пятница, 17 мая 2019 г.

Finding the Beat To keep our hearts beating in time the…


Finding the Beat


To keep our hearts beating in time the autonomic nervous system carries pulses of electrical activity deep into their muscular walls, causing repeating patterns of contractions. Usually hidden behind layers of fatty molecules, the nerves in this mouse heart are revealed in bright colours under a high-powered microscope after a chemical wash to clear the fats away. Computer algorithms help to spot the ‘circuits’ of nerves, colour-coding them by diameter (left, blue thinnest, red thickest) or by their orientation with the heart (right). These patterns reveal fresh details about how heart rhythm in maintained, but also provide a comparison for future studies – using similar techniques to examine how these patterns are disrupted by cardiovascular diseases and conditions such as myocardial infarction.


Written by John Ankers



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Decorated Roman Lead Water Tank Fragments, The Collection, Lincoln, 12.5.19.

Decorated Roman Lead Water Tank Fragments, The Collection, Lincoln, 12.5.19.




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China Plans to Launch Carrier Rocket at Sea


CASC — China Aerospace Science and Technology Corporation logo.


May 17, 2019


China plans to launch a Long March-11 carrier rocket at sea this year, which is expected to lower the cost of entering space.


The rocket has been named «CZ-11 WEY» under an agreement between the China Academy of Launch Vehicle Technology, China Space Foundation and a Chinese automobile producer.


The seaborne launch technology will help China provide launch services for countries participating in the Belt and Road Initiative.



The Long March-11, with a length of 20.8 meters and a takeoff weight of about 57.6 tonnes, is the only rocket using solid propellants among China’s new generation carrier rockets. It has a relatively simple structure and can be launched in a short time.


The rocket can carry a payload of up to 350 kg to a sun-synchronous orbit at an altitude of 700 km and 700 kg to a low-Earth orbit at 200 km. It is mainly used to carry small satellites, and can take multiple satellites into orbit at the same time.


China Aerospace Science and Technology Corporation (CASC):
http://english.spacechina.com/n16421/index.html


Image, Text, Credits: CASC/Xinhua.


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Chang’e Fourth lander and patrol complete the fifth month of work


CLEP — China Lunar Exploration Program logo.


May 17, 2019



Chang’e 4 Lander Terrain Camera Imaging the Yutu No. 2 Patrol

The «Yutu Rabbit No. 2» patrol completed the scientific exploration work of the fifth month and entered the fifth night at 11:05 on the same day. The patrol moves according to the overall plan, and the total walking is 190.66 meters. During the movement of the patrol, the power-on detection of the payloads of the patrol infrared spectrometer, panoramic camera, neutral atomic detector, and moon-receiving radar was organized and implemented as planned, and the ground receiving load data transmission data was normal.



The No. 4 lander was completed at 12 o’clock on May 11 at the end of the night and went to sleep. During the fifth month, the lander working conditions were normal. The payload lunar neutrons and radiation dose detectors and low-frequency radio spectrometers were effectively tested as planned, and the ground receiving scientific detection data was normal.



The fourth engineering ground application system released the latest scientific test data to the research core team, with a total data volume of 6.6 GB and a total of 494 data files. In the follow-up work, the ground scientific research personnel will professionally process and analyze the obtained scientific test data.



Yutu No. 2 Patrol Camera, Panoramic Camera Imaging the No. 4 Lander

Related article:


China’s Yutu-2 rover Enters Standby Mode for ‘Noon Nap’ as Chang’e 4 Tests Continue
https://orbiterchspacenews.blogspot.com/2019/01/chinas-yutu-2-rover-enters-standby-mode.html


Related links:


CNSA Press Release: http://www.cnsa.gov.cn/n6759533/c6806278/content.html


China National Space Administration (CNSA): http://www.cnsa.gov.cn/


Images, Text, Credits: CNSA/CLEP/Orbiter.ch Aerospace/Roland Berga.


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2019 May 17 RS Puppis Image Credit & Copyright: Image Data:…


2019 May 17


RS Puppis
Image Credit & Copyright: Image Data: NASA, ESA, Hubble Legacy Archive;
Processing & Copyright: Rogelio Bernal Andreo (DeepSkyColors.com)


Explanation: Pulsating RS Puppis, the brightest star in the image center, is some ten times more massive than our Sun and on average 15,000 times more luminous. In fact, RS Pup is a Cepheid variable star, a class of stars whose brightness is used to estimate distances to nearby galaxies as one of the first steps in establishing the cosmic distance scale. As RS Pup pulsates over a period of about 40 days, its regular changes in brightness are also seen along its surrounding nebula delayed in time, effectively a light echo. Using measurements of the time delay and angular size of the nebula, the known speed of light allows astronomers to geometrically determine the distance to RS Pup to be 6,500 light-years, with a remarkably small error of plus or minus 90 light-years. An impressive achievement for stellar astronomy, the echo-measured distance also more accurately establishes the true brightness of RS Pup, and by extension other Cepheid stars, improving the knowledge of distances to galaxies beyond the Milky Way.


∞ Source: apod.nasa.gov/apod/ap190517.html


The Birth of the Hunter



NGC 2023
Credit: ESO


The constellation of Orion (The Hunter) is one of the most recognisable collections of stars in the night sky. We have noted Orion’s prominent stars for tens of thousands of years at least, and likely far longer. Chinese astronomers called it 参宿 or Shēn, literally “three stars”, for its three bright dots (which form the Hunter’s belt). The ancient Egyptians regarded it as the gods Sah and Sopdet, manifestations of Osiris and Isis, respectively, whereas Greek astronomers saw a brave hunter — the eponymous Orion — with his sword above his head, ready to strike.


Mythology aside, Orion is a fascinating patch of sky. This image, from ESO’s Very Large Telescope, shows a reflection nebula nestled at the heart of the constellation — NGC 2023. Located close to the well-known Horsehead and Flame Nebulae, NGC 2023 lurks about 1500 light-years away from Earth, and is one of the largest reflection nebulae in the sky.


Reflection nebulae are clouds of interstellar dust that reflect the light from nearby or internal sources, like fog around a car headlight. NGC 2023 is illuminated by a massive young star named HD 37903. The star is extremely hot — several times hotter than the Sun — and its bright blue-white light causes NGC 2023’s milky glow. Such nebulae are often the birthplaces of stars, and contain a clumpy distribution of gas that’s significantly denser than the surrounding medium. Under the influence of gravity, these clumps attract one another and merge, eventually creating a new star. In a few million years time, Orion’s Belt may gain a new star!


The image was taken with the VLT’s FORS (FOcal Reducer and Spectrograph) instrument as part of the ESO Cosmic Gems programme. This initiative produces images of interesting and visually attractive objects using ESO telescopes, for the purposes of education and outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.


Source: ESO/Potw



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Parents unknown: Mysterious larvae found in Panama’s two oceans

Under the microscope, sea water reveals the larval stages of little-known marine creatures called phoronids (horseshoe worms), but finding their parents is another story. Although such fanciful larvae caught the eye of scientists studying plankton—the tiny, drifting plants and animals in the world’s oceans—as long ago as the 1800s, there are only about 15 species of phoronids known worldwide, based on adult specimens. A study of phoronid larvae published this week by scientists at the Smithsonian Tropical Research Institute (STRI) in Panama has detected eight potentially new species.











Parents unknown: Mysterious larvae found in Panama's two oceans
Phoronid larva collected in Bocas del Toro province, Panama (Caribbean Sea, Atlantic Ocean)
[Credit: Michael Boyle]

«The global diversity of small, rare marine animals like phoronids is grossly underestimated,» said STRI staff-scientist Rachel Collin. «We don’t know what animals are out there, and we know even less about what their role might be in the world’s oceans.»
Because phoronid larvae swim and drift in seawater, they are much easier to sample than their adult forms, which live on the sea floor within sands, sediment or rubble. And the larvae do not look like the adults, making it difficult to tell which larva belongs to which adult without doing a sort of paternity testing: comparing larval DNA sequences to the DNA of their potential parents.











Parents unknown: Mysterious larvae found in Panama's two oceans
Phoronid larva collected in Bocas del Toro province, Panama (Caribbean Sea, Atlantic Ocean)
[Credit: Michael Boyle]

Named for the Egyptian goddess Phoronis, tubular adult horseshoe worms anchor their bodies to rocks or corals and wave a crown of ciliated tentacles to capture tiny food particles. To reproduce, their eggs and sperm unite to create embryos that hatch as swimming larvae, which then become members of the microscopic plankton. The larvae have cylindrical bodies topped with a ring of tentacles and a large hood that serves to capture food. Many are decorated with yellow pigment spots and within some it is possible to see reddish or pinkish patches of blood cells through their translucent bodies. Eventually they descend to the seafloor, develop into adults and complete their life cycle, considered the most common cycle in the animal kingdom.
Scientists collected plankton from the Bay of Panama on the Pacific Coast and Bocas del Toro on the Caribbean coast. By examining plankton with a stereomicroscope, they found more than 50 phoronid larvae; 23 from the Pacific and 29 from the Atlantic. Using a genetic technique called barcoding based on DNA sequencing, they were able to distinguish three distinct phoronids in the plankton from the Bay of Panama and four others from the Caribbean.











Parents unknown: Mysterious larvae found in Panama's two oceans
Phoronid larva collected in Bocas del Toro province, Panama (Caribbean Sea, Atlantic Ocean)
[Credit: Michael Boyle]

The DNA of particular genes from each of these animals was different from anything recorded in GenBank, a global collection of DNA from more than 300,000 organisms, suggesting that these larvae may belong to species that are new to science. However, finding the adults of these species may take years, especially since very few scientists study horseshoe worms.
«Because of the cryptic lifestyles of phoronids, the matching adult worms may never be found, yet the presence of their larval forms in plankton confirm that they are here, established and reproducing,» said co-author Michael J. Boyle, previously, a Tupper postdoctoral fellow at the STRI and now a staff biologist and the principal investigator of the Life Histories Program at the Smithsonian Marine Station in Fort Pierce, Florida.



At STRI’s Bocas del Toro Research Station on the Caribbean, Collin, who is the station director, organizes a series of Tropical Taxonomy Training courses, intended to bring researchers who specialize on these and other fairly unknown marine organisms to Panama, where they almost always discover new species and pass their knowledge on to students. They produce a series of YouTube videos to teach students how to capture, preserve and identify new species.


The study is published in Invertebrate Biology.


Source: Smithsonian Tropical Research Institute [May 14, 2019]



TANN



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You are what you eat: How the pursuit of carbs changed mammals’ genes and saliva

Starch, a complex carbohydrate, is a vital source of nutrition for many mammals. Humans farm it in the form of rice, wheat, corn, potatoes and oats. Rats comb our garbage piles for scraps of pizza and bread. Wild boars root for tubers.











You are what you eat: How the pursuit of carbs changed mammals' genes and saliva
Credit: Nathan Rupert/Flickr

Now, a new study is providing insight into how the pursuit of starch may have driven evolutionary adaptations in these and other hungry mammals.


The research, conducted on 46 mammal species, focuses on a biological compound called amylase, which is produced by humans and other animals to break down starch.


The study finds that in the course of mammalian evolution, the genetic machinery that teaches the body how to make amylase has been something of a chameleon. It has evolved in different ways in different beasts, and it’s capable of changing rapidly, possibly in accordance with what animals eat.


The study finds that mammals with starchy diets tend to have more copies of the amylase gene, which carries instructions for building amylase, than mammals that consume little starch (at least among the species studied).


The research also presents evidence that evolutionary changes related to amylase — including duplications of the amylase gene and the ability to produce amylase in saliva — may have arisen independently in some different species. Called convergent evolution, this phenomenon often signals a particularly useful adaptation.


Findings were published in the journal eLife. Overall, the study paints a colorful picture of the evolutionary history of amylase across mammals, ranging from humans, dogs and house cats to hedgehogs and ring-tailed lemurs, along with baboons that store food in their cheeks.


«Amylase is a case where diet may have the potential to change our genes. This is fascinating,» says Omer Gokcumen, PhD, assistant professor of biological sciences in the University at Buffalo College of Arts and Sciences. «The duplications we see in the amylase gene give a very flexible and rapid way in which gene functions can evolve, and this mechanism of evolution is underappreciated.»


«Past studies have explored the evolution of amylase in select species, such as humans and dogs, but our research takes a broader perspective,» says Stefan Ruhl, PhD, DDS, professor of oral biology in the UB School of Dental Medicine. «We examine dozens of mammalian species from different branches of the evolutionary tree, and we see that when it comes to amylase in saliva, genetics and biology may respond to what we eat.»


The study was led by Gokcumen, Ruhl and first author Petar Pajic, a UB oral biology and biological sciences researcher.


The research — supported by the National Institute of Dental and Craniofacial Research, National Cancer Institute and National Science Foundation — included researchers from UB, the Foundation for Research and Technology in Greece, SUNY Plattsburgh, Cornell University and the Friedrich-Loeffler-Institut in Germany.


Details on the findings


Mammals with starchy diets appear to have adapted, genetically, to stomach more carbs: Of the species studied, those with starch in their diets generally have more copies of the amylase gene, which carries instructions for making amylase, than animals like carnivores and herbivores whose strict diets tend to exclude starch. Carb-munching humans, house mice, brown rats, dogs, pigs and boars have lots of copies, while mammals like mountain lions, which subsist on meat, and hedgehogs, which dine on foods such as insects and snails, have few.











You are what you eat: How the pursuit of carbs changed mammals' genes and saliva
These are vials of saliva collected from various mammals, including a pig
[Credit: Douglas Levere/University at Buffalo]

This is important because the gene is akin to a mold in a factory: the more units you have, the more amylase you can theoretically produce. As for how the extra copies of the amylase gene evolved, «It’s like the chicken and the egg — we cannot really tell what came first,» Ruhl says. «Starch in the diet may have led to more amylase, and the ability to digest starch may have led to increased starch intake, and so forth.»


In some cases, close contact with humans — and access to human food — may have spurred an adaptation to starch. The study confirmed past findings from other teams showing that mice and domestic dogs, which live alongside people, have more copies of the amylase gene than their wild cousins (wolves and wild rodents, respectively). The brown rat (Rattus norvegicus) — a species commonly known as the street or sewer rat — also has many copies of the amylase gene.


The genetic expansion of amylase likely occurred independently in multiple species: Based on genetic evidence, the study concluded that mice, rats, dogs, pigs and humans likely acquired some of their extra copies of the amylase gene independently, at separate times in their evolution, rather than inheriting all the copies from a common ancestor. This phenomenon, called convergent evolution, can signal a particularly useful adaptation.


Amylase in saliva is more widespread than previously known (some pet dogs produce it, for example): Most amylase is produced in the pancreas, but some animals also secrete it in saliva. The new research finds that this capability is more common than previously known, and proposes salivary amylase as another adaptation that may have arisen through convergent evolution in some species.


When scientists tested for amylase in the drool of 22 mammalian species, they found it in 15 species, including six species that were not previously known to have amylase in saliva. Perhaps unsurprisingly, baboons and rhesus macaques that store food in cheek pouches for long periods of time were among the most prolific producers of salivary amylase among the mammals tested.











You are what you eat: How the pursuit of carbs changed mammals' genes and saliva
Petar Pajic, a researcher in UB’s oral biology and biological sciences departments, holds a starch lysis plate.
To study how much amylase different species produce in saliva, scientists punched tiny holes
into a starchy gelatinous substance, and filled the holes with saliva from varied species
[Credit: Douglas Levere/University at Buffalo]

Pet dogs were among the species that were newly identified as salivary amylase producers. While not all dogs have amylase, the research found it in several breeds, such as English cream golden retrievers, Labradors and pitbulls.


«This study provides the most comprehensive picture, to date, on how amylase has evolved in the mammalian lineage at both the genetic level and at the level of protein expression in saliva,» says Pajic, the study’s first author. «From a broader theoretical stance, it also reveals how quickly evolution can happen and how something simple, like the food you eat, may drive otherwise unrelated species to evolve similarly.»


For animals who don’t store food in their cheeks, the evolutionary advantage of having amylase in saliva is unclear. But Ruhl, a leading salivary researcher, says one theory is that it helps animals and humans identify starchy foods as desirable to eat.


«Humans have a lot of salivary amylase, but why?» he says. «Unlike the baboons who predigest food in their cheek pouches, we humans do not keep food in our mouths long enough for any substantial digestion to happen. One idea is that salivary amylase evolved to help our ancestors detect starch: They would not be able to taste it otherwise. Amylase liberates sugar in starch, and this may help animals develop a taste preference for starch-rich foods like potatoes or corn.»


Other hypothesized purposes for salivary amylase include cleaning sticky starch residues from teeth: «Amylase in saliva might act as a kind of biochemical toothbrush nature has provided us with,» Ruhl says with a smile. «It could help to regulate the make-up of the oral microbiome.»


Author: Charlotte Hsu | Source: University at Buffalo [May 14, 2019]



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Striking polished Azurite hemisphere | #Geology #GeologyPage…


Striking polished Azurite hemisphere | #Geology #GeologyPage #Mineral


Locality: Poteryaevskoe Mine, Rubtsovskoe Cu-Zn-Pb deposit, Rudnyi Altai, Altaiskii Krai, Western-Siberian Region, Russia


Size: 27mm x 23mm x 13mm


Photo Copyright © Quebul Fine Minerals


Geology Page

www.geologypage.com

https://www.instagram.com/p/BxjjoicDDAP/?igshid=10nu3ac4wx1p8


Purple Fluorite stalactite | #Geology #GeologyPage…


Purple Fluorite stalactite | #Geology #GeologyPage #Mineral


Locality: Yunnan Province, China

Size: 48mm x 18mm x 20mm


Photo Copyright © Quebul Fine Minerals


Geology Page

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Gypsum | #Geology #GeologyPage #Mineral Locality: Red River…


Gypsum | #Geology #GeologyPage #Mineral


Locality: Red River Floodway, Winnipeg, Manitoba, Canada


Size: 115mm x 87mm x 71mm


Photo Copyright © Quebul Fine Minerals


Geology Page

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Fresh off the sledge

As things stand, the closest individual to a Proto-Uralic speaker in the ancient DNA record is arguably OLS10 from an Iron Age tarand grave in what is now Estonia. I say that because:



— isotopic data suggest that OLS10 wasn’t born where he died, and considering his elevated Siberian ancestry relative to earlier and most contemporaneous Baltic ancients, he was very likely a migrant to the Baltic region from the east
— the tarand grave tradition appears to be specifically a Finnic (west Uralic) phenomenon that probably spread from the Volga-Oka region, which is just west of where most people place the Proto-Uralic homeland
— OLS10 belongs to Y-chromosome haplogroup N-L1026, a paternal marker that is especially closely associated with Uralic-speaking populations and probably only appeared in the East Baltic region during the Bronze Age-Iron Age transition



You can find more background info about OLS10 and other relevant samples in Saag et al. 2019 (see here). This is where he sits in my Principal Component Analyses (PCA) focusing on fine scale Northern European genetic diversity. The relevant datasheets are available here and here, respectively.





Note that OLS10 doesn’t cluster strongly with any ancient or modern populations. To investigate this in more detail I ran a series of two-way qpAdm analyses, testing tens of ancient individuals and populations as potential admixture sources. These two models stood out above the rest in terms of their statistical fits, chronology and overall plausibility.



Baltic_EST_IA_0LS10
Baltic_EST_BA 0.826±0.045
RUS_Sintashta_MLBA_o1 0.174±0.045

chisq 12.527
tail prob 0.564048
Full output
Baltic_EST_IA_0LS10
Baltic_EST_BA 0.683±0.102
RUS_Mezhovskaya 0.317±0.102

chisq 13.811
tail prob 0.463864
Full output



Please note that RUS_Sintashta_MLBA_o1 isn’t representative of the Sintashta culture population as a whole. It’s a group of the most extreme genetic outliers among the Sintashta samples, and they may or may not have been Uralic speakers (see here). Interestingly, the Mezhovskaya culture population is generally associated with the Ugric branch of the Uralic language family.
I was also able to closely replicate these results with the Global25/nMonte method; down to almost one per cent. However, the statistical fits (distances) are poor, probably because the reference populations aren’t the real mixture sources. This is in line with the fact that their Y-haplogroups are Q1a, R1a and R1b, rather than any type of N.



Baltic_EST_IA:0LS10
Baltic_EST_BA,83.8
RUS_Sintashta_MLBA_o1,16.2

distance%=4.7955
Baltic_EST_IA:0LS10
Baltic_EST_BA,69.8
RUS_Mezhovskaya,30.2

distance%=3.5783



I do realize that two Bronze Age samples from Bolshoy Oleni Ostrov, Kola Peninsula, belong to N-L1026, but adding them to my mixture models doesn’t help. Little wonder, because the Kola Peninsula lies within the Arctic Circle, and I’m pretty sure that OLS10 and his N-L1026 came from somewhere just north of the mixture cline marked on the map below. Unfortunately, I can’t test this directly yet due to the scarcity of ancient samples from this region.



See also…
It was always going to be this way
On the association between Uralic expansions and Y-haplogroup N
Uralic-specific genome-wide ancestry did make a signifcant impact in the East Baltic

Source


Monitoring Earth’s shifting land…


Monitoring Earth’s shifting land http://www.geologypage.com/2019/05/monitoring-earths-shifting-land.html


Bedbugs evolved more than 100 million years ago “walked the…


Bedbugs evolved more than 100 million years ago “walked the earth with T. rex” http://www.geologypage.com/2019/05/bedbugs-evolved-more-than-100-million-years-ago-walked-the-earth-with-t-rex.html


From Earth’s deep mantle, scientists find a new way volcanoes…


From Earth’s deep mantle, scientists find a new way volcanoes form http://www.geologypage.com/2019/05/from-earths-deep-mantle-scientists-find-a-new-way-volcanoes-form.html


Granite Rocks…


Granite Rocks http://www.geologypage.com/2019/05/granite-rocks.html


NASA’s New Horizons Team Publishes First Kuiper Belt Flyby Science Results


NASA — New Horizons Mission patch.


May 16, 2019


Most distant object ever explored presents mysteries of its formation.


NASA’s New Horizons mission team has published the first profile of the farthest world ever explored, a planetary building block and Kuiper Belt object called 2014 MU69.


Analyzing just the first sets of data gathered during the New Horizons spacecraft’s New Year’s 2019 flyby of MU69 (nicknamed Ultima Thule) the mission team quickly discovered an object far more complex than expected. The team publishes the first peer-reviewed scientific results and interpretations – just four months after the flyby – in the May 17 issue of the journal Science.



Image above: Total Teamwork: Aside from the scientific results it contains, the New Horizons Science paper summarizing early findings from the flyby of Ultima Thule is noteworthy for another reason: it has more than 200 co-authors, representing more than 40 institutions. Principal Investigator Alan Stern, as mission head and lead author, thought it important to give authorship to the full range of team members who had role on the successful flyby. As a result, Stern’s paper includes authors from the science, spacecraft, operations, mission design, management and communications teams, as well as collaborators, such as contributing scientist and stereo imaging specialist (and legendary Queen guitarist) Brian May, NASA Planetary Division Director Lori Glaze, NASA Chief Scientist Jim Green, and NASA Associate Administrator for the Science Mission Directorate Thomas Zurbuchen. Image Credits: AAAS/Science.


In addition to being the farthest exploration of an object in history – four billion miles from Earth – the flyby of Ultima Thule was also the first investigation by any space mission of a well-preserved planetesimal, an ancient relic from the era of planet formation.


The initial data summarized in Science reveal much about the object’s development, geology and composition. It’s a contact binary, with two distinctly differently shaped lobes. At about 22 miles (36 kilometers) long, Ultima Thule consists of a large, strangely flat lobe (nicknamed «Ultima») connected to a smaller, somewhat rounder lobe (nicknamed «Thule»), at a juncture nicknamed “the neck.” How the two lobes got their unusual shape is an unanticipated mystery that likely relates to how they formed billions of years ago.


The lobes likely once orbited each other, like many so-called binary worlds in the Kuiper Belt, until some process brought them together in what scientists have shown to be a «gentle» merger. For that to happen, much of the binary’s orbital momentum must have dissipated for the objects to come together, but scientists don’t yet know whether that was due to aerodynamic forces from gas in the ancient solar nebula, or if Ultima and Thule ejected other lobes that formed with them to dissipate energy and shrink their orbit. The alignment of the axes of Ultima and Thule indicates that before the merger the two lobes must have become tidally locked, meaning that the same sides always faced each other as they orbited around the same point.



New Horizons Ultima Thule flyby. Image Credits: NASA/JHUAPL

“We’re looking into the well-preserved remnants of the ancient past,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “There is no doubt that the discoveries made about Ultima Thule are going to advance theories of solar system formation.”


As the Science paper reports, New Horizons researchers are also investigating a range of surface features on Ultima Thule, such as bright spots and patches, hills and troughs, and craters and pits on Ultima Thule. The largest depression is a 5-mile-wide (8-kilometer-wide) feature the team has nicknamed Maryland crater – which likely formed from an impact. Some smaller pits on the Kuiper Belt object, however, may have been created by material falling into underground spaces, or due to exotic ices going from a solid to a gas (called sublimation) and leaving pits in its place.


In color and composition, Ultima Thule resembles many other objects found in its area of the Kuiper Belt. It’s very red – redder even than much larger, 1,500-mile (2,400-kilometer) wide Pluto, which New Horizons explored at the inner edge of the Kuiper Belt in 2015 – and is in fact the reddest outer solar system object ever visited by spacecraft; its reddish hue is believed to be caused by modification of the organic materials on its surface New Horizons scientists found evidence for methanol, water ice, and organic molecules on Ultima Thule’s surface – a mixture very different from most icy objects explored previously by spacecraft.



Image above: This composite image of the primordial contact binary Kuiper Belt Object 2014 MU69 (nicknamed Ultima Thule) – featured on the cover of the May 17 issue of the journal Science – was compiled from data obtained by NASA’s New Horizons spacecraft as it flew by the object on Jan. 1, 2019. The image combines enhanced color data (close to what the human eye would see) with detailed high-resolution panchromatic pictures. Image Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Roman Tkachenko.


Data transmission from the flyby continues, and will go on until the late summer 2020. In the meantime, New Horizons continues to carry out new observations of additional Kuiper Belt objects it passes in the distance. These additional KBOs are too distant to reveal discoveries like those on MU69, but the team can measure aspects such as the object’s brightness. New Horizons also continues to map the charged-particle radiation and dust environment in the Kuiper Belt.


The New Horizons spacecraft is now 4.1 billion miles (6.6 billion kilometers) from Earth, operating normally and speeding deeper into the Kuiper Belt at nearly 33,000 miles (53,000 kilometers) per hour.


The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built and operates the New Horizons spacecraft, and manages the mission for NASA’s Science Mission Directorate. The MSFC Planetary Management Office provides the NASA oversight for the New Horizons. Southwest Research Institute, based in San Antonio, directs the mission via Principal Investigator Stern, and leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.


Science journal: https://www.sciencemag.org/


New Horizons: http://www.nasa.gov/mission_pages/newhorizons/main/index.html


Images (mentioned), Text, Credits: NASA/Tricia Talbert.


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NASA Taps 11 American Companies to Advance Human Lunar Landers


NASA logo.


May 16, 2019


NASA has selected 11 companies to conduct studies and produce prototypes of human landers for its Artemis lunar exploration program. This effort will help put American astronauts — the first woman and next man — on the Moon’s south pole by 2024 and establish sustainable missions by 2028.


“To accelerate our return to the Moon, we are challenging our traditional ways of doing business. We will streamline everything from procurement to partnerships to hardware development and even operations,” said Marshall Smith, director for human lunar exploration programs at NASA Headquarters. “Our team is excited to get back to the Moon quickly as possible, and our public/private partnerships to study human landing systems are an important step in that process.”



Illustration of a human landing system. Image Credit: NASA

Through Next Space Technologies for Exploration Partnerships (NextSTEP) Appendix E contracts, the selected companies will study and/or develop prototypes during the next six months that reduce schedule risk for the descent, transfer, and refueling elements of a potential human landing system.


NASA’s proposed plan is to transport astronauts in a human landing system that includes a transfer element for the journey from the lunar Gateway to low-lunar orbit, a descent element to carry them to the surface, and an ascent element to return to them to the Gateway. The agency also is looking at refueling capabilities to make these systems reusable.


The total award amount for all companies is $45.5 million. As NextSTEP is a public/private partnership program, companies are required to contribute at least 20% of the total project cost. This partnership will reduce costs to taxpayers and encourage early private investments in the lunar economy.


The awardees, from eight states across the country, are:
— Aerojet Rocketdyne – Canoga Park, California
   One transfer vehicle study


— Blue Origin – Kent, Washington
  One descent element study, one transfer vehicle study, and one transfer vehicle prototype


— Boeing – Houston
  One descent element study, two descent element prototypes, one transfer vehicle study, one transfer vehicle prototype, one refueling element study, and one refueling element prototype


— Dynetics – Huntsville, Alabama
  One descent element study and five descent element prototypes


— Lockheed Martin – Littleton, Colorado
  One descent element study, four descent element prototypes, one transfer vehicle study, and one refueling element study


— Masten Space Systems – Mojave, California
  One descent element prototype


— Northrop Grumman Innovation Systems – Dulles, Virginia
  One descent element study, four descent element prototypes, one refueling element study, and one refueling element prototype


— OrbitBeyond – Edison, New Jersey
  Two refueling element prototypes


— Sierra Nevada Corporation, Louisville, Colorado, and Madison, Wisconsin
  One descent element study, one descent element prototype, one transfer vehicle study, one transfer vehicle prototype, and one refueling element study


— SpaceX – Hawthorne, California
  One descent element study


— SSL – Palo Alto, California
  One refueling element study and one refueling element prototype


To expedite the work, NASA is invoking undefinitized contract actions, which allow the agency to authorize partners to start a portion of the work, while negotiations toward contract award continue in parallel.


“We’re taking major steps to begin development as quickly as possible, including invoking a NextSTEP option that allows our partners to begin work while we’re still negotiating,” said Greg Chavers, human landing system formulation manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “We’re keen to collect early industry feedback about our human landing system requirements, and the undefinitized contract action will help us do that.”


NASA gave industry its first heads up in April, with the issuance of a pre-solicitation, of its intention to partner with American companies on the development of an integrated lander. The formal solicitation, to be issued this summer, will provide the requirements for a 2024 human landing, and leave it to U.S. industry to propose innovative concepts, hardware development and integration.


“This new approach doesn’t prescribe a specific design or number of elements for the human landing system,” Chavers said. “NASA needs the system to get our astronauts on the surface and return them home safely, and we’re leaving a lot of the specifics to our commercial partners.”


NASA is sending astronauts to the Moon and then on to Mars, in a measured and sustainable way. The direction from Space Policy Directive-1 builds on the hard work NASA is doing on its Space Launch System rocket and Orion spacecraft, agency efforts to enable commercial partners, its work with international partners, and what NASA learns from its current robotic missions at the Moon and Mars. Learn more at: https://www.nasa.gov/moontomars


Lunar Gateway: https://www.nasa.gov/topics/moon-to-mars/lunar-outpost


Space Policy Directive-1: https://www.nasa.gov/press-release/new-space-policy-directive-calls-for-human-expansion-across-solar-system


Image (mentioned), Text, Credits: NASA/Sean Potter/Gina Anderson/Cheryl Warner.


Best regards, Orbiter.chArchive link


Caption Spotlight (16 May 2019): The Changing Surface of…


Caption Spotlight (16 May 2019): The Changing Surface of Mars


HiRISE commonly takes images of recent craters on Mars, which are usually found by the MRO Context Camera where they disturb surface dust. An impact site in this area was first imaged in December 2017.


A year and a half later, the scene looks totally different! Dust has eroded from the surface, probably due to the planet-encircling dust storm from 2018. The dark spots around the fresh craters have vanished because they only affected the dust that has since disappeared. See if you can find the craters in the new image by comparing with the old one.


NASA/JPL/University of Arizona


Small, hardy planets most likely to survive death of their stars

Small, hardy planets packed with dense elements have the best chance of avoiding being crushed and swallowed up when their host star dies, new research from the University of Warwick has found.











Small, hardy planets most likely to survive death of their stars
An asteroid torn apart by the strong gravity of a white dwarf has formed a ring of dust particles and debris orbiting
the Earth-sized burnt out stellar core [Credit: University of Warwick/Mark Garlick]

Astrophysicists from the Astronomy and Astrophysics Group have modelled the chances of different planets being destroyed by tidal forces when their host stars become white dwarfs and have determined the most significant factors that decide whether they avoid destruction.


Their ‘survival guide’ for exoplanets could help guide astronomers locate potential exoplanets around white dwarf stars, as a new generation of even more powerful telescopes is being developed to search for them. Their research is published in the Monthly Notices of the Royal Astronomical Society.


Most stars like our own Sun will run out of fuel eventually and shrink and become white dwarfs. Some orbiting bodies that aren’t destroyed in the maelstrom caused when the star blasts away its outer layers will then be subjected to shifts in tidal forces as the star collapses and becomes super-dense. The gravitational forces exerted on any orbiting planets would be intense and would potentially drag them into new orbits, even pushing some further out in their solar systems.


By modelling the effects of a white dwarf’s change in gravity on orbiting rocky bodies, the researchers have determined the most likely factors that will cause a planet to move within the star’s ‘destruction radius’; the distance from the star where an object held together only by its own gravity will disintegrate due to tidal forces. Within the destruction radius a disc of debris from destroyed planets will form.


Although a planet’s survival is dependent on many factors, the models reveal that the more massive the planet, the more likely that it will be destroyed through tidal interactions.


But destruction is not certain based on mass alone: low viscosity exo-Earths are easily swallowed even if they reside at separations within five times the distance between the centre of the white dwarf and its destruction radius. Saturn’s moon Enceladus — often described as a ‘dirty snowball’ — is a good example of a homogeneous very low viscosity planet.


High viscosity exo-Earths are easily swallowed only if they reside at distances within twice the separation between the centre of the white dwarf and its destruction radius. These planets would be composed entirely of a dense core of heavier elements, with a similar composition to the ‘heavy metal’ planet discovered by another team of University of Warwick astronomers recently. That planet has avoided engulfment because it is as small as an asteroid.


Dr Dimitri Veras, from the University of Warwick’s Department of Physics, said: «The paper is one of the first-ever dedicated studies investigating tidal effects between white dwarfs and planets. This type of modelling will have increasing relevance in upcoming years, when additional rocky bodies are likely to be discovered close to white dwarfs.»


«Our study, while sophisticated in several respects, only treats homogenous rocky planets that are consistent in their structure throughout. A multi-layer planet, like Earth, would be significantly more complicated to calculate but we are investigating the feasibility of doing so too.»


Distance from the star, like the planet’s mass, has a robust correlation with survival or engulfment. There will always be a safe distance from the star and this safe distance depends on many parameters. In general, a rocky homogenous planet which resides at a location from the white dwarf which is beyond about one-third of the distance between Mercury and the Sun is guaranteed to avoid being swallowed from tidal forces.


Dr Veras said: «Our study prompts astronomers to look for rocky planets close to — but just outside of — the destruction radius of the white dwarf. So far observations have focussed on this inner region, but our study demonstrates that rocky planets can survive tidal interactions with the white dwarf in a way which pushes the planets slightly outward.


«Astronomers should also look for geometric signatures in known debris discs. These signatures could be the result of gravitational perturbations from a planet which resides just outside of the destruction radius. In these cases, the discs would have been formed earlier by the crushing of asteroids which periodically approach and enter the destruction radius of the white dwarf.»


Author: Peter Thorley | Source: Royal Astronomical Society [May 14, 2019]



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Earth’s evil twin

Appearances can be deceiving. This thick, cloud-rich atmosphere rains sulphuric acid and below lie not oceans but a baked and barren lava-strewn surface. Welcome to Venus.











Earth's evil twin
Credit: ESA/MPS/DLR-PF/IDA

The second planet from the Sun is often coined Earth’s ‘evil twin’ on account of it being almost the same size but instead plagued with a poisonous atmosphere of carbon dioxide and a sweltering 470ºC surface. Its high pressure and temperature is hot enough to melt lead and destroy the spacecraft that dare to land on it. Thanks to its dense atmosphere, it is even hotter than planet Mercury, which orbits closer to the Sun.


ESA’s Venus Express studied the planet from orbit between 2006 and 2014, providing the most in-depth studies of its atmospheric circulation to date. This false-colour image was taken in ultraviolet light with the Venus Monitoring Camera on 23 July 2007. It shows a view of the southern hemisphere from equator (right) to the pole (left) from a distance of 35 000 km from the surface of the planet.


Scientists think that Venus once looked a lot like Earth, but underwent an irreversible climate change that is often used as an extreme example of what happens in a runaway greenhouse effect.


The main source of heat in the Solar System is the Sun’s energy, which warms a planet’s surface up, and then the planet radiates energy back into space. An atmosphere traps some of the outgoing energy, retaining heat – the so-called greenhouse effect. It is a natural phenomenon that helps regulate a planet’s temperature. If it weren’t for greenhouse gases like water vapour, carbon dioxide, methane and ozone, Earth’s surface temperature would be about 30 degrees cooler than its present +15ºC average.


Over the past centuries, humans have altered this natural balance on Earth, strengthening the greenhouse effect since the dawn of industrial activity by contributing additional carbon dioxide along with nitrogen oxides, sulphates and other trace gases and dust and smoke particles into the air. The long-term effects on our planet include global warming, acid rain and the depletion of the ozone layer. The consequences of a warming climate are far-reaching, potentially affecting fresh water resources, global food production and sea level, and triggering an increase in extreme-weather events.


There is no human activity on Venus, but studying its atmosphere provides a natural laboratory to better understand a runaway greenhouse effect. At some point in its history, Venus began trapping too much heat. It was once thought to host oceans like Earth, but the added heat turned water into steam, and in turn, additional water vapour in the atmosphere trapped more and more heat until entire oceans completely evaporated. Water vapour is still escaping from Venus’ atmosphere and into space today.


In the very long term – billions of years into the future – a ‘greenhouse Earth’ is an inevitable outcome at the hands of the aging Sun. Our once life-giving star will eventually swell and brighten, injecting enough heat into Earth’s delicate system that it will eventually become Venus’ true twin.


Source: European Space Agency [May 14, 2019]




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Hunting responsible for mammal declines in half of intact tropical forests

Defaunation — the loss of species or decline of animal populations — is reaching even the most remote and pristine tropical forests. Within the tropics, only 20% of the remaining area is considered intact, where no logging or deforestation has been detected by remote sensing. However, a new study publishing in the open-access journal PLOS Biology, led by Ana Benítez-López from Radboud University, the Netherlands, predicts that even under the seemingly undisturbed canopy, hunting is reducing populations of large mammals by 40% on average, largely due to increased human accessibility to these remote areas.











Hunting responsible for mammal declines in half of intact tropical forests
Credit: Ruth Archer/Pixabay

Overhunting, as opposed to deforestation, is undetectable by remote-sensing techniques, and to date, there were vast understudied areas in the tropics where hunting impacts on mammal communities were unknown. In this study, the authors have projected for the first time the spatial patterns of hunting-induced mammal defaunation in the tropics and have identified areas where hunting impacts on mammal communities are expected to be high.


Predicted hotspots of hunting-induced defaunation are located in West and Central Africa, particularly Cameroon, and in Central America, NW South America and areas in SE Asia (Thailand, Malaysia and SW China).


Predictions were based on a newly developed hunting regression model, based upon socio-economic drivers, such as human population density and hunters’ access points, and species traits, such as body size. The model relies on more than 3,200 abundance data estimates from the last 40 years and included more than 160 studies and hundreds of authors studying approximately 300 mammal species across the tropics.


These defaunation maps are expected to become an important input for large-scale biodiversity assessments, which have routinely ignored hunting impacts due to data paucity, and may inform species extinction risk assessments, conservation planning and progress evaluations to achieve global biodiversity targets.


Source: Public Library of Science [May 14, 2019]



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Reading the dark heart of chromosomes

Although the genomes of thousands of plant and animal species have been sequenced, for most of these genomes a significant portion is missing — the highly repetitive DNA. In the midst of these mysterious genome compartments are the centromeres—essential chromosomal regions that allow cells to accurately pass on chromosomes when the cells divide.











Reading the dark heart of chromosomes
Drosophila melanogaster chromosomes. DNA is shown in gray and the centromeres in green
[Credit: Ankita Chavan (Mellone lab)]

A new study published in the open-access journal PLOS Biology by the Mellone lab at the University of Connecticut and the Larracuente lab at the University of Rochester combine cutting-edge sequencing technology with molecular and high-resolution microscopy methods to discover the sequences of all centromeres in the fruit fly Drosophila melanogaster, a powerful model organism widely used in biomedical research.
Centromeres have been visible under the microscope for over a century, but little is known about their organization at the DNA level because of the difficulty of accessing highly repetitive DNA with traditional sequencing technologies. To sequence a genome, researchers fragment DNA into ‘readable’ units and then assemble these units back into contiguous sequences that represent the genome, in a computational process akin to assembling a jigsaw puzzle. While this process works well for unique DNA sequences in and around genes, in repetitive regions of the genome all of the puzzle pieces look identical, making it difficult to figure out how they fit together.


To get around this problem, the authors combined this traditional ‘jigsaw’ approach with a suite of other methods: sequencing longer sections of DNA, purifying segments of the centromere that stick to a centromere-specific histone protein, and imaging chromatin fibers with high-resolution microscopy. Using these approaches, the authors were able to generate a complete and intact picture of the fly’s centromeres, finding that buried within a sea of highly repetitive sequences, there were ‘islands’ of more complex DNA sequences that might hold the key to how the centromeres function to segregate chromosomes faithfully.


The researchers found that centromeres contain a surprisingly high number of transposable elements—sequences that jump around and selfishly proliferate throughout the genomes. «What is exciting is that the centromere islands are rich in a type of transposable element called retroelements, which we usually consider to be genome parasites,» says Professor Amanda Larracuente, co-lead author on the study. A particular retroelement, called G2/Jockey-3, was found in all centromeres, not only in this species of fruit fly, but also in a closely related one, Drosophila simulans.


Their findings suggest that these selfish DNA elements may have a role in centromere function across a wide range of species, as retroelements have been found to be associated with centromeres in fungi, plants, mammals… and now fruit flies. «With the centromere sequences in hand, we are poised to leverage the powerful fruit fly genetic toolkit to understand the role these sequences play in centromere function and evolution,» says Professor Barbara Mellone, co-lead author of the study.


Source: Public Library of Science [May 14, 2019]



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Dolphin ancestor’s hearing was more like hoofed mammals than today’s sea...

Vanderbilt University paleontologists are looking into the evolutionary origins of the whistles and squeaks that dolphins and porpoises make — part of the rare echolocation ability that allows them to effectively navigate their dark environment.











Dolphin ancestor's hearing was more like hoofed mammals than today's sea creatures
Artist’s rendering of a specimen resembling Olympicetus avitus. This member of the toothed whale
 family was in a branch that died out before modern dolphins and porpoises appeared
[Credit: Robert W. Boessenecker/College of Charleston]

The team, one of the first in the world to examine the ability’s origins, used a small CT scanner to look inside a 30-million-year-old ear bone fossil from a specimen resembling Olympicetus avitus. This member of the toothed whale family, in a branch that died out before modern dolphins and porpoises appeared, lived in what is now the state of Washington. The CT scan revealed cochlear coiling with more turns than in animals with echolocation, indicating hearing more similar to the cloven-hoofed, terrestrial mammals dolphins came from than the sleek sea creatures they are today.
«The simple theory is that there was one origin for echolocation in dolphins, and we’d find it in their 30-million-year-old ancestor,» said Rachel A. Racicot, who completed the research as a visiting scholar at Vanderbilt. «Now, we believe it didn’t evolve just once in this lineage, but more than once and in more than one lineage — at least in xenorophids, which are extinct, and somewhere along the line to the Odontoceti crown group that still survives.»











Dolphin ancestor's hearing was more like hoofed mammals than today's sea creatures
The team, one of the first in the world to examine the ability’s origins, used a small CT scanner to look
inside a 30-million-year-old ear bone fossil from a specimen resembling Olympicetus avitus
[Credit: Heidi Hall/Vanderbilt University]











Dolphin ancestor's hearing was more like hoofed mammals than today's sea creatures
A CT scan of the 30-million-year-old earbone revealed cochlear coiling with more turns than in animals with
echolocation, indicating hearing more similar to the cloven-hooved, terrestrial mammals dolphins came
from than the sleek sea creatures they are today [Credit: Rachel Racicot/Vanderbilt University]

Because echolocation is useful for navigating dark waters, natural selection likely came into play with its development in the branch that survived, she said. The findings appear in The Royal Society journal Biology Letters.
Racicot will join Vanderbilt’s Earth and Environmental Sciences Department after spending a year working in Germany. Her co-author, Assistant Professor of Earth and Environmental Sciences Simon A.F. Darroch, installed the CT scanner, which works the same way as those used in medicine and allows for internal examination of fossils without damaging them.











Dolphin ancestor's hearing was more like hoofed mammals than today's sea creatures
These charts explain the specimen’s evolutionary placement and the theory of
twice-evolving echolocation ability [Credit: Vanderbilt University]

Learning echolocation’s origins also can help preserve modern creatures that use it, Darroch said, by understanding how they’re perceiving sound from ship engines, oil drills and other machinery. Confusion over those sounds may be causing mass stranding events, and solving the mystery could lead to methods of discouraging species such as the vaquita, a small porpoise on the brink of extinction in the Gulf of California, away from boats and nets.



«If we develop correlates for the shapes of the inner ear and how that corresponds to hearing frequencies, we can extrapolate those methods without capturing animals and bombarding them with sounds that don’t work,» Darroch said.


First, according to Racicot and Darroch, paleontologists will have to find and scan a much larger sampling of all the toothed whale group’s ancestors and those of rare modern species.


Author: Heidi Hall | Source: Vanderbilt University [May 14, 2019]



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