среда, 7 ноября 2018 г.

ESA’s gravity-mapper reveals relics of ancient continents under Antarctic ice


ESA – GOCE Mission logo.


7 November 2018


It was five years ago this month that ESA’s GOCE gravity-mapping satellite finally gave way to gravity, but its results are still yielding buried treasure – giving a new view of the remnants of lost continents hidden deep under the ice sheet of Antarctica.


A research team from Germany’s Kiel University and the British Antarctic Survey published their latest GOCE-based findings this week in the journal Scientific Reports.



GOCE reveals Antarctic tectonics

Dubbed ‘the Formula one of space’, the GOCE (Gravity field and Ocean Circulation Explorer) mission orbited Earth for more than four years, from March 2009 to November 2013. This sleek, finned satellite with no moving parts was designed around a single goal: to measure the pull of Earth’s gravity more precisely than any mission before.


GOCE flew at an altitude of just 255 km, more than 500 km nearer than a typical Earth observation satellite, to maximise its sensitivity to gravity.


In its last year in orbit, with its supply of xenon propellant holding out well, GOCE was manoeuvred down still lower, to just 225 km altitude, for even more accurate gravity measurements. The propellant keeping it resistant to air drag was finally spent in October 2013, and it reentered the atmosphere three weeks later.


GOCE’s main output was a high-fidelity global gravity map or ‘geoid’, but the mission also charted localised gravity gradients – measurements of how rapidly the acceleration of gravity changes – across all directions of motion, down to a resolution of 80 km.



GOCE: orbiting on the edge

The team from Kiel University and BAS has converted this patchwork of 3D gravity measurements into curvature-based ‘shape indexes’ across the different regions of our planet, analogous to contours on a map.


The study’s lead author Prof Jörg Ebbing from Kiel University comments, “The satellite gravity data can be combined with seismological data to produce more consistent images of the crust and upper mantle in 3D, which is crucial to understand how plate tectonics and deep mantle dynamics interact.”


In combination with existing seismological data, these gravity gradients show high sensitivity to known features of Earth’s ‘lithosphere’, the solid crust and that section of the molten mantle beneath it.



GOCE’s global tectonic map

These features include dense rocky zones called cratons – remnants of ancient continents found at the heart of modern continental plates – highly folded ‘orogen’ regions associated with mountain ranges and the thinner crust of ocean beds.


The new window into the deep subsurface offered by this data offers novel insights into the structure of all Earth’s continents, but especially Antarctica. With more than 98% of its surface covered by ice with an average thickness of 2 km, the southern continent largely remains a blank spot on current geological maps.


“These gravity images are revolutionising our ability to study the least understood continent on Earth, Antarctica,” says co-author Fausto Ferraccioli, Science Leader of Geology and Geophysics at BAS.


“In East Antarctica we see an exciting mosaic of geological features that reveal fundamental similarities and differences between the crust beneath Antarctica and other continents it was joined to until 160 million years ago.”



GOCE map of Antarctica on bedrock topography

The gravity gradient findings show West Antarctica has a thinner crust and lithosphere compared to that of East Antarctica, which is made up of a mosaic of old cratons separated by younger orogens, revealing a family likeness to Australia and India.


These findings are of more than purely historic geological interest. They give clues to how Antarctica’s continental structure is influencing the behavior of ice sheets and how rapidly Antarctica regions will rebound in response to melting ice.


ESA’s GOCE mission scientist Roger Haagmans adds, “It is exciting to see that direct use of the gravity gradients, which were measured for the first time ever with GOCE, leads to a fresh independent look inside Earth – even below a thick sheet of ice.


“It also provides context of how continents were possibly connected in the past before they drifted apart owing to plate motion.”


Related links:


Scientific Reports: Latest GOCE-based findings: https://www.nature.com/articles/s41598-018-34733-9


GOCE+Antarctica: https://www.bas.ac.uk/project/goceantarctica


Access GOCE data: http://earth.esa.int/GOCE/


GOCE: http://www.esa.int/Our_Activities/Observing_the_Earth/GOCE


ESA EO Science for Society: https://eo4society.esa.int/


Kiel University: https://www.uni-kiel.de/en/


British Antarctic Survey: https://www.bas.ac.uk/


Images, Video, Text, Credits: ESA/Kiel University/P. Haas/BAS.


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Satellite ‘compasses’ open new window on space weather


ESA – European Space Agency logo.


7 November 2018


Researchers have tested a clever new method of monitoring the impact of solar storms on Earth’s magnetic field, based on harnessing the compass-like magnetometers that space missions used to check their orientation.


Some satellites carry extremely sensitive magnetometers for scientific studies; these instruments are placed on booms, away from stray magnetic field sources inside the parent satellite.



Swarm constellation

But many more satellites host less sensitive magnetometers, called ‘platform magnetometers’ that work like compasses, measuring Earth’s magnetic field to check satellites are pointed in the correct position.


Might these platform magnetometers also be used to monitor space weather? An ESA-led research team consisting of Delft University of Technology and the GFZ German Research Centre for Geosciences mounted an investigation.



What is space weather?

ESA space environment researcher Fabrice Cipriani explains: “Quantifying the effects that solar storms have on Earth is extremely important to monitor and assess the impacts on sensitive infrastructure and so we want to exploit as many sources of data as possible that can provide meaningful information, especially when there are no major development costs involved.”


Researchers looked at data from ESA’s magnetic-field-mapping Swarm, gravity-mapping GOCE and technology-testing LISA Pathfinder missions to probe whether platform magnetometer data could also be used for monitoring changing space weather.


The team compared the data from Swarm’s scientific magnetometer with its platform magnetometer to determine the accuracy of the latter. They then applied this knowledge to an analysis of GOCE’s magnetometer. These were both low-Earth orbiting missions, providing a lot of information about Earth’s response to space weather. LISA Pathfinder, conversely, operated from an Earth-Sun Lagrange Point, 1.5 million km away.



LISA Pathfinder

Eelco Doornbos, from TU Delft explains: “LISA Pathfinder is positioned between Earth and the Sun, outside Earth’s magnetosphere. This gives it a great view of the solar wind.”


LISA Pathfinder’s platform magnetometer data was compared with that of US space weather observatories WIND, ACE and DSCOVR.


“We investigated data from LISA Pathfinder, which can observe the solar wind, and from Swarm and GOCE, observing magnetic field currents closer to Earth,” adds Dr. Doornbos. “In both cases the platform magnetometer data was good enough to receive a good signal, even when the magnetometer is not very precise and is close to other instruments.”



GOCE

The team found that platform magnetometers can indeed provide excellent insights into space weather. Their usage could be fostered in future through developing new data processing techniques, relatively low cost compared to developing dedicated instruments and missions.


Traditionally platform magnetometer data are only sent to Earth so that engineers can check a satellite is working properly. The next step is to make this data accessible to more people.


Fabrice adds: “We want to encourage data users to be involved at an early design phase when developing new spacecraft, to help figure out how to enable easier access to the this data.”



Platform magnetometer

“Space weather is such a complicated system that changes so rapidly that the more observations you have, the better,” concludes Dr. Doornbos. “That’s why it’s great to get as many satellites as possible looking into it.”


This research was supported through ESA’s Discovery and Preparation programme, investigating promising new concepts for spaceflight.


Related links:


Space weather: http://www.esa.int/spaceinimages/Images/2018/11/What_is_space_weather


WIND: https://wind.nasa.gov/


ACE: https://science.nasa.gov/missions/ace


DSCOVR: https://www.nesdis.noaa.gov/content/dscovr-deep-space-climate-observatory


Swarm: http://www.esa.int/Our_Activities/Observing_the_Earth/The_Living_Planet_Programme/Earth_Explorers/Earth_Explorers_-_Swarm


GOCE: http://www.esa.int/Our_Activities/Observing_the_Earth/GOCE


LISA Pathfinder: http://sci.esa.int/lisa-pathfinder/


Discovery and Preparation article: ESA’s unexpected fleet of space weather monitors: https://www.esa.int/Our_Activities/Preparing_for_the_Future/Discovery_and_Preparation/ESA_s_unexpected_fleet_of_space_weather_monitors


Delft University of Technology: https://www.tudelft.nl/en/


GFZ Research Centre for Geosciences: http://www.gfz-potsdam.de/en/home/


Images, Text, Credits: ESA, CC BY-SA 3.0 IGO/ZARM Technik AG.


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Early Signs Alzheimer’s disease ravages the brain well before…


Early Signs


Alzheimer’s disease ravages the brain well before patients start to experience memory loss. In an ideal world, pre-symptomatic treatments could slow or even stop the eventual and irreversible degeneration of brain tissue. Unfortunately, these early stages can only be detected post-mortem, typically by looking for neurofibrillary tangles (shown in red in this brain section); these protein clusters are one of the earliest biological indicators of disease onset. However, scientists have recently shown that there may also be psychiatric indicators. Analysing post-mortem brains, the team found that individuals who hadn’t started experiencing memory loss but had neurofibrillary tangles in a particular brain region were more likely to have suffered from anxiety, changes in appetite, difficulties sleeping, and depression. Such symptoms aren’t necessarily causative, but may be a warning that the disease is picking up speed, so giving some hope of earlier diagnosis and even of new therapies to slow its onset.


Written by Gaëlle Coullon



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Despite Indonesian government claims, orangutan populations have not increased

Orangutan populations are still declining rapidly, despite claims by the Indonesian Government that things are looking better for the red apes. In the journal Current Biology, a team of scientists including Maria Voigt of the German Centre for Integrative Biodiversity Research (iDiv) and the Max Planck Institute for Evolutionary Anthropology criticise the use of inappropriate methods for assessing management impacts on wildlife trends. The researchers call for scientifically sound measures to be employed in order to ensure that wildlife monitoring provides reliable numbers.











Despite Indonesian government claims, orangutan populations have not increased
Scientists call for the employment of scientifically sound methods for monitoring orangutan populations
[Credit: HUTAN-KOCP]

A recent report by the Government of Indonesia states that orangutan populations have increased by more than 10% from 2015 to 2017. These numbers are criticised in an article published in the current issue of Current Biology. Lead author Erik Meijaard from the Center of Excellence for Environmental Decisions at the University of Queensland and director of Borneo Futures in Brunei explains: “These numbers are in strong contrast with other recent publications about orangutan status and trends.”
According to the authors, over the past ten years alone, the number of Bornean orangutans has declined by at least 25%, representing a loss of more than 100,000 individuals since the year 1999. Sumatran orangutans and the recently described Tapanuli orangutan lost more than 60% of their forest habitat between 1985 and 2007, and their populations are expected to further decline by 11 to 27% until 2020.


The scientists reiterate that the latest scientific data show how the survival of the three orangutan species continues to be seriously threatened by deforestation and killing; all are “Critically Endangered” under the IUCN Red List.











Despite Indonesian government claims, orangutan populations have not increased
Orangutan populations have been declining dramatically
[Credit: Serge Wich]

How can there be such a mismatch between what the government states and what independent scientists have published about the orangutan conservation status? The paper’s authors offer a few suggestions:


The government monitoring methods focus on nine sampled populations. These populations represent less than 5% of the Bornean and Sumatran orangutan ranges, and zero percent of the Tapanuli orangutan range. All monitoring sites are within protected areas, whereas the majority of orangutans occur in non-protected lands like oil palm plantations, private gardens, community lands, and logging concessions.


Habitat conditions and threats differ vastly across these and thus population trends observed in a few protected sites cannot credibly inform the status of all three species. The government-reported increases are also highly unlikely considering known reproductive rates and ongoing killing observed in many populations.


Senior author Maria Voigt of the iDiv research centre and the Max Planck Institute for Evolutionary Anthropology highlights the clear need to improve collaboration and data sharing between scientists and the Indonesian government authorities: “It appears that the government isn’t always aware of the latest published conservation science,” Voigt notes. “Both parties need to increase their engagement.”











Despite Indonesian government claims, orangutan populations have not increased
Forests are being converted into oil palm plantations. This is a major threat to orangutans
[Credit: HUTAN-KOCP]

According to Voigt, better collaboration between government, non-governmental organisations and scientists is especially important now that Indonesia is developing its new action plan for orangutan conservation for the years 2018 to 2027. “It is critical to ensure that the best data and methods are used to determine which conservation strategies should be applied and where,” Voigt explains. “The choice of possible conservation strategies, such as forest protection, law enforcement, education, community engagement or orangutan rescues and rehabilitation depends on local orangutan trends, survival rate and pressures. This is what science can bring to the table.”


“I am optimistic,” says first author Erik Meijaard. “I still believe that by bringing together science, policy, land-use and species management we can save the orangutan and prevent its extinction in the wild.”


And there is hope that this can help the remaining orangutans. The new moratorium on oil palm licenses by Indonesian President Jokowi, for example, presents a real opportunity for saving the 10,000 orangutans that currently occur in areas allocated to oil palm by giving them permanent forest protection status.


It does, however, require a change of conservation mindset. “We need to learn how to better manage and protect those populations that are found outside of formally protected areas,” Maria Voigt says. “An improvement of the status of the three orangutan species can only be achieved with the genuine collaboration and engagement of all parties that have a stake in these non-protected lands: the agriculture industry, local communities and local governments.”


Source: German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig [November 05, 2018]



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Saber-toothed cats with oral injuries ate softer foods

Saber-toothed cats, the large felid predators that once roamed Southern California, may have eaten softer foods after suffering oral injuries, according to a new study. Microscopic damage patterns on teeth from fossilized cats show the injured predators transitioned to seeking softer prey, like flesh instead of bone, which healthy cats may have provided for them, according to the study.











Saber-toothed cats with oral injuries ate softer foods
Sabertooth cat from the La Brea Tar Pits and Museum that once roamed Southern California
[Credit: Larisa DeSantis]

Saber-toothed cats likely suffered injuries while felling large prey, according to the study’s lead author, vertebrate paleontologist Larisa DeSantis from Vanderbilt University, Tennessee.


The cat’s prey animals were larger 10,000 to 50,000 years ago, DeSantis says, and could have easily broken jaws or kicked teeth completely free from the socket, leading to subsequent and sometimes lethal infection. It’s unlikely that cats with such severe injuries could take down large animals and consume their soft, fleshy meat, she says, or even survive long after the injury.


“The fact that they’re eating food that really shouldn’t be available to them unless they’re being provided for, and that they’re living with these injuries for prolonged periods of time suggests they’re being provisioned food by other cats,” she says.


Microdamage patterns recorded in tooth enamel, like mountains and valleys in a topographic map, tell the history of an animal’s diet. These patterns allow researchers to glean information like whether a predator was scavenging on bone or eating tougher foods like flesh. Anthropologists have pioneered the same technique to explore the diets of early human ancestors.











Saber-toothed cats with oral injuries ate softer foods
Sabertooth cat lower jaw with deep root abscess. Note severe swelling
[Credit: Larisa DeSantis]

DeSantis and her colleagues compared the dental microwear patterns of injured versus uninjured cats, thanks to a large pathology collection available at the La Brea Tar Pits and Museum in Los Angeles, California. Many of the fossils show signs of prolonged infection and bone growth associated with healing — signs that the animals survived after what would have been fatal injuries if not part of a social group.


“What’s really exciting about this,” DeSantis says, “is that you see pretty clear evidence that they’re surviving for longer. That in itself gives you evidence of potential care within the social group.”


These findings further support the idea that saber-toothed cats were social animals, being an exception to the rule of non-sociality in the lion’s share of felid species. Saber-toothed cats consumed both flesh from fresh kills and utilized carcasses.


“There is a lot of evidence that Smilodon was a social and gregarious animal,” says Christopher Shaw, Collections Manager Emeritus at the La Brea Tar Pits and Museum and coauthor on the study, “which implies that they hunted together and fed at group kills. This study adds another provocative aspect to the sociability within this species and, for the first time, addresses new evidence regarding food options and feeding behaviors for injured members of the social group.”


DeSantis’s interest in this work began in an earlier study, where she found that man-eating lions may have turned to human prey, in part, because of similar oral injuries. Preserved teeth of confirmed, man-eating lions stored at the Field Museum of Natural History in Chicago, Illinois, showed patterns of wear that were similar to captive zoo lions, which ate soft foods consisting mostly of beef and horse meat.


Source: Geological Society of America [November 05, 2018]



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Fern plant infusion keeps the doctor away in Medieval Europe

The remains of a medieval skeleton has shown the first physical evidence that a fern plant could have been used for medicinal purposes in cases such as alopecia, dandruff and kidney stones.











Fern plant infusion keeps the doctor away in Medieval Europe
Asplenium trichomanes is a common species that grows in rocky areas worldwide
[Credit: University of York]

The skeleton of a male aged between 21 and 30 years found buried in the medieval necropolis of Can Reiners on the Spanish Balearic Islands, had traces of starch grains consistent with cereal plants, such as wheat and rye, and significantly, a collection of cells in which spores are formed from the underside of a fern leaf.


There is no evidence to suggest that the fern leaf was part of human diets at any point in recorded history, but there are written descriptions dating as far back as the first century AD that suggest the fern leaf was used to alleviate the symptoms of particular non-life-threatening conditions.


Folk medicine stories collected in various books suggest that the fern was used across Europe, but this is the first time any evidence has been found in actual human remains and the first time the particular species of fern has been identified.


Dr Elena Fiorin, from the University of York’s Department of Archaeology, said: “Through analysis of the dental calculus of the skeleton, which we believe dates back to the ninth or 10th century, we were able to determine that the cells were from fern plant, asplenium trichomanes, a common species that grows in rocky areas worldwide.


“These ferns have been used by herbalists, surgeons, doctors, and other healers for centuries across Europe, but until now we have only had written documents that describe their use.











Fern plant infusion keeps the doctor away in Medieval Europe
The skeleton was a male aged between 21 and 30 years of age
[Credit: University of York]

“The finding from the dental remains of this skeleton show just how much information we can get from dental calculus analysis. It demonstrates that in this region of Spain, communities were aware of the medicinal properties of some plants and how to administer them to get the desired result.”


Records show that a liquid infusion was made by pouring water into fresh or dried fern leaves, and sometimes the concoction was flavoured with orange flowers or sweetened sugar or honey.


Herbal texts show that the plants were exclusively used to cure particular diseases, most commonly what we would now recognise as dandruff, a common cold, kidney stones, and alopecia. There is also reference to the plant being used to stimulate menstrual flow in women.


Although there is no way of telling from the skeletal remains of the young male what he was treated for, it is likely he drank a fern leaf infusion to potentially cure a condition of the skin, urinary tract, or as a decongestant.


Dr Fiorin said: “The research demonstrates the use of ferns as healing plants in the Mediterranean during the Middle Ages. We now have the potential to look at other dental remains for similar properties that might tell us more about the use of medicinal herbs in the past.


“These ferns were employed, and are still used in Europe today, to cure a variety of diseases and through the archaeological record we can start to see how human beings have used the natural environment to assist in healthcare throughout our evolution.”


The research is published in the International Journal of Osteoarchaeology.


Author: Samantha Martin | Source: University of York [November 05, 2018]



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White line of algae deaths marks uplift in 2016 Chilean…


White line of algae deaths marks uplift in 2016 Chilean earthquake http://www.geologypage.com/2018/11/white-line-of-algae-deaths-marks-uplift-in-2016-chilean-earthquake.html


Punctuated earthquakes for New Madrid area: New research…


Punctuated earthquakes for New Madrid area: New research uncovers cluster of past events http://www.geologypage.com/2018/11/punctuated-earthquakes-for-new-madrid-area-new-research-uncovers-cluster-of-past-events.html


Nobody wins in a landslide…


Nobody wins in a landslide http://www.geologypage.com/2018/11/nobody-wins-in-a-landslide.html


Enhanced views of Earth tectonics…


Enhanced views of Earth tectonics http://www.geologypage.com/2018/11/enhanced-views-of-earth-tectonics.html


Our New Satellite to Study the Edge of Space

We’re about to launch a new satellite called ICON — the Ionospheric Connection

Explorer
— to study our planet’s boundary to space.


image

The overlap between Earth’s upper atmosphere and outer space

is complicated and constantly changing. It’s made up of a mix of neutral gas

(like the air we breathe) and charged particles, where negatively charged

electrons have separated from positively charged ions. This charged particle

soup reacts uniquely to the changing electric and magnetic fields in near-Earth

space, while weather conditions from here on Earth can also travel upwards and

influence this region. This makes Earth’s interface to space a dynamic,

hard-to-predict region of the atmosphere.


image

Understanding what causes the changes in this region and how

to predict them isn’t just a matter of curiosity. Earth’s boundary to space is

home to many of our Earth-orbiting satellites, and it also plays a role in

transmitting signals for communications and navigation systems. Unpredictable

changes here can garble those signals and even shorten the lifetime of

satellites.


image

ICON, launching on Nov. 7, will study this region with a

unique combination of instruments. Orbiting

about 360 miles above Earth, ICON will use its cameras to measure winds near

the upper edge of Earth’s boundary to space and track atmospheric composition

and temperature by studying a phenomenon called airglow. ICON also carries an instrument that

will capture and measure the particles directly around the spacecraft, or in

situ


image

ICON is launching aboard a Northrop Grumman Pegasus XL

rocket. On launch day, the Pegasus XL is carried out over the ocean by Northrop

Grumman’s L-1011 Stargazer aircraft, which takes off from Cape Canaveral Air

Force Station in Florida. About 50 miles off the coast of Florida, the Pegasus

XL drops from the plane and free-falls for about five seconds before igniting

and carrying ICON into low-Earth orbit.


image

NASA TV coverage of the launch starts at 2:45 a.m. EST on Nov. 7 at nasa.gov/live. You can also

follow along with the mission on Twitter, Facebook

or at nasa.gov/icon.


2018 November 7 NGC 6188: The Dragons of Ara Image Credit…


2018 November 7


NGC 6188: The Dragons of Ara
Image Credit & Copyright: Tian Lee


Explanation: Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large molecular cloud in the southern constellation Ara, about 4,000 light-years away. Born in that region only a few million years ago, the massive young stars of the embedded Ara OB1 association sculpt the fantastic shapes and power the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive stars, that swept up and compressed the molecular gas. With image data from the Chilescope Observatory, a false-color Hubble palette was used to create this gorgeous wide-field image and shows emission from sulfur, hydrogen, and oxygen atoms in red, green, and blue hues. The field of view spans about four full Moons, corresponding to about 150 light years at the estimated distance of NGC 6188.


∞ Source: apod.nasa.gov/apod/ap181107.html


Article of the Week standing in for the Image of the Week – November 5, 2018

With apologies for cross

posting. 


Great article about The

Cell Image Library in The Washington Post.


Where else have you seen

mention of the Cell Image Library? Let us know in the comments.


https://www.washingtonpost.com/national/health-science/an-online-archive-with-amazing-images-of-a-tiny-but-essential-element-of-life/2018/10/26/c453ea40-d6dd-11e8-a10f-b51546b10756_story.html?utm_term=.d3fc989054c7 


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Curiosity on the Move Again


NASA – Mars Science Laboratory (MSL) patch.


Nov. 6, 2018


NASA’s Mars Curiosity rover drove about 197 feet (60 meters) over the weekend to a site called Lake Orcadie, pushing its total odometry to over 12 miles (20 kilometers). This was Curiosity’s longest drive since experiencing a memory anomaly on Sept. 15. The rover switched to a spare computer, called the Side-A computer, on Oct. 3.


After more than two weeks of science operations, and now with this latest drive, the mission is back to business. The team plans to drill a new target later this week.


Curiosity’s engineering team at NASA’s Jet Propulsion Laboratory continues to diagnose the anomaly on the Side-B computer.



Image above: A self-portrait of NASA’s Curiosity rover taken on Sol 2082 (June 15, 2018). A Martian dust storm has reduced sunlight and visibility at the rover’s location in Gale Crater. Image Credits: NASA/JPL-Caltech.


Engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, this week commanded the agency’s Curiosity rover to switch to its second computer. The switch will enable engineers to do a detailed diagnosis of a technical issue that has prevented the rover’s active computer from storing science and some key engineering data since Sept. 15.


Like many NASA spacecraft, Curiosity was designed with two, redundant computers — in this case, referred to as a Side-A and a Side-B computer — so that it can continue operations if one experiences a glitch. After reviewing several options, JPL engineers recommended that the rover switch from Side B to Side A, the computer the rover used initially after landing.


The rover continues to send limited engineering data stored in short-term memory when it connects to a relay orbiter. It is otherwise healthy and receiving commands. But whatever is preventing Curiosity from storing science data in long-term memory is also preventing the storage of the rover’s event records, a journal of all its actions that engineers need in order to make a diagnosis. The computer swap will allow data and event records to be stored on the Side-A computer.


Side A experienced hardware and software issues over five years ago on sol 200 of the mission, leaving the rover uncommandable and running down its battery. At that time, the team successfully switched to Side B. Engineers have since diagnosed and quarantined the part of Side A’s memory that was affected so that computer is again available to support the mission.


“At this point, we’re confident we’ll be getting back to full operations, but it’s too early to say how soon,” said Steven Lee of JPL, Curiosity’s deputy project manager. “We are operating on Side A starting today, but it could take us time to fully understand the root cause of the issue and devise workarounds for the memory on Side B.


“We spent the last week checking out Side A and preparing it for the swap,” Lee said. “It’s certainly possible to run the mission on the Side-A computer if we really need to. But our plan is to switch back to Side B as soon as we can fix the problem to utilize its larger memory size.”


For more about Curiosity, visit: https://mars.nasa.gov/msl/


For more about NASA’s Mars program, visit: https://mars.nasa.gov


Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.


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Astronauts Ready Japanese Ship as Cosmonaut Works Russian Space Science


ISS – Expedition 57 Mission patch.


November 6, 2018


Japan’s seventh resupply ship to the International Space Station is packed and readied for departure Wednesday morning. However, the Japanese cargo ship, H-II Transfer Vehicle-7 (HTV-7), has one more delivery mission before it burns up safely over the Pacific Ocean.



Image above: This view of Japan from the International Space Station looks from north to south and encompasses the cities of Tokyo, Nagoya, Osaka, Hiroshima and Fukuoka. Image Credit: NASA.


Station skipper Alexander Gerst of ESA (European Space Agency) will command the Canadarm2 robotic arm to release the HTV-7 at 11:50 a.m. EST Wednesday. It will spend about an hour maneuvering safely away from the station on a trajectory to begin its next mission. Flight Engineer Serena Auñón-Chancellor will monitor the vehicle until it reaches a point about 200 meters from the space station. NASA TV begins its live coverage of the departure Wednesday at 11:30 a.m.


The HTV-7 will fire its deorbit engines Saturday for a fiery but safe ending to its mission after 41 days attached to the station’s Harmony module. Before the HTV-7 self-destructs in Earth’s atmosphere it will release a small reentry capsule loaded with test cargo for splashdown in the Pacific Ocean near the Japanese islands. The capsule will be retrieved by personnel from the Japan Aerospace Exploration Agency to test the space partner’s ability to safely return precious space cargo for analysis on Earth.



Image above: Earth Enveloped in Airglow. On October 7, 2018, an astronaut aboard the International Space Station (ISS) shot this photograph while orbiting at an altitude of more than 250 miles over Australia. The orange hue enveloping Earth is known as airglow—diffuse bands of light that stretch 50 to 400 miles into our atmosphere. The phenomenon typically occurs when molecules (mostly nitrogen and oxygen) are energized by ultraviolet (UV) radiation from sunlight. To release that energy, atoms in the lower atmosphere bump into each other and lose energy in the collision. The result is colorful airglow. Image Credit: NASA.


As the two Expedition 57 astronauts packed the cargo ship, cosmonaut Sergey Prokopyev continued his space physics research, photo inspections and inventory updates. The cosmonaut explored how microgravity and the Sun impact plasma-dust crystals. Prokopyev also photographed the condition of the station’s Russian segment then updated the station’s inventory system.


Related links:


Expedition 57: https://www.nasa.gov/mission_pages/station/expeditions/expedition57/index.html


H-II Transfer Vehicle-7 (HTV-7): https://www.nasa.gov/feature/kounotori-htv-launches-arrivals-and-departures


NASA TV: https://www.nasa.gov/nasatv


Plasma-dust crystals: https://www.energia.ru/en/iss/researches/process/02.html


Airglow: https://www.atoptics.co.uk/highsky/airglow1.htm


Space weather: https://www.nap.edu/catalog/10249/storms-from-the-sun-the-emerging-science-of-space-weather


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


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


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


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Cosmic Collisions: SOFIA Unravels the Mysterious Formation of Star Clusters


Illustration of a star cluster forming from the collision of turbulent molecular clouds, which appear as dark shadows in front of the background galactic star field.Credits: NASA/SOFIA/Lynette Cook. Hi-res image




Illustration of the molecular clouds surrounded by atomic envelopes, in green, which have been detected by SOFIA via emission from ionized carbon. The spatial offset and motions of these envelopes confirm predictions of simulations of cloud collisions.Credits: NASA/SOFIA/Lynette Cook. Hi-res image


The sun, like all stars, was born in a giant cold cloud of molecular gas and dust. It may have had dozens or even hundreds of stellar siblings – a star cluster – but these early companions are now scattered throughout our Milky Way galaxy. Although the remnants of this particular creation event have long since dispersed, the process of star birth continues today within our galaxy and beyond. Star clusters are conceived in the hearts of optically dark clouds where the early phases of formation have historically been hidden from view. But these cold, dusty clouds shine brightly in the infrared, so telescopes like the Stratospheric Observatory for Infrared Astronomy, SOFIA, can begin to reveal these long-held secrets. 


Traditional models claim that the force of gravity may be solely responsible for the formation of stars and star clusters. More recent observations suggest that magnetic fields, turbulence, or both are also involved and may even dominate the creation process. But just what triggers the events that lead to the formation of star clusters?


Astronomers using SOFIA’s instrument, the German Receiver for Astronomy at Terahertz Frequencies, known as GREAT, have found new evidence that star clusters form through collisions between giant molecular clouds.


The results were published in the Monthly Notices of the Royal Astronomical Society.


“Stars are powered by nuclear reactions that create new chemical elements,” said Thomas Bisbas, a postdoctoral researcher at the University of Virginia, Charlottesville, Virginia, and the lead author on the paper describing these new results. “The very existence of life on earth is the product of a star that exploded billions of years ago, but we still don’t know how these stars — including our own sun — form.”


Researchers studied the distribution and motion of ionized carbon around a molecular cloud where stars can form. There appear to be two distinct components of molecular gas colliding with each other at speeds of more than 20,000 miles per hour. The distribution and velocity of the molecular and ionized gases are consistent with simulations of cloud collisions, which indicate that star clusters form as the gas is compressed in the shock wave created as the clouds collide.


“These star formation models are difficult to assess observationally,” said Jonathan Tan, a professor at Chalmers University of Technology in Gothenburg, Sweden, and the University of Virginia, and a lead researcher on the paper. “We’re at a fascinating point in the project, where the data we are getting with SOFIA can really test the simulations.”


While there is not yet scientific consensus on the mechanism responsible for driving the creation of star clusters, these SOFIA observations have helped scientists take an important step toward unraveling the mystery. This field of research remains an active one, and these data provide crucial evidence in favor of the collision model. The authors expect future observations will test this scenario to determine if the process of cloud collisions is unique to this region, more widespread, or even a universal mechanism for the formation of star clusters.


“Our next step is to use SOFIA to observe a larger number of molecular clouds that are forming star clusters,” added Tan. “Only then can we understand how common cloud collisions are for triggering star birth in our galaxy.”


SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.


Media Point of Contact


Nicholas A. Veronico
Nicholas.A.Veronico@nasa.gov • SOFIA Science Center
NASA Ames Research Center, Moffett Field, California


Editor: Kassandra Bell


Source:  NASA/Stars



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NASA’s ICON to Explore Boundary Between Earth and Space


NASA – ICON Mission logo.


Nov. 6, 2018


Early in the morning of Nov. 7, 2018, NASA launches the Ionospheric Connection Explorer, or ICON, a spacecraft that will explore the dynamic region where Earth meets space: the ionosphere.  


Overlapping the farthest reaches of Earth’s atmosphere and the very beginning of space, the ionosphere stretches roughly 50 to 400 miles above the surface. Solar radiation cooks tenuous gases there until they lose an electron (or two or three), creating a sea of electrically charged ions and electrons. Neither fully Earth nor space, the ionosphere reacts both to winds and weather from the lower atmosphere below and solar energy streaming in from above, changing constantly to form conditions we call space weather.


“After years of work, I’m excited to get into orbit and turn on the spacecraft, open the doors on all our instruments,” said Thomas Immel, ICON principal investigator at the University of California, Berkeley. “ICON carries incredible capacity for science. I’m looking forward to surprising results and finally seeing the world through its eyes.”



Meet ICON: NASA’s Airglow Explorer

Video above: NASA’s Ionospheric Connection Explorer, or ICON, will orbit in the far reaches of the upper atmosphere, the bottom edge of near-Earth space. From this vantage point, ICON observes both the upper atmosphere and a layer of charged particles called the ionosphere. Video Credits: NASA’s Goddard Space Flight Center/G. Duberstein.


As far as space goes, the ionosphere is as close to home as it gets. Its constant changes can affect astronauts, satellites and much of the communications signals modern society relies upon. Scientists want to understand these changes, so they can eventually better predict them and protect our interests in space.


Space may look empty, but the ionosphere brims with electrically charged gases, solar radiation, and electric and magnetic fields. Turbulence in this sea of charged particles can manifest as disruptions that interfere with orbiting satellites or communication and navigation signals used, for example, to guide airplanes, ships and self-driving cars.


Depending on the energy it absorbs from the Sun, the ionosphere grows and shrinks. For that reason, scientists long thought this part of space was only affected by what happens in the space above it.


But over the past decade, a growing body of evidence has indicated the region is much more variable than we can explain with solar activity alone. The ionosphere’s contents are not evenly distributed: Dense patches of its charged gases, called plasma, are scattered throughout. Eventually, researchers linked these patches to global weather patterns — large-scale events such as several hurricanes rushing across the ocean at once, or changes in cloud formation over tropical rainforests.


Though the Sun provides the energy that drives weather we experience on Earth, day-to-day weather is driven by something very different: differences in temperature and moisture, interactions between oceans and land, and regions of high and low atmospheric pressure. Still, scientists were surprised to discover that terrestrial weather and the Sun manage to meet in the middle — at the ionosphere — in a tug-of-war for control.


Vast winds high above Earth’s surface carry energy around the globe and can modify the ionosphere indirectly by pushing around charged particles in the upper atmosphere. That motion creates an electric field, which guides the behavior of particles throughout the electrically charged ionosphere.


Part of the reason the ionosphere has remained so mysterious until now is the region is difficult to observe. Too high for scientific balloons and too low for satellites, the lower ionosphere especially — where Earth and space are most strongly connected — has eluded much of the technology researchers have used to study near-Earth space. But ICON is uniquely equipped to investigate the region.


“We’ve had the smoking gun — that indicated terrestrial and space weather are linked — but we’ve been missing actual observations in the region where these changes are taking place,” said Scott England, ICON project scientist at Virginia Tech in Blacksburg, Virginia. “ICON has all the tools to see the drivers and their effects in the system.”


From low-Earth orbit, ICON will explore these connections by tracking airglow, a quirk of our planet’s upper atmosphere. It refers to the light that shines from the ionosphere, enveloping Earth in a tenuous bubble of red, green and yellow. Airglow is created by a similar process that sparks the aurora: Gas is excited and emits light. Though auroras are typically confined to extreme northern and southern latitudes, airglow shines constantly across the globe, and is much fainter.



Animation above: Red, green and yellow swaths of light — known as airglow — are seen in this video of Earth’s limb, shot from the International Space Station. Animation Credit: NASA.


“It’s amazing that our atmosphere glows like this, but what’s more — it gives us a direct ability to make observations of the key parameters we need in order to investigate the connection between the neutral atmosphere and the ionosphere,” Immel said.


Different atmospheric gases glow in certain colors and at specific altitudes, so scientists can use airglow to probe the different layers of the atmosphere, gleaning information like density, temperature and composition. In addition, Earth’s natural glow helps scientists track motions within the ionosphere itself: As high-altitude winds sweep through the region, pushing its contents around, airglow’s dim light morphs in turn, tracing out global patterns.


“I can’t wait to see what airglow looks like from ICON’s point of view,” Immel said.


ICON’s 90-minute launch window opens at 3:00 a.m. EST on Nov. 7, 2018. ICON launches on a Northrop Grumman Pegasus XL rocket, which is carried aloft by the Stargazer L-1011 aircraft that takes off from Cape Canaveral Air Force Station in Florida. The L-1011 carries the rocket to approximately 40,000 feet over the open ocean, where it is released and free-falls five seconds before igniting its first-stage rocket motor. Release from the Stargazer is anticipated for 3:05 a.m. EST. The spacecraft deploys approximately 11 minutes after the Pegasus drop.


ICON will join another ionospheric mission, GOLD, short for Global-scale Observations of the Limb and Disk, which launched in January 2018. While ICON flies just 357 miles above Earth and will capture close-up images of the region, GOLD flies in geostationary orbit 22,000 miles above the Western Hemisphere, where it specializes in global-scale images of the ionosphere and upper atmosphere. Where ICON takes close-ups, GOLD captures landscapes. 


Together, these missions will provide the most comprehensive ionosphere observations we’ve ever had — data that’s hard to get from Earth, where we can only measure small fractions of the region at a time — enabling a deeper understanding of how our planet interacts with space.



Image above: Illustration of ICON spacecraft. Image Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith.


“It’s a truly wonderful time to be studying heliophysics,” said Nicola Fox, director of NASA’s Heliophysics Division in Washington. “We just launched Parker Solar Probe earlier this year, which will give us the first close-up view of what drives the solar wind. Now, with ICON joining our heliophysics system fleet, we will have the incredibly detailed measurements of the ionosphere’s response to the solar drivers. This is an amazing opportunity to study the whole system response.”


NASA heliophysics missions study a vast interconnected system from the Sun to the space surrounding Earth and other planets, and to the farthest limits of the Sun’s constantly flowing stream of solar wind. ICON’s observations will provide key information about how Earth’s atmosphere is connected to this complex, dynamic system. 


ICON is an Explorer-class mission. NASA Goddard manages the Explorers Program for NASA’s Heliophysics Division within the Science Mission Directorate in Washington. UC Berkeley’s Space Sciences Laboratory developed and operates the ICON mission and built the EUV and FUV imagers. The Naval Research Laboratory in Washington, D.C., developed the MIGHTI instrument, the University of Texas in Dallas developed IVM, and the ICON spacecraft and Pegasus launch vehicle were built by Northrop Grumman in Dulles, Virginia.


NASA launch coverage begins at 2:45 a.m. EST on Nov. 7, 2018. Follow launch coverage on NASA Television at: https://www.nasa.gov/live


Related links:


NASA’s ICON website: https://www.nasa.gov/icon


MIGHTI instrument: https://www.nasa.gov/content/icon-spacecraft-and-instruments


GOLD: http://nasa.gov/gold


Airglow: https://www.nasa.gov/feature/goddard/2018/why-nasa-watches-airglow-the-colors-of-the-upper-atmospheric-wind


Space Weather: https://www.nasa.gov/subject/3165/space-weather


Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center, by Lina Tran.


Greetings, Orbiter.chArchive link


European-Built Service Module Arrives in U.S. for First Orion Moon Mission


NASA – Orion Crew Vehicle patch.


Nov. 6, 2018


The powerhouse that will help NASA’s Orion spacecraft venture beyond the Moon is stateside. The European-built service module that will propel, power and cool during Orion flight to the Moon on Exploration Mission-1 arrived from Germany at the agency’s Kennedy Space Center in Florida on Tuesday to begin final outfitting, integration and testing with the crew module and other Orion elements.


The service module is integral to human missions to the Moon and Mars. After Orion launches on top of the agency’s Space Launch System rocket, the service module will be responsible for in-space maneuvering throughout the mission, including course corrections. The service module will also provide the powerful burns to insert Orion into lunar orbit and again to get out of lunar orbit and return to Earth. It is provided by ESA (European Space Agency) and built by ESA’s prime contractor Airbus of Bremen, Germany. NASA’s prime contractor for Orion, Lockheed Martin, built the crew module and other elements of the spacecraft.



Image above: The European Service Module for NASA’s Orion spacecraft is loaded on an Antonov airplane in Bremen, Germany, on Nov. 5, 2018, for transport to NASA’s Kennedy Space Center in Florida. For the first time, NASA will use a European-built system as a critical element to power an American spacecraft, extending the international cooperation of the International Space Station into deep space. Image Credits: NASA/Rad Sinyak.


“We have a strong foundation of cooperation with ESA through the International Space Station partnership, and the arrival of the service module signifies that our international collaboration extends to our deep space human exploration efforts as well,” said Bill Gerstenmaier, NASA’s associate administrator for Human Exploration and Operations.


The European-built service module brings together new technology and lightweight materials while taking advantage of spaceflight-proven hardware. It is comprised of more than 20,000 components, including four solar array wings that provide enough electricity to power two three-bedroom homes, as well as an orbital maneuvering system engine, a recently refurbished engine previously used for in-orbit control by the space shuttle. Beginning with Exploration Mission-2, the module also will provide air and water for astronauts flying inside Orion, which will carry people to destinations farther than anyone has travelled before and return them safely to Earth.


“Our teams have worked together incredibly hard to develop a service module that will make missions to the Moon and beyond a reality,” said Mark Kirasich, NASA’s Orion program manager. “It is quite an accomplishment of ESA and Airbus to have completed the developmental work on the module and have this major delivery milestone behind us.”



Orion Crew Vehicle. Image Credits: NASA/ESA

Now that the service module is at Kennedy, it will undergo a host of tests and integration work ahead of Exploration Mission-1. Engineers will complete functional checkouts to ensure all elements are working properly before it is connected to the Orion crew module. Teams will weld together fluid lines to route gases and fuel and make electrical wiring connections. The service module and crew module will be mated, and the combined spacecraft will be sent to NASA’s Glenn Research Center’s Plum Brook Station in Ohio early next year where it will undergo 60 days of continuous testing in the world’s largest thermal vacuum chamber to ensure Orion can withstand the harsh environment of deep space. Once that testing is complete, it will return to Kennedy for integration with the SLS rocket in preparation for launch.


NASA is leading the next steps to establish a permanent human presence at the Moon. The first in a series of increasingly complex missions, Exploration Mission-1 is a flight test of an uncrewed Orion spacecraft and SLS rocket that will launch from NASA’s modernized spaceport at Kennedy. The mission will send Orion 40,000 miles beyond the Moon and back and pave the road for future missions with astronauts. Together, NASA and its partners will build the infrastructure needed to explore the Moon for decades to come while laying the groundwork for future missions to Mars.


For more information about Orion, visit: https://www.nasa.gov/orion


Related article:


Goodbye Europe, hello Moon: European Module ships soon:
https://orbiterchspacenews.blogspot.com/2018/10/goodbye-europe-hello-moon-european.html


Related links:


Exploration Mission-1: https://www.nasa.gov/content/exploration-mission-1


Space Launch System (SLS): https://www.nasa.gov/exploration/systems/sls/to-the-moon.html


Exploration Mission-2: https://www.nasa.gov/feature/nasa-s-first-flight-with-crew-will-mark-important-step-on-journey-to-mars


Images (mentioned), Text, Credits: NASA/Kathryn Hambleton​/Karen Northon/JSC/Laura Rochon​/KSC/Brittney Thorpe.


Greetings, Orbiter.chArchive link


Liftoff of Arianespace’s Soyuz mission with Metop-C


ARIANESPACE – Flight VS19 Mission poster.


November 6, 2018


Arianespace’s latest Soyuz mission is now underway following tonight’s liftoff from the Spaceport in French Guiana at 00:47:27 GMT on 7th (7:47:27 p.m. EST on 6th).



Liftoff of Arianespace’s Soyuz mission with Metop-C

An Arianespace Soyuz rocket, designated VS19, launched a mission from the Guiana Space Center in South America. The Soyuz as carry the MetOp C polar-orbiting weather satellite for the European Space Agency and the European Organization for the Exploitation of Meteorological Satellites, or Eumetsat. The Soyuz 2-1b (Soyuz ST-B) rocket use a Fregat upper stage.



Arianespace – VS19 Successful Launch

For its eighth launch of the year, and the second Soyuz liftoff from the Guiana Space Center (CSG) in French Guiana in 2018, Arianespace will orbit Metop-C for EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites.



Metop-C weather satellite

Metop-C is the third and final satellite of its Polar System (EPS), the Metop program dedicated to operational meteorology. By launching the complete Metop fleet, Arianespace once again supports EUMETSAT and Europe in the improvement of global climate monitoring and weather forecasting. The nominal duration of the mission (from liftoff to separation of the satellite) is: 1 hour, 00 minutes, 18 seconds.


Related links:


Metop-C: https://www.esa.int/Our_Activities/Observing_the_Earth/MetOp


EUMETSAT: https://www.eumetsat.int/website/home/index.html


Arianespace: http://www.arianespace.com/


Images, Video, Text, Credits: Arianespace/ESA/EUMETSAT.


Best regards, Orbiter.chArchive link


Widely used mosquito repellent proves lethal to larval salamanders

Insect repellents containing picaridin can be lethal to salamanders. So reports a new study published in Biology Letters that investigated how exposure to two common insect repellents influenced the survival of aquatic salamander and mosquito larvae.











Widely used mosquito repellent proves lethal to larval salamanders
Amphibians like salamanders prey on mosquitoes and keep the pests at bay. Declining salamander
populations could boost mosquito numbers, increasing mosquito-borne disease risk to humans
[Credit: John Clare, PhD]

Insect repellents are a defense against mosquito bites and mosquito-borne diseases like dengue, chikungunya, Zika, and West Nile virus. Salamanders provide natural mosquito control. During their aquatic juvenile phase, they forage on mosquito larvae, keeping populations of these nuisance insects in check.
Emma Rosi, a freshwater ecologist at Cary Institute of Ecosystem Studies and a co-author on the paper explains, “Use of insect repellents is on the rise globally. Chemicals in repellents enter aquatic ecosystems through sewage effluent and are now common in surface waters. We set out to understand the impact of repellent pollution on both larval mosquitoes and the larval salamanders that prey on them.”


The paper is the first to suggest that environmentally realistic concentrations of picaridin-containing repellents in surface waters may increase the abundance of adult mosquitoes due to a decrease in predation pressure on mosquitoes at the larval stages.


Testing the two most popular repellents


The research team tested the effects of two of the most widely used insect repellents — DEET (Repel 100 Insect Repellent) and picaridin (Sawyer Premium Insect Repellent) — on larval salamanders and mosquitoes. In a lab, they exposed mosquito larvae and just-hatched spotted salamander larvae to three environmentally relevant concentrations of these chemicals, as well as a control treatment.











Widely used mosquito repellent proves lethal to larval salamanders
Spotted salamander egg mass [Credit: John Clare, PhD]

Rosi notes, “The concentrations in our experiments are conservative; we prepared them based on unadulterated commercial formulations, not concentrations of pure active compounds.”


Mosquito larvae were not impacted by any of the treatments and matured unhindered. After four days of exposure to repellent with picaridin, salamanders in all of the treatment groups began to display signs of impaired development such as tail deformities. By day 25, 45-65% of picaridin-exposed salamander larvae died.


Co-author Barbara Han, a disease ecologist at Cary Institute explains, “Our findings demonstrate that larval salamanders suffer severe mortality and developmental deformities when exposed to environmentally relevant concentrations of commercially available repellent containing the active ingredient picaridin.”


Adding, “The expediency of salamander mortality was disconcerting. When studying the effects of a chemical on an amphibian, we usually look for a suite of abnormalities. We couldn’t collect these data because the salamanders died so quickly.”


How toxic is toxic?


LC50 tests are used to define a chemical’s environmental toxicity. These standard tests, based on one life stage of a single species, measure how long it takes for 50% of a test population to die with increasing exposure to a chemical in a lab over a four-day period.











Widely used mosquito repellent proves lethal to larval salamanders
Larval salamanders are voracious mosquito predators. Pictured: a larval spotted salamander
[Credit: Keith Eric Costley]

Co-author Alexander Reisinger, an Assistant Professor at University of Florida, Gainesville says, “We observed heavy salamander mortality with picaridin, but not until after the fourth day of exposure. By the LC50 measure, picaridin would be deemed ‘safe’, but clearly, this is not the case. If a substance doesn’t kill organisms within the first few days of exposure, it can still be toxic and have ecological impacts.”


Results may underestimate the problem


Lethal in a controlled setting, picaridin may cause greater mortality in a natural context, where organisms are exposed to numerous stressors. Rosi notes, “Animals don’t exist in isolation. In nature, competition, predation, resource limitation, and social interactions make it difficult for an organism to tolerate the added stress of exposure to a harmful substance, even in small amounts.”


Timing — of both repellent use and amphibian reproduction — is also key. Many amphibians breed in a single seasonal pulse, putting all their eggs in one basket, so to speak. Mosquitoes have an extended breeding season, and reproduce multiple times.











Widely used mosquito repellent proves lethal to larval salamanders
Increasing repellent application could be suppressing salamander populations. Without this key predator,
mosquito populations can expand unchecked [Credit: Almeida et al 2018]

Lead author Rafael Almeida, a postdoctoral researcher at Cornell University, conducted the research as a visiting PhD student at the Cary Institute. He explains, “The amount of repellents entering waterways peaks seasonally. If amphibians are exposed during a sensitive life stage, entire cohorts could perish. The population would not have a chance to recover until the following year. Meanwhile, mosquitoes would continue to reproduce. It suggests a negative feedback loop.”


Additional study


Future work is needed to explore the relationship among mosquito repellents, amphibians, and other ecological factors, and to better assess the severity of repellents’ impact in the wild.


Almeida concludes, “The effects of repellents containing DEET and picaridin need to be studied further to determine the extent to which these chemicals disrupt aquatic ecosystems and potentially increase mosquito-borne disease risk worldwide.”


Source: Cary Institute of Ecosystem Studies [November 01, 2018]



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