пятница, 6 декабря 2019 г.

Hubble Spots Galaxy’s Dramatic Details












NASA - Hubble Space Station patch.

Dec. 6, 2019


Some of the most dramatic events in the universe occur when certain stars die — and explode catastrophically in the process.

Such explosions, known as supernovae, mainly occur in a couple of ways. In one scenario, a massive star depletes its fuel at the end of its life, becoming dynamically unstable and unable to support its bulk, causing it to collapse inward and violently explode. In another outcome, a white dwarf (the dense remnant of a once-normal star) in an orbiting stellar couple siphons more mass off its companion than it is able to support, igniting runaway nuclear fusion in its core and beginning the supernova process. Both types result in an intensely bright object in the sky that can rival the light of a whole galaxy.

In the last 20 years the galaxy NGC 5468, visible in this image, has hosted a number of observed supernovae of both the aforementioned types: SN 1999cp, SN 2002cr, SN2002ed, SN2005P and SN2018dfg. Despite being just over 130 million light-years away, the orientation of the galaxy with respect to us makes it easier to spot these new “stars” as they appear; we see NGC 5468 face on, meaning we can see the galaxy’s loose, open spiral pattern in beautiful detail in images such as this one from the NASA/ESA Hubble Space Telescope.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Text Credits: ESA (European Space Agency)/NASA/Rob Garner/Image, Animation Credits: ESA/Hubble & NASA, W. Li et al.

Greetings, Orbiter.ch

* This article was originally published here

Nearly 40% of species are very rare and are vulnerable to climate change


Almost 40% of global land plant species are categorized as very rare, and these species are most at risk for extinction as the climate continues to change, according to new University of Arizona-led research.

Nearly 40% of species are very rare and are vulnerable to climate change
Global hotspots of rare plant species [Credit: Patrick R. Roehrdanz, Moore Center for Science,
Conservation International Data from Enqist et al.]
The findings are published in a special issue of Science Advances that coincides with the 2019 United Nations Climate Change Conference, also known as COP25, in Madrid. The COP25 is convening nations to act on climate change. The international meeting runs from Dec. 2 through Dec. 13.

"When talking about global biodiversity, we had a good approximation of the total number of land plant species, but we didn't have a real handle on how many there really are," said lead author Brian Enquist, University of Arizona professor of ecology and evolutionary biology.


Thirty-five researchers from institutions around the world worked for 10 years to compile 20 million observational records of the world's land plants. The result is the largest dataset on botanical biodiversity ever created. The researchers hope this information can help reduce loss of global biodiversity by informing strategic conservation action that includes consideration of the effects of climate change.

They found that there are about 435,000 unique land plant species on Earth.

"So that's an important number to have, but it's also just bookkeeping. What we really wanted to understand is the nature of that diversity and what will happen to this diversity in the future," Enquist said. "Some species are found everywhere - they're like the Starbucks of plant species. But others are very rare - think a small standalone cafe."

Nearly 40% of species are very rare and are vulnerable to climate change
Vanessa Buzzard, Sean Michaletz and Brian Enquist collecting data on Mt. Lemmon
Northwest of Tucson, Ariz. [Credit: Brian Enquist]
Enquist and his team revealed that 36.5% of all land plant species are "exceedingly rare," meaning they have only been observed and recorded less than five times ever.

"According to ecological and evolutionary theory, we'd expect many species to be rare, but the actual observed number we found was actually pretty startling," he said. "There are many more rare species than we expected."


Moreover, the researchers found that rare species tend to cluster in a handful of hotspots, such as the Northern Andes in South America, Costa Rica, South Africa, Madagascar and Southeast Asia. These regions, they found, remained climatologically stable as the world emerged from the last ice age, allowing such rare species to persist.

But just because these species enjoyed a relatively stable climate in the past doesn't mean they'll enjoy a stable future. The research also revealed that these very rare-species hotspots are projected to experience a disproportionally high rate of future climatic changes and human disruption, Enquist said.

"We learned that in many of these regions, there's increasing human activity such as agriculture, cities and towns, land use and clearing. So that's not exactly the best of news," he said. "If nothing is done, this all indicates that there will be a significant reduction in diversity - mainly in rare species - because their low numbers make them more prone to extinction."

And it's these rare species that science knows very little about.

By focusing on identifying rare species, "this work is better able to highlight the dual threats of climate change and human impact on the regions that harbor much of the world's rare plant species and emphasizes the need for strategic conservation to protect these cradles of biodiversity," said Patrick Roehrdanz a co-author on the paper and managing scientist at Conservation International.

Source: University of Arizona [November 27, 2019]



* This article was originally published here

Nine climate tipping points now 'active,' warn scientists


More than half of the climate tipping points identified a decade ago are now "active", a group of leading scientists have warned.

Nine climate tipping points now 'active,' warn scientists
The collapse of major ice sheets on Greenland, West Antarctica and part of East Antarctica would commit
the world to around 10 metres of irreversible sea-level rise [Credit: University of Exeter]
This threatens the loss of the Amazon rainforest and the great ice sheets of Antarctica and Greenland, which are currently undergoing measurable and unprecedented changes much earlier than expected.

This "cascade" of changes sparked by global warming could threaten the existence of human civilisations.

Evidence is mounting that these events are more likely and more interconnected than was previously thought, leading to a possible domino effect.

In an article in the journal Nature, the scientists call for urgent action to reduce greenhouse gas emissions to prevent key tipping points, warning of a worst-case scenario of a "hothouse", less habitable planet.

"A decade ago we identified a suite of potential tipping points in the Earth system, now we see evidence that over half of them have been activated," said lead author Professor Tim Lenton, director of the Global Systems Institute at the University of Exeter.

"The growing threat of rapid, irreversible changes means it is no longer responsible to wait and see. The situation is urgent and we need an emergency response."


Co-author Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research, said: "It is not only human pressures on Earth that continue rising to unprecedented levels.

"It is also that as science advances, we must admit that we have underestimated the risks of unleashing irreversible changes, where the planet self-amplifies global warming.

"This is what we now start seeing, already at 1°C global warming.

"Scientifically, this provides strong evidence for declaring a state of planetary emergency, to unleash world action that accelerates the path towards a world that can continue evolving on a stable planet."

In the commentary, the authors propose a formal way to calculate a planetary emergency as risk multiplied by urgency.

Tipping point risks are now much higher than earlier estimates, while urgency relates to how fast it takes to act to reduce risk.

Exiting the fossil fuel economy is unlikely before 2050, but with temperature already at 1.1°C above pre-industrial temperature, it is likely Earth will cross the 1.5°C guardrail by 2040. The authors conclude this alone defines an emergency.

Nine active tipping points:

1. Arctic sea ice

2. Greenland ice sheet

3. Boreal forests

4. Permafrost

5. Atlantic Meridional Overturning Circulation

6. Amazon rainforest

7. Warm-water corals

8. West Antarctic Ice Sheet

9. Parts of East Antarctica

The collapse of major ice sheets on Greenland, West Antarctica and part of East Antarctica would commit the world to around 10 metres of irreversible sea-level rise.

Reducing emissions could slow this process, allowing more time for low-lying populations to move.

The rainforests, permafrost and boreal forests are examples of biosphere tipping points that if crossed result in the release of additional greenhouse gases amplifying warming.


Despite most countries having signed the Paris Agreement, pledging to keep global warming well below 2°C, current national emissions pledges—even if they are met—would lead to 3°C of warming.

Although future tipping points and the interplay between them is difficult to predict, the scientists argue: "If damaging tipping cascades can occur and a global tipping cannot be ruled out, then this is an existential threat to civilization.

"No amount of economic cost-benefit analysis is going to help us. We need to change our approach to the climate problem."

Professor Lenton added: "We might already have crossed the threshold for a cascade of inter-related tipping points.

"However, the rate at which they progress, and therefore the risk they pose, can be reduced by cutting our emissions."

Though global temperatures have fluctuated over millions of years, the authors say humans are now "forcing the system", with atmospheric carbon dioxide concentration and global temperature increasing at rates that are an order of magnitude higher than at the end of the last ice age.

Source: University of Exeter [November 27, 2019]



* This article was originally published here

Studies highlight fragility of Antarctic ecosystems


Two studies published in a special issue of the journal Science Advances this week highlight the fragility of the Antarctic and its ecosystems in the lead up to the UNFCCC COP25 meeting in Madrid next week.

Studies highlight fragility of Antarctic ecosystems
MPAs provide special measures to protect areas of the ocean around Antarctica
[Credit: British Antarctic Survey]
The first study, involving scientists from British Antarctic Survey (BAS), explores the integration of climate change considerations in the global network of Marine Protected Areas, and how this can contribute to ensuring a sustainable ocean future.

Little is known about how well MPAs account for climate impacts, or how climate adaptation can be improved in the global MPA network. A key finding shows that the proportion of marine protected areas that account for climate change cannot be accurately measured, since there is no repository that holds this information.


Developing a database to track climate adaptation plans in MPAs is one of eight recommendations that the researchers present. They also recommend the development of new dynamic management tools to allow a more rapid response to climate impacts.

"The impacts of climate change and biodiversity loss are two of the most significant challenges facing our oceans, yet the policy agendas for these issues have tended to be developed independently. There is now an urgent need to actively integrate climate change as a core consideration in ocean conservation and management." says BAS ecologist scientist Dr Rachel Cavanagh.

Another crucial component of climate-smart conservation and management is that it is centered around building capacity in regions with limited resources, and around inclusiveness, bringing stakeholders fully into the discussion and the decision-making process.

Studies highlight fragility of Antarctic ecosystems
Map of Antarctica, showing locations mentioned in the text, and the Southern Ocean, showing ice-covered
and ice-free areas shallower than 200 m, 200- to 1000-m depth, and deeper than 1000 m
[Credit: P. Fretwell, British Antarctic Survey]
Dr Susie Grant, a marine biogeographer at BAS says: "Establishing marine protected areas (MPAs) that are responsive to climate change is especially important in the Southern Ocean, where the marine ecosystem is already changing rapidly. These new recommendations can help to improve the way in which MPAs are used to address both biodiversity conservation and climate adaptation."

The second study also published in the journal Science Advances, is a review by BAS scientists. It discusses how Antarctica's unique and delicate ecosystems face the dual problems of climate change and direct human impacts, in particular the accidental introduction of non-native or 'alien' species.' The scientists analyzed existing literature on the environmental challenges facing the continent and the Southern Ocean.


The study reaffirms the importance of all parties of the Antarctic Treaty continuing their commitment to governance of the region, as it still contains the best mechanisms to protect and preserve the environment. The scientists praise the establishment of the first genetic database of Antarctic species in New Zealand and recommend this is extended to create a comprehensive genetic archive for future generations to use.

The Southern Ocean has some of the highest levels of biodiversity in the globe, second only to that of coral reefs. In contrast, Antarctica's terrestrial ecosystems include some of the least diverse on the planet. However, both have long been effectively cut off from the rest of the world, leading to evolutionary radiation and adaptation to it unique environments.

Lead author Professor Peter Convey from BAS says: "Numbers of visitors to Antarctica is still relatively small, with around 50,000 tourists and 5,000 research staff per year. There has been no recorded establishment of non-native marine species around Antarctica, however, its terrestrial ecosystems are already feeling the serious impacts these can have, especially on the sub-Antarctic islands. Climate change and increasing human activity in the region can act together to drastically increase the likelihood of non-native species establishments, providing an urgent challenge that the Antarctic Treaty System's governance system must respond to quickly and effectively in order to fulfill its responsibility of effectively protecting Antarctica's unique ecosystems and biodiversity."

Source: British Antarctic Survey [November 29, 2019]



* This article was originally published here

2019 December 6 Pleiades to Hyades Image Credit &...



2019 December 6

Pleiades to Hyades
Image Credit & Copyright: Amir H. Abolfath (TWAN)

Explanation: This cosmic vista stretches almost 20 degrees from top to bottom, across the dusty constellation Taurus. It begins at the Pleiades and ends at the Hyades, two star clusters recognized since antiquity in Earth’s night sky. At top, the compact Pleiades star cluster is about 400 light-years away. The lovely grouping of young cluster stars shine through dusty clouds that scatter blue starlight. At bottom, the V-shaped Hyades cluster looks more spread out in comparison and lies much closer, 150 light-years away. The Hyades cluster stars seem anchored by bright Aldebaran, a red giant star with a yellowish appearance. But Aldebaran actually lies only 65 light-years distant and just by chance along the line of sight to the Hyades cluster. Faint and darkly obscuring dust clouds found near the edge of the Taurus Molecular Cloud are also evident throughout the celestial scene. The wide field of view includes the dark nebula Barnard 22 at left with youthful star T Tauri and Hind’s variable nebula just above Aldebaran in the frame.

∞ Source: apod.nasa.gov/apod/ap191206.html



* This article was originally published here

Iron Age Logboat (Loch Lotus, 2and century BCE to 2nd century CE), The National Museum of Scotland,...

Iron Age Logboat (Loch Lotus, 2and century BCE to 2nd century CE), The National Museum of Scotland, Edinburgh, November 2019.



* This article was originally published here

New evolutionary insights into the early development of songbirds


An international team led by Alexander Suh at Uppsala University has sequenced a chromosome in zebra finches called the germline-restricted chromosome (GRC). This chromosome is only found in germline cells, the cells that hold genetic information which is passed on to the next generation. The researchers found that the GRC is tens of millions of years old and plays a key role in songbird biology, having collected genes used for embryonic development.

New evolutionary insights into the early development of songbirds
Zebra finch [Credit: WikiCommons]
The ability to reproduce is a fundamental trait of all life. How reproduction has evolved and how it functions on a genetic level is therefore of great interest to evolutionary biologists. During the early development of an animal embryo, cells are divided into two major types, germline and somatic cells. Germline cells are present in the reproductive organs and hold genetic information which is passed on to the next generation, whereas somatic cells are the cells which make up the rest of the organism. Biologists have discovered that in some organisms, certain genes and repetitive DNA-sequences are eliminated when cells become either somatic or germline, which means that not all cells in an organism contain the same genome.


In certain species, entire chromosomes are specific to the germline. One such chromosome in zebra finches is called the germline restricted chromosome (GRC). For the first time, an international team led by Alexander Suh at the Department of Ecology and Genetics at Uppsala University has performed a comprehensive genomic, transcriptomic, and proteomic analysis of the GRC in zebra finches. The GRC is the largest chromosome in the zebra finch genome and constitutes more than 10 percent of the genome.

"The GRC is a very strange chromosome. We found that some of its genes are repeated tens or even hundreds of times, whereas the somatic cells have only one gene copy." says Cormac Kinsella, one of the first authors of the study.


By identifying specific genes and comparing them with genomic data from other species, the scientists could unravel the evolutionary history of the GRC. The results showed that the GRC is tens of millions of years old and likely present across all songbird species, which represent half of all bird species. The scientists also think that the GRC became an important factor in bird development because many genes associated with early embryonic development are found there. Because the GRC is not present in somatic cells, expression of its genes only affects germline cells thereby protecting somatic cells from possible negative effects.

"Because we found GRC expression on the RNA and protein level, we expect our evidence for selection acting on the GRC to become the starting point of further exciting discoveries." says Francisco Ruiz-Ruano, the other first author of the study.

The findings are published in Nature Communications.

Source: Uppsala University [November 29, 2019]



* This article was originally published here

Radiation rotifer













ISS - International Space Station logo.

Dec. 5, 2019

The 19th SpaceX Dragon supply mission to the International Space Station will carry cargo for astronauts to run experiments for European researchers on Earth. One curious cargo is the microscopic organism, rotifers, that researchers will study in space to hopefully reveal some secrets of their unique powers.

Rotifers, commonly called wheel animals, can be found in almost all pools of water no matter how small including moist ground, moss and even on other animals. Most species are less than a millimetre in size and are fascinating to biologists as they are masters of survival.

A species of rotifers called bdelloids are exceptional as no male has ever been found, meaning they produce offspring from unfertilised eggs. Despite the genetic similarity they can survive for very long periods without water; rolling up into a pod they can survive year-long droughts in the Sahara desert as well as in the frozen plains of Antarctica. Simply add water and the bdelloids will uncurl and spring back to normal function.

Adineta vaga rotifer

Bdelloids have another trick up their sleeve: they are extremely resistant to radiation. Understanding how they survive radiation levels that would kill many other organisms (and indeed ourselves) will gain insights into how we could improve spacecraft and protect astronauts against cosmic radiation. Earth’s atmosphere protects us from cosmic radiation but at 400 km altitude on the International Space Station astronauts already receive radiation doses 250 times higher than at sea level.

As humankind ventures farther to explore our Solar System on longer missions, finding ways to protect ourselves from radiation is key. The results from the Rotifer-B study could also lead to measures to improve protection of professionals who are exposed to radiation in their work or cancer patients during radiation therapy.

Kubik on Space Station

The experiment is split into two halves: one focuses explicitly on the effects of microgravity (Part 1) and the other on DNA damage and repair (Part 2). Part 1 will see culture bags of fresh rotifers with a meal of lettuce juice and water launched to the ISS, where they will experience conditions inside the Columbus module on the ISS in a special temperature-controlled Kubik facility. Once back on ground, researchers will examine the gene expression of the rotifers that were frozen in space to get a clear snapshot of what they were experiencing at the time at the molecular level. 

Rotifer-B science team

In Part 2, the rotifers will be dried onto special agarose gels, where they will be strongly irradiated using an X-Ray machine. This will deliberately destroy their DNA but not kill them. Once in space, the dried rotifers will be reactivated with the lettuce juice and water mixture, exposed to space conditions and sent back to Earth in the frozen state. Eventually, researchers will examine the effects that their trip to space had on their ability to repair their own DNA, compared to ground controls.

The experiment is being designed and run by the University of Namur and result institute SCK-KEN of Belgium with the facility hardware built by Kayser Italia.

Human and Robotic Exploration: http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration

Science & Exploration: http://www.esa.int/Science_Exploration

Images, Text, Credits: ESA/NASA.

Best regards, Orbiter.ch

* This article was originally published here

Foot from a larger than life Roman Statue, (Milsington, 2and century CE), The National Museum of...

Foot from a larger than life Roman Statue, (Milsington, 2and century CE), The National Museum of Scotland, Edinburgh, November 2019.



* This article was originally published here

Ancient microbes helped to keep Earth's early climate warm


Ancient ancestors of modern microbes played a critical role in setting the stage for life on a dimly lit early Earth, and in creating the world's largest iron ore deposits, according to new research.

Ancient microbes helped to keep Earth's early climate warm
Ancient microbes, such as the Chlorobium phaeoferrooxidans pictured here, played an important role
 in the development of Archean banded iron formations and the warming of Earth’s early climate
[Credit to Katharine Thompson]
The study, conducted by an international consortium of researchers including the University of Alberta and the University of British Columbia, examined modern bacteria from an iron-rich lake in the Democratic Republic of Congo. Results show that these ancient microbes may have been key to keeping Earth's early climate warm while simultaneously forming massive iron-rich deposits.


"These ancient microorganisms used energy from the sun to transform iron into rusty minerals, without oxygen," said Kurt Konhauser, professor in the Department of Earth and Atmospheric Sciences and co-author on the study. "They also served as a source of food for other microbes, which then produced methane, helping to warm Earth's early atmosphere."

In the Precambrian era, sunlight on Earth was much less bright than it is today because the sun itself was less luminous. The research supports that the methane created by the consumption of these microbes helped to keep the planet's atmosphere warm, setting the stage for other forms of early life.

"The fundamental knowledge we're gaining from studies using modern geomicrobiological tools and techniques is transforming our view of Earth's history as well as how we know and interact with the world around us today," said Katharine Thompson, lead author of the study and PhD student in the Department of Microbiology and Immunology at UBC.


The research also has applications for Earth's current and future climate, as well. Understanding how life and the solid Earth interact not only has the potential to inform about possible environmental feedbacks, but the processes that caused Earth's early warming has relevance for large-scale remediation efforts, such as removing carbon dioxide from the atmosphere through bacteria-mineral interactions.

This research was conducted in collaboration with the University of British Columbia, the University of Tubingen, Universitat Auto?noma de Barcelona, and the Georgia Institute of Technology.

The paper was published in Science Advances.

Source: University of Alberta [November 29, 2019]



* This article was originally published here

NASA’s Exoplanet-Hunting Mission Catches a Natural Comet Outburst in Unprecedented Detail

This animation shows an explosive outburst of dust, ice and gases from comet 46P/Wirtanen that occurred on September 26, 2018 and dissipated over the next 20 days. The images, from NASA’s TESS spacecraft, were taken every three hours during the first three days of the outburst. Credits: Farnham et al./NASA. View enlarged image

Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS), astronomers at the University of Maryland (UMD), in College Park, Maryland, have captured a clear start-to-finish image sequence of an explosive emission of dust, ice and gases during the close approach of comet 46P/Wirtanen in late 2018. This is the most complete and detailed observation to date of the formation and dissipation of a naturally-occurring comet outburst. The team members reported their results in the November 22 issue of The Astrophysical Journal Letters.

“TESS spends nearly a month at a time imaging one portion of the sky. With no day or night breaks and no atmospheric interference, we have a very uniform, long-duration set of observations,” said Tony Farnham, a research scientist in the UMD Department of Astronomy and the lead author of the research paper. “As comets orbit the Sun, they can pass through TESS’ field of view. Wirtanen was a high priority for us because of its close approach in late 2018, so we decided to use its appearance in the TESS images as a test case to see what we could get out of it. We did so and were very surprised!”

Normal comet activity is driven by sunlight vaporizing the ices near the surface of the nucleus, and the outflowing gases drag dust off the nucleus to form the coma. However, many comets are known to experience occasional spontaneous outbursts that can significantly, but temporarily increase the comet's activity. It is not currently known what causes outbursts, but they are related to the conditions on the comet's surface. A number of potential trigger mechanisms have been proposed, including a thermal event, in which a heat wave penetrates into a pocket of highly volatile ices, causing the ice to rapidly vaporize and produce an explosion of activity, and a mechanical event, where a cliff collapses, exposing fresh ice to direct sunlight. Thus, studies of the outburst behavior, especially in the early brightening stages that are difficult to capture, can help us understand the physical and thermal properties of the comet.

Although Wirtanen came closest to Earth on December 16, 2018, the outburst occurred earlier in its approach, beginning on September 26, 2018. The initial brightening of the outburst occurred in two distinct phases, with an hour-long flash followed by a more gradual second stage that continued to grow brighter for another 8 hours. This second stage was likely caused by the gradual spreading of comet dust from the outburst, which causes the dust cloud to reflect more sunlight overall. After reaching peak brightness, the comet faded gradually over a period of more than two weeks. Because TESS takes detailed, composite images every 30 minutes, the team was able to view each phase in exquisite detail.

“With 20 days’ worth of very frequent images, we were able to assess changes in brightness very easily. That’s what TESS was designed for, to perform its primary job as an exoplanet surveyor,” Farnham said. “We can’t predict when comet outbursts will happen. But even if we somehow had the opportunity to schedule these observations, we couldn’t have done any better in terms of timing. The outburst happened mere days after the observations started.”

The team has generated a rough estimate of how much material may have been ejected in the outburst, about one million kilograms (2.2 million pounds), which could have left a crater on the comet of around 20 meters (about 65 feet) across. Further analysis of the estimated particle sizes in the dust tail may help improve this estimate. Observing more comets will also help to determine whether multi-stage brightening is rare or commonplace in comet outbursts.

TESS has also detected for the first time Wirtanen’s dust trail. Unlike a comet’s tail—the spray of gas and fine dust that follows behind a comet, growing as it approaches the sun—a comet’s trail is a field of larger debris that traces the comet’s orbital path as it travels around the sun. Unlike a tail, which changes direction as it is blown by the solar wind, the orientation of the trail stays more or less constant over time.

“The trail more closely follows the orbit of the comet, while the tail is offset from it, as it gets pushed around by the sun’s radiation pressure. What’s significant about the trail is that it contains the largest material,” said Michael Kelley, an associate research scientist in the UMD Department of Astronomy and a co-author of the research paper. “Tail dust is very fine, a lot like smoke. But trail dust is much larger—more like sand and pebbles. We think comets lose most of their mass through their dust trails. When the Earth runs into a comet’s dust trail, we get meteor showers.”

While the current study describes initial results, Farnham, Kelley and their colleagues look forward to further analyses of Wirtanen, as well as other comets in TESS’ field of view. “We also don’t know what causes natural outbursts and that’s ultimately what we want to find,” Farnham said. “There are at least four other comets in the same area of the sky where TESS made these observations, with a total of about 50 comets expected in the first two years’ worth of TESS data. There’s a lot that can come of these data.”

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.

Claire Andreoli
NASA’s Goddard Space Flight Center
301-286 -1940
claire.andreoli@nasa.gov

Matthew Wright
University of Maryland, College Park
301-405-9267
mewright@umd.edu

Source: NASA/TESS




* This article was originally published here

Divers of the past


In the Mesozoic era, about 250 to 65 million years ago a large number of reptiles populated the oceans. The most successful were the plesiosaurs, which existed for about the same time as the dinosaurs. Enlarged red blood cells ensured their survival. This was discovered by paleontologists at Bonn University and zoologist Kai R. Caspar from Duisburg-Essen University (UDE). The results can be read in the international bioscientific online journal PeerJ.

Divers of the past
Plesiosaur – Life reconstruction [Credit: Kai Caspar]
Why did the size of the red blood cells increase? The scientists explain this with the environment of the marine animals. "Obviously, the plesiosaur firstly developed in the open sea after their ancestors had migrated from the shallow coastal waters to the high seas. The processes in their bodies adapted accordingly," says Kai Caspar. The enlarged red blood cells were advantageous for their longer, repeated dives in the open sea. "The larger they are, the more oxygen can be bound per cell," says the biologist.


For their investigation, the scientists created microscopically thin sections of fossil bones of the plesiosaurs, large (ancient) marine reptiles, and compared them with those of coastal ancestors. "The pattern found is unequivocal: By moving to the high seas, the blood cell size of these marine animals increased rapidly," summarises the UDE-scientist.

From an evolutionary perspective, this change is obviously still useful. Today`s whales, seals and penguins also have unusually large red blood cells, but their close relatives on land and in freshwater do not. "This supports our assumption that this is a significant adaption of warm-blooded marine life," says Kai Caspar.

Source: Universitat Duisburg-Essen [November 29, 2019]



* This article was originally published here

Glancing Back













NASA - JUNO Mission logo.

Dec. 5, 2019


Just after its close flyby of Jupiter on Nov. 3, 2019, NASA's Juno spacecraft caught this striking view of Jupiter's southern hemisphere as the spacecraft sped away from the giant planet. This image captures massive cyclones near Jupiter's south pole, as well as the chaotic clouds of the folded filamentary region — the turbulent area between the orange band and the brownish polar region.

When this image was taken, Juno was traveling at about 85,000 mph (137,000 kilometers per hour) relative to the planet. A little more than an hour earlier — at the point of closest approach to the cloud tops — the spacecraft reached speeds relative to Jupiter in excess of 130,000 mph (209,000 kilometers per hour).

Citizen scientist Ali Abbasi created this image using data from the spacecraft's JunoCam imager. It was taken on Nov. 3, 2019, at 3:29 p.m. PST (6:29 p.m. EST) as Juno performed its 23rd close flyby of Jupiter. At the time the image was taken, the spacecraft was about 65,500 miles (104,600 kilometers) from the planet at a latitude of about -70 degrees.

Juno spacecraft orbiting Jupiter. Animation Credit: NASA

JunoCam's raw images are available for the public to peruse and process into image products at
https://missionjuno.swri.edu/junocam/processing.

More information about Juno is at http://www.nasa.gov/juno and http://missionjuno.swri.edu.

Animation (mentioned), Image data: NASA/JPL-Caltech/SwRI/MSSS/Image processing by AliAbbasiPov, © CC BY/Text, Credits: NASA/Sarah Loff.

Greetings, Orbiter.ch

* This article was originally published here

Facial deformity in royal dynasty was linked to inbreeding, scientists confirm


The "Habsburg jaw", a facial condition of the Habsburg dynasty of Spanish and Austrian kings and their wives, can be attributed to inbreeding, according to new results published in the Annals of Human Biology.

Facial deformity in royal dynasty was linked to inbreeding, scientists confirm
King Charles II of Spain was the last in the Habsburg line and one of the most
afflicted with the facial deformity [Credit: Don Juan Carreno de Miranda]
The new study combined diagnosis of facial deformities using historical portraits with genetic analysis of the degree of relatedness to determine whether there was a direct link. The researchers also investigated the genetic basis of the relationship.

Generations of intermarriage secured the family's influence across a European empire including Spain and Austria for more than 200 years but led to its demise when the final Habsburg monarch was unable to produce an heir. However, until now no studies have confirmed whether the distinct chin known as "Habsburg jaw" was a result of inbreeding.

"The Habsburg dynasty was one of the most influential in Europe, but became renowned for inbreeding, which was its eventual downfall. We show for the first time that there is a clear positive relationship between inbreeding and appearance of the Habsburg jaw," says lead researcher Professor Roman Vilas from the University of Santiago de Compostela.


The researchers recruited 10 maxillofacial surgeons to diagnose facial deformity in 66 portraits of 15 members of the Habsburg dynasty. Despite differences in artistic style, the portraits are characterised by a realistic approach to the human face. The surgeons were asked to diagnose 11 features of mandibular prognathism, otherwise known as "Habsburg jaw", as well as seven features of maxillary deficiency, the most recognisable of which are a prominent lower lip and an overhanging nasal tip.

The portraits, which can be viewed online, are preserved by some of the most important art museums in the world, including the Kunsthistorisches Museum in Vienna and the Prado Museum in Madrid.

The surgeons gave scores for the degree of mandibular prognathism and maxillary deficiency in each member of the Habsburg family. Mary of Burgundy, who married into the family in 1477, showed the least degree of both traits. Mandibular prognathism was most pronounced in Philip IV, King of Spain and Portugal from 1621 to 1640. Maxillary deficiency was diagnosed to the greatest degree in five members of the family: Maximilian I (regent from 1493), his daughter Margaret of Austria, his nephew Charles I of Spain, Charles' great-grandson Philip IV and the last in the Habsburg line, Charles II.


The study authors detected a correlation between the two conditions, suggesting that "Habsburg jaw" is in fact characterised by them both and that they share a common genetic basis. The extent of inbreeding was calculated from a large-scale family tree, including more than 6,000 individuals belonging to more than 20 generations. Analysis was carried out to determine if it was connected to the degree of facial deformity. The researchers detected a strong relationship between the degree of inbreeding and the degree of mandibular prognathism. The relationship to maxillary deficiency was also positive, but it was only statistically significant in two of the seven features diagnosed.

The causes of the relationship between inbreeding and facial deformity remain unclear, but the authors suggest it's because the main effect of mating between relatives is an increase in the chances of offspring inheriting identical forms of a gene from both parents, known as genetic homozygosity. This reduces people's genetic fitness, so "Habsburg jaw" should be considered a recessive condition.

However, the authors note that the study involves only a small number of individuals so it's possible that the prevalence of Habsburg jaw is due to the chance appearance of traits, or genetic drift. They suggest this scenario is unlikely, but can't rule it out.

"While our study is based on historical figures, inbreeding is still common in some geographical regions and among some religious and ethnic groups, so it's important today to investigate the effects," says Vilas. "The Habsburg dynasty serves as a kind of human laboratory for researchers to do so, because the range of inbreeding is so high."

Source: Taylor & Francis Group [December 01, 2019]



* This article was originally published here

SpaceX Dragon Heads to Space Station with NASA Science, Cargo









SpaceX - CRS-19 Dragon Mission patch.

Dec. 5, 2019


Image above: SpaceX launches its 19th cargo resupply mission to the International Space Station at 12:29 p.m. EST Dec. 5, 2019, from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. Image Credit: NASA TV.

A SpaceX Dragon cargo spacecraft is on its way to the International Space Station after launching at 12:29 p.m. EST Thursday. Dragon will deliver more than 5,700 pounds of NASA cargo and science investigations, including studies of malting barley in microgravity, the spread of fire, and bone and muscle loss.

The spacecraft launched on a Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida and is scheduled to arrive at the orbital outpost on Sunday, Dec. 8. Coverage of the spacecraft’s approach and arrival at the space station will begin at 4:30 a.m. on NASA Television and the agency’s website.

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Breathing? Thank volcanoes, tectonics and bacteria


Earth's breathable atmosphere is key for life, and a new study suggests that the first burst of oxygen was added by a spate of volcanic eruptions brought about by tectonics.

Breathing? Thank volcanoes, tectonics and bacteria
The evolution of life as depicted in a mural at NASA Ames Research Center in Mountain View, California. The rise
of oxygen from a trace element to a primary atmospheric component was an important evolutionary development
[Credit: NASA Ames/David J. Des Marais/Thomas W. Scattergood/Linda L. Jahnke]
The study by geoscientists at Rice University offers a new theory to help explain the appearance of significant concentrations of oxygen in Earth's atmosphere about 2.5 billion years ago, something scientists call the Great Oxidation Event (GOE). The research appears this week in Nature Geoscience.

"What makes this unique is that it's not just trying to explain the rise of oxygen," said study lead author James Eguchi, a NASA postdoctoral fellow at the University of California, Riverside who conducted the work for his Ph.D. dissertation at Rice. "It's also trying to explain some closely associated surface geochemistry, a change in the composition of carbon isotopes, that is observed in the carbonate rock record a relatively short time after the oxidation event. We're trying explain each of those with a single mechanism that involves the deep Earth interior, tectonics and enhanced degassing of carbon dioxide from volcanoes."

Eguchi's co-authors are Rajdeep Dasgupta, an experimental and theoretical geochemist and professor in Rice's Department of Earth, Environmental and Planetary Sciences, and Johnny Seales, a Rice graduate student who helped with the model calculations that validated the new theory.


Scientists have long pointed to photosynthesis -- a process that produces waste oxygen -- as a likely source for increased oxygen during the GOE. Dasgupta said the new theory doesn't discount the role that the first photosynthetic organisms, cyanobacteria, played in the GOE.

"Most people think the rise of oxygen was linked to cyanobacteria, and they are not wrong," he said. "The emergence of photosynthetic organisms could release oxygen. But the most important question is whether the timing of that emergence lines up with the timing of the Great Oxidation Event. As it turns out, they do not."

Cyanobacteria were alive on Earth as much as 500 million years before the GOE. While a number of theories have been offered to explain why it might have taken that long for oxygen to show up in the atmosphere, Dasgupta said he's not aware of any that have simultaneously tried to explain a marked change in the ratio of carbon isotopes in carbonate minerals that began about 100 million years after the GOE. Geologists refer to this as the Lomagundi Event, and it lasted several hundred million years.

Breathing? Thank volcanoes, tectonics and bacteria
This figure illustrates how inorganic carbon cycles through the mantle more quickly than organic carbon, which contains
 very little of the isotope carbon-13. Both inorganic and organic carbon are drawn into Earth's mantle at subduction
zones (top left). Due to different chemical behaviors, inorganic carbon tends to return through eruptions at arc
volcanoes above the subduction zone (center). Organic carbon follows a longer route, as it is drawn deep into
 the mantle (bottom) and returns through ocean island volcanos (right). The differences in recycling times,
in combination with increased volcanism, can explain isotopic carbon signatures from rocks that are
associated with both the Great Oxidation Event, about 2.4 billion years ago, and the Lomagundi
Event that followed [Credit: J. Eguchi/University of California, Riverside]
One in a hundred carbon atoms are the isotope carbon-13, and the other 99 are carbon-12. This 1-to-99 ratio is well documented in carbonates that formed before and after Lomagundi, but those formed during the event have about 10% more carbon-13.

Eguchi said the explosion in cyanobacteria associated with the GOE has long been viewed as playing a role in Lomagundi.

"Cyanobacteria prefer to take carbon-12 relative to carbon-13," he said. "So when you start producing more organic carbon, or cyanobacteria, then the reservoir from which the carbonates are being produced is depleted in carbon-12."

Eguchi said people tried using this to explain Lomagundi, but timing was again a problem.

"When you actually look at the geologic record, the increase in the carbon-13-to-carbon-12 ratio actually occurs up to 10s of millions of years after oxygen rose," he said. "So then it becomes difficult to explain these two events through a change in the ratio of organic carbon to carbonate."


The scenario Eguchi, Dasgupta and Seales arrived at to explain all of these factors is:

- A dramatic increase in tectonic activity led to the formation of hundreds of volcanoes that spewed carbon dioxide into the atmosphere.

- The climate warmed, increasing rainfall, which in turn increased "weathering," the chemical breakdown of rocky minerals on Earth's barren continents.

- Weathering produced a mineral-rich runoff that poured into the oceans, supporting a boom in both cyanobacteria and carbonates.

- The organic and inorganic carbon from these wound up on the seafloor and was eventually recycled back into Earth's mantle at subduction zones, where oceanic plates are dragged beneath continents.

- When sediments remelted into the mantle, inorganic carbon, hosted in carbonates, tended to be released early, re-entering the atmosphere through arc volcanoes directly above subduction zones.

- Organic carbon, which contained very little carbon-13, was drawn deep into the mantle and emerged hundreds of millions of years later as carbon dioxide from island hotspot volcanoes like Hawaii.

Breathing? Thank volcanoes, tectonics and bacteria
Earth’s atmosphere as seen from the International Space Station July 20, 2006
[Credit: NASA]
"It's kind of a big cyclic process," Eguchi said. "We do think the amount of cyanobacteria increased around 2.4 billion years ago. So that would drive our oxygen increase. But the increase of cyanobacteria is balanced by the increase of carbonates. So that carbon-12-to-carbon-13 ratio doesn't change until both the carbonates and organic carbon, from cyanobacteria, get subducted deep into the Earth. When they do, geochemistry comes into play, causing these two forms of carbon to reside in the mantle for different periods of time. Carbonates are much more easily released in magmas and are released back to the surface at a very short period. Lomagundi starts when the first carbon-13-enriched carbon from carbonates returns to the surface, and it ends when the carbon-12-enriched organic carbon returns much later, rebalancing the ratio."


Eguchi said the study emphasizes the importance of the role that deep Earth processes can play in the evolution of life at the surface.

"We're proposing that carbon dioxide emissions were very important to this proliferation of life," he said. "It's really trying to tie in how these deeper processes have affected surface life on our planet in the past."

Dasgupta is also the principal investigator on a NASA-funded effort called CLEVER Planets that is exploring how life-essential elements might come together on distant exoplanets. He said better understanding how Earth became habitable is important for studying habitability and its evolution on distant worlds.

"It looks like Earth's history is calling for tectonics to play a big role in habitability, but that doesn't necessarily mean that tectonics is absolutely necessary for oxygen build up," he said. "There might be other ways of building and sustaining oxygen, and exploring those is one of the things we're trying to do in CLEVER Planets."

Author: Jade Boyd | Source: Rice University [December 02, 2019]



* This article was originally published here

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