воскресенье, 10 ноября 2019 г.

5000 "eyes" to follow the expanding universe







École Polytechnique Fédérale de Lausanne logo.

November 2, 2019

Involving researchers from EPFL, a project to unravel the nature of dark energy is entering its final phase of testing.


Image above: The Dark Energy Spectroscopic Instrument (DESI) is a project led by the United States to measure the accelerated expansion of the Universe to discover the nature of dark energy. This project, to which EPFL astrophysicists have contributed significantly, is entering its last phase of testing to map the sky.

The Dark Energy Spectroscopic Instrument (DESI) is a project led by the United States to discover the nature of dark energy. This project, to which EPFL astrophysicists have contributed, is entering its last phase of testing. The first results are expected in 2021.

Dozens of millions of galaxies

The DESI was developed to examine the nature of dark energy by measuring in detail the accelerated expansion of the Universe, said Wednesday the Swiss Federal Institute of Technology Lausanne (EPFL) in a statement. Dark energy is a mysterious element that constitutes about 68% of the mass-energy of the current Universe.

DESI has announced its "first light", entering its final testing and commissioning phase on the Mayall telescope at the Kitt Peak Observatory. This means that the instrument will be ready to begin its scientific observations in early 2020. The first major publication of data is expected by 2021.

Over the next four years, optical spectra of tens of millions of galaxies and quasars will be collected to create a 3D map covering the Near Universe up to 11 billion light-years.

To do this, DESI will use 5000 "eyes" of optical fiber to capture the light of 5000 different objects, mainly galaxies, but also quasars and some stars that will be used mainly to calibrate the instrument.

Distance to the Earth

DESI is designed to automatically point a predetermined series of galaxies, collect their light, and then, thanks to ten spectrographs, separate this light into narrow color bands to represent on a map their distance from the Earth. Scientists will be able to calculate the expansion of the Universe according to the light of the galaxies that has reached our planet.

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Researchers use drones reveal secrets of ancient Florida village


Using drone technology, a team of UF researchers has uncovered how an ancient Florida village played a pivotal role in pre-Columbian geopolitics.

Researchers use drones reveal secrets of ancient Florida village
A drone equipped with Light Detection and Ranging quickly collected architectural details and topographic data
about he Raleigh Island settlement with unprecedented resolution. The images revealed rings made
of oyster shells surrounding 37 residences [Credit: University of Florida]
In research led by anthropology Ph.D. student Terry Barbour, the team discovered that the settlement on Raleigh Island, located on the northern Gulf coast of Florida around 900–1200 AD, operated as a major producer of beads made from seashells. The beads, used in rituals at the time, were highly prized in communities as far from the coast as the lower Midwest.

"In form, scale and purpose, the Raleigh Island settlement has no parallel in the archaeological record of the American Southeast," said Ken Sassaman, Barbour's advisor and the co-creator of the study. Sassaman is the Hyatt and Cici Brown Professor of Florida Archaeology in the Department of Anthropology.


The researchers used drones to survey the ancient settlement in a fraction of the time traditional methods would have taken. Working with UF partners at the GatorEye Unmanned Flying Laboratory, the team equipped the drone with Light Detection and Ranging (LiDAR) scanners that quickly collected architectural details and topographic data with unprecedented resolution.

The LiDAR shed light on how the settlement—a complex of at least 37 residential spaces surrounded by 4-meter-tall ridges of oyster shells—was organized to make beads in the very place where shells were found. In several of the living spaces, the researchers' excavations uncovered ample evidence of large-scale bead production.


The Raleigh Island settlement is one of the few coastal communities where such extensive craft production has been found.

"What we have here is a settlement at the source of this raw material at the time when marine shell was starting to become a heavily demanded social item," Barbour said. "The fact we have strong evidence of bead manufacture at a site with equally impressive architecture to guide us in understanding how production was organized socially makes this place really special, and as of now the only place like it we are aware of."

The findings have been published in Proceedings of the National Academy of Sciences.

Source: University of Florida [November 06, 2019]



* This article was originally published here

Not all galaxies are lonely. Some have galaxy squads. ⁣NGC 1706,...



Not all galaxies are lonely. Some have galaxy squads. ⁣

NGC 1706, captured in this image by our Hubble Space Telescope, belongs to something known as a galaxy group, which is just as the name suggests — a group of up to 50 galaxies which are gravitationally bound and relatively close to each other. ⁣

Our home galaxy, the Milky Way, has its own squad — known as the Local Group, which also contains the Andromeda galaxy, the Large and Small Magellanic clouds and the Triangulum galaxy.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.



* This article was originally published here

2019 November 10 A Mercury Transit Sequence Image Credit &...



2019 November 10

A Mercury Transit Sequence
Image Credit & Copyright: Dominique Dierick

Explanation: Tomorrow – Monday – Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2016. Because the plane of Mercury’s orbit is not exactly coincident with the plane of Earth’s orbit, Mercury usually appears to pass over or under the Sun. The featured time-lapse sequence, superimposed on a single frame, was taken from a balcony in Belgium shows the entire transit of 2003 May 7. That solar crossing lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart. The north pole of the Sun, the Earth’s orbit, and Mercury’s orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspots are visible. After Monday, the next transit of Mercury will occur in 2032.

∞ Source: apod.nasa.gov/apod/ap191110.html

U.S. Cygnus Cargo Ship Reaches Orbit for Monday Delivery













Northrop Grumman - Antares - NG-12 / S.S. Alan Bean Cygnus Mission patch.

November 2, 2019

On the anniversary of the arrival of the first crew members to live aboard the International Space Station, Northrop Grumman’s Cygnus resupply spacecraft is on its way to the station with nearly 8,200 pounds of science investigations and cargo after launching at 9:59 a.m. EDT Saturday, Nov. 2 from NASA’s Wallops Flight Facility in Virginia. At the time of lift off, the International Space Station was traveling over the south Atlantic southwest of Cape Town, South Africa, at an altitude of 257 statute miles.


Image above: The Antares rocket lifts off on time from Virginia carrying the Cygnus cargo craft to orbit. Image Credit: NASA TV.

The spacecraft launched on an Antares 230+ rocket from the Virginia Mid-Atlantic Regional Spaceport’s Pad 0A at Wallops. Automated command to initiate solar array deploy will begin about 2 hours and 53 minutes after launch (about 12:53 p.m.). Solar array deployment will take about 30 minutes.

Cygnus is scheduled to arrive at the orbiting laboratory around 4:10 a.m. Monday, Nov. 4. Coverage of the spacecraft’s approach and arrival will begin at 2:45 a.m. on NASA Television and the agency’s website. Expedition 61 astronauts Jessica Meir and Christina Koch of NASA will use the space station’s robotic arm to capture Cygnus, while NASA’s Andrew Morgan monitors telemetry. The spacecraft is scheduled to stay at the space station until January.

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Revealing interior temperature of Antarctic ice sheet


As ESA's SMOS satellite celebrates 10 years in orbit, yet another result has been added to its list of successes. This remarkable satellite mission has shown that it can be used to measure how the temperature of the Antarctic ice sheet changes with depth—and it's much warmer deep down.

Revealing interior temperature of Antarctic ice sheet
ESA’s SMOS mission has been used to show how the temperature of the Antarctic ice sheet changes with depth. The image
shows how the ice is colder (blue) at the surface but warmer (red) at the base. Temperature is one of the things that
determines how ice flows and slides over the bedrock beneath. In turn, this flow affects the temperature profile through
strain heating – so it’s a complicated process. Temperature information is also fundamental for understanding the
presence of aquifers inside or at the bottom part of ice sheets. This can be relevant for indicating the presence
of sub-glacial lakes, for example, which in turn influence ice-sheet dynamics
[Credit: European Space Agency]
The Antarctic ice sheet is, on average, about two kilometers thick, but in some places the bedrock is almost five kilometers below the surface of this huge polar ice cap.

Most of us would probably think that the temperature of ice, no matter how thick, remains pretty much the same throughout: basically very cold

However, although the surface of the ice sheet is cold, the temperature increases with depth primarily because of the basal geothermal heating from beneath Earth's crust. In places, it is warm enough to melt the ice, which accounts for the presence of lakes and a vast hydrological network at the bedrock.

Nevertheless, there is little accurate information on exactly how temperature varies with depth other than from ice core borehole locations.


Since the massive white ice sheets that blanket Antarctica and Greenland reflect incident solar radiation back out into space, they are extremely important regulators in the climate system and, therefore, play a key role in the health of our planet.

But, ice sheets are also victims of climate change. For example, this year scientists discovered that warming ocean waters have caused the ice to thin so rapidly that a quarter of the glacier ice in West Antarctica is now unstable.

With melting ice sheets largely responsible for rising sea levels, which, in turn, threaten hundreds of millions of people around the world, it is vital that more is understood about how temperature influences ice-sheet dynamics.

Satellite data are used, in particular, to measure changes in the height of ice sheets and consequently their "mass balance," where the ice sheet ends and the floating ice shelves begin—their grounding lines, their surface temperature and how fast ice streams flow.

Revealing interior temperature of Antarctic ice sheet
Temperature is one of the things that determines ice viscosity and therefore how ice sheets flow and slide
over the bedrock beneath. In turn, this flow affects the ice-sheet temperature profile through strain
heating – so it’s a complicated process. Information on temperature is also fundamental for understanding
the presence of aquifers inside or at the bottom of ice sheets. This can be relevant for indicating the presence
 of sub-glacial lakes, for example, which in turn influence ice-sheet dynamics. ESA’s SMOS satellite
 mission has shown that it can be used to measure how the temperature of the Antarctic ice sheet
changes with depth [Credit: IFAC]
However, temperature is one of the things that determines ice viscosity and how ice flows and slides over the bedrock beneath. In turn, ice flow affects the temperature profile through strain heating—so it's a complicated process.

Temperature information is also fundamental for understanding the presence of aquifers inside or at the bottom part of ice sheets. This can be relevant for indicating the presence of sub-glacial lakes, for example, which, in turn, influence ice-sheet dynamics.

How temperature varies according to the depth of the ice is not something that could be measured from space until now—but according to a paper published recently in Remote Sensing of Environment, SMOS is opening up new opportunities to do so.

Giovanni Macelloni from the Institute of Applied Physics Nello Carrara of the National Research Council (IFAC-CNR) in Italy, said, "We typically get ice-sheet temperature profiles from models, or from in situ measurements taken in boreholes—but these are obviously fairly sparse."


Information on temperature from space has, so far, been limited to the surface or just below the surface from thermal-infrared sensors and microwave sensors.

The researchers from IFAC-CNR and the Institute of Environmental Geosciences in France, therefore used ESA's SMOS satellite to see if there is a way of gaining this information rather than relying on models and boreholes.

"We combined SMOS' L-band passive microwave observations over Antarctica with glaciological and emission models to infer information on glaciological properties of the ice sheet at various depths, including temperature," continued Dr. Macelloni.

"With temperature playing such an important role in ice-sheet dynamics, we are happy to say that our research, when compared with models, shows a better estimation of temperature increase with depth, with the largest differences close to the bedrock.

"SMOS is clearly opening up more possibilities that we ever thought when it was launched 10 years ago."

Source: European Space Agency [November 05, 2019]



* This article was originally published here

Watch Mercury Transit the Sun on Nov. 11On Nov. 11, Earthlings will be treated to a rare cosmic...

Watch Mercury Transit the Sun on Nov. 11

On Nov. 11, Earthlings will be treated to a rare cosmic event — a Mercury transit.

image

For about five and a half hours on Monday, Nov. 11 — from about 7:35 a.m. EST to 1:04 p.m. EST — Mercury will be visible from Earth as a tiny black dot crawling across the face of the Sun. This is a transit and it happens when Mercury lines up just right between the Sun and Earth.

Mercury transits happen about 13 times a century. Though it takes Mercury only about 88 days to zip around the Sun, its orbit is tilted, so it’s relatively rare for the Sun, Mercury and Earth to line up perfectly. The next Mercury transit isn’t until 2032 — and in the U.S., the next opportunity to catch a Mercury transit is in 2049!

How to watch

Our Solar Dynamics Observatory satellite, or SDO, will provide near-real time views of the transit. SDO keeps a constant eye on the Sun from its position in orbit around Earth to monitor and study the Sun’s changes, putting it in the front row for many eclipses and transits.

Visit mercurytransit.gsfc.nasa.gov to tune in!

image

Our Solar Dynamics Observatory also saw Mercury transit the Sun in 2016.

If you’re thinking of watching the transit from the ground, keep in mind that it is never safe to look directly at the Sun. Even with solar viewing glasses, Mercury is too small to be easily seen with the unaided eye. Your local astronomy club may have an opportunity to see the transit using specialized, properly-filtered solar telescopes — but remember that you cannot use a regular telescope or binoculars in conjunction with solar viewing glasses.

Transits in other star systems

Transiting planets outside our solar system are a key part of how we look for exoplanets.

Our Transiting Exoplanet Survey Satellite, or TESS, is NASA’s latest planet-hunter, observing the sky for new worlds in our cosmic neighborhood. TESS searches for these exoplanets, planets orbiting other stars, by using its four cameras to scan nearly the whole sky one section at a time. It monitors the brightness of stars for periodic dips caused by planets transiting those stars.

image

This is similar to Mercury’s transit across the Sun, but light-years away in other solar systems! So far, TESS has discovered 29 confirmed exoplanets using transits — with over 1,000 more candidates being studied by scientists!

image

Discover more transit and eclipse science at nasa.gov/transit, and tune in on Monday, Nov. 11, at mercurytransit.gsfc.nasa.gov.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.



* This article was originally published here

CMS measures Higgs boson’s mass with unprecedented precision













CERN - European Organization for Nuclear Research logo.

November 2, 2019

The CMS collaboration reported the Higgs boson’s mass with a precision of about 0.1%


Image above: A candidate from CMS of a Higgs boson transforming into two photons; the two large green towers show energy deposits from the photons (Image: Thomas McCauley, CMS/CERN).

The Higgs boson is a special particle. It is the manifestation of a field that gives mass to elementary particles. But this field also gives mass to the Higgs boson itself. A precise measurement of the Higgs boson’s mass not only furthers our knowledge of physics but also sheds new light on searches planned at future colliders.

Since discovering this unique particle in 2012, the ATLAS and CMS collaborations at CERN’s Large Hadron Collider have been busy determining its properties. In the Standard Model of particle physics, the Higgs boson’s mass is closely related to the strength of the particle’s interaction with itself. Comparing precise measurements of these two properties is a crucial means of testing the predictions of the Standard Model and helps search for physics beyond the predictions of this theory. In addition to probing its “self-interaction” strength, the researchers have also paid careful attention to the exact mass of the Higgs boson.

When it was first discovered, the particle’s mass was measured to be around 125 gigaelectronvolts (GeV) but it wasn’t known with high precision. Analysis of much more data was needed before reducing the errors in such a measurement. Indeed, ATLAS and CMS have been improving this precision with their respective measurements over the years. Last year, ATLAS measured the Higgs mass to be 124.97 GeV with a precision of 0.24 GeV or 0.19%. Now, the CMS collaboration has announced the most precise measurement so far of this property: 125.35 GeV with a precision of 0.15 GeV, or 0.12%.

Large Hadron Collider (LHC). Animation Credit: CERN

Like most members of the zoo of known particles, the Higgs boson is unstable and transforms – or “decays” – nearly instantaneously into lighter particles. The mass measurement was based on two very different transformations of the Higgs boson, namely decays to four leptons via two intermediate Z bosons and decays to pairs of photons. To arrive at the mass value, the scientists combined CMS results of these two decays from two datasets: the first was recorded in 2011 and 2012 while the second came from 2016.

This measurement adds another piece to the puzzle of the exciting world of subatomic particles.

More details on the CMS website: https://cms.cern/news/cms-precisely-measures-mass-higgs-boson

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related links:

Higgs boson: https://home.cern/science/physics/higgs-boson

Standard Model: https://home.cern/science/physics/standard-model

ATLAS: https://home.cern/science/experiments/atlas

CMS: https://home.cern/science/experiments/cms

Large Hadron Collider (LHC): https://home.cern/science/accelerators/large-hadron-collider

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Image (mentioned), Animation (mentioned), Text, Credits: European Organization for Nuclear Research (CERN).

Best regards, Orbiter.ch

* This article was originally published here

Lligwy Prehistoric Burial Chamber, Anglesey, North Wales, 9.11.19.

Lligwy Prehistoric Burial Chamber, Anglesey, North Wales, 9.11.19.



* This article was originally published here

Figuring out the total human impacts on biodiversity


How much have humans affected the population of other species on the planet? A new methodology for documenting the cumulative human impacts on biodiversity aims to answer this question.

Figuring out the total human impacts on biodiversity
Gulf grouper [Credit: Alfredo Barroso, Flickr/Sea Around Us]
Dubbed EPOCH -for Evaluation of Population Change- the methodology was developed by a group of scientists from universities in Europe, Asia, and North America. It provides a standardized framework for organizing disperse data on individual species or populations of animals and plants that have been affected by urbanization, pollution, fishing, hunting, over-harvesting, and other anthropogenic activities.

Assessing impact requires contrasting the status of current populations with a reference state or baseline. However, the experts were faced with the challenge that for many species the baseline is not known because they have been impacted for a long time and those impacts have been forgotten. This phenomenon responds to the concept of 'Shifting Baseline Syndrome' developed by the Sea Around Us' principal investigator and University of British Columbia professor Daniel Pauly.


"So we decided to define baseline not as a particular date but as a reference state, that is, the population size expected today in the absence of human actions," said Ana Rodrigues, lead author of the study from the University of Montpellier. "This means that any changes in relation to this baseline reveal the cumulative extent of human impacts."

Rodrigues explained that the flexible definition allows for the baseline to be tailored to each population being studied and to be estimated from historical data, by comparing with an area where a species is still relatively intact, or by relating a less-known to a better-known species.

"For example, for Gulf grouper, we set the baseline in the 1940s, before industrial exploitation kicked off. Back then, it was considered a fish commonly present in the Gulf of California, according to historical records and interviews with old fishers. However, as time passed, data shows that it has been depleted through past overfishing and that in more recent years it is considered rare by new generations," Rodrigues said. "This is an example of a relatively recent temporal baseline but for the bowhead whales in the Barents Sea we went back 400 years, prior to industrial whaling."

Figuring out the total human impacts on biodiversity
Credit: Valentina Ruiz Leotaud
Each assessed species is classified into one of 11 EPOCH categories, based on the extent to which humans have affected their population numbers. Species can have experienced little change, their numbers may have moderately or severely increased or decreased, they may have been extirpated, or they may be newly present in a certain area.

"The advantage of going back in time and establishing these categories is that we can see the whole picture of how much more we have lost over hundreds of years," said Deng Palomares, a co-author of the study and the Sea Around Us project manager at UBC's Institute for the Oceans and Fisheries.


According to Palomares, her own experience setting an as-early-as-possible baseline, as it is done with the Sea Around Us' fisheries data, has already been useful to establish the reality of how much has been lost.

"Now, imagine going back hundreds of years, when explorers describe codfish as being so abundant in the coastal waters off Newfoundland that one could walk on their backs. With this framework, we bring the baseline nearer to a population's 'virgin biomass,' that is, the biomass that was there before humans invented powerful machines to harvest these resources and in the process destroy them."

For Rodrigues, Palomares, and their colleagues, these assessments that show the cumulative level of population change through time should help set realistic targets for the recovery of affected populations. "With the United Nations having just declared 2021-2030 the Decade of Ecosystem Restoration, ensuring future conservation efforts take into account the history of past change is more pertinent than ever," they wrote in their paper.

The paper was published in Philosophical Transactions B.

Author: Valentina Ruiz Leotaud | Source: Sea Around Us [November 05, 2019]



* This article was originally published here

2019 November 1 The Day After Mars Image Credit &...



2019 November 1

The Day After Mars
Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST)

Explanation: October 31, 1938 was the day after Martians encountered planet Earth, and everything was calm. Reports of the invasion were revealed to be part of a Halloween radio drama, the now famous broadcast based on H.G. Wells’ scifi novel War of the Worlds. On Mars October 20, 2014 was calm too, the day after its close encounter with Comet Siding Spring (C/2013 A1). Not a hoax, this comet really did come within 86,700 miles or so of Mars, about 1/3 the Earth-Moon distance. Earth’s spacecraft and rovers in Mars orbit and on the surface reported no ill effects though, and had a ringside seat as a visitor from the outer solar system passed by. Spanning over 2 degrees against stars of the constellation Ophiuchus, this colorful telescopic snapshot captures our view of Mars on the day after. Bluish star 51 Ophiuchi is at the upper right and the comet is just emerging from the Red Planet’s bright glare.

∞ Source: apod.nasa.gov/apod/ap191101.html

Solar Arrays Deployed, Cygnus Powered Up for Space Delivery













NASA / Northrop Grumman - NG/CRS-12 Cygnus patch.

November 3, 2019

The solar arrays have successfully deployed on Northrop Grumman’s Cygnus spacecraft that is on its way to deliver about 8,200 pounds of science and research, crew supplies, and hardware to the International Space Station. This is the company’s 12th contracted cargo resupply mission with NASA.

This mission, designated NG-12, will be in orbit at the same time as its predecessor, the NG-11 Cygnus spacecraft, which launched in April on an extended duration flight. The NG-12 Cygnus spacecraft will remain at the space station until January before it disposes of several thousand pounds of trash through its fiery reentry into Earth’s atmosphere. The ability to fly two vehicles at once further demonstrates the robustness of Cygnus to support the goals of NASA’s ambitious missions.


Image above: The Northrop Grumman Antares rocket, with the Cygnus resupply spacecraft onboard, launches from Pad-0A of NASA’s Wallops Flight Facility, Saturday, November 2, 2019, in Virginia. Image Credits: NASA/Bill Ingalls.

Coverage of the spacecraft’s approach and arrival to the orbiting laboratory will begin Monday, Nov. 4 at 2:45 a.m. on NASA Television and the agency’s website. Expedition 61 astronauts Jessica Meir and Christina Koch of NASA will use the space station’s robotic arm to capture Cygnus at around 4:10 a.m., while NASA’s Andrew Morgan monitors telemetry. The spacecraft is scheduled to stay at the space station until January.

Cygnus spacecraft. Image Credit: NASA

Meanwhile, JAXA (Japan Aerospace Exploration Agency) flight controllers at Tsukuba, Japan are preparing to deorbit the HTV-8 cargo vehicle tonight, with the final deorbit maneuver expected around 8:33pm Central time, 9:33pm Eastern time. HTV-8 will enter the Earth’s atmosphere and burn up harmlessly over the south Pacific.

Related links:

Cargo resupply mission: https://www.nasa.gov/sites/default/files/atoms/files/ng_crs-12_overview.pdf

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

HTV-8 cargo vehicle: https://blogs.nasa.gov/spacestation/2019/11/01/astronauts-release-japanese-spaceship-2/

Science and research: https://www.nasa.gov/mission_pages/station/research/news/ng12-research/

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

Capel Garmon Prehistoric Burial Chamber, North Wales, 9.11.19.

Capel Garmon Prehistoric Burial Chamber, North Wales, 9.11.19.



* This article was originally published here

Astronomers map new emission line to trace most common molecule in the universe


Molecular hydrogen (H2) makes up 99 percent of the cold, dense gas in galaxies. So mapping where stars are born basically means measuring H2, which lacks a strong characteristic signature at low temperatures. Astronomers from SRON Netherlands Institute for Space Research and the University of Groningen have now mapped an emission signal from the trace molecule hydrogen fluoride (HF) in a place where the standard trace molecule carbon monoxide is absent. They are the first to produce a map of HF for a region in space, creating a new tool to indirectly map H2.

Astronomers map new emission line to trace most common molecule in the universe
Orion Bar [Credit: Weilbacher et al. 2019]
In all galaxies, stars are dying and forming. And while life on Earth is based on a rich jumble of elements and molecules, the cold, dense gas out of which stars form is pretty monotonous, composed of 99 percent molecular hydrogen (H2). So mapping where stars are born requires a detecting H2.

Unfortunately, this material is hard to observe due to a lack of a strong characteristic signal at low temperatures—unlike its atomic cousin (H), which emits radio waves at an easily distinguishable wavelength of 21 cm. Astronomers from SRON Netherlands Institute for Space Research and the University of Groningen have now discovered a new tool to measure H2 indirectly by mapping hydrogen fluoride (HF) and linking its abundance to that of H2.


The new tool comes in handy when other tools fail, for example, in the Orion Bar, in between regions around the Orion Trapezium stars and the Orion Molecular Cloud. In these areas, carbon is ionized, meaning that carbon monoxide (CO)—usually a reliable trace molecule to find H2—can't work as a tracer. Floris van der Tak (SRON/RuG) and his team were surprised to find a characteristic HF signal in data from the Herschel telescope coming from the Orion Bar, as astronomers have previously only detected hydrogen fluoride as a silhouette: HF absorbing other radiation. HF and H2 abundance can be linked because HF is produced in a chemical reaction where H2 reacts with atomic fluorine (F) to form HF and atomic hydrogen (H). Without H2, there is no HF.

The team, led by SRON Ph.D. student Umit Kavak, used their map of HF to examine a few mechanisms through which it could emit its signal. Collisions of HF molecules with electrons and molecular hydrogen turns out to be the main mechanism. The collisions excite the HF molecules to a higher energy state, after which they drop to their ground state while emitting infrared light at a characteristic wavelength of 1.2 THz.

The study was published in Astronomy & Astrophysics.

Source: SRON Netherlands Institute for Space Research [November 06, 2019]



* This article was originally published here

Hubble Views a Not-So-Lonely Galaxy













NASA - Hubble Space Telescope patch.

Nov. 3, 2019


Galaxies may seem lonely, floating alone in the vast, inky blackness of the sparsely populated cosmos — but looks can be deceiving. This image of NGC 1706, taken by the NASA/ESA Hubble Space Telescope, is a good example of this. NGC 1706 is a spiral galaxy, about 230 million light-years away, in the constellation of Dorado (the Swordfish).

NGC 1706 is known to belong to something known as a galaxy group, which is just as the name suggests — a group of up to 50 galaxies which are gravitationally bound and hence relatively close to each other. Around half of the galaxies we know of in the universe belong to some kind of group, making them incredibly common cosmic structures. Our home galaxy, the Milky Way, belongs to the Local Group, which also contains the Andromeda galaxy, the Large and Small Magellanic clouds, and the Triangulum galaxy.

Groups are the smallest of galactic gatherings; others are clusters, which can comprise hundreds of thousands of galaxies bound loosely together by gravity, and subsequent superclusters, which bring together numerous clusters into a single entity.

Hubble Space Telescope (HST)

For more information about Hubble, visit:
http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: European Space Agency (ESA)/NASA/Lynn Jenner/Image, Animation Credits: ESA/Hubble & NASA, A. Bellini et al.

Best regards, Orbiter.ch

* This article was originally published here

Prehistoric Cup and Ring Rock Art Fragments, McManus Museum and Gallery, Dundee, 24.10.19.

Prehistoric Cup and Ring Rock Art Fragments, McManus Museum and Gallery, Dundee, 24.10.19.



* This article was originally published here

NASA's TESS presents panorama of southern sky


The glow of the Milky Way -- our galaxy seen edgewise -- arcs across a sea of stars in a new mosaic of the southern sky produced from a year of observations by NASA's Transiting Exoplanet Survey Satellite (TESS). Constructed from 208 TESS images taken during the mission's first year of science operations, completed on July 18, the southern panorama reveals both the beauty of the cosmic landscape and the reach of TESS's cameras.

NASA's TESS presents panorama of southern sky
This mosaic of the southern sky was assembled from 208 images taken by NASA's Transiting Exoplanet Survey Satellite
(TESS) during its first year of science operations, completed in July 2019. The mission divided the southern sky into
 13 sectors, each of which was imaged for nearly a month by the spacecraft's four cameras. Among the many notable
celestial objects visible is the glowing band (left) of the Milky Way, our home galaxy seen edgewise, the Orion
Nebula (top), a nursery for newborn stars, and the Large Magellanic Cloud (center), a nearby galaxy
 located about 163,000 light-years away. The prominent dark lines are gaps between the detectors
in TESS's camera system [Credit: NASA/MIT/TESS and Ethan Kruse (USRA)]
"Analysis of TESS data focuses on individual stars and planets one at a time, but I wanted to step back and highlight everything at once, really emphasizing the spectacular view TESS gives us of the entire sky," said Ethan Kruse, a NASA Postdoctoral Program Fellow who assembled the mosaic at NASA's Goddard Space Flight Center in Greenbelt, Maryland.


Within this scene, TESS has discovered 29 exoplanets, or worlds beyond our solar system, and more than 1,000 candidate planets astronomers are now investigating.




TESS divided the southern sky into 13 sectors and imaged each one of them for nearly a month using four cameras, which carry a total of 16 charge-coupled devices (CCDs). Remarkably, the TESS cameras capture a full sector of the sky every 30 minutes as part of its search for exoplanet transits.

Transits occur when a planet passes in front of its host star from our perspective, briefly and regularly dimming its light. During the satellite's first year of operations, each of its CCDs captured 15,347 30-minute science images. These images are just a part of more than 20 terabytes of southern sky data TESS has returned, comparable to streaming nearly 6,000 high-definition movies.

In addition to its planet discoveries, TESS has imaged a comet in our solar system, followed the progress of numerous stellar explosions called supernovae, and even caught the flare from a star ripped apart by a supermassive black hole. After completing its southern survey, TESS turned north to begin a year-long study of the northern sky.

Author: Francis Reddy | Source: NASA's Goddard Space Flight Center [November 06, 2019]



* This article was originally published here

2019 November 2 Inside the Flame Nebula Image Credit &...



2019 November 2

Inside the Flame Nebula
Image Credit & Copyright: Optical: DSS; Infrared: NASA/JPL-Caltech;
X-ray: NASA/CXC/PSU/ K.Getman, E.Feigelson, M.Kuhn & the MYStIX team

Explanation: The Flame Nebula stands out in this optical image of the dusty, crowded star forming regions toward Orion’s belt, a mere 1,400 light-years away. X-ray data from the Chandra Observatory and infrared images from the Spitzer Space Telescope can take you inside the glowing gas and obscuring dust clouds though. Swiping your cursor (or clicking the image) will reveal many stars of the recently formed, embedded cluster NGC 2024, ranging in age from 200,000 years to 1.5 million years young. The X-ray/infrared composite image overlay spans about 15 light-years across the Flame’s center. The X-ray/infrared data also indicate that the youngest stars are concentrated near the middle of the Flame Nebula cluster. That’s the opposite of the simplest models of star formation for the stellar nursery that predict star formation begins in the denser center of a molecular cloud core. The result requires a more complex model; perhaps star formation continues longer in the center, or older stars are ejected from the center due to subcluster mergers.

∞ Source: apod.nasa.gov/apod/ap191102.html

Cygnus Resupply Ship Attached to Unity for Cargo Operations














ISS - Expedition 61 Mission patch / NASA & Northrop Grumman - NG-CRS-12 S.S. Alan Bean Cygnus Mission patch.

November 4, 2019

After its capture this morning at 4:10 a.m. EST, the Northrop Grumman Cygnus spacecraft was bolted into place on the International Space Station’s Earth-facing port of the Unity module at 6:21 a.m. At the time of installation, Cygnus was flying over the south Pacific.


Image above: Nov. 4, 2019: International Space Station Configuration. Four spaceships are attached to the space station including the Northrop Grumman Cygnus resupply ship and Russia’s Progress 73 resupply ship and Soyuz MS-13 and MS-15 crew ships. Image Credit: NASA.

This mission, designated NG CRS-12, will be in orbit at the same time as its predecessor, the NG CRS-11 Cygnus spacecraft, which launched in April on an extended duration flight. The NG CRS-12 Cygnus spacecraft will remain at the space station until January before it disposes of several thousand pounds of trash through its fiery reentry into Earth’s atmosphere. The ability to fly two vehicles at once further demonstrates the robustness of Cygnus to support the goals of NASA’s ambitious missions.

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