суббота, 23 ноября 2019 г.

2019 November 23 Apollo 12 and Surveyor 3 Stereo View Image...

2019 November 23

Apollo 12 and Surveyor 3 Stereo View
Image Credit: NASA, Apollo 12, Alan Bean - Stereo Image Copyright: Kevin Frank

Explanation: Put on your red/blue glasses and gaze across the western Ocean of Storms on the surface of the Moon. The 3D view features Apollo 12 astronaut Pete Conrad visiting the Surveyor 3 spacecraft 50 years ago in November of 1969. Surveyor 3 had landed at the site on the inside slope of a small crater about 2 ½ years earlier in April of 1967. Visible on the horizon beyond the far crater wall, Apollo 12’s Lunar Module Intrepid touched down less than 200 meters (650 feet) away, easy moonwalking distance from the robotic Surveyor spacecraft. The stereo image was carefully created from two separate pictures (AS12-48-7133, AS12-48-7134) taken on the lunar surface. They depict the scene from only slightly different viewpoints, approximating the separation between human eyes.

∞ Source: apod.nasa.gov/apod/ap191123.html

* This article was originally published here

Pleiades Night vision satellite & UFO Hunting

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Channel: déjà vu  

Night vision filming around the Pleiades start cluster Messier 45.

Equipment used for filming-

Canon 60D through a Twiggy L4A1 + P8079HP image intensified F350mm telescope.

Canon Rebel T3i + P8079HP intensifier through a 50mm lens.

Canon 1300D full spectrum conversion, 75-300 mm lens & 760nm infrared filter.

© Music, ambient sounds and atmospherics created by déjà vu

Video length: 5:49
Category: Science & Technology

A Crisis in Cosmology

W. M. Keck Observatory's AO system was used for the first time to obtain the hubble constant by observing three gravitationally lensed systems, including HE0435-1223 (pictured). 

Maunakea, Hawaii – A group of astronomers led by University of California, Davis has obtained new data that suggest the universe is expanding more rapidly than previously thought.

The study comes on the heels of a hot debate over just how fast the universe is ballooning; measurements thus far are in disagreement.

The team’s new measurement of the Hubble Constant, or the expansion rate of the universe, involved a different method. They used NASA’s Hubble Space Telescope (HST) in combination with W. M. Keck Observatory’s Adaptive Optics (AO) system to observe three gravitationally-lensed systems. This is the first time ground-based AO technology has been used to obtain the Hubble Constant.
“When I first started working on this problem more than 20 years ago, the available instrumentation limited the amount of useful data that you could get out of the observations,” says co-author Chris Fassnacht, Professor of Physics at UC Davis. “In this project, we are using Keck Observatory’s AO for the first time in the full analysis. I have felt for many years that AO observations could contribute a lot to this effort.”

The team’s results are published in the latest online issue of the Monthly Notices of the Royal Astronomical Society.

To rule out any bias, the team conducted a blind analysis; during the processing, they kept the final answer hidden from even themselves until they were convinced that they had addressed as many possible sources of error as they could think of. This prevented them from making any adjustments to get to the “correct” value, avoiding confirmation bias. 

“When we thought that we had taken care of all possible problems with the analysis, we unblind the answer with the rule that we have to publish whatever value that we find, even if it’s crazy. It’s always a tense and exciting moment,” says lead author Geoff Chen, a graduate student at the UC Davis Physics Department.

The unblinding revealed a value that is consistent with Hubble Constant measurements taken from observations of “local” objects close to Earth, such as nearby Type Ia supernovae or gravitationally-lensed systems; Chen’s team used the latter objects in their blind analysis. 

The team’s results add to growing evidence that there is a problem with the standard model of cosmology, which shows the universe was expanding very fast early in its history, then the expansion slowed down due to the gravitational pull of dark matter, and now the expansion is speeding up again due to dark energy, a mysterious force.

An artist’s depiction of the standard model of cosmology
Credit: BICEP2 Collaboration/CERN/NASA

This model of the expansion history of the universe is assembled using traditional Hubble Constant measurements, which are taken from “distant” observations of the cosmic microwave background (CMB) – leftover radiation from the Big Bang when the universe began 13.8 billion years ago.

Recently, many groups began using varying techniques and studying different parts of the universe to obtain the Hubble Constant and found that the value obtained from “local” versus “distant” observations disagree.

“Therein lies the crisis in cosmology,” says Fassnacht. “While the Hubble Constant is constant everywhere in space at a given time, it is not constant in time. So, when we are comparing the Hubble Constants that come out of various techniques, we are comparing the early universe (using distant observations) vs. the late, more modern part of the universe (using local, nearby observations).”

This suggests that either there is a problem with the CMB measurements, which the team says is unlikely, or the standard model of cosmology needs to be changed in some way using new physics to correct the discrepancy.


Using Keck Observatory’s AO system with the Near-Infrared Camera, second generation (NIRC2) instrument on the Keck II telescope, Chen and his team obtained local measurements of three well-known lensed quasar systems: PG1115+ 080, HE0435-1223, and RXJ1131-1231. 

Quasars are extremely bright, active galaxies, often with massive jets powered by a supermassive black hole ravenously eating material surrounding it. 

Though quasars are often extremely far way, astronomers are able to detect them through gravitational lensing, a phenomenon that acts as nature’s magnifying glass. When a  sufficiently massive galaxy closer to Earth gets in the way of light from a very distant quasar, the galaxy can act as a lens; its gravitational field warps space itself, bending the background quasar’s light into multiple images and making it look extra bright.

At times, the brightness of the quasar flickers, and since each image corresponds to a slightly different path length from quasar to telescope, the flickers appear at slightly different times for each image – they don’t all arrive on Earth at the same time. 

With HE0435-1223, PG1115+ 080, and RXJ1131-1231, the team carefully measured those time delays, which are inversely proportional to the value of the Hubble Constant. This allows astronomers to decode the light from these distant quasars and gather information about how much the universe has expanded during the time the light has been on its way to Earth.

Multiple lensed quasar images of HE0435-1223 (left), PG1115+ 080 (center), and RXJ1131-1231 (right). 
Image credit: G. Chen, C. Fassnacht, UC Davis

“One of the most important ingredients in using gravitational lensing to measure the Hubble Constant is sensitive and high-resolution imaging,” said Chen. “Up until now, the best lens-based Hubble Constant measurements all involved using data from HST. When we unblinded, we found two things. First, we had consistent values with previous measurements that were based on HST data, proving that AO data can provide a powerful alternative to HST data in the future. Secondly, we found that combining the AO and HST data gave a more precise result.”

Next Steps

Chen and his team, as well as many other groups all over the planet, are doing more research and observations to further investigate. Now that Chen’s team has proven Keck Observatory’s AO system is just as powerful as HST, astronomers can add this methodology to their bucket of techniques when measuring the Hubble Constant.

“We can now try this method with more lensed quasar systems to improve the precision of our measurement of the Hubble Constant. Perhaps this will lead us to a more complete cosmological model of the universe,” says Fassnacht.

About NIRC2

The Near-Infrared Camera, second generation (NIRC2) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

About Adaptative Optics

W. M. Keck Observatory is a distinguished leader in the field of adaptive optics (AO), a breakthrough technology that removes the distortions caused by the turbulence in the Earth’s atmosphere. Keck Observatory pioneered the astronomical use of both natural guide star (NGS) and laser guide star adaptive optics (LGS AO) on large telescopes and current systems now deliver images three to four times sharper than the Hubble Space Telescope at near-infrared wavelengths. Keck AO has imaged the four massive planets orbiting the star HR8799, measured the mass of the giant black hole at the center of our Milky Way Galaxy, discovered new supernovae in distant galaxies, and identified the specific stars that were their progenitors. Support for this technology was generously provided by the Bob and Renee Parsons Foundation, Change Happens Foundation, Gordon and Betty Moore Foundation, Mt. Cuba Astronomical Foundation, NASA, NSF, and W. M. Keck Foundation.

About W.M. Keck Observatory

The W. M. Keck Observatory telescopes are among the most scientifically productive on Earth. The two, 10-meter optical/infrared telescopes on the summit of Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems.

Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c) 3 non-profit organization operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.

* This article was originally published here

The Beehive cluster in Cancer Night vision satellite & UFO Hunting

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Channel: déjà vu  

Night vision filming the Beehive cluster, Messier 44, Praesepe, NGC 2632 in the constellation of Cancer.

Equipment used for filming-

Canon 60D through a Twiggy L4A1 + P8079HP image intensified F350mm telescope.

Canon Rebel T3i + P8079HP intensifier through a 50mm lens.

Canon 1300D full spectrum conversion, 18-135 mm lens

© Music, ambient sounds and atmospherics created by déjà vu

Video length: 6:49
Category: Education

Astronauts Complete Intricate Tasks During Second Cosmic Repair Spacewalk

ISS - Expedition 61 Mission patch / EVA - Extra Vehicular Activities patch.

November 22, 2019

Expedition 61 Commander Luca Parmitano of ESA (European Space Agency) and NASA Flight Engineer Andrew Morgan concluded their spacewalk at 1:35 p.m. EST. During the six-hour and 33-minute spacewalk, the two astronauts successfully cut a total of eight stainless steel tubes, including one that vented the remaining carbon dioxide from the old cooling pump. The crew members also prepared a power cable and installed a mechanical attachment device in advance of installing the new cooling system.

Image above: Spacewalker Luca Parmitano is guided on the Canadarm2 robotic arm toward the work site on the Alpha Magnetic Spectrometer, the space station’s cosmic particle detector. Image Credit: NASA TV.

In addition to revitalizing an important piece of scientific equipment, the process of creating the tools and procedures for these spacewalks is preparing teams for the types of spacewalks that may be required on Moon and Mars missions. The tools include plumbing instruments to cut into the cooling lines, new screwdriver bits and devices to capture the fasteners the astronauts remove from AMS. Learn more about the unique tools developed for the spacewalks to repair AMS.

Image above: ESA (European Space Agency) astronaut Luca Parmitano is pictured attached to the Canadarm2 robotic arm during the first spacewalk to repair the International Space Station’s cosmic particle detector. Image Credit: NASA TV.

Today’s work clears the way for Parmitano and Morgan’s next spacewalk in the repair series Monday Dec. 2. The plan is to bypass the old thermal control system by attaching a new one off the side of AMS during the third spacewalk, and then conduct leak checks on a fourth spacewalk.

For more on the AMS science and spacewalks, listen to the recent podcasts:

- Houston We Have a Podcast Ep 117: Alpha Magnetic Spectrometer: The Science

- Houston We Have a Podcast Ep 118: Alpha Magnetic Spectrometer: The Spacewalks

- Houston We Have a Podcast Ep 119: Alpha Magnetic Spectrometer: The Tools

Space station crew members have conducted 223 spacewalks in support of assembly and maintenance of the orbiting laboratory. Spacewalkers have now spent a total of 58 days 9 hours and 41 minutes working outside the station. Parmitano has now conducted three spacewalks in his career and Morgan has now logged four spacewalks since his arrival on the station in July.

Related links:

Expedition 61: https://www.nasa.gov/mission_pages/station/expeditions/expedition61/index.html

Alpha Magnetic Spectrometer’s (AMS): https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=729

Unique tools: https://nasa.tumblr.com/post/189210016829/from-discovering-the-secrets-of-the-universe-to

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

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

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

* This article was originally published here

APT weather satellite images: NOAA-19 flyover from 24.02.2019, 15:16 UTC.

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Channel: OGVT - Observatoire géophysique, Val Terbi  

How APT weather satellite images with WXtoImg are produced: NOAA-19 flyover from 24.02.2019, 15:16 UTC. Recorded on 137.1 MHz in Montsevelier ValTerbi

Video length: 16:06
Category: Science & Technology

Gas content and quenching of local galaxies

Top panel: gas fraction (fgas) and bottom panel: star formation efficiency (SFE) plotted as functions of distance from the MS in four bins of total stellar mass. Each point corresponds to a median value with a bootstrapped error estimate. The grey shaded area covers the range in ∆SFMS with 10% completeness in each bin.

During galactic transition towards quiescence 'it is not only the gas reservoir of a galaxy which decreases but also the efficiency with which the gas is turned into stars' - suggests a new study led by KICC researchers.

Galaxies in the observable Universe divide into two broad categories: blue, star-forming and red, quiescent. When observed across cosmic, time the distribution of galaxies shifts from the star-formation dominated to passive (quiescent) and hence these two states are interpreted as an evolutionary sequence.

Understanding the physical processes responsible for ceasing star formation is one of the long-standing questions in the area of galaxy evolution. Ultimately, galaxies may quench either due to a lack of fuel or a decrease in star formation efficiency (i.e. an increase in thedepletion time). In order to differentiate between the two possibilities one needs to measure the dense neutral gas within galaxies. However, observing the faint gas emission typically requires long exposure times on premier facilities, thus limiting the sample sizes to only a few hundred detections.

In this work led by Joanna Piotrowska, a PhD student at the Kavli, the KICC researchers use an indirect method to obtain gas mass estimates for ~62 000 local galaxies in the Sloan Digital Sky Survey which allows them to investigate the variation of gas fraction and star formation efficiency of objects on their path towards quiescence. They show that as galaxies deviate from the star-forming Main Sequence (a tight relation between the galaxy stellar mass and star formation rate) it is not only the gas reservoir of a galaxy which decreases but also the efficiency with which the gas is turned into stars as shown in the figure at the above of the page.

These results call for a better understanding of the physical processes driving the decrease in star formation efficiency, which has received relatively little attention in the theory of quenching until now.

You can freely access the article at this link  or with a subscription in the MNRAS Letters here.

* This article was originally published here

New finding on origin of avian predentary in Mesozoic birds

The predentary bone is one of the most enigmatic skeletal elements in avian evolution. Located at the tip of the lower jaw, this bone is absent in more primitive birds and in living birds; it is thought to have been lost during evolution. For over 30 years, the origin and function of the avian predentary has remained mysterious.

New finding on origin of avian predentary in Mesozoic birds
This is a reconstruction of Yanornis martini feeding on fish along a shallow
 lakeshore of the Jehol biota [Credit: Michael Rothman]
Now, however, Alida Bailleul, LI Zhiheng, Jingmai O'Connor and ZHOU Zhonghe from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have made significant progress towards solving this long-standing mystery. Their findings were published in Proceedings of the National Academy of Sciences.

Using a battery of analytical methods, the team, led by Dr. Bailleul, presents strong evidence that the avian predentary was covered by a keratinous beak - a horny sheath that covers the bones of the rostrum in all living birds, all of which are edentulous and have beaks. It also provides evidence the predentary was proprioceptive, i.e., it was able to detect external mechanical stimuli; and was mobile - thus representing a now extinct form of cranial kinesis.

Cranial kinesis occurs when joints are able to move within the skull - mainly between the upper jaw and the braincase. This feature is widespread in living birds; however, it is thought to be mostly absent in Mesozoic birds.

Based on her examination of the fossilized tissues of the predentary and other jaw elements of Yanornis martini from the Jehol Biota, Dr. Bailleul identified a specific type of cartilage inside the joint between the predentary and dentary that strongly suggests some movement between these elements.

New finding on origin of avian predentary in Mesozoic birds
The pink arrow points to the predentary and the blue arrow points to the upper portion of the jaw,
which has no teeth. Together, they may have been covered by a keratinous beak,
and the predentary was most likely mobile [Credit: IVPP]
The team noticed that the predentary is only found in ornithuromorphs that have teeth. However, the tip of the premaxilla - the bone of the upper bill that would have occluded with the predentary - is without teeth. This suggests that the tip of the upper jaw, like the predentary, was also covered with a keratinous beak.

The tiny beak at the tip of the skull, combined with the sensitive and mobile predentary bone and teeth that were most likely also proprioceptive, represents a unique feeding adaptation that allowed greater dexterity when manipulating food. Although bizarre and now extinct, this unique feeding apparatus persisted in the ornithuromorph clade for at least 58 million years, from the Early to the Late Cretaceous.

Using information from the fossilized tissues and preexisting data on the embryology of living birds, the team also formulated a hypothesis regarding the origin of this bone, suggesting it is a sesamoid, similar to the human knee cap. Identification as a sesamoid means this bone is a novel skeletal innovation unique to one lineage of ornithuromorphs, and that it did not arise from a preexisting skull bone.

Although additional research on fossils birds (and also extant birds) is required to confirm some of these hypotheses, the predentary is such a small bone that it is only rarely preserved, thus making it very difficult - if not impossible - to find specimens that can shed light on the remaining pieces of this mystery.

Source: Chinese Academy of Sciences [November 18, 2019]

* This article was originally published here

Extremely Fast Moving White Object Or UFO Over Ukraine.

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Channel: Terry's Theories  

If you like the channel and the videos and your able please donate at https://www.paypal.me/Franklin1275?locale.x=en_US

I had two videos emailed to me by YouTube channel Strannik Vechnyi that was recorded by his drone over a forest close to chernobyl. The video shows white objects hard to make out a shape but they are moving at extreme speeds. If you have a video you would like me to look at that has to do with Ufology please email me at terrystheories@outlook.cok
Source YouTube channel is Strannik Vechnyi https://www.youtube.com/channel/UC5eFuuafr7jVLy0wweXDGFg

Video length: 4:25
Category: Science & Technology

A SpaceX rocket explodes on its launch-pad

SpaceX logo.

Nov. 22, 2019

SpaceX rocket explodes on its launch-pad at Cape Canaveral

A rocket prototype of the American company partially exploded Wednesday in Texas. No injuries are to be deplored.

Billionaire Elon Musk's week has certainly not been easy. Before the misadventure, Thursday, during the presentation of the new pickup of Tesla, it is a rocket Starship which made of hers.

While engineers performed tank fill tests on the Starship Mk1 prototype in Boca Chica, Texas on Wednesday, a loud detonation took place on top of the ship, accompanied by a thick cloud of smoke. The whole thing was filmed live.

2405 views   58 likes   1 dislikes  

Channel: déjà vu  

Night vision filming in the constellation Orion. During the 90 minute shoot, 19 objects were filmed. 13 of the best are shown here with 2 being identified.

Equipment used for filming-

Canon 60D through a Twiggy L4A1 + P8079HP image intensified F350mm telescope.

Canon Rebel T3i + P8079HP intensifier through a 50mm lens.

Canon 1300D full spectrum conversion, 18-135 mm lens & 760nm infrared filter.

© Music, ambient sounds and atmospherics created by déjà vu

Video length: 5:06
Category: Science & Technology

Space Station Science Highlights: Week of November 18, 2019

ISS - Expedition 61 Mission patch.

Nov. 22, 2019

Crew members aboard the International Space Station conducted research on remote-controlled rovers, launched scientific satellites and connected with people on the ground. NASA astronaut Andrew Morgan and ESA (European Space Agency) astronaut Luca Parmitano conducted a second spacewalk in as many weeks on Friday, Nov. 22, part of a series to extend the life of the space station’s Alpha Magnetic Spectrometer (AMS-02). The AMS captures data from cosmic particle impacts, and with more than 140 billion impacts documented to date, indicates sources of positrons at high energies that could be evidence of dark matter. This invisible form of matter makes up most of the mass content of the universe.

Image above: ESA (European Space Agency) astronaut Luca Parmitano attached to the Canadarm2 robotic arm during the first spacewalk to repair the Alpha Magnetic Spectrometer, which captures data from cosmic particle impacts in a search for evidence of dark matter. Image Credit: NASA.

This month marks the beginning of the 20th year of continuous human presence aboard the space station, the only platform for long-duration research in microgravity. Learning to live and work in space is one of the biggest challenges of long-duration spaceflight, and the experience gained on the space station supports Artemis, NASA’s program to go forward to the Moon and on to Mars.

Here are details on some of the science conducted on the orbiting lab the week of Nov. 18:

Sending rovers to test the waters

Analog-1 tests operating an exploration rover on Moon-like terrain on Earth from the space station. An astronaut controls the rover as it collects rock and soil samples and remotely investigates them, a plausible scenario for future lunar or Martian exploration. The crew performed a successful proficiency simulation run in preparation for the science run next week, using the rover to locate several rocks and perform appropriate maneuvers to pick up some of them. Future exploration of the solar system may send robotic explorers to uncharted planets before sending humans and Analog-1 is part of the METERON project, a European initiative to help prepare for such human-robotic exploration missions. It involves a series of preparatory steps toward gaining the experience needed to support operations of combined human and robotic elements on a planetary surface.

Small satellites that do big jobs

Image above: NASA astronaut Drew Morgan prepares CubeSats for their launch from the JEM Small Satellite Orbital Deployer (J-SSOD). The launch includes three satellites, one each from Japan, Egypt and Rwanda, with flags from the last two countries visible on the equipment. Image Credit: NASA.

Crew members used the Japanese Small Satellite Orbital Deployer-12 (JSSOD – 12) to launch CubeSats from Japan, Rwanda and Egypt. The J-SSOD provides launch capability for small satellites using the Japanese Experiment Module Remote Manipulator System (JEMRMS) on the outside of the space station. Japan’s AQT-D CubeSat tests a propulsion system using water as a propellant. The Egyptian CubeSat NARSScube-1, which carries a small camera, provides experience building and operating a CubeSat, demonstrates technology for producing reliable data from space and promotes applied research in space engineering at Egyptian universities and research institutes. RWASAT-1 from Rwanda provides Earth observation capabilities for environmental, agricultural and other applications in that country.

Connecting with the space station

Two programs connect people on the ground and aboard the space station: ISS HAM, which gives students an opportunity to talk directly with crew members via ham radio, and The ISS Experience, which is currently filming a virtual reality cinematic experience about different aspects of crew life, execution of science and the international partnerships involved. The crew conducted an ISS HAM Pass with students from Lakeside Elementary School in Utah, with questions ranging from their thoughts on the first all-female spacewalk to how a spaceship is driven. Crew members also filmed several segments for The ISS Experience, including installation of the J-SSOD-12 satellite deployer and footage to explain the general concept of an airlock.

Other investigations on which the crew performed work:

- Radi-N2, an investigation by the Canadian Space Agency (CSA), characterizes the neutron radiation environment on the space station to help define the risk to crew members and support development of advanced protective measures for future spaceflight.

- Rodent Research-14 uses mice to examine the effects of disruptions to the body’s circatidal rhythm or sleep/wake cycle in microgravity on a cellular and key organ level. This 12-hour body clock is an important mechanism controlling stress-responsive pathways.

- Veg-04B, part of a phased research project to address the need for fresh food production in space, focuses on the effects of light quality and fertilizer on a leafy crop, Mizuna mustard greens.

Image above: NASA astronauts Jessica Meir, left, and Christina Koch harvest a crop of Mizuna mustard greens grown for the Veg-04B investigation, part of a phased research project to address the need for fresh food production in space. Image Credit: NASA.

- NutrISS, an investigation by the Italian Space Agency (ASI), assesses the body composition of crew members during spaceflight using a device that measures long-term energy balance modification over time. Adjusting diet to maintain a near-neutral energy balance and/or increasing protein intake may limit microgravity-induced bone and muscle loss.

- Food Acceptability examines changes in the appeal of food aboard the space station during long-duration missions. “Menu fatigue” from repeatedly consuming a limited choice of foods may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases.

- Zero-G Oven examines heat transfer properties and the process of baking food in microgravity. On future long-duration missions, fresh-baked food could have psychological and physiological benefits for crew members.

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Channel: Meteors  

This beautiful and slow meteor overflew the Mediterranean Sea on 2019 November 20 at about 3:48 local time (equivalent to 2:48 universal time). It was generated by a rock from a comet that hit the atmosphere at about 47,000 km/h. It began at an altitude of about 81 km over the sea, and ended at a height of around 38 km after traveling about 81 km in the Earth's atmosphere.

The event was recorded in the framework of the SMART project, operated by the Southwestern Europe Meteor Network (SWEMN), from the meteor-observing stations located at Calar Alto (Almería), Sierra Nevada (Granada), La Sagra (Granada), La Hita (Toledo), and Sevilla.
Esta preciosa y lenta bola de fuego sobrevoló el mar Mediterráneo en la madrugada del 20 de noviembre, a las 3:48 hora local. Se produjo al entrar en la atmósfera terrestre una roca procedente de un cometa a una velocidad de unos 47 mil kilómetros por hora. El evento se inició a una altitud de unos 81 km, frente a la costa de Málaga. Desde allí la bola de fuego avanzó en dirección noreste. Finalmente se extinguió a una altitud de 38 kilómetros sobre el nivel del mar, sobre un punto situado a unos 78 km de la costa de Málaga y a 83 km de la costa de Marruecos, tras recorrer una trayectoria de 81 km en la atmósfera.

La bola de fuego ha sido registrada por los detectores del proyecto SMART desde los observatorios astronómicos de Calar Alto (Almería), Sierra Nevada (Granada), La Sagra (Granada), La Hita (Toledo) y Sevilla. Estos detectores operan en el marco de la Red de Bólidos y Meteoros del Suroeste de Europa (SWEMN), que tiene como objetivo monitorizar continuamente el cielo con el fin de registrar y estudiar el impacto contra la atmósfera terrestre de rocas procedentes de distintos objetos del Sistema Solar.

Video length: 1:07
Category: Science & Technology

Ancient gas cloud shows that the first stars must have formed very quickly

Astronomers found a pristine gas cloud in the proximity of one of the most distant quasars known, seen just 850 million after the Big Bang (1/14th of the universe's current age). The gas cloud absorbs some of the light from the background quasar, leaving signatures that allow astronomers to study its chemical composition. This is the most distant gas cloud for which astronomers have been able to measure a metallicity to date. This system has one of the smallest amount of metals ever identified in a gas cloud but the ratio of its chemical elements are still similar to what observed in more evolved systems. © graphics department.

Astronomers led by Eduardo Bañados of the Max Planck Institute for Astronomy have discovered a gas cloud that contains information about an early phase of galaxy and star formation, merely 850 million years after the Big Bang. The cloud was found serendipitously during observations of a distant quasar, and it has the properties that astronomers expect from the precursors of modern-day dwarf galaxies. When it comes to relative abundances, the cloud's chemistry is surprisingly modern, showing that the first stars in the universe must have formed very quickly after the Big Bang. The results have been published in the Astrophysical Journal.

When astronomers look at distant objects, they necessarily look back in time. The gas cloud discovered by Bañados et al. is so distant that its light has taken nearly 13 billion years to reach us; conversely, the light reaching us now tells us how the gas cloud looked nearly 13 billion years ago, no more than about 850 million years after the Big Bang. For astronomers, this is an extremely interesting epoch. Within the first several hundred million years after the Big Bang, the first stars and galaxies formed, but the details of that complex evolution are still largely unknown.

This very distant gas cloud was a fortuitous discovery. Bañados, then at the Carnegie Institution for Science, and his colleagues were following up on several quasars from a survey of 15 of the most distant quasars known (z³6.5), which had been prepared by Chiara Mazzucchelli as part of her PhD research at the Max Planck Institute for Astronomy. At first, the researchers just noted that the quasar P183+05 had a rather unusual spectrum. But when Bañados analyzed a more detailed spectrum, obtained with the Magellan Telescopes at Las Campanas Observatory in Chile, he recognized that there was something else going on: The weird spectral features were the traces of a gas cloud that was very close to the distant quasar – one of the most distant gas clouds astronomers have yet been able to identify.

Lit up by a distant quasar

Quasars are the extremely bright active nuclei of distant galaxies. The driving force behind their luminosity is the galaxy’s central supermassive black hole. Matter swirling around that black hole (before falling in) heats up to temperatures reaching hundreds of thousands of degrees, giving off enormous amounts of radiation. This allows astronomers to use quasars as background sources to detect hydrogen and other chemical elements in absorption: If a gas cloud is directly between the observer and a distant quasar, some of the quasar’s light will be absorbed.

Astronomers can detect this absorption by studying the quasar’s spectrum, that is, the rainbow-like decomposition of the quasar’s light into the different wavelength regions. The absorption pattern contains information about the gas cloud’s chemical composition, temperature, density and even about the cloud’s distance from us (and from the quasar). Behind this is the fact that each chemical element has a “fingerprint” of spectral lines – narrow wavelengths region in which that element’s atoms can emit or absorb light particularly well. The presence of a characteristic fingerprint reveals the presence and abundance of a specific chemical element.

Not quite the cloud they were looking for

From the spectrum of the gas cloud, the researchers could immediately tell the distance of the cloud, and that they were looking back into the first billion years of cosmic history. They also found traces of several chemical elements including carbon, oxygen, iron, and magnesium. However, the amount of these elements was tiny, about 1/800 times the abundance in the atmosphere of our sun. Astronomers summarily call all elements heavier than helium “metals;” this measurement makes the gas cloud one of the most metal-poor (and distant) systems known in the universe. Michael Rauch from the Carnegie Institution of Science, who is co-author of the new study, says: "After we were convinced that were were looking at such pristine gas only 850 million years after the Big Bang we started wondering whether this system could still retain chemical signatures produced by the very first generation of stars."

Finding these first generation, so-called “population III” stars is one of the most important goals in reconstructing the history of the universe. In the later universe, chemical elements heavier than hydrogen play an important role in letting gas clouds collapse to form stars. But those chemical elements, notably carbon, are themselves produced in stars, and flung into space in supernova explosions. For the first stars, those chemical facilitators would simply not have been there, since directly after the Big Bang phase, there were only hydrogen and helium atoms. That is what makes the first stars fundamentally different from all later stars.

The analysis showed that the cloud’s chemical make-up was not chemically primitive, but instead the relative abundances were surprisingly similar to the chemical abundances observed in today’s intergalactic gas clouds. The ratios of the abundances of heavier elements were very close to the ratios in the modern universe. The fact that this gas cloud in the very early universe already contains metals with modern relative chemical abundances poses key challenges for the formation of the first generation of stars.

So many stars, so little time

This study implies that the formation of the first stars in this system must have begun much earlier: the chemical yields expected from the first stars had already been erased by the explosions of at least one more generation of stars. A particular time constraint comes from supernovae of type Ia, cosmic explosions that would be required to produce metals with the observed relative abundances. Such supernovae typically need about 1 billion years to happen, which puts a serious constraint on any scenarios of how the first stars formed.

Now that the astronomers have found this very early cloud, they are systematically looking for additional examples. Eduardo Bañados says: “It is exciting that we can measure metallicity and chemical abundances so early in the history of the universe, but if we want to identify the signatures of the first stars we need to probe even earlier in cosmic history. I am optimistic that we will find even more distant gas clouds, which could help us understand how the first stars were born.”

Background information

The results described here have been published in Bañados et al., “A metal–poor damped Lyαsystem at redshift 6.4,” in the Astrophysical Journal.

The MPIA researchers involved are Eduardo Bañados (also Carnegie Institution for Science), Emanuele Farina and Joe Hennawi (both also UCSB), Bram P. Venemans, and Fabian Walter (also NRAO), in collaboration with Michael Rauch (Carnegie Institution for Science), Roberto Decarli (INAF Bologna), Chiara Mazzucchelli (ESO), Robert A. Simcoe (MIT-Kavli Center for Astrophysics and Space Research), J. Xavier Prochaska (UCSC), Thomas Cooper (Carnegie Institution for Science), Frederick B. Davies (UCSB) and Shi-Fan S. Chen (MIT-Kavli Center for Astrophysics and Space Research and UC Berkeley)

e-print of the article  


Eduardo Banados Torres
Phone: +49 6221 528-461
Email: banados@mpia.de
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Links: Personal homepage

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Phone:+49 6221 528-261
Email: pr@mpia.de

* This article was originally published here

British Museum set to return ancient Greek statue looted from Libya

London’s British Museum is set to return a looted ancient Greek statue of the goddess Persephone to Libya which is estimated to be worth £1.5m.

British Museum set to return ancient Greek statue looted from Libya
Statue of Persephone dating from 3rd century BC to be returned from the UK to Libya
[Credit: Middle East Eye]
According to Al-Wasat newspaper, Mohammed al-Kouni, the Libyan charge d’affaires, visited the British Museum along with his delegation on Thursday to see the artefact and make arrangements for its return.

Libya's cultural heritage has been under threat from looting in the turbulent years that have followed the 2011 uprising against longtime autocrat Muammar Gaddafi.

The ancient Greek statue currently in the British Museum's possession was taken from a world heritage site in Shahhat in 2012.

The piece was illegally excavated from a grave in the ruins of Cyrene, an important Hellenic city located in the north of what is now Libya, and then subsequently smuggled into the United Kingdom.

The four-foot marble relic is of a hooded woman believed to be a representation of the queen of the underworld, Persephone.

The statue dates from the third or fourth century BC, and Dr Peter Higgs, a curator of Greek sculpture at the British Museum, described it as “one of the best examples of its type and … extremely rare”.

A 2015 ruling by Judge John Zani ruled that the statue, which was in the possession of Jordanian national Riad al-Qassas, had been “misdeclared” on arrival to the UK as border officials believed it was worth £72,000 and originally Turkish.

The artefact was discovered in a west London warehouse by customs officials, before being handed to the British Museum as the court ruled on its ownership.

Qassas was ordered to pay £50,000 costs in the 2015 ruling. Meanwhile, a claim from Emirati businessman Hassan Fazeli that the statue had been in his family since 1977 was waved away.

The return is part of a drive by the Libyan Antiquities Authority to repatriate stolen goods, a process that can take many years to see fruition.

There are currently five UNESCO world heritage sites in Libya that are classified by the United Nations as endangered: Ghadames, Cyrene, Tadrart Acacus, Leptis Magna and Sabratha.

Though the North African country boasts several archaelological sites and centuries of cultural history, some regions of Libya have not yet archived or documented many of their excavated artefacts.

This has left it difficult to assess how many ancient artefacts have been looted since 2011, though it is estimated that some 8,000 ancient coins and small artefacts have been lost.

In early October, the United States returned a Libyan statue known as the “Head of a Veiled Woman” following an 11-year investigation.

Author: Haneen Shlebak | Source: Middle East Eye [November 12, 2019]

* This article was originally published here

Meteore im März 2019

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Channel: OGVT - Observatoire géophysique, Val Terbi  

Die hellsten, im März aufgezeichneten Meteore in Montsevelier (Val Terbi) JU. Alle Daten und Bilder unter: http://www.ogvt.org/astronomie/medienarchiv.php und http://www.ogvt.org/astronomie/dbabfrage.php

Video length: 1:07
Category: Science & Technology

The Whole Picture of Distant Supercluster in Three Dimensions

Figure 1: The 3-D and 2-D maps of the number density of galaxies associated with the supercluster. In the 2-D map, the large-scale structures of galaxies located in the slice at about 7.3 billion years ago are shown. The white areas show the structures already known from previous studies, and the yellow areas show the structures newly discovered by this study. The structures marked by the dotted ellipses are to be confirmed by future works. The white vertical line in the figure corresponds to a distance of about 30 million light-years (i.e., 10 Mpc). (Credit: NAOJ)

Using the Subaru Telescope and Gemini-North Telescope, a team of astronomers has revealed that the supercluster CL1604, a distant supercluster located about 7.3 billion light-years away, is a large-scale 3-D structure extending over about 160 million light-years in the north-south direction. This is more than two times more extended than what was already known. Until now, we saw merely the “tip of the iceberg” of the supercluster. The wide-field capability of the Subaru Telescope enabled us to survey the whole of the supercluster and the Gemini-North Telescope played a critical role in confirming the structures. This is the outcome of the good synergy of the telescopes of the Maunakea observatories.

Galaxies are distributed inhomogeneously in the Universe. It is well-known that nearby galaxies are strongly influenced by their environment, e.g., whether they are located in dense areas called galaxy clusters or less dense areas called voids. However, how galaxies form and evolve along with the growth of the cosmic web structures is one of the hot topics of astronomy. A wide-field survey of the distant Universe allows us to witness what actually happened with galaxies in the early phase of structure formation in the Universe. Among the few superclusters currently known, one of the best targets for study is the supercluster CL1604. Based on previous studies, its extent is 80 million light-years and its era is 7.3 billion years ago.

The uniqueness of the data taken by Hyper Suprime-Cam (HSC) on the Subaru Telescope is the deep imaging data over a field wide enough to fully cover the known supercluster and the surrounding area. A team led by Masao Hayashi and Yusei Koyama from NAOJ estimated the distances of individual galaxies from the galaxy colors using a technique called “photometric redshift.” Then, the three dimensional picture of the large-scale structures appears, which consists of several galaxy clusters newly discovered in the north-south direction as well as the structures already known (Figure 1). 

Figure 2: The distribution of redshift (i.e., distance in the depth direction) of the galaxies confirmed by our spectroscopic observations. In each area, the histogram is color-coded by the distance of the galaxies. The same color for the histograms means that the galaxy clusters are located at the same distance in the depth direction irrespective of the location on the sky. (Credit: NAOJ)

Furthermore, the team used the Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope and the Gemini Multi-Object Spectrograph (GMOS) on Gemini-North to confirm the precise distances of 137 galaxies associated with the galaxy clusters revealed by HSC (Figure 2). It is found that the supercluster is a complex large-scale structure not only over the vast projected area but also along the line-of-sight direction in 3D. The galaxies spread over the 160 million light-years seem to be independent due to the vast area, however, the spectroscopic observations tell us that the galaxies formed simultaneously and then evolve along with the growth of large-scale structures. 

Our Galaxy is a member of Local Group on the outskirts of Virgo Galaxy Cluster. A team led by an astronomer from the University of Hawaii recently revealed that the Virgo Cluster is a member of a more extended enormous large-scale structure named the Laniakea Supercluster. "The supercluster we discovered 7.3 billion years ago may grow to be a huge large-scale structure similar to Laniakea where we live" said Hayashi. 

These results were published in Publications of the Astronomical Society of Japan (Hayashi et al., "The whole picture of the large-scale structure of the CL1604 supercluster at z∼0.9"). A preprint is available here.


* This article was originally published here

1500-year-old ‘Hero Stones’ found in southern India

‘Hero stones’ considered as old as 1,500 years were retrieved from Desur village near Vandavasi in Tiruvannamalai district, in the state of Tamil Nadu, in South India.

1500-year-old ‘Hero Stones’ found in southern India
Credit: Deccan Chronicle
Based on information provided by personal assistant of Tiruvannamalai Collector, S Janaki, Desur revenue inspector A. Venkatesh accompanied by S Balamurugan, secretary, Tiruvannamalai District History Research Centre, and professor Sudhakar, visited the spot and found an ancient dilapidated mosque-like structure with five ‘Hero stones’ near it.

Of the five, two stones had two lines of Tamil inscriptions on them considered to date back to the fourth or the fifth century.

Explaining its significance, Historian, professor R Punguntran said that in two of the ‘Hero stones’ got from Desur village, one had ‘Kottrampak Kizhar’ inscribed on it. On the other stone was inscribed ‘Son of Kottrampak Kizhar - Seelan’.

The four-feet-tall stone tablets had the sculpture of a hero wielding a sword and a shield. Besides these stones, were three other ‘Hero stones’ which were ravaged by time.

It is likely that there could have been a village clash or a bullfight during the reign of one Banaraisaru in Seeyamangalam, where the father and son would have lost their lives, said Prof. Punguntran. Elucidating further, Punguntran said that these stones should have been installed in memory of them.

It is said that earlier to this finding, one Tamarai Kannan had found a stone which inscribed Seeyamangalam on it. Hence, Punguntran alleges that since these two stones also had Seeya mangalam inscribed on them, the place could be the ancient ‘Baanaadu’ which was ruled by the ‘Baanaraisar’ community.

Further, this ‘Baanaadu’ region is presumed to have spread as far as Cuddalore. It is also thought that ‘Kottrampak Kizhar’ could have been some important ‘head man’ of the ‘Baanaraisar’ community, who lived there.

Author: K. Senthil Nathan | Source: Deccan Chronicle [November 13, 2019]

* This article was originally published here


https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...