среда, 9 января 2019 г.

Sexual Revealing Fungi aren’t sexy, but for some species, like…

Sexual Revealing

Fungi aren’t sexy, but for some species, like the meningitis-causing Cryptococcus neoformans, sex is the secret to their success. Sexual reproduction combines material from two separate strains, providing ever-increasing genetic diversity, which helps them quickly develop resistance to drugs. A key part of this reproduction is producing spores, which help the fungus spread and survive between infections. Spores are made when the basidium [the spore-making cell] matures, and following meiosis, a process which mixes genetic information. Both of these steps are necessary, so discovering how they coordinate might help halt progress. New research has identified two genes, CSA1 and CSA2, regulating the parallel processes. When either of these genes are silenced, the natural spore production (clearly visible in the normal fungus, left), can’t proceed (right). By revealing the details of this microscopic mating, the research has identified a new potential target for treatments looking to cool down the fungal fornication.

Written by Anthony Lewis

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Hut Circles and Buildings of Tre’r Ceiri Iron Age Hillfort, North Wales,...

Hut Circles and Buildings of Tre’r Ceiri Iron Age Hillfort, North Wales, 4.1.19.

Photos don’t really do justice to the volume and diversity of hut circles and Buildings within Tre’r Ceiri Iron Age Hillfort. It must have been quite a crowded complex with different shapes and generational styles of building, ranging from earlier round structures to later multi-room Roundhouses to ultimately rectangular buildings.

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2019 January 9 Quadrantids Image Credit & Copyright: …

2019 January 9

Image Credit & Copyright: Daniel López (El Cielo de Canarias)

Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower is an annual event for planet Earth’s northern hemisphere skygazers It usually peaks briefly in the cold, early morning hours of January 4. The shower’s radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That position is situated near the boundaries of the modern constellations Hercules, Bootes, and Draco. About 30 Quadrantid meteors can be counted in this skyscape composed of digital frames recorded in dark and moonless skies between 2:30am and local dawn. The shower’s radiant is rising just to the right of the Canary Island of Tenerife’s Teide volcano, and just below the familiar stars of the Big Dipper on the northern sky. A likely source of the dust stream that produces Quadrantid meteors was identified in 2003 as an asteroid. Look carefully and you can also spot a small, telltale greenish coma above the volcanic peak and near the top of the frame. That’s the 2018 Christmas visitor to planet Earth’s skies, Comet Wirtanen.

∞ Source: apod.nasa.gov/apod/ap190109.html

China’s Yutu-2 rover Enters Standby Mode for ‘Noon Nap’ as...

CLEP – China Lunar Exploration Program logo.

January 8, 2019

China’s Chang’e 4 lander and Yutu 2 rover have tested out payloads and systems on the far side of the moon, with the rover now taking a “noon nap” as a precaution against high temperatures.

The Chang’e 4 lander made its historic landing at 177.6 degrees east longitude and 45.5 degrees south within Von Kármán Crater within the South Pole-Aitken basin at 9:26 p.m. EST Jan. 2 (0226 GMT on Jan. 3), following two weeks in lunar orbit.

Image above: China’s Yutu 2 rover after deployment on the surface of the moon’s far side. Image Credits: CLEP/CNSA.

The rover was deployed from the lander just under 12 hours later, at 9:22 a.m. EST (1422 GMT) Jan. 3. The rover also officially received the name Yutu 2 (“Jade Rabbit 2”), following on from China’s first lunar rover for the 2013 Chang’e 3 mission.

Monitoring cameras on the lander imaged the rover wheels during deployment and the craft on the surface, with the images returned to Earth via the Queqiao relay satellite stationed in a halo orbit around the second Earth-moon Lagrange point.

After reaching a predetermined point, the Yutu 2 rover has entered a standby mode to protect itself from temperatures reaching toward 390 degrees Fahrenheit (200 degrees Celsius), the China Lunar Exploration Program under the China National Space Administration (CNSA) announced.

The 310-lb. (140 kilograms)  rover, which has six drivable wheels with four, at the front and back, steerable to allow for pivoting, will resume activities Jan. 10 Beijing time.

Animation above: Chang’e-4 Yutu-2 rover starts exploring the Von Karman Crater. Animation Credits: CLEP/CNSA/Orbiter.ch Aerospace/Roland Berga.

Zhang Yuhua, deputy chief commander and designer of the mission, told Chinese state media that next up for the rover will be to travel to the front side of the lander and image the craft.

“After that, the rover will go to its planned area and start a series of scientific exploration projects in the Von Kármán Crater as planned by scientists,” Zhang said.

Shen Zhenrong, design director of the Yutu 2 rover, told China Central Television that the team adopted a new method to enclose Chang’e 4’s cables because of the harsh lunar surface, citing rock edges that scratch cables and trigger short circuits.

The Chang’e 3 Yutu rover traveled just 374 feet (114 meters) before becoming immobilized during its second lunar daytime on Mare Imbrium on the near side of the moon in early 2014.

Chang’e 3 Yutu rover (Jade Rabbit or Yutu-1). Image Credits: CLEP/CNSA

Jade Rabbit was the companion to the lunar goddess Chang’e from Chinese mythology, for which China’s robotic lunar exploration is named.

Preparations for entering a dormant state for the lunar nighttime to take place Jan. 12, when temperatures may drop to around minus 290 degrees Fahrenheit (minus 180 degrees Celsius).

During this time, the lander — which has a small radioisotope thermoelectric generator — will be capable of limited functions.

Chang’e 4 payload tests

Since touching down, both spacecraft have been testing the science payloads and communications and optical systems.

On the lander, the three 16.5-foot (5 m) antennas of the low-frequency spectrometer for pioneering astronomy have been deployed, which will be visible in future Yutu 2 images of the front of the lander.

The lander’s topography camera has also been tested and transmitted images back to Earth. The Yutu 2 rover’s panchromatic camera and lunar penetrating radar, payloads aboard the first Yutu rover with the Chang’e 3 mission, have also been tested.

Chang’e 4 lander-rover relayed back via satellite relay.Image Credits: CASC/CNSA

Robert F. Wimmer-Schweingruber of the University of Kiel, Germany, which developed the Lunar Lander Neutrons and Dosimetry (LND) experiment on the lander, told SpaceNews that the instrument had been turned on before descent from the lander and again tested after deployment of the rover.

“As we understand, LND is healthy and working nominally,” Wimmer-Schweingruber said.

LND will seek to understand the radiation to which lunar soils and rocks are exposed in preparation for potential human exploration, as well as detect subsurface water.

Related articles:

“Small step for the rover, big step for China”

Chang’e 4 spacecraft sends images after landing on far side of the Moon

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

For more information about China National Space Administration (CNSA), visit: http://www.cnsa.gov.cn/

Images (mentioned), Animation (mentioned), Text, Credits: SpaceNews/Space.com/Andrew Jones/Orbiter.ch Aerospace/Roland Berga.

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Young Planets Orbiting Red Dwarfs May Lack Ingredients for Life

AU Microscopii

Credits: NASA, ESA, J. Wisniewski (University of Oklahoma), C. Grady (Eureka Scientific), and G. Schneider (Steward Observatory). Released images

AU Microscopii 2018 Detail

Credits: NASA, ESA, J. Wisniewski (University of Oklahoma), C. Grady (Eureka Scientific), and G. Schneider (Steward Observatory).

Rocky planets orbiting red dwarf stars may be bone dry and lifeless, according to a new study using NASA’s Hubble Space Telescope. Water and organic compounds, essential for life as we know it, may get blown away before they can reach the surface of young planets.

This hypothesis is based on surprising observations of a rapidly eroding dust-and-gas disk encircling the young, nearby red dwarf star AU Microscopii (AU Mic) by Hubble and the European Southern Observatory’s Very Large Telescope (VLT) in Chile. Planets are born in disks like this one.

Red dwarfs, which are smaller and fainter than our Sun, are the most abundant and longest-lived stars in the galaxy.

Fast-moving blobs of material appear to be ejecting particles from the AU Mic disk. If the disk continues to dissipate at this rapid pace, it will be gone in about 1.5 million years. In that short time, icy material from comets and asteroids could be cleared out of the disk. Comets and asteroids are important because they are believed to have seeded rocky planets such as Earth with water and organic compounds, the chemical building blocks for life. If this same transport system is needed for planets in the AU Mic system, then they may end up “dry” and dusty — inhospitable for life as we know it.

“The Earth, we know, formed ‘dry,’ with a hot, molten surface, and accreted atmospheric water and other volatiles for hundreds of millions of years, being enriched by icy material from comets and asteroids transported from the outer solar system,” said co-investigator Glenn Schneider of Steward Observatory in Tucson, Arizona.

The observations are led by John Wisniewski of the University of Oklahoma in Norman, whose team is composed of 14 astronomers from the U.S. and Europe.

If the activity around AU Mic is typical of the planet-birthing process among red dwarfs, it could further reduce prospects of habitable worlds across our galaxy. Previous observations suggest that a torrent of ultraviolet light from young red dwarf stars quickly strips away the atmosphere of any orbiting planets. This particular star is only 23 million years old.

Surveys have shown that terrestrial planets are common around red dwarfs. In fact, they should contain the bulk of our galaxy’s planet population, which could number tens of billions of worlds. Planets have been found within the habitable zone of several nearby red dwarfs, but their physical characteristics are largely unknown.

Blown Out by Blobs

Observations by Hubble’s Space Telescope Imaging Spectrograph (STIS) and the VLT show that the AU Mic circumstellar disk is being excavated by fast-moving blobs of circumstellar material, which are acting like a snowplow by pushing small particles — possibly containing water and other volatiles — out of the system. Researchers don’t yet know how the blobs were launched. One theory is that powerful mass ejections from the turbulent star expelled them. Such energetic activity is common among young red dwarfs.

“These observations suggest that water-bearing planets might be rare around red dwarfs because all the smaller bodies transporting water and organics are blown out as the disk is excavated,” explained Carol Grady of Eureka Scientific in Oakland, California, co-investigator on the Hubble observations.

Conventional theory holds that billions of years ago Earth formed as a comparatively dry planet. Gravitationally perturbed asteroids and comets, rich in water from the cooler outer solar system, bombarded Earth and seeded the surface with ice and organic compounds. “However, this process may not work in all planetary systems,” Grady said.

The team determined the disk’s lifespan by using an estimated mass of the disk from an independent study, as well as calculating the mass of the escaping blobs in their STIS visible-light data. The mass of each blob is about four ten-millionths the mass of Earth. The disk’s mass — about 1.7 times more massive than Earth — is based on data taken by the Atacama Large Millimeter/submillimeter Array (ALMA).

Although the mass of the wayward blobs seems tiny, the diameter of each blob could stretch at least from the Sun to Jupiter. At present, the team has spotted six outbound blobs, but it is possible that there is a continuous stream of them. Groups of blobs careening through the disk could sweep out material fairly quickly.

“The fast dissipation of the disk is not something I would have expected,” Grady said. “Based on the observations of disks around more luminous stars, we had expected disks around fainter red dwarf stars to have a longer time span. In this system, the disk will be gone before the star is 25 million years old.” She added that AU Mic likely started out with an outer rim of small icy bodies, like the Kuiper belt found within our own solar system. If the disk weren’t being eroded, it would have provided ices to any dry inner planets.

Probing the Blob Mystery

Hubble astronomers spotted the blobs in STIS visible-light images taken in 2010-2011. As a follow-up to the Hubble study, the SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument mounted on the European Southern Observatory’s Very Large Telescope in Chile, made near-infrared observations. Features in the disk were hinted at in observations taken in 2004 by ground-based telescopes and Hubble’s Advanced Camera for Surveys.

So far, the team has uncovered blobs on the disk’s southeast side, with estimated ejection speeds between 9,000 miles per hour and 27,000 miles per hour, fast enough to escape the star’s gravitational clutches. They currently range in distance from roughly 930 million miles to more than 5.5 billion miles from the star.

Hubble is also showing that these blobs may not just be giant balls of dusty debris. The telescope has resolved substructure in one of the blobs, including a mushroom-shaped cap above the plane of the disk itself and a complex “loop-like” structure below the disk. “These structures could yield clues to the mechanisms that drive these blobs,” Schneider said.

The system resides 32 light-years away in the southern constellation Microscopium.

“AU Mic is ideally placed,” Schneider said. “But it is only one of about three or four red-dwarf systems with known starlight-scattering disks of circumstellar debris. The other known systems are typically about six times farther away, so it’s challenging to conduct a detailed study of the types of features in those disks that we see in AU Mic.”

However, astronomers are beginning to identify some possibly similar activity in these other systems. “It shows that AU Mic is not unique,” Grady said. “In fact, you could argue that because it is one of the nearest systems of this type, it would be unlikely that it would be unique.”

The AU Mic observations show the importance of a star’s disk environment on planet formation and evolution. “What we have learned is that disks seem to be a normal part of the history of planetary systems,” Grady said. “If you don’t understand a star’s disk, you don’t have a good understanding of the resulting planetary system.”

Grady will present the team’s results at a press conference Jan. 8, 2019, at the 233rd meeting of the American Astronomical Society in Seattle, Washington.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

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Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore, Maryland
410-338-4493 / 410-338-4514
dweaver@stsci.edu / villard@stsci.edu

Carol Grady
Eureka Scientific, Oakland, California

Glenn Schneider
Steward Observatory, Tucson, Arizona

John Wisniewski
University of Oklahoma, Norman, Oklahoma

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Roman Aqueduct Rehabilitation Project at Jordan’s Gadara-Umm Qais completed

The U.S. Embassy in Amman is pleased to announce the completion of a project funded by the U.S. Ambassadors Fund for Cultural Preservation (AFCP) that has conserved and rehabilitated the Roman Aqueduct of Gadara in Umm Qais.

Roman Aqueduct Rehabilitation Project at Jordan's Gadara-Umm Qais completed
The project, which began in 2015, to better preserve the Roman Aqueduct of Gadara in Umm Qais concluded
with a ceremony on Tuesday. It is expected to boost tourism to the Umm Qais archaeological site seen
in this undated photo [Credit: Jordan Tourism Board]

“Through our partnership with the Faculty of Archaeology and Anthropology of Yarmouk University on this $160,000 grant, this important historical site is better preserved for the people of Jordan and for the many visitors and tourists who will come to marvel at the ingenuity of ancient builders”, said an embassy spokeman.

Today, Yarmouk University, in collaboration with the U.S. Embassy, held a ceremony, to officially open the tunnel to the Jordanian public and tourists.

The Roman Aqueduct in Umm Qais is the largest Roman water system in the world, covering 170 km from Jordan to Syria — a distance more than nine times the length of the second longest subterranean aqueduct in Italy.

Work under this AFCP grant took place from 2015-2018 and enabled the Department of Conservation and Management of Cultural Resources at Yarmouk University to prepare the aqueduct to welcome tourists and increase overall interest in the site as a tourist attraction in the North of Jordan.

The U.S. Ambassadors Fund for Cultural Preservation supports the preservation of cultural sites, objects, and forms of traditional cultural expression around the world.

Since 2001, Jordan has received over $2 million in grants to fund 18 unique cultural heritage preservation projects in places like Petra, al-Beidha, Umm al-Jimaal, Abila, the Jordan Valley and in downtown Amman.

“The United States is proud to stand as a partner in preserving and protecting Jordan’s heritage sites,” said U.S. Chargé d’Affaires Jim Barnhart. “Tourism remains one of the foundations of Jordan’s economy and the United States is committed to supporting its continued growth.”

Source: US Embassy in Jordan [December 27, 2018]



99 ancient tombs found in Inner Mongolia

A cluster of 99 ancient tombs, more than 2,000 years old, has been found in north China’s Inner Mongolia Autonomous Region, according to local authorities.

99 ancient tombs found in Inner Mongolia
File photo taken in 2010 shows a burial site near Hulun Buir city, Inner Mongolia
Autonomous Region, China [Credit: VCG]

An archaeological team from the regional institute of cultural relics and archaeology discovered a complex of tombs in Jungar Banner, including 99 tombs and a sacrificial pit dating between the late Warring States Period (475-221 B.C.) and the early Western Han Dynasty (202 B.C.-8 A.D.).
Most of the tomb owners were found without coffins in tombs that vary in size. The biggest one measured about five meters in length, three meters in width and three meters in height, and the smallest one was barely larger than a human body.

Animal offerings, including skeletons of goats, cattle, and dogs, were found in nearly one-third of the tombs.

99 ancient tombs found in Inner Mongolia
A section of the Northern Zhao Wall in Inner Mongolia Autonomous Region, China,
December 21, 2018 [Credit: VCG]

Animal sacrifice was a familiar burial ritual among residents living along the Great Wall during the Warring States Period, according to archaeologists. The Great Wall wound through part of northern China at that time.
Cooking utensils, dating back to the late Warring States Period, such as ceramic kettles, were unearthed, as well as 10 bronze government seals from the Western Han Dynasty.

“This shows the area of the tombs was under the control of the central government during the early Western Han Dynasty,” said Hu Chunbai, head of the archaeological team.

Source: CGTN [December 28, 2018]



NASA’s TESS Rounds Up its First Planets, Snares Far-flung Supernovae

NASA – TESS Mission logo.

January 8, 2019

Image above: NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets in the data from the space telescope’s four cameras. Image Credits: NASA/MIT/TESS.

NASA’s Transiting Exoplanet Survey Satellite (TESS) has found three confirmed exoplanets, or worlds beyond our solar system, in its first three months of observations.

The mission’s sensitive cameras also captured 100 short-lived changes — most of them likely stellar outbursts — in the same region of the sky. They include six supernova explosions whose brightening light was recorded by TESS even before the outbursts were discovered by ground-based telescopes.

The new discoveries show that TESS is delivering on its goal of discovering planets around nearby bright stars. Using ground-based telescopes, astronomers are now conducting follow-up observations on more than 280 TESS exoplanet candidates.

TESS First Planet Locations

Video above: Zoom into the first sky sector observed by NASA’s Transiting Exoplanet Survey Satellite (TESS) and learn more about the new worlds it has discovered. Image Credits: NASA/MIT/TESS.

The first confirmed discovery is a world called Pi Mensae c about twice Earth’s size. Every six days, the new planet orbits the star Pi Mensae, located about 60 light-years away and visible to the unaided eye in the southern constellation Mensa. The bright star Pi Mensae is similar to the Sun in mass and size.

“This star was already known to host a planet, called Pi Mensae b, which is about 10 times the mass of Jupiter and follows a long and very eccentric orbit,” said Chelsea Huang, a Juan Carlos Torres Fellow at the Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research (MKI) in Cambridge. “In contrast, the new planet, called Pi Mensae c, has a circular orbit close to the star, and these orbital differences will prove key to understanding how this unusual system formed.”

Animation above: An artist’s visualization of the exoplanet Pi Mensae c

Next is LHS 3884b, a rocky planet about 1.3 times Earth’s size located about 49 light-years away in the constellation Indus, making it among the closest transiting exoplanets known. The star is a cool M-type dwarf star about one-fifth the size of our Sun. Completing an orbit every 11 hours, the planet lies so close to its star that some of its rocky surface on the daytime side may form pools of molten lava.

The third — and possibly fourth — planets orbit HD 21749, a K-type star about 80 percent the Sun’s mass and located 53 light-years away in the southern constellation Reticulum.

The confirmed planet, HD 21749b, is about three times Earth’s size and 23 times its mass, orbits every 36 days, and has a surface temperature around 300 degrees Fahrenheit (150 degrees Celsius). “This planet has a greater density than Neptune, but it isn’t rocky. It could be a water planet or have some other type of substantial atmosphere,” explained Diana Dragomir, a Hubble Fellow at MKI and lead author of a paper describing the find. It is the longest-period transiting planet within 100 light-years of the solar system, and it has the coolest surface temperature of a transiting exoplanet around a star brighter than 10th magnitude, or about 25 times fainter than the limit of unaided human vision.

Animation above: An artist’s visualization of the exoplanet LHS 3884b

What’s even more exciting are hints the system holds a second candidate planet about the size of Earth that orbits the star every eight days. If confirmed, it could be the smallest TESS planet to date.

TESS’s four cameras, designed and built by MKI and MIT’s Lincoln Laboratory in Lexington, Massachusetts, spend nearly a month monitoring each observing sector, a single swath of the sky measuring 24 by 96 degrees. The primary aim is to look for exoplanet transits, which occur when a planet passes in front of its host star as viewed from TESS’s perspective. This causes a regular dip in the measured brightness of the star that signals a planet’s presence.

In its primary two-year mission, TESS will observe nearly the whole sky, providing a rich catalog of worlds around nearby stars. Their proximity to Earth will enable detailed characterization of the planets through follow-up observations from space- and ground-based telescopes.

But in its month-long stare into each sector, TESS records many additional phenomena, including comets, asteroids, flare stars, eclipsing binaries, white dwarf stars and supernovae, resulting in an astronomical treasure trove.

TESS Supernovae Locations

Video above: NASA’s Transiting Exoplanet Survey Satellite (TESS) recorded more than 100 short-lived changes – most of them likely stellar outbursts of various types – in its first observing sector. Six of these events, highlighted in this movie, are supernovae – exploding stars – located in distant galaxies. Image Credits: NASA/MIT/TESS.

In the first TESS sector alone, observed between July 25 and Aug. 22, 2018, the mission caught dozens of short-lived, or transient, events, including images of six supernovae in distant galaxies that were later seen by ground-based telescopes.

“Some of the most interesting science occurs in the early days of a supernova, which has been very difficult to observe before TESS,” said Michael Fausnaugh, a TESS researcher at MKI. “NASA’s Kepler space telescope caught six of these events as they brightened during its first four years of operations. TESS found as many in its first month.”

These early observations hold the key to understanding a class of supernovae that serve as an important yardstick for cosmological studies. Type Ia supernovae form through two channels. One involves the merger of two orbiting white dwarfs, compact remnants of stars like the Sun. The other occurs in systems where a white dwarf draws gas from a normal star, gradually gaining mass until it becomes unstable and explodes. Astronomers don’t know which scenario is more common, but TESS could detect modifications to the early light of the explosion caused by the presence of a stellar companion.

All science data from the first two TESS observation sectors were recently released to the scientific community through the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute in Baltimore.

More than a million TESS images were downloaded from MAST in the first few days,” said Thomas Barclay, a TESS researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, Baltimore County. “The astronomical community’s reaction to the early data release showed us that the world is ready to jump in and add to the mission’s scientific bounty.

Image above: An artist’s conception of the Transiting Exoplanet Survey Satellite, or TESS, an Earth-orbiting satellite that will help scientists search for planets outside our solar system. Image Credits: NASA/GSFC.

George Ricker, the mission’s principal investigator at MKI, said that TESS’s cameras and spacecraft were performing superbly. “We’re only halfway through TESS’s first year of operations, and the data floodgates are just beginning to open,” he said. “When the full set of observations of more than 300 million stars and galaxies collected in the two-year prime mission are scrutinized by astronomers worldwide, TESS may well have discovered as many as 10,000 planets, in addition to hundreds of supernovae and other explosive stellar and extragalactic transients.”

TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA’s Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT’s Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.

Related links:

Massachusetts Institute of Technology’s (MIT) Kavli Institute for Astrophysics and Space Research (MKI): http://space.mit.edu/

Diana Dragomir, a Hubble Fellow at MKI paper: https://arxiv.org/abs/1901.00051

Mikulski Archive for Space Telescopes (MAST): http://archive.stsci.edu/tess/

TESS Guest Investigator Program: https://heasarc.gsfc.nasa.gov/docs/tess/proposing-investigations.html

TESS (Transiting Exoplanet Survey Satellite): http://www.nasa.gov/tess

Image (mentioned), Animations (mentioned), Videos (mentioned), Text, Credits: NASA/Elizabeth Landau.

Greetings, Orbiter.chArchive link

Crew Wraps Up Science Packing After Robotic Arm Grips Dragon

ISS – Epedition 58 Mission patch.

January 8, 2019

The SpaceX Dragon space freighter is in the grips of the Canadarm2 robotic arm today as the Expedition 58 crew wraps up cargo transfers inside the vessel. The space trio is also on lab duty conducting a variety of microgravity research aboard the International Space Station.

Image above: When the SpaceX Dragon cargo craft returns to Earth it will splash down in the Pacific Ocean a few hundred miles off the coast of southern California and Baja California. Image Credit: NASA.

Overnight, robotics controllers remotely commanded the Canadarm2 to grapple Dragon before its release from the Harmony module. Meanwhile, the hatches are still open and Flight Engineers Anne McClain and David Saint-Jacques continue loading time-critical space experiments inside the U.S. cargo craft.

The crew will shut the hatch to Dragon Wednesday and disconnect power cables. Then robotics controllers will take over, uninstall Dragon from Harmony overnight and maneuver it into release position. McClain will be in the cupola Thursday monitoring Dragon when it is released from the Canadarm2 around 4:35 a.m. EDT.

Image above: Flying over Pacific Equator, seen by EarthCam on ISS, speed: 27’607 Km/h, altitude: 406,17 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam’s from ISS on January 8, 2019 at 20:03 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

After its departure, Dragon will orbit Earth a few more hours before splashing down in the Pacific Ocean off the coast of southern California. SpaceX personnel will retrieve Dragon and return it to port where NASA engineers will extract the precious cargo for immediate shipment to investigators around the country.

Related links:

Expedition 58: https://www.nasa.gov/mission_pages/station/expeditions/expedition58/index.html

SpaceX Dragon: https://www.nasa.gov/mission_pages/station/structure/launch/spacex.html

Canadarm2 robotic arm: https://www.nasa.gov/mission_pages/station/structure/elements/mobile-servicing-system.html

Harmony module: https://www.nasa.gov/mission_pages/station/structure/elements/harmony

Space experiments: https://www.nasa.gov/mission_pages/station/research/index.html

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/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.chArchive link

Tre’r Ceiri Iron Age Hillfort at late dawn, North Wales, 4.1.19.

Tre’r Ceiri Iron Age Hillfort at late dawn, North Wales, 4.1.19.

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Princeton University sued over ‘stolen’ Byzantine-era manuscripts

Ecumenical Patriarch Vartholomaios has filed a lawsuit against Princeton University, New Jersey, demanding the return of four Byzantine-era manuscripts allegedly stolen from a monastery in Greece’s Macedonia region during World War I.

Princeton University sued over ‘stolen’ Byzantine-era manuscripts
Credit: Kathimerini

The lawsuit, filed December 13, alleges that Bulgarian guerrillas stormed the Theotokos Eikosiphoinissa Monastery in 1917, assaulted the monks and made off with the manuscripts, gold florins and other precious items which they loaded onto 24 mules. The looted treasures were subsequently disseminated to dealers and auction houses across Central Europe.
Princeton bought one of the manuscripts from the Frankfurt-based auction house Joseph Baer & Co four years after the raid, in 1921. A trustee and alumnus purchased the remaining three manuscripts from the same auction house three years later, before donating them to the college in 1942.

Princeton officials have said they have no evidence that the manuscripts, currently housed at the college library, were stolen.

Author: Yiannis Papadopoulos | Source: Kathimerini [December 29, 2018]



Dark matter on the move

Scientists have found evidence that dark matter can be heated up and moved around, as a result of star formation in galaxies. The findings provide the first observational evidence for the effect known as ‘dark matter heating’, and give new clues as to what makes up dark matter. The research is published in the journal Monthly Notices of the Royal Astronomical Society.

Dark matter on the move
Star formation in tiny dwarf galaxies can slowly “heat up” the dark matter, pushing it outwards. The left image shows the
hydrogen gas density of a simulated dwarf galaxy, viewed from above. The right image shows the same for a real dwarf
galaxy, IC 1613. In the simulation, repeated gas inflow and outflow causes the gravitational field strength at the centre
of the dwarf to fluctuate. The dark matter responds to this by migrating out from the centre of the galaxy,
an effect known as ‘dark matter heating’ [Credit: J. Read et al. 2018]

In the new work, scientists from the University of Surrey, Carnegie Mellon University and ETH Zürich set out to hunt for evidence for dark matter at the centres of nearby dwarf galaxies. Dwarf galaxies are small, faint galaxies that are typically found orbiting larger galaxies like our own Milky Way. They may hold clues that could help us to better understand the nature of dark matter.

Dark matter is thought to make up most of the mass of the universe. However since it doesn’t interact with light in the same way as normal matter, it can only be observed through its gravitational effects. The key to studying it may however lie in how stars are formed in these galaxies.

When stars form, strong winds can push gas and dust away from the heart of the galaxy. As a result, the galaxy’s centre has less mass, which affects how much gravity is felt by the remaining dark matter. With less gravitational attraction, the dark matter gains energy and migrates away from the centre, an effect called ‘dark matter heating’.

The team of astrophysicists measured the amount of dark matter at the centres of 16 dwarf galaxies with very different star formation histories. They found that galaxies that stopped forming stars long ago had higher dark matter densities at their centres than those that are still forming stars today. This supports the theory that the older galaxies had less dark matter heating.

Professor Justin Read, lead author of the study and Head of the Department of Physics at the University of Surrey, said: “We found a truly remarkable relationship between the amount of dark matter at the centres of these tiny dwarfs, and the amount of star formation they have experienced over their lives. The dark matter at the centres of the star-forming dwarfs appears to have been ‘heated up’ and pushed out.”

The findings provide a new constraint on dark matter models: dark matter must be able to form dwarf galaxies that exhibit a range of central densities, and those densities must relate to the amount of star formation.

Professor Matthew Walker, a co-author from Carnegie Mellon University, added: “This study may be the “smoking gun” evidence that takes us a step closer to understanding what dark matter is. Our finding that it can be heated up and moved around helps to motivate searches for a dark matter particle.”

The team hope to expand on this work by measuring the central dark matter density in a larger sample of dwarfs, pushing to even fainter galaxies, and testing a wider range of dark matter models.

Source: University of Surrey [January 03, 2019]



Melting ice sheets release tons of methane into the atmosphere

The Greenland Ice Sheet emits tons of methane according to a new study, showing that subglacial biological activity impacts the atmosphere far more than previously thought.

Melting ice sheets release tons of methane into the atmosphere
This is Guillaume Lamarche-Gagnon deploying the methane sensor that was used in the study
 into the proglacial river that drains the Greenland Glacier [Credit: Marie Bulinova]

An international team of researchers led by the University of Bristol camped for three months next to the Greenland Ice Sheet, sampling the meltwater that runs off a large catchment (> 600 km2) of the Ice Sheet during the summer months.

As reported in Nature, using novel sensors to measure methane in meltwater runoff in real time, they observed that methane was continuously exported from beneath the ice.

They calculated that at least six tons of methane was transported to their measuring site from this portion of the Ice Sheet alone, roughly the equivalent of the methane released by up to 100 cows.

Professor Jemma Wadham, Director of Bristol’s Cabot Institute for the Environment, who led the investigation, said: “A key finding is that much of the methane produced beneath the ice likely escapes the Greenland Ice Sheet in large, fast flowing rivers before it can be oxidized to CO2, a typical fate for methane gas which normally reduces its greenhouse warming potency.”

Methane gas (CH4) is the third most important greenhouse gas in the atmosphere after water vapour and carbon dioxide (CO2). Although, present in lower concentrations that CO2, methane is approximately 20-28 times more potent. Therefore smaller quantities have the potential to cause disproportionate impacts on atmospheric temperatures. Most of the Earth’s methane is produced by microorganisms that convert organic matter to CH4 in the absence of oxygen, mostly in wetlands and on agricultural land, for instance in the stomachs of cows and rice paddies. The remainder comes from fossil fuels like natural gas.

Melting ice sheets release tons of methane into the atmosphere
This photo shows a rhodamine dye injection into the proglacial river, just before a waterfall.
The pink dye (the rhodamine) is used to calculate the water discharge of the proglacial river
 (i.e. how much water/melt if flowing in the river at that time) [Credit: Jakub D Zarsky]

While some methane had been detected previously in Greenland ice cores and in an Antarctic Subglacial Lake, this is the first time that meltwaters produced in spring and summer in large ice sheet catchments have been reported to continuously flush out methane from the ice sheet bed to the atmosphere.

Lead author, Guillaume Lamarche-Gagnon, from Bristol’s School of Geographical Sciences, said: “What is also striking is the fact that we’ve found unequivocal evidence of a widespread subglacial microbial system. Whilst we knew that methane-producing microbes likely were important in subglacial environments, how important and widespread they truly were was debatable. Now we clearly see that active microorganisms, living under kilometres of ice, are not only surviving, but likely impacting other parts of the Earth system. This subglacial methane is essentially a biomarker for life in these isolated habitats.”

Most studies on Arctic methane sources focus on permafrost, because these frozen soils tend to hold large reserves of organic carbon that could be converted to methane when they thaw due to climate warming. This latest study shows that ice sheet beds, which hold large reserves of carbon, liquid water, microorganisms and very little oxygen — the ideal conditions for creating methane gas — are also atmospheric methane sources.

Co-researcher Dr Elizabeth Bagshaw from Cardiff University added: “The new sensor technologies that we used give us a window into this previously unseen part of the glacial environment. Continuous measurement of meltwater enables us to improve our understanding of how these fascinating systems work and how they impact the rest of the planet.”

With Antarctica holding the largest ice mass on the planet, researchers say their findings make a case for turning the spotlight to the south. Mr Lamarche-Gagnon added: “Several orders of magnitude more methane has been hypothesized to be capped beneath the Antarctic Ice Sheet than beneath Arctic ice-masses. Like we did in Greenland, it’s time to put more robust numbers on the theory.”

Source: University of Bristol [January 03, 2019]



Protecting proboscis monkeys from deforestation

A 10-year study of proboscis monkeys in Borneo has revealed that forest conversion to oil palm plantations is having a significant impact on the species.

Protecting proboscis monkeys from deforestation
Credit: Cardiff University

Nearly half of all primate species are threatened with extinction, with habitat destruction acting as the key driving force. New research studied proboscis monkeys from 2004 to 2014, finding that the protection of swamp forests is vital for their survival.

The study led by Cardiff University, Chubu University, Hokaido University, Sun Yat-sen University, Living Landscape Alliance, the NGO HUTAN, Sabah Wildlife Department and Danau Girang Field Centre, tracked changes in population sizes over a decade, revealing significantly reduced sizes of proboscis monkey groups.

Dr. Benoit Goossens, Director of Danau Girang Field Centre and Reader at Cardiff University School of Biosciences, said: “We compared population sizes from 2004 and 2014, and it revealed subtle changes, where population densities fluctuated but had neither increased nor decreased. But importantly, we discovered that the sizes of the groups were significantly reduced.

Mr Augustine Tuuga, Director of Sabah Wildlife Department, said: “Proboscis monkeys are endemic to the island of Borneo. They are classified as endangered and are also a Totally Protected species in Sabah. Despite these levels of protection, lowland swamp forest habitats that are important for this species are still decreasing, mainly through forest conversion to oil palm plantations.

“Our analysis of the habitat changes showed that within protected reserves, there was relatively little forest loss in the potential range of the proboscis monkey, which mainly lies 800m from riverbanks.”

“This suggests that the protection of swamp forests can contribute immensely to the sustainability of proboscis monkeys within these important habitats. However, larger losses of interior forests meant that habitats had generally become more degraded and fragmented, and this could have contributed to reduced group sizes and limited population growth,” added Dr. Marc Ancrenaz, Scientific Director at the NGO HUTAN.

Dr. Benoit Goossens concluded: “Although the protection of forests within the proboscis monkeys’ range had proved effective, this was not the case in unprotected forests, where 12 percent of the forest was lost and could eventually lead to 23 percent of the population being threatened.

“At least a third of these forests has been allocated for oil palm cultivation. Further efforts must be undertaken to more effectively conserve high value habitats and to restore swamp forest areas – this is vital for ensuring the survival of this endangered species.”

Source: Cardiff University [January 03, 2019]




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