четверг, 28 марта 2019 г.

20 марта 2019 взрыв гигантского огненного шара над...

 In this animated sequence of photos taken by Japan's Himawari 8 weather satellite on Dec. 18, 2018, you can follow the progress of the dark streak — a combination of the shadow left by the meteoroid's plume (orange patch to the right) and dust stripped from the object as it came crashing down into Earth's atmosphere at an estimated 32 km/s (72,000 mph).  Japan Meteorological Agency
In this animated sequence of photos taken by Japan’s Himawari 8 weather satellite on Dec. 18, 2018, you can follow the progress of the dark streak — a combination of the shadow left by the meteoroid’s plume (orange patch to the right) and dust stripped from the object as it came crashing down into Earth’s atmosphere at an estimated 32 km/s (72,000 mph). Japan Meteorological Agency

Last December 18th at 11:48 a.m. local time, a meteoroid exploded with 10 times the force of the Hiroshima atomic bomb over the Bering Sea. It became the second most powerful meteor blast this century, after the Chelyabinsk explosion in 2013 that released the energy equivalent of 20 to 30 atomic bombs.


 These are the individual images taken 10 minutes apart by the Himawari 8 satellite showing the evolution of the plume and shadow. Japan Meteorological Agency
These are the individual images taken 10 minutes apart by the Himawari 8 satellite showing the evolution of the plume and shadow. Japan Meteorological Agency

https://www.jma.go.jp/jma/indexe.html


https://en.wikipedia.org/wiki/Chelyabinsk_meteor


 In this frame taken by NASA's Terra satellite, the dense plume of ablated dust billows in the aftermath of the fireball. A more diffuse trail of dust seems to extend from the main plume toward and into the shadow. Rocked by its high-speed impact with the atmosphere, the meteoroid exploded about 26 kilometers above Earth's surface.   NASA/GSFC/LaRC/JPL-Caltech, MISR Team
In this frame taken by NASA’s Terra satellite, the dense plume of ablated dust billows in the aftermath of the fireball. A more diffuse trail of dust seems to extend from the main plume toward and into the shadow. Rocked by its high-speed impact with the atmosphere, the meteoroid exploded about 26 kilometers above Earth’s surface. NASA/GSFC/LaRC/JPL-Caltech, MISR Team

 


 


 This is an earlier Terra image showing the plume and the shadow which appears reddened. Could this reddening be caused in part from meteoric dust hovering above the shadow?  NASA/GSFC/LaRC/JPL-Caltech, MISR Team
This is an earlier Terra image showing the plume and the shadow which appears reddened. Could this reddening be caused in part from meteoric dust hovering above the shadow? NASA/GSFC/LaRC/JPL-Caltech, MISR Team

 


 Fireballs and their magnitude as reported by U.S. government sensors.  Alex Chamberlin / JPL-Caltech
Fireballs and their magnitude as reported by U.S. government sensors. Alex Chamberlin / JPL-Caltech


Fireball explosion over Pinar del Rio, Cuba, on February 1st. You can hear the explosion at the 55-second mark.


Astronomers have discovered more than 90% of near-Earth asteroids larger than a kilometer across — the ones that would have serious consequences in the event of a strike. But little ones, like Chelyabinsk or Tunguska? Nearly all are unannounced simply because they’re so tiny, they escape our notice. Fortunately, the atmosphere serves as an excellent defense against objects up to several tens of meters.


Amazing Images Capture Giant Fireball Exploding Over the Bering Sea



 


The JAXA Space Exploration Hub Center Co-Produces Results on Remote and Automatic Control...


JAXA – Japan Aerospace Exploration Agency logo.


March 28, 2019


National Research and Development Agency Japan Aerospace Exploration Agency (President: Hiroshi Yamakawa, hereafter JAXA) and Kajima Corporation (President and Representative Director: Yoshikazu Oshimi) have promoted research and development on the remote construction system by coordination of remote and automatic control. * The project got started in 2016 with the participation of schools; Shibaura Institute of Technology, The University of Electro-Communications and Kyoto University. With application in view to remotely controlled construction of a lunar base, the experiment conducted at the Kajima Seisho Experiment Site, Odawara, Kanagawa, of two kinds of the automated construction functionality has produced some results.


*Remote construction system by coordination of remote and automatic control: A joint research theme of the JAXA Space Exploration Innovation Hub Center.




Computer generated images of remotely operated construction of lunar base

Research Background


Remote control is a feasible method to build a human base off of Earth, on the moon and Mars in the future. Compensation of the considerable delay caused by sending any command to construction machinery from Earth has been an issue, however, along with others such as productivity and efficiency. On Earth, too, the same technologies are in need to deal with a predicted shortage of adept human resources in the construction industry, which has conventionally been human labor oriented. Since 2015, A4CSEL, developed by Kajima Corporation to automate construction machinery has been on site. The research took off by the parties of five – JAXA, Kajima Corporation and three schools as technologies of A4CSEL can be used to realize the remote construction functionality in space by coordination of remote and automatic control.


Research Overview


Remote, autonomous control to build a human lunar base will require the following steps;
①     Site preparation work for the module for human habitation
②     Excavation that meets the required depth
③     Installation of the module
④     Shielding the module with the surface material to protect it from meteoroids and radiation






Remote Construction of Manned Lunar Base

A seven-ton class earth mover has been modified with onboard survey instruments and an automatic operation control console. The instruments that the tractor and backhoe are installed with autonomously measure the position and direction of its own, making it both remotely and automatically operable.


In addition to full automation, this research is designed to acquire the following to establish remote construction functionality by coordination of remote and automatic control;


– Operational support to compensate for delays: remote control functionality that could compensate for considerable communication delays for 3 to 8 seconds without undermining the operation and stability of the remotely controlled machinery


– Motion recognition that adapts to environment: autonomous operation that opts for plausible solution in variable space topography due to communication delays


– Coordination of multiple construction machines: interference avoidance that facilitates synchronization of several operations


Various commands have been executed – the routine operation is repeated, driving over specified distances is automated, and operations requiring fine tuning are controlled remotely. The operational process has shown feasibility of the unmanned technologies to build a lunar base.




Autonomously operated tractor and backhoe

Future Directions for Research


Research and development continues to advance the obtained results and to improve the functions and performance of the system. Practical technologies are to be sought for to estimate position on the Moon and Mars where Global Navigation Satellite System (GNSS) is unavailable, and to precisely recognize and navigate terrains, and to ensure the system stability in the uncertain cosmic communication environment.


This ongoing joint research has been carried out as part of the Japan Science and Technology Agency Support program to start up an innovation hub center.


Related links:


Kajima Corporation: https://www.kajima.co.jp/english/welcome.html


INNOVATION HUB CENTER: http://www.ihub-tansa.jaxa.jp/english/index.html


Images, Text, Credits: Japan Aerospace Exploration Agency (JAXA)/National Research and Development Agency/Kajima Corporation.


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State geologist, partners create new surface geology maps for…


State geologist, partners create new surface geology maps for Massachusetts http://www.geologypage.com/2019/03/state-geologist-partners-create-new-surface-geology-maps-for-massachusetts.html


Massive earthquakes provide new insight into deep Earth…


Massive earthquakes provide new insight into deep Earth http://www.geologypage.com/2019/03/massive-earthquakes-provide-new-insight-into-deep-earth.html


Signs of 1906 earthquake revealed in mapping of offshore…


Signs of 1906 earthquake revealed in mapping of offshore northern San Andreas Fault http://www.geologypage.com/2019/03/signs-of-1906-earthquake-revealed-in-mapping-of-offshore-northern-san-andreas-fault.html


2019 March 28 The Gaia Stars of M15 Image Credit: Robert…


2019 March 28


The Gaia Stars of M15
Image Credit: Robert Vanderbei (Princeton University), ESA, Gaia, DPAC


Explanation: Messier 15 is a 13 billion year old relic of the early formative years of our galaxy, one of about 170 globular star clusters that still roam the halo of the Milky Way. About 200 light-years in diameter, it lies about 35,000 light years away toward the constellation Pegasus. But this realistic looking view of the ancient globular star cluster is not a photograph. Instead it’s an animated gif image constructed from remarkably precise individual measurements of star positions, brightness, and color. The astronomically rich data set used was made by the sky-scanning Gaia satellite which also determined parallax distances for 1.3 billion Milky Way stars. In the animated gif, twinkling stars are M15’s identified RR Lyrae stars. Plentiful in M15, RR Lyrae stars are evolved pulsating variable stars whose brightness and pulsation period, typically less than a day, are related.


∞ Source: apod.nasa.gov/apod/ap190328.html


What ionized the universe?

The sparsely distributed hot gas that exists in the space between galaxies, the intergalactic medium, is ionized. The question is, how? Astronomers know that once the early universe expanded and cooled enough, hydrogen (its main constituent) recombined into neutral atoms. Then, once newly formed massive stars began to shine in the so-called “era of reionization,” their extreme ultraviolet radiation presumably ionized the gas in processes that continue today.











What ionized the universe?
A NASA/ESA Hubble Space Telescope image of the rapidly fading visible-light fireball from a gamma-ray
burst (GRB) in a distant galaxy. A new study used the spectra of 140 GRB afterglows to estimate
the amount of ionizing radiation from massive stars that escapes from galaxies to ionize
the intergalactic medium, and finds the surprising result that it is very small
[Credit: Andrew Fruchter (STScI) and NASA/ESA]

One of the key steps, however, is not well understood, namely the extent to which the stellar ionizing radiation escapes from the galaxies into the IGM. Only if the fraction escaping was high enough during the era of reionization could starlight have done the job, otherwise some other significant source of ionizing radiation is required. That might imply the existence of an important population of more exotic objects like faint quasars, X-ray binary stars, or perhaps even decaying/annihilating particles.


Direct studies of extreme ultraviolet light are difficult because the neutral gas absorbs it very strongly. Because the universe is expanding, the spectrum absorbed covers more and more of the optical range with distance until optical observations of cosmologically remote galaxies are essentially impossible. CfA astronomer Edo Berger joined a large team of colleagues to estimate the amount of absorbing gas by looking at the spectra of gamma-ray burst (GRB) afterglows. GRBs are very bright bursts of radiation produced when the core of a massive star collapses.


They are bright enough that when their radiation is absorbed in narrow spectral features by gas along the line-of sight, those features can be measured and used to calculate the amount of absorbing atomic hydrogen. That number can then be directly converted into an escape fraction for the ultraviolet light of the associated galaxy. Although a single observation of a GRB in one galaxy does not provide a robust measure, a sample of GRBs is thought to be able to provide a representative measure across all sightlines to massive stars.


The astronomers carefully measured the spectra of 140 GRB afterglows in galaxies ranging as far away as epochs slightly less than one billion years after the big bang. They find a remarkably small escape fraction – less than about 1% of the ionizing photons make it out into the intergalactic medium. The dramatic result finds that stars provide only a small contribution to the ionizing radiation budget in the universe from that early period until today, not even in galaxies actively making new stars.


The authors discuss possible reasons why GRBs might not provide an accurate measure of the absorption, although none is particularly convincing. The result needs confirmation and additional measurements, but suggests that a serious reconsideration of the ionizing budget of the intergalactic medium of the universe is needed.


The research is published in Monthly Notices of the Royal Astronomical Society.


Source: Harvard-Smithsonian Center for Astrophysics [March 24, 2019]



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Hubble captures birth of giant storm on Neptune

Images taken by the Hubble Space Telescope document the formation of a Great Dark Spot on Neptune for the first time, report researchers in a new study.











Hubble captures birth of giant storm on Neptune
This composite picture shows images of storms on Neptune from the Hubble Space Telescope (left) and the Voyager 2
 spacecraft (right). The Hubble Wide Field Camera 3 image of Neptune, taken in Sept. and Nov. 2018, shows a new
dark storm (top center). In the Voyager image, a storm known as the Great Dark Spot (GDS) is seen at the center.
 It is about 13,000 km by 6,600 km in size — as large along its longer dimension as the Earth. The white
 clouds seen hovering in the vicinity of the storms are higher in altitude than the dark material
[Credit: NASA/ESA/GSFC/JPL]

Like Jupiter’s Great Red Spot, Neptune’s Great Dark Spots are storms that form from areas of high atmospheric pressure. In contrast, storms on Earth form around areas of low pressure.


Scientists have seen a total of six dark spots on Neptune over the years. Voyager 2 identified two storms in 1989. Since Hubble launched in 1990, it has viewed four more of these storms.


In the new study, planetary scientists analyzed Hubble’s photos of the ice giant taken over the past several years and chronicled the growth of a new Great Dark Spot that became visible in 2018.


By studying companion clouds that showed up two years before the new Great Dark Spot, the researchers conclude dark spots originate much deeper in Neptune’s atmosphere than previously thought.


The Hubble images also helped the researchers pinpoint how often Neptune gets dark spots and how long they last. The new findings give scientists insights on the inner workings of the poorly-understood ice giant planets but also have implications for studying exoplanets of similar size and composition.


“If you study the exoplanets and you want to understand how they work, you really need to understand our planets first,” said Amy Simon, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and lead author of the new study published in AGU’s journal Geophysical Research Letters. “We have so little information on Uranus and Neptune.”


A history of dark spots


Scientists first saw a Great Dark Spot on Neptune in 1989, when NASA’s Voyager 2 probe flew past the mysterious blue planet. As the spacecraft zoomed by, it snapped pictures of two giant storms brewing in Neptune’s southern hemisphere. Scientists dubbed the storms “The Great Dark Spot” and “Dark Spot 2.”











Hubble captures birth of giant storm on Neptune
The cyclic motion of the Great Red Spot imaged by the Cassini spacecraft. Unlike on Neptune, Thin jet streams
on Jupiter keep the Great Red Spot from breaking apart and from changing latitude; it rotates around
Jupiter but doesn’t move north or south [Credit: NASA]

Just five years later, the Hubble Space Telescope took sharp images of Neptune that revealed both the Earth-sized Great Dark Spot and the smaller Dark Spot 2 had vanished.


“It was certainly a surprise,” Simon said. “We were used to looking at Jupiter’s Great Red Spot, which presumably had been there for more than a hundred years.”


A new Great Dark Spot appeared on Neptune in 2018, nearly identical in size and shape to the one Voyager saw in 1989. Simon and her colleagues were analyzing Hubble images of a smaller dark spot that appeared in 2015 when they discovered small, bright white clouds in the region where the 2018 Great Dark Spot would later appear.


“We were so busy tracking this smaller storm from 2015, that we weren’t necessarily expecting to see another big one so soon,” Simon said.


The high-altitude clouds are made up of methane ice crystals, which give them their characteristic bright white color. Scientists suspect these methane clouds accompany the storms that form dark spots, hovering above them the way lenticular clouds cap tall mountains on Earth.


Lifespan of a spot


Simon and co-authors Michael Wong and Andrew Hsu at the University of California Berkeley tracked the methane clouds from 2016 to 2018. They found the clouds were brightest in 2016 and 2017, before the new Great Dark Spot became visible.











Hubble captures birth of giant storm on Neptune
A view of the first Great Dark Spot scientists observed on Neptune
[Credit: NASA]

Computer models of Neptune’s atmosphere have shown the deeper the storm, the brighter its companion clouds. That these white clouds appeared two years before the Great Dark Spot and that they lost some brightness when it became visible suggests dark spots may originate much deeper in Neptune’s atmosphere than previously thought, according to the new study.


Simon, Wong and Hsu also used images from Hubble and Voyager 2 to pinpoint how long these storms last and how frequently they occur. They report in a second study published today in the Astronomical Journal that they suspect new storms crop up on Neptune every four to six years. Each storm may last up to six years, though two-year lifespans are more likely, according to the findings.


Dark versus Red


The new findings show how Neptune’s Great Dark Spots differ from Jupiter’s Great Red Spot. The Great Red Spot has been observed since at least 1830 and could be up to 350 years old. Thin jet streams on Jupiter keep the Great Red Spot from breaking apart and from changing latitude; it rotates around Jupiter but doesn’t move north or south.


But Neptunian winds operate in much wider bands around the planet, so storms like the Great Dark Spot slowly drift across latitudes. These storms typically hover between westward equatorial wind jets and eastward-blowing currents in the higher latitudes before strong winds pull them apart.


Planetary scientists hope to next study changes in the shape of the vortex and wind speed in storms that form dark spots. “We have never directly measured winds within Neptune’s dark vortices, but we estimate the wind speeds are in the ballpark of 328 feet (100 meters) per second, quite similar to wind speeds within Jupiter’s Great Red Spot,” said Wong. More frequent observations using Hubble will help paint a clearer picture of how storm systems on Neptune evolve, he said.


Source: American Geophysical Union [March 25, 2019]




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Race at the edge of the Sun: Ions are faster than atoms

Ions move faster than atoms in the gas streams of a solar prominence. Scientists at the University of Göttingen, the Institut d’Astrophysique in Paris and the Istituto Ricerche Solari Locarno have observed this. The results of the study were published in The Astrophysical Journal.











Race at the edge of the Sun: Ions are faster than atoms
Solar prominence taken from SOT (Solar Optical Telescope) onboard the HINODE satellite showing
approx 150,000 km of the curved edge of the sun [Credit: Hinode JAXA/NASA]

In astrophysics, the “fourth state” of matter plays a crucial role. Apart from solid, liquid and gaseous states, there is also “plasma,” which means an accumulation of atoms that have lost shell electrons through collisions or high-energy radiation and thus become ions. These ions are subject to magnetic forces that do not affect electrically neutral atoms. If there are not too many collisions in the plasma, both particle types can flow independently of each other.
The researchers have now succeeded in observing the physics phenomena in just such a “partially ionised plasma without impact equilibrium” in gas streams of the Sun. The result: in clouds above the edge of the Sun, also known as prominences, ions of the element strontium move 22 per cent faster than sodium atoms.











Race at the edge of the Sun: Ions are faster than atoms
Solar prominence measuring approx 50,000 km above the solar edge taken at the Tenerife Observatory
[Credit: Dr Eberhard Wiehr]

16 hours later, the ions were only eleven percent faster. “Evidently, the neutral sodium atoms were more strongly carried along by the strontium ions,” says Dr Eberhard Wiehr of the University of Göttingen, first author of the study. This could be caused by an increased particle density, which increases the probability of impact. “In addition, the flow behaviour of the prominence could have changed in the 16 hours,” says Wiehr.
The faster ions move in sync with the oscillation of the magnetic fields. This keeps the prominence in suspension despite the attraction of the Sun. Movements in deeper layers of the sun cause the magnetic lines of force to fluctuate. The ions immediately follow the reversal of the direction of oscillation, while the neutral atoms have to repeatedly reorient themselves with the ions.


The researchers are now planning a systematic search for prominences with suitable oscillations that can be measured over a longer period of time.


Source: University of Göttingen [March 25, 2019]



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‘Space Butterfly’ Is Home to Hundreds of Baby Stars


NASA – Spitzer Space Telescope patch.


March 27, 2019



Image above: Officially known as W40, this red butterfly in space is a nebula, or a giant cloud of gas and dust. The “wings” of the butterfly are giant bubbles of gas being blown from the inside out by massive stars. Image Credits: NASA/JPL-Caltech.


What looks like a red butterfly in space is in reality a nursery for hundreds of baby stars, revealed in this infrared image from NASA’s Spitzer Space Telescope. Officially named Westerhout 40 (W40), the butterfly is a nebula — a giant cloud of gas and dust in space where new stars may form. The butterfly’s two “wings” are giant bubbles of hot, interstellar gas blowing from the hottest, most massive stars in this region.


Besides being beautiful, W40 exemplifies how the formation of stars results in the destruction of the very clouds that helped create them. Inside giant clouds of gas and dust in space, the force of gravity pulls material together into dense clumps. Sometimes these clumps reach a critical density that allows stars to form at their cores. Radiation and winds coming from the most massive stars in those clouds — combined with the material spewed into space when those stars eventually explode — sometimes form bubbles like those in W40. But these processes also disperse the gas and dust, breaking up dense clumps and reducing or halting new star formation.


The material that forms W40’s wings was ejected from a dense cluster of stars that lies between the wings in the image. The hottest, most massive of these stars, W40 IRS 1a, lies near the center of the star cluster. W40 is about 1,400 light-years from the Sun, about the same distance as the well-known Orion nebula, although the two are almost 180 degrees apart in the sky. They are two of the nearest regions in which massive stars — with masses upwards of 10 times that of the Sun — have been observed to be forming.


Another cluster of stars, named Serpens South, can be seen to the upper right of W40 in this image. Although both Serpens South and the cluster at the heart of W40 are young in astronomical terms (less than a few million years old), Serpens South is the younger of the two. Its stars are still embedded within their cloud but will someday break out to produce bubbles like those of W40. Spitzer has also produced a more detailed image of the Serpens South cluster.


A mosaic of Spitzer’s observation of the W40 star-forming region was originally published as part of the Massive Young stellar clusters Study in Infrared and X-rays (MYStIX) survey of young stellar objects.



The Spitzer picture is composed of four images taken with the telescope’s Infrared Array Camera (IRAC) during Spitzer’s prime mission, in different wavelengths of infrared light: 3.6, 4.5, 5.8 and 8.0 μm (shown as blue, green, orange and red). Organic molecules made of carbon and hydrogen, called polycyclic aromatic hydrocarbons (PAHs), are excited by interstellar radiation and become luminescent at wavelengths near 8.0 microns, giving the nebula its reddish features. Stars are brighter at the shorter wavelengths, giving them a blue tint. Some of the youngest stars are surrounded by dusty disks of material, which glow with a yellow or red hue.


The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space Systems in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.


More information on Spitzer can be found at its website: http://www.spitzer.caltech.edu/ and http://www.nasa.gov/mission_pages/spitzer/main/index.html


Image (mentioned), Animation, Text, Credits: NASA/Tony Greicius/JPL/Calla Cofield.


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Biodiversity loss in the oceans can be reversed through habitat restoration

Activities such as laying gas pipelines, trawling for fish, drilling for oil, and even burying internet cables in the deep sea, are destroying marine ecosystems. But studies have shown that reintroducing seaweed and corals to these habitats could ward off the worst effects – and recover marine life.











Biodiversity loss in the oceans can be reversed through habitat restoration
The fan mussel depends on seagrass meadows in the Mediterranean
[Credit: Arnaud Abadie]

Biodiversity loss is considered to be one of the most severe global environmental problems. In our oceans, this decline is heavily influenced by habitat degradation stemming from human activities.


Without action, more than half of the world’s marine species could be on the brink of extinction by the year 2100, according to UNESCO.


Marine biodiversity loss hinders the ocean’s ability to provide food for our growing population, with an estimated three billion people dependent on fish as their primary source of dietary protein.


We’re also economically dependent on healthy oceans. According to the World Wide Fund for Nature, the ocean provides the world with goods and services worth at least €2.2 trillion every year.


Some effects of biodiversity loss are less tangible. Many of the chemicals used in medical drugs and industrial compounds today came from marine plants and animals. With less known about the oceans than the moon, potentially useful marine organisms could be wiped out or seriously depleted before they are even discovered.


“If we lose biodiversity, we lose the opportunity to discover these crucially important compounds,” said Professor Roberto Danovaro, president of the Stazione Zoologica Anton Dohrn in Naples, Italy.


Restoration


The good news is that in the oceans, ecosystem restoration can cause species that disappeared from a particular region to return, says Prof. Danovaro.


“The concept of biodiversity loss is different in marine and in terrestrial ecosystems. Because of the dimension of connection between seas and oceans, it’s difficult to have a complete loss of biodiversity, an extinction,” said Prof. Danovaro.


“But, at the regional and the local scale, we have a loss of biodiversity if there is a decrease of a species to nothing in a certain region.”


Prof. Danovaro coordinates a project called MERCES, which is restoring habitats in biologically depleted regions of Europe by reintroducing key species, which are mainly plants and corals.











Biodiversity loss in the oceans can be reversed through habitat restoration
Gorgonians are being reintroduced in hard-bottom habitats in European seas
[Credit: Pxhere]

If marine habitats can successfully be replenished with life, this means that ecosystems could recover from the damage caused by industrial development, from gas pipeline construction, for example, or mining activities.


“This is an opportunity not to stop (building) infrastructure but to find a solution to encourage blue growth (economic growth in the marine sector) development along with biodiversity conservation and habitat conservation,” Prof. Danovaro said.


In the seagrass meadows of the Mediterranean, Baltic and North Atlantic the team is replanting seaweed species, in hard-bottom habitats they are reintroducing gorgonians (sea fans) and in deep-sea areas, corals. Several species of seaweed, called kelp, and brown algae encourage the return of sea urchins, crustaceans, gastropods, bivalves, starfish and their predators. Prof. Danovaro says that so far between 50% and 90% of animals have returned to these habitats, depending on the species reintroduced.


The action taken by MERCES essentially speeds up how a natural ecosystem would recover in the absence of further impacts, according to Prof. Danovaro. “We are doing in a few years what can be done by nature in a 100 years or more,” he said.


New species


Ecosystem threats also come from the introduction of new species – sometimes but not always precipitated by harmful human activities and warming oceans – that can take over habitats. Newcomers often have defence mechanisms or other characteristics that allow them to outdo native animals when it comes to securing food and other resources.


Scientists from a project called EMERTOX have found an increasing amount of toxins from tropical algae native to the Caribbean and the Indian and Pacific Oceans is winding up the Mediterranean and North Atlantic.


Professor Vitor Vasconcelos, the project’s lead coordinator and biotechnology and ecotoxicology expert at the Interdisciplinary Centre of Marine and Environmental Research (CIIMAR) in Porto, Portugal, says that their increased presence is probably due to climate change, and possibly ballast water from ships.


When ships dock or set sail, they usually either release water or take a certain volume of water into their ballast tank. The stored water ensures the ship’s stability at sea, but can contain small sea creatures which are then released at a different port and can become established in a new area.


“Many of our activities are stressing the ecosystems, such as aquaculture and shipping. (Shipping) takes in a lot of ballast water and brings organisms to our waters that are not supposed to be here,” he said.











Biodiversity loss in the oceans can be reversed through habitat restoration
Dinoflagellate is found over many different oceans, but their DNA helps to determine
where they are from [Credit: NMNH/Mr.TinDC]

The toxins that the algae produce are poisonous to humans. They can accumulate to deadly levels in fish and shellfish like mussels and sea snails, which are eaten in many European countries. Severe human non-fatal intoxications, due to eating fish or shellfish contaminated with these invasive toxins, have been reported in Portugal, Spain, France and Italy in the past 14 years.


They can also disrupt the delicate balance of ecosystems. Toxic substances can be added to the arsenal of defences that shellfish deploy, increasing their chances of defeating predators.


“We already have evidence that these emerging toxins have an impact on the marine ecosystems because they are absorbed by species that never had them before. The balance is affected because they have new defence systems,” said Dr. Marisa Silva, a researcher involved in the EMERTOX project.
Toxins


The EMERTOX project will put together a series of maps of current and predicted toxin presence so that European authorities are well-informed about the likelihood of future toxic algae scenarios before someone is poisoned.


To do this, they’ll map the presence of the marine toxins and the organisms that produce them, a type of phytoplankton known as a dinoflagellate.


First, a photograph of the organism is taken so that the researchers can identify it by its size, colour and shape. Next, they extract its DNA using primers – tools that cut the DNA in specific places – and finally identify it by comparing the DNA fragments with others that are available in public databases.


Examining the DNA in this way allows the team not only to identify the species but also to tell what region the microorganism calls home.


“DNA from populations of the same species but coming from different areas have slight differences. It’s like having an identity card,” said Prof. Vasconcelos.


“For instance, the organisms from the Mediterranean have a different “fingerprint” compared to those that are coming from the Caribbean or the Pacific. By analysing the DNA we can understand these slight differences within the same species and by that we can understand the routes of dispersion of the species.”


The future scenarios will be built based on the DNA analyses and temperature and other data collected at various sites around Europe where the tropical toxins are already present.


“We want to develop models that will help us to predict what will the future occurrence of (toxin-producing) organisms in this area be if we increase the temperature by 5 or 10°C,” said Prof. Vasconcelos.


Author: Catherine Collins | Source: Horizon: The EU Research & Innovation Magazine [March 25, 2019]



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A petrifying virus key to evolution

A research team consisting of scientists from Kyoto University, Tokyo University of Science, National Institute for Physiological Sciences, and Tokyo Institute of Technology, report in the Journal of Virology the Medusavirus, a unique giant virus that gives pause to current theory on viral evolution.











A petrifying virus key to evolution
This virus was found infecting amoebas in the hot springs of northern Japan. The amoeba forms cysts, and produces
a hard protective covering, giving it the name: Medusavirus [Credit: (Kyoto University/Robin Hoshino]

The name Medusavirus was given for the effect this virus has on its host, Acanthamoeba castellanii. Once infected, the amoeba forms cysts, a phenomenon called encystment. This is a typical response to environments hostile to survival, and leaves the amoeba with a hard, protective covering. Perhaps it was not a coincidence then that Medusavirus was found in the hot springs in northern Japan, the first giant virus to have been isolated from a heated environment.


Along with the location of its discovery, Medusavirus holds a number of distinguishing features compared with other giant viruses. Its DNA codes for all five types of histones, the key proteins that help compact DNA within the nucleus. In fact, no other known virus has all five types. Further, Medusavirus encoded neither RNA polymerase nor DNA topoimerase II, whereas all other giant viruses encode at least one.


These features could explain why the replication of Medusavirus DNA begins and completes in the host nucleus to eventually fill the amoeba nucleus with viral DNA, which again is unlike other giant viruses.


Moreover, the morphology of the capsid surface was unique, in that it was covered with an extraordinary number of spherical-headed spikes. In addition, the amoeba genome encoded several capsid surface proteins.


The existence of histone genes in Medusavirus and capsid protein genes in amoeba suggest lateral gene transfer going both directions — host-to-virus and virus-to-host.


Overall, the findings suggest that Medusavirus offers a new model for host-virus co-evolution and that the Medusavirus is a new family of large DNA viruses.


Source: Kyoto University [March 25, 2019]



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Experts reveal that clouds have moderated warming triggered by climate change

A new study has revealed how clouds are modifying the warming created by human-caused climate change in some parts of the world.











Experts reveal that clouds have moderated warming triggered by climate change
Trees are removed from cold lake beds in Scandinavia [Credit: Professor Mary Gagen, Swansea University]

Led by Swansea University’s Tree Ring Research Group, researchers from Sweden, Finland and Norway analysed information contained in the rings of ancient pine trees from northern Scandinavia to reveal how clouds have reduced the impact of natural phases of warmth in the past and are doing so again now to moderate the warming caused by anthropogenic climate change.
Even though northern Scandinavia should be strongly affected by global warming, the area has experienced little summer warming over recent decades – in stark contrast to the hemispheric trend of warming temperatures, which is strongly linked to rising greenhouse gas emissions. According to the study, temperature changes have been accompanied by an increase in cloudiness over northern Scandinavia, which in turn has reduced the impact of warming.


Mary Gagen, Professor of Geography at Swansea University, said: “The surface warming caused by rising greenhouse gases is modified by many complicated feedbacks – one thing changing in response to another – meaning that there are large geographical variations in the temperature of a particular place at a particular time, as the global average temperature rises. One of the most important, and most poorly understood, climate feedbacks is the relationship between temperature and clouds. We might think that, simply, when it is cool it is cloudy, and when it is warm it is sunny, but that is not always the case.”











Experts reveal that clouds have moderated warming triggered by climate change
Professor Mary Gagen core sampling a tree [Credit: Professor Mary Gagen,
Swansea University]

The research team analysed tree ring records to find out what summer temperatures were like in the past, and how cloudy it was. Using their collected data, the team produced a new reconstruction of summer cloud cover for northern Scandinavia and compared it to existing temperature reconstructions to establish the relationship between temperature and cloud cover.
Professor Mary Gagen said: “Most people know that the width of a tree ring can tell us what the temperature was like in the summer that ring grew, but we can also measure other things in tree rings such as the isotopes of carbon and water that the wood is made from. Isotopes are just different types of an element, the amount of the different isotopes of carbon in the wood tells us how cloudy it was in the summer the tree ring grew. By combining the tree ring width and tree ring carbon measurements we built a record of both past summer temperatures and past summer cloud cover. Summer temperatures in Scandinavia have increased by less than the global average in recent decades because it also got cloudier at the same time, and that modified and reduced the warming. That turns out to also be the case back through time.”


Author Professor Danny McCarroll explained: “We found that over short timescales, increased cloud cover lead to cooler temperatures and vice versa in the past. However, over longer timescales -decades to centuries-we found that in warmer times, such as the medieval, there was increased cloud cover in this part of the world, which reduced local temperatures. The opposite being true in cool periods, such as the Little Ice Age.











Experts reveal that clouds have moderated warming triggered by climate change
The preserved rings of a pine tree, that started growing in 1369 and fell into a cold lake in 1716, allow scientists
to measure what the temperature was like in the summers of each year’s growth and how sunny it was
[Credit: Risto Jalkanen]

“These finding are important as they help to explain the feedback relationship between cloud cover and temperature, which is one of the major uncertainties in modelling future climate. Understanding the past relationship between temperature and cloud cover in this part of the world means we can now predict that, as the global temperature continues to rise, that warming will be moderated in northern Scandinavia by increasing cloud cover. The next step is to find out whether the same is true for other parts of the world.”


Professor Mary Gagen added: “One of the main sources of uncertainty about future climate change is the way that clouds are going to respond to warming, cloud cover has a really big influence on temperature at the surface of the Earth.


“Clouds are going to be critical in modify warming of the climate. In some places, like Scandinavia, it turns out that the summer climate gets cloudier as the planet warms, in other places though it is likely that warming will be enhanced by a reduction in cloudiness which will make the surface of the Earth even warmer. What is really worrying is that climate models have shown that, if greenhouse gas emissions are allowed to continue until there is double or even triple the pre industrial amount of carbon dioxide in the atmosphere, then some of the most important clouds for cooling our planet, the big banks of oceanic clouds that reflect a lot of sunlight back to space, could stop forming altogether and this would really accelerate warming.”


The study is published in Geophysical Research Letters.


Source: Swansea University [March 25, 2019]



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The struggle for life in the Dead Sea sediments: Necrophagy as a survival mechanism

The Dead Sea is not completely dead. The most saline lake on Earth (more than 10 times saltier than sea water) is a harsh environment where only salt-loving microbes from the Archaea domain, known as extreme halophiles, are able to survive. Geologists are interested in the evolution of this lake and have been investigating its subsurface to reconstruct its biological and geological history. The salty sediments of the Dead Sea are still full of mysteries, in particular regarding the life forms harbored there, commonly called the deep subsurface biosphere.











The struggle for life in the Dead Sea sediments: Necrophagy as a survival mechanism
Aerial photograph of the Dead Sea western shore. Parallel paleo shorelines show the intense water level drop
(currently about 1 m per year). Salt (halite) actively precipitating from the water column gives this light
blue colour to the lake [Credit: International Continental scientific Drilling Program]

There is a vast microbial biomass below Earth’s surface, which survives without oxygen, light, or fresh food delivery. This subsurface biosphere has been the subject of numerous scientific studies. Its importance in global biogeochemical cycles is largely acknowledged, and constant efforts are being carried out to estimate the limits of life development in these extreme environments, as they present an immense potential for medical and biotechnology research. Given its exceptional salinity, the Dead Sea subsurface is an environment where life is pushed to its limits and, as such, constitutes a prime choice to investigate how life forms can adapt and thrive.


The new study for Geology by Camille Thomas and colleagues describes a novel strategy used by some microorganisms to survive in the hypersaline, carbon-, and water-deprived environment of the Dead Sea subsurface.


By looking at molecular fossils preserved in deep sediments, the team of Swiss and French scientists found unique molecular compounds, known as storage lipids, in the most saline sedimentary layers of the lake. The chemical structure of these lipid compounds indicates that remains from extreme halophilic archaea were recycled by other microbial populations, likely from the bacteria domain, previously thought to be unadapted to such a harsh locale. This necrophagic behavior allowed them to build carbon stocks in this food-deprived environment. It also provided water to mitigate the extreme salinity of the Dead Sea subsurface.


This all constitutes an unprecedented strategy for survival in the deep biosphere. These findings widen the understanding of adaptations exhibited by microorganisms to live in extreme environments, a research domain scientists are only beginning to understand.


Source: Geological Society of America [March 25, 2019]




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Scientists solve mystery shrouding oldest animal fossils

Scientists from The Australian National University (ANU) have discovered that 558 million-year-old Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially had mouths and guts.











Scientists solve mystery shrouding oldest animal fossils
Scientists from The Australian National University have discovered the have discovered that 558 million-year-old
Dickinsonia fossils do not reveal all of the features of the earliest known animals, which potentially
had mouths and guts [Credit: Ilya Bobrovskiy, The Australian National University (ANU)]

ANU PhD scholar Ilya Bobrovskiy, lead author of the study, said the study shows that simple physical properties of sediments can explain Dickinsonia’s preservation, and implies that what can be seen today may not be what these creatures actually looked like.


“These soft-bodied creatures that lived 558 million years ago on the seafloor could, in principle, have had mouths and guts — organs that many palaeontologists argue emerged during the Cambrian period tens of millions of years later,” said Mr Bobrovskiy from the ANU Research School of Earth Sciences.


“Our discovery about Dickinsonia — and many other Ediacaran fossils — opens up new possibilities as to what they actually looked like.”


Ediacara biota were strange creatures that lived on the seafloor 571 to 541 million years ago. They grew up to two metres long and include the earliest known animals as well as colonies of bacteria.


The fact that Dickinsonia and other Ediacara biota fossils were preserved at all in the geological record has been a big mystery — until now.


The team, which includes scientists from Russian institutions, discovered how Ediacara biota fossils were preserved, despite the macroorganisms not having skeletons or shells.


“As the organisms decayed, softer sediment from below gradually flowed into the forming void, creating a cast,” Mr Bobrovskiy said.


“Now we know that what we are looking at is an impression of a soft organic skeleton that may have been anywhere within Dickinsonia’s body. What we’re seeing could be a part of Dickinsonia’s bottom, the inside of its body or part of its back.”


Mr Bobrovskiy said Dickinsonia had different types of tissues and must have been a true animal, a Eumetazoa, the lineages eventually leading to humans.


Co-researcher and RSES colleague Associate Professor Jochen Brocks said the team used a melting cast of a Death Star made of ice to show the physical properties of sediments that enabled the soft-bodied Ediacara biota to be preserved.


“This process of fossilisation could tell us more about what Ediacara biota were and how they lived,” he said.


“These fossils comprise our best window into earliest animal evolution and are the key to understanding our own deep origins.”


The findings are published in Nature Ecology & Evolution.


Source: Australian National University [March 25, 2019]



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Deep time tracking devices: Fossil barnacles reveal prehistoric whale migrations

Many whales take long journeys each year, spending summers feeding in cold waters and moving to warm tropical waters to breed. One theory suggests that these long-distance migrations originated around 5 million years ago, when ocean productivity became increasingly patchy. But patterns of ancient whale migrations have, until recently, been shrouded in mystery. Scientists from the Smithsonian Tropical Research Institute (STRI) and the University of California, Berkeley approached this question with an ingenious technique: barnacles.











Deep time tracking devices: Fossil barnacles reveal prehistoric whale migrations
Fossil whale barnacles from the Pleistocene were retrieved from the Burica Peninsula
of Panama for analyses [Credit: Larry Taylor]

“Instead of looking for clues to migration patterns from the whale’s bones, we used hitch-hiking whale barnacles instead,” said Larry Taylor, STRI visiting scientist and doctoral student at UC Berkeley who led the study.


Barnacles are crustaceans (crabs, lobsters, shrimp) that live stuck in one place in a hard shell. Most glue themselves to rocks, but whale barnacles attach to a whale’s skin by sucking the skin in.


“Whale barnacles are usually species specific –one species of barnacle on one type of whale,” said Aaron O’Dea, staff scientist at STRI and co-author of the study. “This gives the barnacle several advantages– a safe surface to live on, a free ride to some of the richest waters in the world and a chance to meet up with others when the whales get together to mate.”


As whale barnacles grow, their shells record the conditions by taking up oxygen isotopes from the water. By carefully reading the unique isotope signatures left in the shells, the barnacles can reveal the water bodies the barnacle passed through, helping reconstruct the whale’s movements over time.











Deep time tracking devices: Fossil barnacles reveal prehistoric whale migrations
Modern whale barnacles attach to a humpback whale’s skin
[Credit: Aleria Jensen, NOAA/NMFS/AKFSC]

The study, published in Proceedings of the National Academy of Sciences looked at a number of fossil and modern whale barnacles from the Pacific coast of Panama and California.
“The signals we found in the fossil barnacles showed us quite clearly that ancient humpback and grey whales were undertaking journeys very similar to those that these whales make today,” Taylor said. “It seems like the summer-breeding and winter-feeding migrations have been an integral part of the way of life of these whales for hundreds of thousands of years.”


“We want to push the technique further back in time and across different whale populations,” said Seth Finnegan, co-author from UC Berkeley. “Hunting for fossil whale barnacles is easier than whales, and they provide a wealth of information waiting to be uncovered.”


Source: Smithsonian Tropical Research Institute [March 25, 2019]



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Spacewalk Reassignments: What’s the Deal?


EVA – Extra Vehicular Activities patch.


March 27, 2019


On Friday, March 29, Christina Koch and Anne McClain were scheduled to perform a spacewalk together to upgrade the power systems of the International Space Station. It would have been the first all-female spacewalk in human history. While disappointing to many people, after the last spacewalk was completed March 22, NASA changed the assignments to protect the safety of the crew and the timing of the mission. Now, Christina Koch and Nick Hague will be performing this upcoming spacewalk, leaving lots of people are wondering: What’s the deal?


1. Why did the availability of spacesuit sizes affect the schedule?


Spacesuits are not “one size fits all.” We do our best to anticipate the spacesuit sizes each astronaut will need, based on the spacesuit size they wore in training on the ground, and in some cases astronauts train in multiple sizes.


McClain trained in both a medium and a large on Earth. However, living in microgravity can change the size of your body! In fact, Anne McClain has grown two inches since she launched to the Space Station.



Image above: Astronaut Anne McClain gets assistance putting on her spacesuit during her ASCAN EVA Skills 3 Training. Image Credits: NASA/Lauren Harnett.


McClain realized that the medium she wore during the March 22 spacewalk was a better fit for her in space. She had planned to wear a large during the March 29 spacewalk.


In a tweet, McClain explained: “This decision was based on my recommendation. Leaders must make tough calls, and I am fortunate to work with a team who trusts my judgement. We must never accept a risk that can instead be mitigated. Safety of the crew and execution of the mission come first.”


To provide each astronaut the best fitting spacesuit during their spacewalks, Koch will wear the medium torso on March 29, and McClain will wear it again on April 8.


2. Why is spacesuit sizing so important?


The spacesuit is a mini spaceship that keeps our astronauts alive while they are spacewalking!


Astronauts train several hours on Earth in the Neutral Buoyancy Lab for every hour they spend spacewalking. Spacewalks are the most physically demanding thing we ask astronauts to do, which is why an optimally fitted spacesuit is important to completing the assigned tasks and overall mission!


3. How come you don’t have enough spacesuits in the right size?


We do have enough torsos. The spacesuit takes into account more than 80 different body measurements to be configured for each astronaut. The suit has three sizes of upper torso, eight sizes of adjustable elbows, over 65 sizes of gloves, two sizes of adjustable waists, five sizes of adjustable knees and a vast array of padding options for almost every part of the body.


In space, we have two medium hard upper torsos, two larges and two extra larges; however, one of the mediums and one of the extra larges are spares that would require 12 hours of crew time for configuration.



Spacesuit description.Image Credit: NASA

12 hours might not seem like a long time, but the space station is on a very busy operational schedule — every five minutes of an astronaut’s life in space is scheduled to conduct science experiments, maintain their spaceship, and stay healthy (they exercise two hours a day to keep their bones and muscles strong!).


The teams don’t want to delay this spacewalk because two resupply spacecraft – Northrop Grumman Cygnus and SpaceX cargo Dragon – are scheduled to launch to the space station in the second half of April. That will keep the crew very busy for a while!


Configuring the spare medium also poses a risk: The intricate life support and controls system[DBK(1]  (in addition to the pressure garment components) must be moved, and then, after being reconfigured, must complete additional functional checks to ensure it all was reassembled correctly with no chance of leaks.


Nothing is more important than the safety of our crew!


4. Why has there not already been an all-female spacewalk?


NASA does not make assignments based on gender.


The first female space shuttle commander, the first female space station commander and the first female spacewalker were all chosen because they the right individuals for the job, not because they were women. It is not unusual to change spacewalk assignments as lessons are learned during operations in space.



Astronaut McClain first spacewalk. Image Credit: NASA

McClain became the 13th female spacewalker on March 22, and Koch will be the 14th this Friday – both coincidentally during Women’s History Month! Women also are filling two key roles in Mission Control: Mary Lawrence as the lead flight director and Jaclyn Kagey as the lead spacewalk officer.


5. When will the all-female spacewalk happen?


An all-female spacewalk is inevitable! As the percentage of women who have become astronauts increases, we look forward to celebrating the first spacewalk performed by two women! McClain, Koch (and Hague!) are all part of the first astronaut class that was 50 percent women, and five of the 11 members of the 2017 astronaut candidate class are also women.


You can watch the upcoming spacewalk on March 29 at 6:30 ET, which is one in a series to upgrade the station’s power technology with new batteries that store power from the solar arrays for the station to use when it is in orbital night: https://www.nasa.gov/nasalive/


Related links:


Life support and controls system (DBK(1): https://www.nasa.gov/feature/spacewalk-reassignments-what-s-the-deal#_msocom_1


Spacewalk: https://www.nasa.gov/mission_pages/station/spacewalks/


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


Images (mentioned), Text, Credits: NASA/Thalia Patrinos.


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