суббота, 22 сентября 2018 г.

Popping Sound It’s a nightmare for bubble blowers – the moment…


Popping Sound


It’s a nightmare for bubble blowers – the moment when, instead of leaving a bubble wand, a wobbling nearly-bubble seems to change its mind and deflate – hurtling back towards a terrified face and a soapy pop. This unfortunate quirk of surface tension is reversed here, inflating droplets of a soapy substance using ultrasound, as a step towards transforming drug delivery. Acoustic vibrations cause the edge of the droplet to buckle and rise (top row). Resonating vibrations grow the bubble, and a split second later it floats away (bottom right). Adapting the technique for industry, ultrasound could be used to create pharmacological foams – increasingly used over creams to deliver topical drugs onto skin when treating conditions like dermatitis and psoriasis.


Written by John Ankers



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Bryn Eryr Double Iron Age Roundhouse, St. Fagan Museum of Welsh Life, Cardiff, 22.9.18.






Bryn Eryr Double Iron Age Roundhouse, St. Fagan Museum of Welsh Life, Cardiff, 22.9.18.


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The Welsh Crannog Centre, Llangorse Lake, Brecon, South Wales, 22.9.18.


The Welsh Crannog Centre, Llangorse Lake, Brecon, South Wales, 22.9.18.


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Seismic research cruise provides new data on US Atlantic margin…


Seismic research cruise provides new data on US Atlantic margin gas hydrates http://www.geologypage.com/2018/09/seismic-research-cruise-provides-new-data-on-us-atlantic-margin-gas-hydrates.html


Experiments using Diamond Anvils Yield New Insight into the Deep…


Experiments using Diamond Anvils Yield New Insight into the Deep Earth http://www.geologypage.com/2018/09/experiments-using-diamond-anvils-yield-new-insight-into-the-deep-earth.html


Scientists identify three causes of Earth’s spin axis drift…


Scientists identify three causes of Earth’s spin axis drift http://www.geologypage.com/2018/09/scientists-identify-three-causes-of-earths-spin-axis-drift.html


Japan’s largest complete dinosaur skeleton comes to life…


Japan’s largest complete dinosaur skeleton comes to life http://www.geologypage.com/2018/09/japans-largest-complete-dinosaur-skeleton-comes-to-life.html


What makes a mammal a mammal?…


What makes a mammal a mammal? http://www.geologypage.com/2018/09/what-makes-a-mammal-a-mammal.html


558 million years ago reveals earliest known animal…


558 million years ago reveals earliest known animal http://www.geologypage.com/2018/09/558-million-years-ago-reveals-earliest-known-animal.html


Sunset at Castle of Torrechiara, Langhirano, Italy Source 


Sunset at Castle of Torrechiara, Langhirano, Italy


Source 


Source http://irisharchaeology.tumblr.com/post/178278633884 Irish Archaeology


This beautiful silver ring is decorated with a spiral motif that…


This beautiful silver ring is decorated with a spiral motif that is inspired by prehistoric Irish art.  Available here


Source http://irisharchaeology.tumblr.com/post/178283126179 Irish Archaeology


An early Christian cross at St Mullins, Co Carlow,…


An early Christian cross at St Mullins, Co Carlow, Ireland


Source 


Source http://irisharchaeology.tumblr.com/post/178310088029 Irish Archaeology


The impressive 12th century motte and bailey castle at St…




The impressive 12th century motte and bailey castle at St Mullins, Co Carlow. Originally this large man-made mound would have been surmounted by a wooden tower and surrounded by a defensive enclosure


Source http://irisharchaeology.tumblr.com/post/178310104334 Irish Archaeology


A prehistoric standing stone on the Dingle peninsula, Co…


A prehistoric standing stone on the Dingle peninsula, Co Kerry, Ireland


Source http://irisharchaeology.tumblr.com/post/178341791649 Irish Archaeology


This sterling silver Thor’s Hammer pendant contains a…


This sterling silver Thor’s Hammer pendant contains a centrally placed fox face and is surmounted by a bearded depiction of Thor. Thor’s hammers such as this one were widely used as religious amulets during the Viking Age, with wearers hoping to invoke the favour of the thunder and fertility god Thor.


The hammer is available here 


Source http://irisharchaeology.tumblr.com/post/178341999919 Irish Archaeology


Detail of ‘Muiredach’s’ high cross at…


Detail of ‘Muiredach’s’ high cross at Monasterboice, Co Louth. An inscription on the base of the cross indicates that it was commissioned by a man named Muiredach, most likely abbot Muiredach mac Dohhnaill, who died in AD 923.


Source   


Source http://irisharchaeology.tumblr.com/post/178342765924 Irish Archaeology


This bronze pendant of a raven in flight is inspired by an…


This bronze pendant of a raven in flight is inspired by an ancient Irish goddess, The Morrigan. A prominent figure in Irish mythology, The Morrigan appears to have been associated with warfare and sovereignty. She is often depicted as a raven flying over the battlefield. Available here: Celtic Raven Pendant


Source http://irisharchaeology.tumblr.com/post/178342854474 Irish Archaeology


The remote monastic hermitage on Skellig Michael, Co. Kerry….




The remote monastic hermitage on Skellig Michael, Co. Kerry. Founded sometime in the 6th or 7th century AD, the monastery was raided a number of times by the Vikings. These included an attack in AD 832, when its abbot, Eitgall of Skellig, was captured. He subsequently died of starvation. 


Photo source 


Source http://irisharchaeology.tumblr.com/post/178343100769 Irish Archaeology


Corded Ware people =/= Proto-Uralics (Tambets et al. 2018)

A new paper on the genetic structure of Uralic-speaking populations has just appeared at Genome Biology (see here). It looks to me like the prelude to a forthcoming paleogenetics paper on the same topic that was discussed in the Estonian media recently (see here). Although not exactly ground breaking (because it basically argues what I’ve been saying at this blog for years, like here and here), it’s a very nice effort all round and must be read by anyone with an interest in this topic. From the paper, emphasis is mine:



Background The genetic origins of Uralic speakers from across a vast territory in the temperate zone of North Eurasia have remained elusive. Previous studies have shown contrasting proportions of Eastern and Western Eurasian ancestry in their mitochondrial and Y chromosomal gene pools. While the maternal lineages reflect by and large the geographic background of a given Uralic-speaking population, the frequency of Y chromosomes of Eastern Eurasian origin is distinctively high among European Uralic speakers. The autosomal variation of Uralic speakers, however, has not yet been studied comprehensively.
Results: Here, we present a genome-wide analysis of 15 Uralic-speaking populations which cover all main groups of the linguistic family. We show that contemporary Uralic speakers are genetically very similar to their local geographical neighbours. However, when studying relationships among geographically distant populations, we find that most of the Uralic speakers and some of their neighbours share a genetic component of possibly Siberian origin. Additionally, we show that most Uralic speakers share significantly more genomic segments identity-by-descent with each other than with geographically equidistant speakers of other languages. We find that correlated genome-wide genetic and lexical distances among Uralic speakers suggest co-dispersion of genes and languages. Yet, we do not find long-range genetic ties between Estonians and Hungarians with their linguistic sisters that would distinguish them from their non-Uralic-speaking neighbours.
Conclusions: We show that most Uralic speakers share a distinct ancestry component of likely Siberian origin, which suggests that the spread of Uralic languages involved at least some demic component.

Recent aDNA studies have shown that extant European populations draw ancestry form three main migration waves during the Upper Palaeolithic, the Neolithic and Early Bronze Age [2, 3, 45]. The more detailed reconstructions concerning NE Europe up to the Corded Ware culture agree broadly with this scenario and reveal regional differences [65–67]. However, to explain the demographic history of extant NE European populations, we need to invoke a novel genetic component in Europe—the Siberian. The geographic distribution of the main part of this component is likely associated with the spread of Uralic speakers but gene flow from Siberian sources in historic and modern Uralic speakers has been more complex, as revealed also by a recent study of ancient DNA from Fennoscandia and Northwest Russia [68]. Thus, the Siberian component we introduce here is not the perfect but still the current best candidate for the genetic counterpart in the spread of Uralic languages.





Citation…
Tambets et al., Genes reveal traces of common recent demographic history for most of the Uralic-speaking populations, Genome Biology, (2018) 19:139 https://doi.org/10.1186/s13059-018-1522-1
See also…
Indo-European crackpottery
Late PIE ground zero now obvious; location of PIE homeland still uncertain, but…
Genetic and linguistic structure across space and time in Northern Europe

Source


2018 September 22 Window Seat over Hudson Bay Image Credit…


2018 September 22


Window Seat over Hudson Bay
Image Credit & Copyright: Ralf Rohner


Explanation: On the August 18 night flight from San Francisco to Zurich, a window seat offered this tantalizing view when curtains of light draped a colorful glow across the sky over Hudson Bay. Constructed by digitally stacking six short exposures made with a hand held camera, the scene records the shimmering aurora borealis or northern lights just as the approaching high altitude sunrise illuminated the northeastern horizon. It also caught the flash of a Perseid meteor streaking beneath the handle stars of the Big Dipper of the north. A few days past the meteor shower’s peak, its trail still points across the sky toward Perseus. Beautiful aurorae and shower meteors both occur in Earth’s upper atmosphere at altitudes of 100 kilometers or so, far above commercial airline fights. The aurora are caused by energetic charged particles from the magnetosphere, while meteors are trails of comet dust.


∞ Source: apod.nasa.gov/apod/ap180922.html


NASA’s MAVEN Selfie Marks Four Years in Orbit at Mars


NASA – MAVEN Mission logo.


Sept. 21, 2018


Today, NASA’s MAVEN spacecraft celebrates four years in orbit studying the upper atmosphere of the Red Planet and how it interacts with the Sun and the solar wind. To mark the occasion, the team has released a selfie image of the spacecraft at Mars.


“MAVEN has been a tremendous success,” said Bruce Jakosky, MAVEN principal investigator from the University of Colorado, Boulder. “The spacecraft and instruments continue to operate as planned, and we’re looking forward to further exploration of the Martian upper atmosphere and its influence on climate.”



Image above: This image is a composite selfie taken by MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument that normally looks at ultraviolet emissions from the Martian upper atmosphere. Lines are sketched in to show approximately where components of the spacecraft are that were not able to be imaged due to the limited motion of the instrument around its support boom. Thrusters can be seen at the lower left and right, the Electra communications antenna at the bottom toward the left, the magnetometer and sun sensor at the end of the solar-panels at the upper left, the tip of the communications antenna at the top middle. In addition, the shadow of the IUVS and of its support boom can be seen down the middle of the spacecraft body. Image Credits: University of Colorado/NASA.


MAVEN has obtained a selfie image, looking at ultraviolet wavelengths of sunlight reflected off of components of the spacecraft. The image was obtained with the Imaging Ultraviolet Spectrograph (IUVS) instrument that normally looks at ultraviolet emissions from the Martian upper atmosphere. The IUVS instrument is mounted on a platform at the end of a 1.2-m boom (its own “selfie stick”), and by rotating around the boom can look back at the spacecraft. The selfie was made from 21 different images, obtained with the IUVS in different orientations, that have been stitched together.


The mission launched on Nov. 18, 2013, and went into orbit around Mars on Sept. 21, 2014. During its time at Mars, MAVEN has answered many questions about the Red Planet.



Image above: This image identifies the various parts of the MAVEN spacecraft selfie, with an artist’s sketch of the spacecraft for comparison. Individual components are identified in both the selfie and the computer image. Notice that the computer-generated image shows the IUVS instrument, but that it is not visible in the actual selfie (because that’s what’s taking the picture!). Image Credits: University of Colorado/NASA.


The spacecraft has made the following discoveries and science results, among others:


– Acquired compelling evidence that the loss of atmosphere to space has been a major driver of climate change on Mars.


– Determined that the stripping of ions from the upper atmosphere to space during a solar storm can be enhanced by a factor of 10 or more, possibly making these storms a major driver of loss of the atmosphere through time.


– Discovered two new types of Martian auroras – diffuse aurora and proton aurora. Neither type has a direct connection to the local or global magnetic field or to magnetic cusps, as auroras do on Earth.


– MAVEN has made direct observations of a metal-ion layer in the Martian ionosphere, the first direct detection on any planet other than the Earth. The ions are produced by a steady influx of incoming interplanetary dust.


– Demonstrated that the majority of the CO2 on the planet has been lost to space and that there isn’t enough left to terraform the planet by warming it, even if the CO2 could be released and put back into the atmosphere.


Next year, engineers will initiate an aerobraking maneuver by skimming the spacecraft through Mars’ upper atmosphere to slow it. This will reduce the highest altitude in MAVEN’s orbit to enhance its ability to serve as a communications relay for data from rovers on the surface. Currently, MAVEN carries out about one relay pass per week with one of the rovers. This number will increase after NASA’s InSight mission lands on Mars in November.



Image above: This image shows part of the MAVEN spacecraft and the limb of Mars in the background. This is one of the individual images that make up the selfie, showing the magnetometer and sun sensor at the end of the solar panel. Mars is seen in the background; the dark spot at the top of the image is the Olympus Mons volcano. Image Credits: University of Colorado/NASA.


MAVEN completed its primary mission in November 2015 and has been operating in an extended mission since that time, continuing its productive investigation of Mars’ upper atmosphere and exploring additional opportunities for science that the new relay orbit will bring.


MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project and provided two science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. The University of California at Berkeley’s Space Sciences Laboratory also provided four science instruments for the mission. NASA’s Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.


For more information on the MAVEN mission, visit: https://www.nasa.gov/maven
and http://lasp.colorado.edu/home/maven/


Images (mentioned), NASA/Karl Hille/GSFC/Nancy Jones.


Greetings, Orbiter.chArchive link


Space Station Science Highlights: Week of September 17, 2018


ISS – Expedition 56 Mission patch.


Sept. 21, 2018


The Expedition 56 crew members aboard the International Space Station conducted a variety of biomedical and physical science research this week as they continued to await the arrival of Japan Aerospace Exploration Agency’s (JAXA) HTV-7 resupply vehicle.



Image above: A view of the European Space Agency Columbus Lab Module, looking across into the Japanese Experiment Module. Image Credit: NASA.


As a result of inclement weather, JAXA has postponed the launch of a cargo spacecraft from the Tanegashima Space Center in southern Japan to Saturday, Sept. 22. Live coverage of the launch will begin at 1:30 p.m. on NASA Television and the agency’s website.


Learn more about the science happening on station below:


Crew prepares for ACME operations


The Advanced Combustion Microgravity Experiment (ACME) investigation is a set of five independent studies of gaseous flames to be conducted in the Combustion Integration Rack (CIR), one of which being Electric-Field Effects on Laminar Diffusion Flames (E-FIELD Flames).


In E-FIELD Flames, an electric field with voltages as high as 10,000 volts is established between the burner and a mesh electrode. The motion of the charged ions, which are naturally produced within the flame, are strongly affected by a high-voltage electric field. The resulting ion-driven wind can dramatically influence the stability and sooting behavior of the flame. Measurements are made of electric-field strength, the ion current passing through the flame, and flame characteristics such as the size, structure, temperature, soot, and stability. Conducting the tests in microgravity allows for simplifications in the analysis, enabling new understanding and the potential development of less polluting and more efficient combustion technology for use on Earth.



Animation above: Oleg Artemyev of Roscosmos works within the Combustion Integration Rack (CIR) as a part of the ACME investigation.
The crew conducted maintenance on the rack in order to prepare for E-FIELD Flames to begin. Animation Credit: NASA.


This week, in preparation for E-FIELD Flames operations, crew members replaced several components including power supply, burner, igniter tip and controller, as well as installing the mesh.


Crew replaces materials for experiment run


The Atomization experiment uses a high-speed camera to observe the disintegration processes of low-speed water jets under various conditions. These observations validate a new atomization concept, developed from drop tower experiments on Earth, to correctly predict the breakup positions of a liquid stream. This information is key to improving spray combustion processes inside rocket and jet engines.



Animation above: NASA astronaut Serena Auñón-Chancellor works to replace sample syringes and a water trip in preparation for an Atomization experiment run. Animation Credit: NASA.


This week, the crew replaced sample syringes and a water trap, allowing the ground team to initiate and complete an experiment run.


Samples collected, DNA sequenced as a part of BEST investigation


Biomolecule Extraction and Sequencing Technology (BEST) seeks to advance use of sequencing in space in three ways: identifying microbes aboard the space station that current methods cannot detect, assessing microbial mutations in the genome because of spaceflight and performing direct RNA sequencing.



Image above: View during Biomolecule Extraction and Sequencing Technology (BEST) Experiment 1 Part 1. The objective is to identify bacteria directly from ISS surfaces through the swabbing and extraction of DNA from the swab using mini PCR. The DNA will undergo further sample preparation and sequencing with the Biomolecule Sequencer. Image Credit: NASA.


This week, crew members performed operations to initiate DNA sequences from samples collected on Monday of this week. 


Learn more about the BEST investigation here: https://www.nasa.gov/mission_pages/station/research/news/BEST_DNA_RNA


Crew conducts maintenance on camera used in sediment investigation


Binary Colloidal Alloy Test – Cohesive Sediment (BCAT-CS) studies dynamic forces between sediment particles that cluster together. For the study, scientists sent mixtures of quartz and clay particles to the space station and subjected them to various levels of simulated gravity. Conducting the experiment in microgravity makes it possible to separate out different forces that act on sediments and look at the function of each.



View from inside ISS Cupola. Image Credit: NASA

Understanding how sediments behave has a range of applications on Earth, including predicting and mitigating erosion, improving water treatment, modeling the carbon cycle,  sequestering contaminants and more accurately finding deep sea oil reservoirs.



Space to Ground: Long Distance Call: 09/21/2018

Video credits: NASA Johnson.


This week, the crew conducted maintenance such as adjusting the camera’s alignment, changing the battery on the camera’s flash, and refocusing the camera itself.


Other work was done on these investigations: Microbial Tracking-2, Plant Habitat-1, Plant Habitat, ISS HAM, SpaceTex-2, DOSIS-3D, Metabolic Space, Biochemical Profile, Cell Free Epigenome/Medical Proteomics, Veggie, HRF-2, MUSES, ZeroG Battery Testing, JAXA ELF, and Team Task Switching.


Related links:


Expedition 56: https://www.nasa.gov/mission_pages/station/expeditions/expedition56/index.html


NASA Television: https://www.nasa.gov/live


Advanced Combustion Microgravity Experiment (ACME): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1651


Combustion Integration Rack (CIR): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=317


E-FIELD Flames: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2058


Atomization: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=282


Biomolecule Extraction and Sequencing Technology (BEST): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687


Binary Colloidal Alloy Test – Cohesive Sediment (BCAT-CS): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7668


Microbial Tracking-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1663


Plant Habitat-1: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=2032


Plant Habitat: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=2036


ISS HAM: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337


SpaceTex-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7571


DOSIS-3D: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=177


Metabolic Space: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7574


Biochemical Profile: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=980


Cell Free Epigenome: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7555


Medical Proteomics: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7590


Veggie: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=374


HRF-2: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=58


MUSES: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1147


ZeroG Battery Testing: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7712


JAXA ELF: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1738


Team Task Switching: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7538


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


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


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


Images (mentioned), Animations (mentioned), Video (mentioned), Text, Credits: NASA/Michael Johnson/Yuri Guinart-Ramirez, Lead Increment Scientist Expeditions 55 & 56.


Best regards, Orbiter.chArchive link


Great IMC 2018 in Slovakia

imc2018

It is already two weeks since the annual International Meteor Conference (IMC) took place. This year the conference was hosted by Modra Observatory of the Comenius University in Bratislava and took place in Pezinok, not far from the capital. With 127 participants from 28 countries and fully booked, the conference thanks to its splendid organization, excelled in being a great success. The IMC was just after the General Assembly of the International Astronomical Union (IAU) and attracted an extra number of professionals. As always: the conference is a great opportunity to meet with participants around the globe, works as magnet, being the ideal place for cross fertilization!


Meteor science is one of the very few astronomy specializations were amateurs and professionals have a tight relation. Even today they work together and make use of each other’s work. An excellent example is the visual work which would be impossible without amateurs as they take care of the majority of (if not all) observations. All visual recordings are stored in a central database and together form the biggest long-term archive on meteor shower activity and due to the standardized observing method, provide a wealth of information for shower evolution studies and models, including prediction work.

Video networks I think are the other area where amateurs significantly contribute. But video technology quickly evolves, resulting in many different technical solutions, and thus standardization unfortunately is much more difficult. This is -even today- the power of visual work!


This year the conference was preceded by two workshops: one on visual data reduction; the other one on spectroscopic work. For conference participants that could not attend these workshops, exciting summaries were given in the main conference. Great highlight was that the new visual ‘R’ analysis software was applied to a very recent set of data: the Perseids 2018, which soon will result in a paper in WGN, being very encouraging news.


Spectroscopy among amateurs has since long been a rare field. Since a few years, it gains interest, thanks to the availability of sensitive video cameras and relatively cheap gratings. A link to the scientific use (and needs) still seemed missing and many questions arose. The spectroscopy workshop exactly focused on this, dug into problems with calibration and which spectral resolution is needed to contribute to our scientific understanding. Two great talks clearly showed what can be done, if next to flux and orbital elements also the spectral composition is known.


Fireballs and meteorites are evidently becoming an increasingly large topic: they are ‘hot’. Fireball networks, hunting for new meteorites, grow and gain in quality. Knowing that worldwide there are not more than a few tens of meteorite recoveries that also have an accurate orbit, explains maybe why: the combination of meteorite and orbit is very valuable. At the IMC it became clear that fireball cameras still gain in accuracy, and networks spread around the world.

Although meteorites are not precisely our topic, nor are asteroids and comets, the chain comets/asteroids – meteoroids – meteors – meteorites is an exciting one, as together they learn so much on the formation of our solar system. The space (sample and/or recovery) missions to asteroids and comets add (new) knowledge to our parameter space.


The IMC also showed how our modern ‘social network’ world a) creates enhanced awareness among the public on meteor showers and fireballs and b) provides a source of new information (‘citizen science’). The largest fireball event captured by the IMO fireball form contains no less than 2000 reports!


Meteor science, as other areas of astronomy, both contains observational work as well as theoretical work (models) to explain these observations, gain our understanding in, e.g., predicting new events. A typical IMC now covers it all: observations (balloon missions!, automated radio data analysis), simulations (a new realistic meteor shower simulator), neural network software development, high-tech lab experiments and even backyard experiments with an air cannon!

This year we learned on meteorite ablation, that most shower meteors fragment, and almost all of them decelerate. Hyperbolic orbits are still frequently seen and the Geminid shower, while already being the ’shower of the year’ will keep doing that by slowly but steadily increasing its activity.


If you are interested, then put the IMC 2019 in your agenda (Bollmansruh, Germany, October 3-6, 2019), and maybe also Meteoroids 2019 (June 17-21, Bratislava, Slovakia). This tri-annual conference is a real professional one but has one session on amateur work too, which so well illustrates how well appreciated amateur work is. Meteor science indeed is exciting. But we should never forget that meteor astronomy is our hobby, and the fun of it is our biggest motivator. IMCs with their splendid atmosphere clearly contribute to it. Organizers, thanks again for this wonderful event!


Did you miss this IMC? Go to the program and check most of the presentations given by the participants. And stay tuned for the Proceedings of the IMC!


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Meteor Activity Outlook for 22-28 September 2018

Eliot Herman captured this fine example of a September epsilon Perseid on September 11, 2018 from Tucson, Arizona USA

During this period the moon will reach its full phase on Tuesday September 25th. At that time the moon will lie opposite the sun and will lie above the horizon all night long. This is the worst time of the month to view meteor activity as the brilliant moonlight will obscure all but the brightest meteors. The estimated total hourly meteor rates for evening observers this week is near 2 as seen from mid-northern latitudes and 1 for those viewing from subtropical southern latitudes (25S). For morning observers the estimated total hourly rates should be near 8 for those viewing from mid-northern latitudes and 6 for those viewing from subtropical southern latitudes (25S). The actual rates will also depend on factors such as personal light and motion perception, local weather conditions, alertness and experience in watching meteor activity. Rates are reduced during this period due to moonlight. Note that the hourly rates listed below are estimates as viewed from dark sky sites away from urban light sources. Observers viewing from urban areas will see less activity as only the brighter meteors will be visible from such locations.


The radiant (the area of the sky where meteors appear to shoot from) positions and rates listed below are exact for Saturday night/Sunday morning September 22/23. These positions do not change greatly day to day so the listed coordinates may be used during this entire period. Most star atlases (available at science stores and planetariums) will provide maps with grid lines of the celestial coordinates so that you may find out exactly where these positions are located in the sky. A planisphere or computer planetarium program is also useful in showing the sky at any time of night on any date of the year. Activity from each radiant is best seen when it is positioned highest in the sky, either due north or south along the meridian, depending on your latitude. It must be remembered that meteor activity is rarely seen at the radiant position. Rather they shoot outwards from the radiant so it is best to center your field of view so that the radiant lies near the edge and not the center. Viewing there will allow you to easily trace the path of each meteor back to the radiant (if it is a shower member) or in another direction if it is a sporadic. Meteor activity is not seen from radiants that are located far below the horizon. The positions below are listed in a west to east manner in order of right ascension (celestial longitude). The positions listed first are located further west therefore are accessible earlier in the night while those listed further down the list rise later in the night.





Radiant Positions at 21:00 LST


Radiant Positions at 21:00

Local Summer Time






Radiant Positions at 01:00 LST


Radiant Positions at 0100

Local Summer Time






Radiant Positions at 5:00 LST


Radiant Positions at 05:00

Local Summer Time





These sources of meteoric activity are expected to be active this week.


Details of each source will continue next week as moonlight becomes less of a nuisance.






















































































SHOWER DATE OF MAXIMUM ACTIVITY CELESTIAL POSITION ENTRY VELOCITY CULMINATION HOURLY RATE CLASS
RA (RA in Deg.) DEC Km/Sec Local Summer Time North-South
Oct. Capricornids (OCC) Oct 03 19:32 (293) -12 10 21:00 <1 – <1 IV
Northern Taurids (NTA) Nov 02 00:30 (007) +10 28 02:00 1 – 1 II
Southern Taurids (STA) Oct 29 00:49 (012) +03 27 02:00 1 – 1 II
September Epsilon Perseids (SPE) Sep 10 04:11 (063) +41 65 06:00 <1 – <1 II
Orionids (ORI) Oct 22 04:24 (066) +17 66 06:00 <1 – <1 II
nu Eridanids (NUE) Sep 24 05:05 (076) +06 67 07:00 1 – 1 IV
Daytime Sextantids (DSX) Sep 29 09:54 (149) +01 33 12:00 <1 – <1 IV

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Early Anatolian farmers were overwhelmingly of local hunter-gatherer origin (Feldman et...

Over at bioRxiv at this LINK. The dataset in this preprint includes just one Anatolian hunter-gatherer, but that’s enough to make the point that in Anatolia, unlike in Europe, there was very strong genetic continuity between the local foragers and earliest farmers. His Y-chromosome haplogroup is an interesting one: C1a2, which has been recorded in European remains from the Upper Paleolithic. Below is the abstract and a pertinent quote. I think this preprint basically confirms what I argued about the origin of the so called Villabruna hunter-gatherer clade back in 2016 (see here). Emphasis is mine.



Anatolia was home to some of the earliest farming communities. It has been long debated whether a migration of farming groups introduced agriculture to central Anatolia. Here, we report the first genome-wide data from a 15,000 year-old Anatolian hunter-gatherer and from seven Anatolian and Levantine early farmers. We find high genetic continuity between the hunter-gatherer and early farmers of Anatolia and detect two distinct incoming ancestries: an early Iranian/Caucasus related one and a later one linked to the ancient Levant. Finally, we observe a genetic link between southern Europe and the Near East predating 15,000 years ago that extends to central Europe during the post-last-glacial maximum period. Our results suggest a limited role of human migration in the emergence of agriculture in central Anatolia.

Among the Later European HG, recently reported Mesolithic hunter-gatherers from the Balkan peninsula, which geographically connects Anatolia and central Europe (‘Iron Gates HG’) [18], are genetically closer to AHG when compared to all the other European hunter-gatherers, as shown in the significantly positive statistic D(Iron_Gates_HG, European hunter-gatherers; AHG, Mbuti/Altai). Iron Gates HG are followed by Epigravettian and Mesolithic individuals from Italy and France (Villabruna [14] and Ranchot88 respectively [17]) as the next two European hunter-gatherers genetically closest to AHG [20] (Fig. 3A and data table S5). Iron Gates HG have been suggested to be genetically intermediate between WHG and eastern European hunter-gatherers (EHG) with an additional unknown ancestral component [18]. We find that Iron Gates HG can be modeled as a three-way mixture of Near-Eastern hunter-gatherers (25.8 ± 5.0 % AHG or 11.1 ± 2.2 % Natufian), WHG (62.9 ± 7.4 % or 78.0 ± 4.6 % respectively) and EHG (11.3 ± 3.3 % or 10.9 ± 3 % respectively); (tables S4 and S9). The affinity detected by the above D-statistic can be explained by gene flow from Near-Eastern hunter-gatherers into the ancestors of Iron Gates or by a gene flow from a population ancestral to Iron Gates into the Near-Eastern hunter-gatherers as well as by a combination of both. To distinguish the direction of the gene flow, we examined the Basal Eurasian ancestry component (α), which is prevalent in the Near East [6] but undetectable in European hunter-gatherers [17]. Following a published approach [6], we estimated α to be 24.8 ± 5.5 % in AHG and 38.5 ± 5.0 % in Natufians (Fig. 3B, table S10), consistent with previous estimates for the latter [6]. Under the model of unidirectional gene flow from Anatolia to Europe, 6.4 % is expected for α of Iron Gates by calculating (% AHG in Iron Gates HG) × (α in AHG). However, Iron Gates can be modeled without any Basal Eurasian ancestry or with a non-significant proportion of 1.6 ± 2.8 % (Fig. 3B, table S10), suggesting that unidirectional gene flow from the Near East to Europe alone is insufficient to explain the extra affinity between the Iron Gates HG and the Near-Eastern hunter-gatherers. Thus, it is plausible to assume that prior to 15,000 years ago there was either a bidirectional gene flow between populations ancestral to Southeastern Europeans of the early Holocene and Anatolians of the late glacial or a dispersal of Southeastern Europeans into the Near East. Presumably, this Southeastern European ancestral population later spread into central Europe during the post-last-glacial maximum (LGM) period, resulting in the observed late Pleistocene genetic affinity between the Near East and Europe.



Feldman et al., Late Pleistocene human genome suggests a local origin for the first farmers of central Anatolia, biRxiv, posted September 20, 2018, doi: https://doi.org/10.1101/422295 Source


Hubble’s Galaxies With Knots, Bursts


NASA – Hubble Space Telescope patch.


Sept. 21, 2018



In the northern constellation of Coma Berenices (Berenice’s Hair) lies the impressive Coma Cluster —  a structure of over a thousand galaxies bound together by gravity. Many of these galaxies are elliptical types, as is the brighter of the two galaxies dominating this image: NGC 4860 (center). However, the outskirts of the cluster also host younger spiral galaxies that proudly display their swirling arms. Again, this image shows a wonderful example of such a galaxy in the shape of the beautiful NGC 4858, which can be seen to the left of its bright neighbor and which stands out on account of its unusual, tangled, fiery appearance.


NGC 4858 is special. Rather than being a simple spiral, it is something called a “galaxy aggregate,” which is as the name suggests a central galaxy surrounded by a handful of luminous knots of material that seem to stem from it, extending and tearing away and adding to or altering its overall structure. It is also experiencing an extremely high rate of star formation, possibly triggered by an earlier interaction with another galaxy. As we see it, NGC 4858 is forming stars so frantically that it will use up all of its gas long before it reaches the end of its life. The color of its bright knots indicates that they are formed of hydrogen, which glows in various shades of bright red as it is energized by the many young, hot stars lurking within.



Hubble Space Telescope (HST)

This scene was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 (WFC3), a powerful camera designed to explore the evolution of stars and galaxies in the early universe.


For more information about Hubble, visit:


http://hubblesite.org/
http://www.nasa.gov/hubble
http://www.spacetelescope.org/


Image, Animation, Credit: ESA/Hubble & NASA/Text: European Space Agency (ESA)/NASA/Karl Hille.


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A satellite captures space junk for the first time


Space Debris illustration.


September 21, 2018



Image above: In this September 2018 image made from video provided by the University of Surrey, a net is launched from a satellite to catch a test object. The experiment was conducted to research ways to clean up debris in orbit around Earth. Image Credit: University of Surrey.


An experimental cleanup device called RemoveDebris has successfully cast a net around a dummy satellite, simulating a technique that could one day capture spaceborne garbage.


The test, which was carried out this week, is widely believed to be the first successful demonstration of space cleanup technology, experts told CNN. And it signals an early step toward solving what is already a critical issue: debris in space.


Millions of pieces of junk are whirling around in orbit, the result of 50 years of space travel and few regulations to keep space clean. At orbital speeds, even a small fleck of paint colliding with a satellite can cause critical damage.


Various companies have plans to send thousands of new satellites into low-Earth orbit, already the most crowded area.


The RemoveDebris experiment is run by a consortium of companies and researchers led by the UK’s Surrey Space Centre and includes Airbus, Airbus-owned Surrey Satellite Technology Ltd. and France’s Ariane Group.



Researchers captured the test capture on video, which was shared online Wednesday

Guglielmo Aglietti, the director of Surrey Space Centre, said that an operational version of the RemoveDebris technology would cast out a net that remains tethered to the main satellite so the debris can be dragged out of orbit. It could target large pieces of junk, including dead satellites up to 10 meters long.


For the test, however, the dummy satellite and net were left to orbit freely. So it essentially created another piece of uncontrolled debris. But Aglietti said it won’t pose a risk for long. The experiment was conducted in a very low orbit, so the dummy satellite should fall out of the sky within a few months and plummet to its grave.


The RemoveDebris satellite will conduct a few more experiments in the coming months, including testing navigation features that could help guide the satellite to a specific piece of debris. It will also test out a harpoon technology that could capture hulking satellites with a spear attached to a string.


Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, said the success of this week’s experiment was exciting, but he cautioned against “over-hyping” it.


“There are dozens of good ideas about how to address this problem, but the devil is always in the details,” he said.



A company called AGI helps track and map orbital debris

There are still enormous barriers to clear before operational cleanup missions will be underway, he said, and the most daunting is figuring out how to fund such projects.


The RemoveDebris experiment cost roughly 15 million euros, or $18 million, and it was jointly funded by the European Commission and the groups involved in the project. That’s relatively cheap as far as space travel goes. But McDowell pointed out that it will take more than one satellite to make a significant impact.


“You can’t just have like one garbage truck going around and picking up each [piece of debris]. To change from one orbit to another requires just as much rocket fuel as getting up there in the first place, so it’s tricky to find a solution that is cost effective,” McDowell said.



RemoveDebris Net Experiment Raw Footage

Aglietti, the Surrey professor who helped lead the RemoveDebris project, said “the challenge will be to convince the relevant authorities to sponsor these mission.”


Aglietti said he hopes RemoveDebris will conduct a few cleanup missions per year, targeting the largest pieces of junk in the most crowded orbits.


But there’s geopolitical issues to grapple with as well. International agreements prevent a project carried out by one nation to touch objects that were put into orbit by another country. For example, a UK-led cleanup project couldn’t go after a defunct Russian-built rocket booster.


“Currently space debris is a global problem as it affects all nations. Each piece of junk in space is owned by the original operators and orbital debris is not addressed explicitly in current international law,” Xander Hall, a mission systems engineer at Airbus, said in an email. “[A]n international effort must be made to claim ownership of the debris and help fund its safe removal.” Aglietti is hopeful.


“I think all the stakeholders should get around the table, because it’s in everybody’s interest to remove that debris,” he said.


Related links:


Application form: http://www.esa.int/Education/ESA_Academy/Application_form5


ESA’s Space Debris Office: http://www.esa.int/Our_Activities/Operations/gse/ESA_Space_Debris_Office


ESA’s Education Office: http://www.esa.int/Education


Surrey Space Centre (University of Surrey): https://www.surrey.ac.uk/surrey-space-centre


Swiss Space Center (EPFL): https://www.spacecenter.ch/activities/news/


Image, Animations, Video, Text, Credits: ESA/EPFL/University of Surrey/CNN/Jackie Wattles.


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