rosetta’s exploration of Šteins – then in 2010 the mammoth 100 km-diameter Lutetia asteroid – took the form of brief flybys as it sought its main target. Hera would be surveying the Didymos asteroid for a prolonged period.

Hera at Didymos

“First and foremost Hera would be a planetary defence and technology demonstration mission, but there would also be a lot of chances for what I call ‘ride-along’ science.

“For instance, the crater formed by the DART impact would allow us to survey pristine subsurface asteroidal material that has not undergone any weathering by micrometeorites, the solar wind and space radiation. That might allow us to find an analogue for it from collections of meteorites that have previously landed on Earth, boosting our understanding of its make-up.

Hera mission

“And because we will know the exact properties of the spacecraft that formed the DART impact crater  we would gain insights into the impact physics shaping all the bodies of the Solar System.”

Related article:

A Japanese probe reaches its target asteroid

Related links:

Hera: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Hera

Hayabusa2: http://global.jaxa.jp/projects/sat/hayabusa2/

Rosetta: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Šteins asteroid: http://sci.esa.int/rosetta/43356-2867-steins/

Images, Text, Credits: ESA/JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST/ESA/MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA/ScienceOffice.org.

Greetings, Orbiter.chArchive link


Martian atmosphere behaves as one

ESA – Mars Express Mission patch.

18 July 2018

New research using a decade of data from ESA’s Mars Express has found clear signs of the complex martian atmosphere acting as a single, interconnected system, with processes occurring at low and mid levels significantly affecting those seen higher up.

Understanding the martian atmosphere is a key topic in planetary science, from its current status to its past history. Mars’ atmosphere continuously leaks out to space, and is a crucial factor in the planet’s past, present, and future habitability – or lack of it. The planet has lost the majority of its once much denser and wetter atmosphere, causing it to evolve into the dry, arid world we see today.

The Red Planet

However, the tenuous atmosphere Mars has retained remains complex, and scientists are working to understand if and how the processes within it are connected over space and time.

A new study based on 10 years of data from the radar instrument on Mars Express now offers clear evidence of a sought-after link between the upper and lower atmospheres of the planet. While best known for probing the interior of Mars via radar sounding, the instrument has also gathered observations of the martian ionosphere since it began operating in 2005.

“The lower and middle levels of Mars’ atmosphere appear to be coupled to the upper levels: there’s a clear link between them throughout the martian year,” says lead author Beatriz Sánchez-Cano of the University of Leicester, UK.

“We found this link by tracking the amount of electrons in the upper atmosphere – a property that has been measured by the MARSIS radar for over a decade across different seasons, areas of Mars, times of day, and more – and correlating it with the atmospheric parameters measured by other instruments on Mars Express.”

From the polar caps to Mars’ upper atmosphere

The amount of charged particles in Mars’ upper atmosphere – at altitudes of between 100 and 200 km – is known to change with season and local time, driven by changes in solar illumination and activity, and, crucially for this study, the varying composition and density of the atmosphere itself. But the scientists found more changes than they were expecting.

“We discovered a surprising and significant increase in the amount of charged particles in the upper atmosphere during springtime in the Northern hemisphere, which is when the mass in the lower atmosphere is growing as ice sublimates from the northern polar cap,” adds Beatriz.

Mars’ polar caps are made up of a mix of water ice and frozen carbon dioxide. Each winter, up to a third of the mass in Mars’ atmosphere condenses to form an icy layer at each of the planet’s poles. Every spring, some of the mass within these caps sublimates to rejoin the atmosphere, and the caps visibly shrink as a result.

“This sublimation process was thought to mostly only affect the lower atmosphere – we didn’t expect to see its effects clearly propagating upwards to higher levels,” says co-author Olivier Witasse of the European Space Agency, and former ESA Project Scientist for Mars Express.

“It’s very interesting to find a connection like this.”

The finding suggests that the atmosphere of Mars behaves as a single system.

This could potentially help scientists to understand how Mars’ atmosphere evolves over time – not only with respect to external disturbances such as space weather and the activity of the Sun, but also with respect to Mars’ own strong internal variability and surface processes. 

Mars Express

Understanding the complex atmosphere of Mars is one of the key objectives of ESA’s Mars Express mission, which has been operating in orbit around the Red Planet since 2003.

“Mars Express is still going strong, with one of its current key objectives being to explore exactly how the martian atmosphere behaves, and how different layers of it are connected to one another,” says ESA Mars Express Project Scientist Dmitri Titov. 

“Having a long baseline of data is fundamental to our study of Mars – there’s now over a decade of observations to work with. These data don’t just cover a long time period, but also the entirety of Mars and its atmosphere.

“This wealth of comprehensive and complementary observations by different instruments on Mars Express makes studies like this one possible and, together with ESA’s Trace Gas Orbiter and NASA’s MAVEN mission, is helping us to unravel the secrets of the martian atmosphere.”

Notes for Editors:

“Spatial, seasonal and solar cycle variations of the Martian total electron content (TEC): Is the TEC a good tracer for atmospheric cycles?” by Sánchez-Cano et al. is published in the Journal of Geophysical Research, doi: 10.1029/2018JE005626.

The study is based on data collected by the Mars Express MARSIS instrument, the Mars Advanced Radar for Subsurface and Ionosphere Sounding.

Mars Express was launched on 2 June 2003 and reaches 15 years in space this year.

Related links:

ESA’s Trace Gas Orbiter (TGO): http://exploration.esa.int/mars/46475-trace-gas-orbiter/

ESA’s Mars Express: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute)/Mars Express/MARSIS/B. Sánchez-Cano et al 2018/ESA/ATG medialab; Mars: ESA/DLR/FU Berlin, CC BY-SA 3.0 IGO.

Best regards, Orbiter.chArchive link


HiPOD (18 July 2018): A Degraded Crater and Lineated Flow in…

HiPOD (18 July 2018): A Degraded Crater and Lineated Flow in Deuteronilus Mensae 

   – 343 km above the surface. Black and white is less than 5 km across; enhanced color is less than 1 km.

NASA/JPL/University of Arizona


One of the densest clusters of galaxies in the universe is revealed

A study published recently in the journal Nature Astronomy and which questions current models of structure formation in the universe is based on data obtained with the Gran Telescopio Canarias and among its authors is a team of researchers from the Instituto de Astrofísica de Canarias (IAC).

One of the densest clusters of galaxies in the universe is revealed
Credit: Instituto de Astrofisica de Canarias

The structure of the universe can be compared to that of a sponge, often referred to as the cosmic web. Matter is concentrated along filaments which cross over each other, forming zones where most matter accumulates, and others where there is very little. At the densest points, galaxies group together, forming clusters. These systems, which can contain thousands of galaxies, are the most massive structures in the universe.

Studying the cosmic web is one of the current challenges in astrophysics. The properties of the main components of matter on these scales are not well known, so we use terms such as “dark matter” and “dark energy” The former makes up around 20 percent of the mass of the universe and is what keeps the structures bound by their own gravity—it acts a bit like glue. The second, on the other hand, makes up 75 percent of the universe and is related to the way in which the universe expands. The “normal” matter, the galaxies with their stars, gas, and dust, make up barely 5 percent of the mass of the universe, but they play the important role in tracing the forces and the properties of the dark matter and dark energies.

An international team led by Mauro Sereno of the University of Bologna (Italy), with participation by the IAC and by the Instituto de Astrofísica de Andalucía (IAA), has located one of the densest clusters of galaxies in the universe. The study analyses, for the first time, the outer zones of the galaxy cluster PSZ2 G099.86+58.45 out to a radius of 90 million light years, a region in which the distribution of matter was not known previously, nor whether the material in these zones is bound together by the gravity of the cluster.

The environment of the clusters of galaxies includes other structures such as the filaments and other neighbouring clusters, and the material which is falling toward the most massive central cluster. “This study shows that the density of matter around the cluster we studied is up to six times greater than expected,” says Mauro Sereno, the principal investigator. In addition, the researchers have discovered that the mechanisms which accrete mass can give rise to very high densities, even at large distances from these clusters of galaxies.

The work is based on the “gravitational lens” effect, which happens when the mass of a cluster and its surrounding material bend the light from very distant galaxies, changing the shapes of the images of these background galaxies. The denser and more concentrated the body acting as a lens, the greater is the deformation of the background galaxies. The statistical study of the deformations for over 150,000 background galaxies via the so-called “weak lensing” effect using deep images obtained with the CFHT (Canada-France-Hawaii Telescope) have enabled the team to find the distribution, mass, and density around the cluster PSZ2 G099.86+58.45. The results show that this cluster is a rare exception, which does not fit well with the models of structure formation. This implies that there must be mechanisms for accreting matter that are much more efficient than those we know.

Although the models give good fits to the density of the matter in the inner regions of galaxy clusters out to a distance of 15 to 20 million light years, in the outer regions, the models need an additional component to fit the observed data. ” This component of mass is completely unknown, and the numerical simulations of galaxy clusters do not predict it,” explains Rafael Barrena, an IAC researcher,one of the authors of the article published in Nature Astronomy.” So we are faced with observational evidence for large quantities of matter where we did not expect to find it.”

The IAC group participating in this publication has made spectroscopic observations of a sample of galaxies that form a part of the PSZ2 G099.86+58.45 cluster using the multiobject OSIRIS spectrograph on the Gran Telescopio Canaris (GTC) at the Roque de los Muchachos Observatory (Garafía, La Palma). By measuring the velocities of the motions of the galaxies in the cluster it is possible to measure its total mass.

As a practical problem, this is equivalent to measuring the mass of the sun by using the velocities of the planets in their orbits. Using this method, they have managed to measure the total mass of the cluster. The results confirm that PSZ2 G099.86+58.45 is a very massive, dense cluster of galaxies, and that the effects of its very powerful gravitational field extend to distances very far from its centre, much greater than the models predict.

“We have produced a study that opens the door to a region of the universe that has been insufficiently explored until now, the boundary between clusters of galaxies,” says the IAC researcher Alina Streblyanska, one of the authors of the article. This is a region that can give us a lot of information when we study these systems, how they formed, and how these, the most massive structures in the universe, have evolved. With this study, we have taken another small step toward understanding dark matter and how it is distributed in the cosmic web of the universe,” concludes Antonio Ferragamo, IAC researcher.

Source: Instituto de Astrofísica de Canarias [July 14, 2018]




Outrage as Iceland fishermen kill rare whale

Is it a blue whale or not? The slaughter in Iceland of what is claimed was a member of the endangered species has triggered outrage and left experts puzzled about its true identity.

Outrage as Iceland fishermen kill rare whale
This handout photo shows what Sea Shepherd claims is a Blue whale awaiting slaughter
at the Hvalur hf whaling station in Iceland [Credit: AFP/Robert Read]

“There has not been a blue whale harpooned by anyone for the last 50 years until this one,” Sea Shepherd, an international non-profit marine conservation movement, said in a statement on Wednesday.

The group, which published photos of the mammal being butchered for export at an Icelandic whaling station on the night of July 7, said the fishermen “posed for photos next to and even on top of the whale in a sign they knew very well this was a rare blue whale”.

But Icelandic experts are not completely certain whether it is indeed the world’s largest leviathan, which the International Whaling Commission has been protecting since 1966.

They’re also not sure if it could be the endangered fin whale, the second largest animal on the planet, which can only be legally hunted in Iceland despite an international moratorium on whaling.

Kristjan Loftsson, CEO of Hvalur hf, the whaling station which slaughtered the animal, said they did so believing it was a fin whale.

Most of the fin whales killed are exported as meat to Japan.

“We see blue whales all the time and identify them by their blowholes…but we leave them alone,” he told AFP.

DNA tests

For Gisli Vikingsson, a scientist at the Marine and Freshwater Research Institute in Reyjkavik, the butchered whale’s characteristics are similar to both the blue and fin whale.

Outrage as Iceland fishermen kill rare whale
Some experts say the slaughtered mammal is a fin whale [Credit: AFP/Don Emmert]

“There is a large dorsal side with a small dorsal fin like a fin whale…this explains perhaps why it was hunted as such,” he told AFP, adding its “size and markings on the side are like those of a blue whale.”

He added the whale could even be a hybrid species resulting from cross-breeding between the fin and blue whale, which is a rare phenomenon.

Since 1987, five such animals have been observed in Icelandic waters and they are known to be infertile.

All killed whales in Iceland undergo DNA tests after the hunting season and the results are released during the fall.

However, due to the controversy surrounding this particular case, a test will be done earlier than planned and the results are expected at the end of July.

But Sea Shepherd said the fishing crew which butchered the animal mixed its parts with previously caught fin whales, making “it difficult or impossible to locate during potential inspections by the authorities”.

“This shows how inaccurate and imperfect this hunting is and there is no need to continue it,” Sigursteinn Masson, Iceland representative for the International Fund for Animal Welfare, told AFP.

Should the killed whale be confirmed as a hybrid, then things could become even more complicated as there are no laws to protect them.

“Hybrids are much more rarer than the blue whales,” Masson said.

Author: Jeremie Richard | Source: AFP [July 15, 2018]




Geologists found out how over 2.6 Ga years old rocks were formed at Limpopo Complex

Cratons (from the Greek “power” or “might”) are the areas of the oldest continental crust on Earth that are preserved only in several places on our planet. According to scientists, the Kaapvaal Craton in the South Africa and the Pilbara Craton in Australia (the most ancient of these structures) were the parts of Vaalbara, an Archean supercontinent.

Geologists found out how over 2.6 Ga years old rocks were formed at Limpopo Complex
Graphite flakes (above) and CO2 fluid inclusions in quartz (below) from the granites of the Limpopo complex
(South Africa) dated back to the late Archaean age (2.68 Ga) [Credit: Oleg Safonov]

The transformation of the lower parts of the cratons under the influence of heat emitted by the Earth’s mantle may lead to the formation of rocks called granulites that frame cratons like belts. However, the processes that cause granulites to move upwards from the lower part of the crust to the surface along the craton borders are still largely debatable. The oldest granulite belts were formed in the Archean (3 Ga years ago), which is only several hundred million years younger than the life on Earth. The youngest granulites are about 0.5 billion years old. One ancient (2.7 Ga) granulite belt is situated at the Kaapvaal Craton at the borders of South Africa, Zimbabwe, and Botswana not far from the famous Limpopo River. The Limpopo Complex is considered as a natural laboratory for study of relations between the oldest tectonic structures in the continental crust and therefore is of great interest for geologists.

“For the first time we got strong reasons to assume that granite magmas in the Neo-Archean granulite complex of Limpopo (South Africa) have been formed in the course of tectonic interaction of this complex with the rocks of the Kaapvaal Craton as the complex was rising from the lower part of the continental crust,” tells Oleg Safonov, a co-author of the work, Doctor of Geology and Mineralogy, Professor of the Petrology Department of the Geological Faculty, MSU, and Director of the Korzhinskii Institute of Experimental Mineralogy of the Russian Academy of Sciences.

Granulite is a metamorphic rock. It means that it forms in the course of transformation of other rocks under the influence of high temperatures. In the case of granulites, these temperatures are 750 to 1,000 °C. Feldspars, quartz, garnet, pyroxenes, cordierite, and other minerals are formed under these temperature giving the rock its granular texture.

According to one of the models, an important role in the formation of granulites is played by fluids (liquids heated to over-critical temperatures) rich in CO2. Graphite that is present in metamorphic rocks may help establish whether this model is true. Usually graphite is formed in the course of modification of organic matter or decomposition of carbonates (salts of carbonic acid with CO32-anion). However, granulites form at considerable deep levels where no organic matter is present, therefore the graphite formation mechanism is different: graphite is the result of interaction of granulites with mantle flows (fluids) rich in CO2. Therefore, the presence of graphite in granulites is often considered as an evidence for the aforementioned model. Its formation depends on pressure, temperature, and other parameters, and the study of graphite can tell a lot about them.

Geologists found graphite samples and fluid inclusions in quartz (volatile components trapped in the small cavities of minerals in the course of crystal growth) in granite rocks of the Limpopo granulite belt and analyzed them.

The researchers found out that granite rocks intruded the Limpopo granulite belt began to crystallize at the temperature of 900-940 °C and the pressure of 7-9 kbar. The analysis of fluid inclusions in quartz confirmed that CO2-rich fluids took part in their formation. The deviation of C-13 isotope content from standard values was found to be 6.52 to 8.65 permille (tenth of percent) for graphite and 2.5 to 5.58 permille for the fluids in quartz. This isotopic composition of carbon is usually prescribed to deep fluid flows from the mantle, confirming their external origin once again. This, in turn, coincides with the model of CO2-rich deep external fluids participating in the formation of granulite rocks and accompanying granites. However, having compared this data with the isotopic composition of carbon from the rocks of ancient cratons, the scientists concluded that the fluids migrated through the Limpopo complex from the cratonic rocks in the course of collision with the Kaapvaal Craton.

While the study of the rocks in the Limpopo granulite complex was of fundamental nature, the knowledge about the processes of their formation may be used for ore prospecting. “Rocks of ancient cratons are rich sources of various ore components. They are carried by magmas and fluids that originate in the course of transformation of these rocks.” comments Oleg Safonov.

The data about the formation of the South African granulite complex is also relevant for Russia. The scientists plan to compare their conditions with the data about the formation of granulites in the Lapland belt that is situated between the Karelian Craton and the Inari Craton at the border between Russia and Finland.

The findings are published in Gondwana Research.

Source: Lomonosov Moscow State University [July 17, 2018]




The ancient armour of fish — scales — provide clues to hair, feather...

When sea creatures first began crawling and slithering onto land about 385 million years ago, they carried with them their body armor: scales. Fossil evidence shows that the earliest land animals retained scales as a protective feature as they evolved to flourish on terra firma.

The ancient armour of fish -- scales -- provide clues to hair, feather development
In this image of zebrafish scales, yellow marks the cells that produce bony material. Magenta marks
 the bony material [Credit: Andrew Aman, David Parichy, University of Virginia, eLife]

But as time passed, and species diversified, animals began to shed the heavy scales from their ocean heritage and replace them with fur, hair and feathers.

Today the molecular mechanisms of scale development in fish remain remarkably similar to the mechanisms that also produce feathers on birds, fur on dogs and hair on humans – suggesting a common evolutionary origin for countless vastly different skin appendages.

A new study, published in the journal eLife, examines the process as it occurs in a common laboratory genetics model, the zebrafish.

“We’ve found that the molecular pathways that underlie development of scales, hairs and feathers are strikingly similar,” said the study’s lead author, Andrew Aman, a postdoctoral researcher in biology at the University of Virginia.

Aman and his co-authors, including UVA undergraduate researcher Alexis Fulbright, now a Ph.D. candidate at the University of Utah, used molecular tools to manipulate and visualize scale development in zebrafish and tease out the details of how it works. It turns out, as the researchers suspected, skin appendages seen today originated hundreds of millions of years ago in primitive vertebrate ancestors, prior to the origin of limbs, jaws, teeth or even the internal skeleton.

While zebrafish have been studied for decades in wide-ranging genetic experiments, their scale development has mostly been overlooked, according to Aman.

“Zebrafish skin, including the bony scales, is largely transparent and researchers probably have simply looked past the scales to the internal structures,” he said. “This is an area ripe for investigation, so we got the idea to look at the molecular machinery that drives the development of patterning in surface plating. We discovered profound similarities in the development of all skin appendages, whether scales, hair, fur or feathers.”

The ancient armour of fish -- scales -- provide clues to hair, feather development
In this image of zebrafish scales, yellow marks the cells that produce bony material. Magenta marks
 the bony material [Credit: Andrew Aman, David Parichy, University of Virginia, eLife]

Aman works in the lab of David Parichy, the study’s senior author and the Pratt-Ivy Foundation Distinguished Professor of Morphogenesis in UVA’s Department of Biology. Parichy’s lab investigates developmental genetics of adult morphology, stem cell biology and evolution, using zebrafish and related species as models. A high percentage of the genes in these common aquarium fish are the same as in humans – reflecting a common ancestry going back to the earliest common vertebrates that populated the ancient seas.

Developmental patterning – such as how scales take shape and form in slightly overlapping layers (in the case of zebrafish, there are more than 200 round scales on each side of the fish) – is a critical part of all development, including how stem cells differentiate and become, for example, bone cells, skin cells and any of the hundreds of kinds of cells that comprise the 37 trillion or so cells in the human body.

How cells differentiate and organize into precise shapes (and sometimes develop into misshapen forms that can result in congenital diseases, cancers and other abnormalities) is of utmost interest to developmental biologists like Parichy and Aman. Understanding the process provides insights into birth defects, cancer and genetic disease, and how the process might be fixed when gone awry.

As an example, teeth, which are actually an epidermal appendage, sometimes are subject to developmental problems. “Defects we find in fish scale development are reminiscent of the developmental problems that can occur with teeth,” Parichy said. “Since scales regenerate, maybe there is a way to get teeth to regenerate.”

“This research helps us make important links between the natural history of life on Earth, the evolutionary process and human disease,” Aman said.

Source: University of Virginia [July 17, 2018]




2018 July 18 Dark Slope Streaks Split on Mars Image Credit:…

2018 July 18

Dark Slope Streaks Split on Mars
Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA

Explanation: What is creating these dark streaks on Mars? No one is sure. Candidates include dust avalanches, evaporating dry ice sleds, and liquid water flows. What is clear is that the streaks occur through light surface dust and expose a deeper dark layer. Similar streaks have been photographed on Mars for years and are one of the few surface features that change their appearance seasonally. Particularly interesting here is that larger streaks split into smaller streaks further down the slope. The featured image was taken by the HiRISE camera on board the Mars-orbiting Mars Reconnaissance Orbiter (MRO) several months ago. Currently, a global dust storm is encompassing much of Mars.

∞ Source: apod.nasa.gov/apod/ap180718.html


Ri Cruin Prehistoric Burial Cairn, Kilmartin Glen, Argyll,…

Ri Cruin Prehistoric Burial Cairn, Kilmartin Glen, Argyll, Scotland, 14.7.18.

The interior of the peripheral cist space has a stone wall carved with four axe head designs.

Source link


Jupiter has twelve new satellites

NASA – Galileo Mission badge.

July 17, 2018

The moons that have just been identified around Jupiter are all small. Jupiter’s new moons were observed for the first time in 2017.

Twelve new moons were discovered around Jupiter. The planet now has 79 known satellites, a record among the planets of our solar system, said Tuesday an American team of astronomers.

Jupiter and Ganymede. Image Credits: NASA/Hubble/STScI

The moons that have just been identified are all small. If Jupiter has large satellites like Ganymede (the largest in the solar system with a diameter of 5268 km), those who have just been spotted are only between 1 km and 4 km in diameter. This is tiny compared to the diameter of Jupiter, which borders on 143’000 km.

Researcher Scott Sheppard of the Carnegie Institution for Science has called one of these new moons a “strange ball” because of its size: just under one kilometer in diameter, making it “probably” the smallest satellite of Jupiter. Its orbit is also “different from that of all other known Jupiterian moons,” said the astronomer.

Unstable situation

It takes about a year and a half for this “strange ball” to circle Jupiter, whose inclined orbit intersects those of a cloud of other moons moving in the opposite direction of the rotation of Jupiter.

“It’s an unstable situation,” said Sheppard. “Frontal collisions can quickly dislocate satellites and reduce them to dust.” The “strange ball”, like two recently discovered moons, turns in the same direction as Jupiter.

Images above: Images taken in May 2018 with Carnegie’s 6.5-meter Magellan telescope at the Las Campanas Observatory in Chile. Lines point to Valetudo, the newly discovered “oddball” moon. Images Credits: Carnegie Institution for Science.

Astronomers have proposed to christen it “Valetudo”, named after the great-granddaughter of the Roman god Jupiter, goddess of health and hygiene.

Half ice, half rock

It takes about a year for the nearest satellites to circle the planet, compared to two years for those more distant. All these moons could be fragments resulting from collisions between larger cosmic bodies.

Image above: This image shows the different groupings of moons orbiting Jupiter, with the newly discovered moons displayed in bold. The “oddball” moon, known as Valetudo, can be seen in green in a prograde orbit that crosses over the retrograde orbits. Image Credits: Roberto Molar-Candanosa, courtesy of Carnegie Institution for Science.

“Jupiter is like a big vacuum, so this planet is massive,” said Scott Sheppard. “These objects started spinning in orbit around Jupiter rather than being rushed against it. We think these are objects halfway between rocky asteroids and icy comets. Probably half ice, half rock.

Discoveries by Galileo

The Italian astronomer Galileo discovered in 1610 the first four moons of Jupiter. The team of astronomers behind the recent discovery was not looking for new Jupiter satellites, but they appeared in the field of their telescopes as they searched for planets beyond Pluto.

Artist’s view of Galileo spacecraft. Image Credit: NASA

The new moons were observed for the first time in 2017 for a Chile-based telescope operated by the US National Astronomical Observatory. It took a year to confirm the trajectory of their orbits using several other telescopes in the United States and Chile.

Related article:

Old Data, New Tricks: Fresh Results from NASA’s Galileo Spacecraft 20 Years On

Related links:

Carnegie Institution for Science: https://carnegiescience.edu/

NASA Galileo mission: https://www.jpl.nasa.gov/missions/galileo/

Images (mentioned), Text, Credits: ATS/NASA/Orbiter.ch Aerospace/Roland Berga.

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Supersharp Images from New VLT Adaptive Optics

Neptune from the VLT with MUSE/GALACSI Narrow Field Mode adaptive optics

PR Image eso1824b

Neptune from the VLT with and without adaptive optics

PR Image eso1824c

Neptune from the VLT and Hubble

PR Image eso1824d

MUSE images of the globular star cluster NGC 6388


ESOcast 172 Light: Supersharp Images from New VLT Adaptive Optics (4K UHD)

ESOcast 172 Light: Supersharp Images from New VLT Adaptive Optics (4K UHD)

Zooming in on the globular star cluster NGC 6388

Zooming in on the globular star cluster NGC 6388 

ESO’s Very Large Telescope (VLT) has achieved first light with a new adaptive optics mode called laser tomography — and has captured remarkably sharp test images of the planet Neptune, star clusters and other objects. The pioneering MUSE instrument in Narrow-Field Mode, working with the GALACSI adaptive optics module, can now use this new technique to correct for turbulence at different altitudes in the atmosphere. It is now possible to capture images from the ground at visible wavelengths that are sharper than those from the NASA/ESA Hubble Space Telescope. The combination of exquisite image sharpness and the spectroscopic capabilities of MUSE will enable astronomers to study the properties of astronomical objects in much greater detail than was possible before.

The MUSE (Multi Unit Spectroscopic Explorer) instrument on ESO’s Very Large Telescope (VLT) works with an adaptive optics unit called GALACSI. This makes use of the Laser Guide Star Facility, 4LGSF, a subsystem of the Adaptive Optics Facility (AOF). The AOF provides adaptive optics for instruments on the VLTs Unit Telescope 4 (UT4). MUSE was the first instrument to benefit from this new facility and it now has two adaptive optics modes — the Wide Field Mode and the Narrow Field Mode [1].

The MUSE Wide Field Mode coupled to GALACSI in ground-layer mode corrects for the effects of atmospheric turbulence up to one kilometre above the telescope over a comparatively wide field of view. But the new Narrow Field Mode using laser tomography corrects for almost all of the atmospheric turbulence above the telescope to create much sharper images, but over a smaller region of the sky [2]

With this new capability, the 8-metre UT4 reaches the theoretical limit of image sharpness and is no longer limited by atmospheric blur. This is extremely difficult to attain in the visible and gives images comparable in sharpness to those from the NASA/ESA Hubble Space Telescope. It will enable astronomers to study in unprecedented detail fascinating objects such as supermassive black holes at the centres of distant galaxies, jets from young stars, globular clusters, supernovae, planets and their satellites in the Solar System and much more.

Adaptive optics is a technique to compensate for the blurring effect of the Earth’s atmosphere, also known as astronomical seeing, which is a big problem faced by all ground-based telescopes. The same turbulence in the atmosphere that causes stars to twinkle to the naked eye results in blurred images of the Universe for large telescopes. Light from stars and galaxies becomes distorted as it passes through our atmosphere, and astronomers must use clever technology to improve image quality artificially.

To achieve this four brilliant lasers are fixed to UT4 that project columns of intense orange light 30 centimetres in diameter into the sky, stimulating sodium atoms high in the atmosphere and creating artificial Laser Guide Stars. Adaptive optics systems use the light from these “stars” to determine the turbulence in the atmosphere and calculate corrections one thousand times per second, commanding the thin, deformable secondary mirror of UT4 to constantly alter its shape, correcting for the distorted light.

MUSE is not the only instrument to benefit from the Adaptive Optics Facility. Another adaptive optics system, GRAAL, is already in use with the infrared camera HAWK-I. This will be followed in a few years by the powerful new instrument ERIS. Together these major developments in adaptive optics are enhancing the already powerful fleet of ESO telescopes, bringing the Universe into focus.

This new mode also constitutes a major step forward for the ESO’s Extremely Large Telescope, which will need Laser Tomography to reach its science goals. These results on UT4 with the AOF will help to bring ELT’s engineers and scientists closer to implementing similar adaptive optics technology on the 39-metre giant.


[1] MUSE and GALACSI in Wide-Field Mode already provides a correction over a 1.0-arcminute-wide field of view, with pixels 0.2 by 0.2 arcseconds in size. This new Narrow-Field Mode from GALACSI covers a much smaller 7.5-arcsecond field of view, but with much smaller pixels just 0.025 by 0.025 arcseconds to fully exploit the exquisite resolution.

[2] Atmospheric turbulence varies with altitude; some layers cause more degradation to the light beam from stars than others. The complex adaptive optics technique of Laser Tomography aims to correct mainly the turbulence of these atmospheric layers. A set of pre-defined layers are selected for the MUSE/GALACSI Narrow Field Mode at 0 km (ground layer; always an important contributor), 3, 9 and 14 km altitude. The correction algorithm is then optimised for these layers to enable astronomers to reach an image quality almost as good as with a natural guide star and matching the theoretical limit of the telescope.

More Information

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile and with Australia as a strategic partner. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.



Joël Vernet
ESO MUSE and GALACSI Project Scientist
Garching bei München, Germany
Tel: +49 89 3200 6579

Roland Bacon
MUSE Principal Investigator / Lyon Centre for Astrophysics Research (CRAL)
Cell: +33 6 08 09 14 27

Calum Turner
ESO Public Information Officer
Garching bei München, Germany
Tel: +49 89 3200 6655
Cell: +49 151 1537 3591

Source: ESO/News


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From an almost perfect Universe to the best of both worlds

ESA – Planck Mission patch.

17 July 2018

It was 21 March 2013. The world’s scientific press had either gathered in ESA’s Paris headquarters or logged in online, along with a multitude of scientists around the globe, to witness the moment when ESA’s Planck mission revealed its ‘image’ of the cosmos. This image was taken not with visible light but with microwaves.

Whereas light that our eyes can see is composed of small wavelengths – less than a thousandth of a millimetre in length – the radiation that Planck was detecting spanned longer wavelengths, from a few tenths of a millimetre to a few millimetres. Most importantly, it had been generated at very beginning of the Universe.

Collectively, this radiation is known as the cosmic microwave background, or CMB. By measuring its tiny differences across the sky, Planck’s image had the ability to tell us about the age, expansion, history, and contents of the Universe. It was nothing less than the cosmic blueprint.

The cosmic microwave background

Astronomers knew what they were hoping to see. Two NASA missions, COBE in the early 1990s and WMAP in the following decade, had already performed an analogous set of sky surveys that resulted in similar images. But those images did not have the precision and sharpness of Planck.

The new view would show the imprint of the early Universe in painstaking detail for the first time. And everything was riding on it.

If our model of the Universe were correct, then Planck would confirm it to unprecedented levels of accuracy. If our model were wrong, Planck would send scientists back to the drawing board.

When the image was revealed, the data had confirmed the model. The fit to our expectations was too good to draw any other conclusion: Planck had showed us an ‘almost perfect Universe’. Why almost perfect? Because a few anomalies remained, and these would be the focus of future research.

Now, five years later, the Planck consortium has made their final data release, known as the legacy data release. The message remains the same, and is even stronger.

“This is the most important legacy of Planck,” says Jan Tauber, ESA’s Planck Project Scientist. “So far the standard model of cosmology has survived all the tests, and Planck has made the measurements that show it.”

The legacy of Planck

All cosmological models are based upon Albert Einstein’s General Theory of Relativity. To reconcile the general relativistic equations with a wide range of observations, including the cosmic microwave background, the standard model of cosmology includes the action of two unknown components.

Firstly, an attractive matter component, known as cold dark matter, which unlike ordinary matter does not interact with light. Secondly, a repulsive form of energy, known as dark energy, which is driving the currently accelerated expansion of the Universe. They have been found to be essential components to explain our cosmos in addition to the ordinary matter we know about. But as yet we do not know what these exotic components actually are.

Planck was launched in 2009 and collected data until 2013. Its first release – which gave rise to the almost perfect Universe – was made in the spring of that year. It was based solely on the temperature of the cosmic microwave background radiation, and used only the first two sky surveys from the mission.

The data also provided further evidence for a very early phase of accelerated expansion, called inflation, in the first tiny fraction of a second in the Universe’s history, during which the seeds of all cosmic structures were sown. Yielding a quantitative measure of the relative distribution of these primordial fluctuations, Planck provided the best confirmation ever obtained of the inflationary scenario.

CMB temperature and polarisation

Besides mapping the temperature of the cosmic microwave background across the sky with unprecedented accuracy, Planck also measured its polarisation, which indicates if light is vibrating in a preferred direction. The polarisation of the cosmic microwave background carries an imprint of the last interaction between the radiation and matter particles in the early Universe, and as such contains additional, all-important information about the history of the cosmos. But it could also contain information about the very first instants of our Universe, and give us clues to understand its birth.

In 2015, a second data release folded together all data collected by the mission, which amounted to eight sky surveys. It gave temperature and polarisation but came with a caution.

“We felt the quality of some of the polarisation data was not good enough to be used for cosmology,” says Jan. He adds that – of course – it didn’t prevent them from doing cosmology with it but that some conclusions drawn at that time needed further confirmation and should therefore be treated with caution.

And that’s the big change for this 2018 Legacy data release. The Planck consortium has completed a new processing of the data. Most of the early signs that called for caution have disappeared. The scientists are now certain that both temperature and polarisation are accurately determined.

“Now we really are confident that we can retrieve a cosmological model based on solely on temperature, solely on polarisation, and based on both temperature and polarisation. And they all match,” says Reno Mandolesi, principal investigator of the LFI instrument on Planck at the University of Ferrara, Italy.

The history of the Universe

“Since 2015, more astrophysical data has been gathered by other experiments, and new cosmological analyses have also been performed, combining observations of the CMB at small scales with those of galaxies, clusters of galaxies, and supernovae, which most of the time improved the consistency with Planck data and the cosmological model supported by Planck,” says Jean-Loup Puget, principal investigator of the HFI instrument on Planck at the Institut d’Astrophysique Spatiale in Orsay, France.

This is an impressive feat and means that cosmologists can be assured that their description of the Universe as a place containing ordinary matter, cold dark matter and dark energy, populated by structures that had been seeded during an early phase of inflationary expansion, is largely correct. 

But there are some oddities that need explaining – or tensions as cosmologists call them. One in particular is related to the expansion of the Universe. The rate of this expansion is given by the so-called Hubble Constant.

To measure the Hubble constant astronomers have traditionally relied on gauging distances across the cosmos. They can only do this for the relatively local Universe by measuring the apparent brightness of certain types of nearby variable stars and exploding stars, whose actual brightness can be estimated independently. It is a well-honed technique that has been developed over the course of the last century, pioneered by Henrietta Leavitt and later applied, in the late 1920s, by Edwin Hubble and collaborators, who used variable stars in distant galaxies and other observations to reveal that the Universe was expanding.

The figure astronomers derive for the Hubble Constant using a wide variety of cutting-edge observations, including some from Hubble’s namesake observatory, the NASA/ESA Hubble Space Telescope, and most recently from ESA’s Gaia mission, is 73.5 km/s/Mpc, with an uncertainty of only two percent. The slightly esoteric units give the velocity of the expansion in km/s for every million parsecs (Mpc) of separation in space, where a parsec is equivalent to 3.26 light-years.

Measurements of the Hubble constant

A second way to estimate the Hubble Constant is to use the cosmological model that fits the cosmic microwave background image, which represents the very young Universe, and calculate a prediction for what the Hubble Constant should be today. When applied to Planck data, this method gives a lower value of 67.4 km/s/Mpc, with a tiny uncertainty of less than a percent.

On the one hand, it is extraordinary that two such radically different ways of deriving the Hubble constant – one using the local, mature Universe, and one based on the distant, infant Universe – are so close to each other. On the other hand, in principle these two figures should agree to within their respective uncertainties. This is the tension, and the question is how can they be reconciled?

Both sides are convinced that any remaining errors in their measurement methodologies are now too small to cause the discrepancy. So could it be that there is something slightly peculiar about our local cosmic environment that makes the nearby measurement somewhat anomalous? We know for example that our Galaxy sits in a slightly under-dense region of the Universe, which could affect the local value of the Hubble constant. Unfortunately, most astronomers think that such deviations are not large enough to resolve this problem.

“There is no single, satisfactory astrophysical solution that can explain the discrepancy. So, perhaps there is some new physics to be found,” says Marco Bersanelli, deputy principal investigator of the LFI instrument at the University of Milan, Italy.

‘New physics’ means that exotic particles or forces could be influencing the results. Yet, as exciting as this prospect feels, the Planck results place severe constraints on this train of thought because it fits so well with the majority of observations.


“It is very hard to add new physics alleviating the tension and still keep the standard model’s precise description of everything else that already fits,” says François Bouchet, deputy principal investigator of the HFI instrument at the Institut d’Astrophysique de Paris, France.

As a result, no one has been able to come up with a satisfactory explanation for the differences between the two measurements, and the question remains to be resolved.

“For the moment, we shouldn’t get too excited about finding new physics: it could well be that the relatively small discrepancy can be explained by a combination of small errors and local effects. But we need to keep improving our measurements and thinking about better ways to explain it,” says Jan.

This is the legacy of Planck: with its almost perfect Universe, the mission has given researchers confirmation of their models but with a few details to puzzle over. In other words: the best of both worlds.

Related article:

Hubble and Gaia Team Up to Fuel Cosmic Conundrum

2015 second data release:

Planck reveals first stars were born late

Notes for Editors:

A series of scientific papers describing the new results was published on 17 July and can be downloaded here: https://www.cosmos.esa.int/web/planck/publications

The Planck Legacy Archive: http://pla.esac.esa.int/pla/

More about Planck: http://sci.esa.int/planck/

Images, Video, Text, Credits: ESA/NASA/Markus Bauer/Jan Tauber/Planck Collaboration.

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