четверг, 18 апреля 2019 г.

Nervous in Defence Our nervous system plays a key role in…


Nervous in Defence


Our nervous system plays a key role in regulating immunity. Illustrated, for example, by the finding that stimulating a major nerve serving the heart, lungs and gut – the vagus – can relieve a damaging inflammatory response made by the immune system. But many of the details of how these two systems communicate remain to be uncovered. One important link is a kind of T cell, an immune cell that produces a neurotransmitter Ach when it senses release of an adrenalin-like hormone by nerves in response to stresses, such as tissue damage or infection. Called ChAT+ T cells, researchers investigated their role during bacterial infection. On the left is a section of gut of a normal mouse infected with C. rodentium (in red), and on the right gut from a mouse genetically-engineered to lack ChAT+ cells. Without ChAT+ cells the bacterial infection is heavier, demonstrating how important these neuro-immune go-betweens are for host defence.


Written by Lindsey Goff



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Reconstruction of a Neolithic boat (of a similar type to those thought to have been used...










Reconstruction of a Neolithic boat (of a similar type to those thought to have been used to move bluestone from the Preseli Hills to the site of Stonehenge), Castell Henllys Iron Age Settlement, Newport, Wales, 12.4.19.


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Caption Spotlight (17 April 2019): Bedrock on the Floor of…


Caption Spotlight (17 April 2019): Bedrock on the Floor of Kaiser Crater


HiRISE has often imaged inside Kaiser Crater to monitor active sand dunes and gullies. Surrounding these dunes, we often find clean bedrock exposures, because the actively moving sand clears off the dust.


Kaiser Crater is 207 kilometers wide and was named after Frederik Kaiser, a Dutch astronomer (1808—1872).


NASA/JPL/University of Arizona


2019 April 18 The Leo Trio Image Credit & Copyright: …


2019 April 18


The Leo Trio
Image Credit & Copyright: Markus Bauer


Explanation: This group is popular in the northern spring. Famous as the Leo Triplet, the three magnificent galaxies gather in one field of view. Crowd pleasers when imaged with even modest telescopes, they can be introduced individually as NGC 3628 (left), M66 (bottom right), and M65 (top). All three are large spiral galaxies but they tend to look dissimilar because their galactic disks are tilted at different angles to our line of sight. NGC 3628, also known as the Hamburger Galaxy, is temptingly seen edge-on, with obscuring dust lanes cutting across its puffy galactic plane. The disks of M66 and M65 are both inclined enough to show off their spiral structure. Gravitational interactions between galaxies in the group have left telltale signs, including the tidal tails and warped, inflated disk of NGC 3628 and the drawn out spiral arms of M66. This gorgeous view of the region spans almost two degrees (four full moons) on the sky. The field covers about a million light-years at the trio’s estimated distance of 30 million light-years. Of course the spiky foreground stars lie within our own Milky Way.


∞ Source: apod.nasa.gov/apod/ap190418.html


A “Jellyfish” Galaxy Swims Into View of NASA’s Upcoming Webb Telescope


Galaxy ESO 137-001 (Visible)


The spiral galaxy ESO 137-001 is an example of a “jellyfish” galaxy, because blue tendrils of star formation stream away from it like jellyfish tentacles. NASA’s Webb Space Telescope will study those sites of star formation to learn more about conditions there. Credits: NASA, ESA



Galaxy ESO 137-001 (Visible and X-ray) 


This composite view of ESO 137-001 includes visible light from Hubble and X-ray light from the Chandra X-ray Observatory (in blue). It reveals a tail of hot gas that has been stripped from the galaxy.  Credits: NASA, ESA, CXC





Webb will examine clumps of newly formed stars in the galaxy’s tail


As the spiral galaxy ESO 137-001 plunges into a galaxy cluster, gas is being pulled off of it as though it faced a cosmic headwind. Within that gas, stars are forming to create the appearance of giant, blue tentacle-like streamers. Astronomers, puzzled that stars could form within such tumult, plan to use Webb to study this galaxy and its stellar offspring.


If you look at the galaxy ESO 137-001 in visible light, you can see why it’s considered an example of a “jellyfish” galaxy. Blue ribbons of young stars dangle from the galaxy’s disk like cosmic tentacles. If you look at the galaxy in X-ray light, however, you will find a giant tail of hot gas streaming behind the galaxy. After launch, NASA’s James Webb Space Telescope will study ESO 137-001 to learn how the gas is being removed from the galaxy, and why stars are forming within that gaseous tail.


The newly forming stars in the tail are mysterious because processes common in large groups of galaxies should make it difficult for new stars to emerge. Most galaxies live in groups — for example, the Milky Way is a member of the Local Group, which also contains galaxies like Andromeda and the Triangulum spiral. Some galaxies reside in much larger gatherings of hundreds or even thousands of galaxies known as a galaxy cluster. The “jellyfish” galaxy ESO 137-001 is part of a cluster called Abell 3627.


A galaxy cluster isn’t just galaxies surrounded by empty space. The realm between the galaxies is filled with hot, tenuous gas. For galaxies living in the cluster or a wandering galaxy that gets pulled in by the cluster’s gravity, that gas acts like a headwind. That wind can remove gas and dust from the hapless galaxy in a process known as “ram pressure stripping.”


As a result, ram pressure stripping can slow star formation in the affected galaxy. Galaxies need gas to form stars. Eventually, all galaxies run out of gas and star formation stops. Ram pressure stripping can hasten that end.


This is one reason why galaxies in clusters stop forming new stars sooner than their relatives outside of clusters. But, the mechanisms involved are still mysterious.


“Both gas and dust are getting stripped off, but how much and what happens to the stripped material and the galaxy itself are still open questions,” said Stacey Alberts of the University of Arizona, a co-investigator on the project.

A star formation mystery


ESO 137-001 is a spiral galaxy similar in size to the Milky Way, and slightly less massive. Its tail extends across 260,000 light-years of space, almost three times the galaxy’s width. Galactic tails like this are difficult to spot because they are so tenuous. Surprisingly, stars seem to be forming in this tail.


Webb will target sites of star formation at different points along the tail: close to the galaxy, in the middle, and near the end of the tail. Since material at the tail’s end was removed before material close to the galaxy, astronomers can learn how the stripping process changed over time and how that affected conditions to form new stars.


Researchers aren’t sure how stars are able to form at all within the tail since the stripping process should have heated the gas. “We think it’s hard to strip off a molecular cloud that’s already forming stars because it should be tightly bound to the galaxy by gravity. Which means either we’re wrong, or this gas got stripped off and heated up, but then had to cool again so that it could condense and form stars,” explained Alberts.

“Telling these two scenarios apart is one of the things we want to get at,” she added.


Mid-infrared completes the puzzle


The team will examine ESO 137-001 using Webb’s Mid-Infrared Instrument (MIRI). MIRI observes infrared light at wavelengths of 5 to 28 microns, a range known as the mid-infrared. MIRI’s observations will provide 50 times more spatial detail and 20 times better spectral detail than previous work by other infrared observatories.


MIRI is sensitive to light emitted from hydrogen molecules as well as chemical elements like sulfur and oxygen. MIRI also will detect more complex, sooty molecules of carbon and hydrogen known as polycyclic aromatic hydrocarbons (PAHs), which are signposts of star formation. In addition to learning about the composition of gas and dust within these star-forming regions, astronomers will measure the physical conditions of the gas like temperature and density.


The team will combine the new Webb observations with existing data in visible light, X-rays, and at longer far-infrared wavelengths to get a more complete picture of ESO 137-001 and its environment. “Each different wavelength gives you a piece of the puzzle,” said Alberts.


Ultimately, astronomers want to learn more about how stars came to form in the tail. They also want to understand how gas is being stripped from the galaxy, how much is being stripped, and how efficiently it’s being removed. This will provide clues to the eventual fate of ESO 137-001 and the question of whether ram pressure stripping will shut down star formation, leaving behind a dead relic filled with aging, red stars.


The observations described here will be taken as part of Webb’s Guaranteed Time Observation (GTO) program. The GTO program provides dedicated time to the scientists who have worked with NASA to craft the science and instrument capabilities of Webb throughout its development.


The James Webb Space Telescope will be the world’s premier space science observatory when it launches in 2021. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.





Galaxies are concentrations of stars, gas, dust, and dark matter. They come in a variety of shapes and sizes. Some are fated to collide, like the Milky Way and Andromeda. Credits: NASA, and J. Olmsted (STScI). Youtube








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theancientwayoflife: ~ Offering Box (Arca) and Key.Culture: Gallo-RomanPlace of origin:...

theancientwayoflife:





~ Offering Box (Arca) and Key.


Culture: Gallo-Roman


Place of origin: Roman Empire (Place Created); Eastern Gaul (France), France (Place Found)


Date: ca. A.D. 130–180


Medium: Bronze



Source


theancientwayoflife: ~ Standing Figure.Date: A.D. 1st–5th centuryPlace of…

theancientwayoflife:




~ Standing Figure.


Date: A.D. 1st–5th century


Place of origin: Ecuador


Culture: Jama-Coaque


Medium: Ceramic



Source


theancientwayoflife: ~Mosaic with the scene of gladiatorial fight (so-called...

theancientwayoflife:




~Mosaic with the scene of gladiatorial fight (so-called Simmachius mosaic).


Date: A.D. 3rd century


Medium: Marble, limestone and glass paste.


Provenance: Madrid, National Archaeological Museum



Source


Mercury has a solid inner core…


Mercury has a solid inner core http://www.geologypage.com/2019/04/mercury-has-a-solid-inner-core.html


Small fossils with big applications – BP Gulf of Mexico time…


Small fossils with big applications – BP Gulf of Mexico time scale http://www.geologypage.com/2019/04/small-fossils-with-big-applications-bp-gulf-of-mexico-time-scale.html


Coelacanth reveals new insights into skull evolution…


Coelacanth reveals new insights into skull evolution http://www.geologypage.com/2019/04/coelacanth-reveals-new-insights-into-skull-evolution.html


New evidence suggests volcanoes caused biggest mass extinction…


New evidence suggests volcanoes caused biggest mass extinction ever http://www.geologypage.com/2019/04/new-evidence-suggests-volcanoes-caused-biggest-mass-extinction-ever.html


Engineering Geology…


Engineering Geology http://www.geologypage.com/2019/04/engineering-geology.html


2 Fireballs caught on the night of 16 to 17 April, 2019

Last night was a busy night for the AMS: 2 very bright fireball events occurred less than 6 hours apart.


If you witnessed one of these events and/or if you have a video or a photo of these events, please

Submit an Official Fireball Report


If you want to learn more about Fireballs: read our Fireball FAQ.



Fireball over Germany: 45 reports from 4 countries


We first received 45 reports (so far) about of a slow green fireball seen above north Germany on Tuesday, April 16th 2019 around 21:50 Universal Time (23:50 local time – CEST). The event was mainly seen from Germany but we also received reports from Sweden, Denmark and the Netherlands.


AMS Event #1774-2019 – Witness location and estimated ground trajectory

Trajectory


The preliminary 3D trajectory computed based on all the reports submitted to the AMS* shows that the fireball was traveling from South East to North West and ended its flight right above Hamburg.


* through our partners: Arbeitskreis Meteore e.V. (D), the International Meteor Organization, Werkgroep Meteoren (NL), Vallendesterren (NL) and UKMON (UK).


AMS Event #1774-2019 – Estimated 3D trajectory

Video


AMS AllSky6 Camera operators André Knöfel from Lindenberg, Germany and Sirko Molau from Seysdorf, Germany caught the event on this cam (see video below). It is the only media we received about this event so far.


Fireball over Delaware: 325 reports from 12 states


We also received 325 reports so far about another bright and green fireball that happened over Delaware the same night at 02:57 Universal Time (10:57pm EDT). We received reports from Washington DC, Delaware, Massachusetts, Maryland, North Carolina, New Hampshire, New Jersey, Pennsylvania, South Carolina, Virginia, Vermont and West Virginia.


AMS Event #1775-2019 – Witness location and estimated ground trajectory

Trajectory


The preliminary 3D trajectory computed based on all the reports submitted to the AMS shows that the fireball was traveling from North to South and ended its flight in the Atlantic Ocean in front of Bethany Beach, DE. It means that if anything survived, it’s in the water.


AMS Event #1775-2019 – Estimated 3D trajectory

Video


Both AMS AllSky6 Camera operators Elizabeth Warner (MD) and Ed Abel Mathias (WV) caught the event:



Fireball, Meteorite…?


Several thousand meteors of fireball magnitude occur in the Earth’s atmosphere each day. The vast majority of these, however, occur over the oceans and uninhabited regions, and a good many are masked by daylight. Those that occur at night also stand little chance of being detected due to the relatively low numbers of persons out to notice them.


Additionally, the brighter the fireball, the more rare is the event. As a general thumb rule, there are only about 1/3 as many fireballs present for each successively brighter magnitude class, following an exponential decrease. Experienced observers can expect to see only about 1 fireball of magnitude -6 or better for every 200 hours of meteor observing, while a fireball of magnitude -4 can be expected about once every 20 hours or so.


AMS TERMINOLOGY

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The Universe’s First Type of Molecule Is Found at Last


NASA & DLR — SOFIA Mission patch.


April 17, 2019


The first type of molecule that ever formed in the universe has been detected in space for the first time, after decades of searching. Scientists discovered its signature in our own galaxy using the world’s largest airborne observatory, NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, as the aircraft flew high above the Earth’s surface and pointed its sensitive instruments out into the cosmos.



SOFIA aircraft is a Boeing 747SP, telescope door opening. Animation Credit: NASA

When the universe was still very young, only a few kinds of atoms existed. Scientists believe that around 100,000 years after the big bang, helium and hydrogen combined to make a molecule called helium hydride for the first time. Helium hydride should be present in some parts of the modern universe, but it has never been detected in space — until now.


SOFIA found modern helium hydride in a planetary nebula, a remnant of what was once a Sun-like star. Located 3,000 light-years away near the constellation Cygnus, this planetary nebula, called NGC 7027, has conditions that allow this mystery molecule to form. The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe and how it evolved over billions of years into the complex chemistry of today. The results are published in this week’s issue of Nature.


“This molecule was lurking out there, but we needed the right instruments making observations in the right position — and SOFIA was able to do that perfectly,” said Harold Yorke, director of the SOFIA Science Center, in California’s Silicon Valley.


Today, the universe is filled with large, complex structures such as planets, stars and galaxies. But more than 13 billion years ago, following the big bang, the early universe was hot, and all that existed were a few types of atoms, mostly helium and hydrogen. As atoms combined to form the first molecules, the universe was finally able to cool and began to take shape. Scientists have inferred that helium hydride was this first, primordial molecule.



Image above: Illustration of planetary nebula NGC 7027 and helium hydride molecules. In this planetary nebula, SOFIA detected helium hydride, a combination of helium (red) and hydrogen (blue), which was the first type of molecule to ever form in the early universe. This is the first time helium hydride has been found in the modern universe. Image Credits: NASA/SOFIA/L. Proudfit/D.Rutter.


Once cooling began, hydrogen atoms could interact with helium hydride, leading to the creation of molecular hydrogen — the molecule primarily responsible for the formation of the first stars. Stars went on to forge all the elements that make up our rich, chemical cosmos of today. The problem, though, is that scientists could not find helium hydride in space. This first step in the birth of chemistry was unproven, until now.


“The lack of evidence of the very existence of helium hydride in interstellar space was a dilemma for astronomy for decades,” said Rolf Guesten of the Max Planck Institute for Radio Astronomy, in Bonn, Germany, and lead author of the paper.


Helium hydride is a finicky molecule. Helium itself is a noble gas making it very unlikely to combine with any other kind of atom. But in 1925, scientists were able to create the molecule in a laboratory by coaxing the helium to share one of its electrons with a hydrogen ion.


Then, in the late 1970s, scientists studying the planetary nebula called NGC 7027 thought that this environment might be just right to form helium hydride. Ultraviolet radiation and heat from the aging star create conditions suitable for helium hydride to form. But their observations were inconclusive. Subsequent efforts hinted it could be there, but the mystery molecule continued to elude detection. The space telescopes used did not have the specific technology to pick out the signal of helium hydride from the medley of other molecules in the nebula.


In 2016, scientists turned to SOFIA for help. Flying up to 45,000 feet, SOFIA makes observations above the interfering layers of Earth’s atmosphere. But it has a benefit space telescopes don’t— it returns after every flight.


“We’re able to change instruments and install the latest technology,” said Naseem Rangwala SOFIA deputy project scientist. “This flexibility allows us to improve observations and respond to the most pressing questions that scientists want answered.”


A recent upgrade to one of SOFIA’s instruments called the German Receiver at Terahertz Frequencies, or GREAT, added the specific channel for helium hydride that previous telescopes did not have. The instrument works like a radio receiver. Scientists tune to the frequency of the molecule they’re searching for, similar to tuning an FM radio to the right station. When SOFIA took to the night skies, eager scientists were onboard reading the data from the instrument in real time. Helium hydride’s signal finally came through loud and clear.


“It was so exciting to be there, seeing helium hydride for the first time in the data,” said Guesten. “This brings a long search to a happy ending and eliminates doubts about our understanding of the underlying chemistry of the early universe.



The Universe’s First Molecule is Found at Last

Video above: Scientists on the airborne observatory SOFIA detected the first type of molecule that ever formed in the universe. They found the combination of helium and hydrogen, called helium hydride, in a planetary nebula near the constellation Cygnus. This discovery confirms a key part of our basic understanding of the early universe and how it evolved over billions of years into the complex chemistry of today. Video Credits: NASA/Ames Research Center.


SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California.


Related links:


Nebulae: https://www.nasa.gov/subject/6893/nebulae


Universe: https://www.nasa.gov/topics/solarsystem/index.html


SOFIA: http://www.nasa.gov/mission_pages/SOFIA/index.html


Image (mentioned), Animation (mentioned), Text, Credits: NASA/Kassandra Bell/Elizabeth Landau/Ames Research Center/Nicholas Veronico.


Greetings, Orbiter.chArchive link


Liftoff!


Northrop Grumman — Cygnus NG-11 Mission patch.


 April 17, 2019


NASA’s commercial partner Northrop Grumman launched its Antares rocket carrying its Cygnus cargo spacecraft to the International Space Station at about 4:46 p.m. EDT today, April 17.



Image above: The Northrop Grumman Antares rocket, with Cygnus resupply spacecraft onboard, launches from Pad-0A, Wednesday, April 17, 2019, at NASA’s Wallops Flight Facility in Virginia. Northrop Grumman’s 11th contracted cargo resupply mission for NASA to the International Space Station will deliver about 7,600 pounds of science and research, crew supplies and vehicle hardware to the orbital laboratory and its crew. Photo Credits: NASA/Bill Ingalls.



NG-11: Antares 230 launches S.S. Roger Chaffee Cygnus

Loaded with 7,600 pounds of research, crew supplies and hardware, this is Northrop Grumman’s 11th commercial resupply NASA-contracted mission. Launched from Virginia Space’s Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility.



Image above: Mission engineers load the final cargo into the Cygnus resupply spacecraft on board the Northrop Grumman Antares rocket, Tuesday, April 16, 2019, at launch Pad-0A. Photo Credits: NASA/Bill Ingalls.


Commercial Resupply Services (CRS) NG-11 mission, Cygnus delivers about 3450 kilograms (7600 pounds) of cargo to the International Space Station and is scheduled to arrive on 19 April 2019, at 09:30 UTC (05:30 EDT). The NG-11 Cygnus Cargo Delivery Spacecraft is named in honor of the American astronaut Roger Chaffe, the pilot of the Apollo 1 spacecraft, the first manned mission of the Apollo program.


Related article:


Northrop Grumman Carries Technology, Scientific Investigations on Mission to Space Station
https://orbiterchspacenews.blogspot.com/2019/04/northrop-grumman-carries-technology.html


Related links:


Northrop Grumman: https://www.nasa.gov/mission_pages/station/structure/launch/northrop-grumman.html


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


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


Images (mentioned), Video, Text, Credits: NASA/Rob Garner/NASA TV/SciNews.


Best regards, Orbiter.chArchive link


ancientpeoples: Limestone statue of Tutu  The god Tutu was the…


ancientpeoples:



Limestone statue of Tutu 


The god Tutu was the Greek and Ptolemaic god of daily magic. A powerful protective deity that people could turn to. He becomes very popular in Egypt in the Ptolemaic Period (Greek period). 


Egyptian, Ptolemaic Period, 300 — 150 BC. 


Source: Metropolitan Museum



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greek-museums: Archaeological Museum of Ancient Sicyon: Marble…



greek-museums:



Archaeological Museum of Ancient Sicyon:



Marble statuette of a pony with archaising features. Found in the Roman Baths.


(I have also posted another view of it here)




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margadirube: doll61: lalulutres: Richly-detailed fresco on an…


margadirube:



doll61lalulutres: Richly-detailed fresco on an arched ceiling, Pompeii, 79 AD Bliss ~doll61



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