Stellar Cocoon With Organic Molecules Discovered at Extreme Edge of Our Galaxy

By NATIONAL ASTRONOMICAL OBSERVATORY OF JAPAN JANUARY 4, 2022

Artist’s conceptual image of the protostar discovered in the extreme outer Galaxy. Credit: Niigata University

For the first time, astronomers have detected a newborn star and the surrounding cocoon of complex organic molecules at the edge of our Galaxy, which is known as the extreme outer Galaxy. The discovery, which revealed the hidden chemical complexity of our Universe, appears in a paper in The Astrophysical Journal.

The scientists from Niigata University (Japan), Academia Sinica Institute of Astronomy and Astrophysics (Taiwan), and the National Astronomical Observatory of Japan, used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe a newborn star (protostar) in the WB89-789 region, located in the extreme outer Galaxy. A variety of carbon-, oxygen-, nitrogen-, sulfur-, and silicon-bearing molecules, including complex organic molecules containing up to nine atoms, were detected. Such a protostar, as well as the associated cocoon of chemically-rich molecular gas, were for the first time detected at the edge of our Galaxy.

The ALMA observations reveal that various kinds of complex organic molecules, such as methanol (CH₃OH), ethanol (C₂H₅OH), methyl formate (HCOOCH₃), dimethyl ether (CH₃OCH₃), formamide (NH₂CHO), propanenitrile (C₂H₅CN), etc., are present even in the primordial environment of the extreme outer Galaxy. Such complex organic molecules potentially act as the feedstock for larger prebiotic molecules.

Top: Radio spectrum of a protostar in the extreme outer Galaxy discovered with ALMA. Bottom: Distributions of radio emissions from the protostar. Emissions from dust, formaldehyde (H2CO), ethynylradical (CCH), carbon monosulfide (CS), sulfur monoxide (SO), silicon monoxide (SiO), acetonitrile (CH3CN), formamide (NH2CHO), propanenitrile (C2H5CN), methyl formate (HCOOCH3), ethanol (C2H5OH), acetaldehyde (CH3CHO), deuterated water (HDO), and methanol (CH3OH) are shown as examples. In the bottom right panel, an infrared 2-color composite image of the surrounding region is shown (red: 2.16 μm and blue: 1.25 μm, based on 2MASS data). Credit: ALMA (ESO/NAOJ/NRAO), T. Shimonishi (Niigata University)

Interestingly, the relative abundances of complex organic molecules in this newly discovered object resemble remarkably well what is found in similar objects in the inner Galaxy. The observations suggest that complex organic molecules are formed with similar efficiency even at the edge of our Galaxy, where the environment is very different from the solar neighborhood.

It is believed that the outer part of our Galaxy still harbors a primordial environment that existed in the early epoch of galaxy formation. The environmental characteristics of the extreme outer Galaxy, e.g., low abundance of heavy elements, small or no perturbation from Galactic spiral arms, are very different from those seen in the present-day solar neighborhood. Because of its unique characteristics, the extreme outer Galaxy is an excellent laboratory to study star formation and the interstellar medium in the past Galactic environment.

“With ALMA we were able to see a forming star and the surrounding molecular cocoon at the edge of our Galaxy,” says Takashi Shimonishi, an astronomer at Niigata University, Japan, and the paper’s lead author. “To our surprise, a variety of abundant complex organic molecules exists in the primordial environment of the extreme outer Galaxy. The interstellar conditions to form the chemical complexity might have persisted since the early history of the Universe,” Shimonishi adds.

“These observations have revealed that complex organic molecules can be efficiently formed even in low-metallicity environments like the outermost regions of our Galaxy. This finding provides an important piece of the puzzle to understand how complex organic molecules are formed in the Universe,” says Kenji Furuya, an astronomer at the National Astronomical Observatory of Japan, and the paper’s co-author.

It is not yet clear, however, if such a chemical complexity is common in the outer part of the Galaxy. Complex organic molecules are of special interest, because some of them are connected to prebiotic molecules formed in space. The team is planning to observe a larger number of star-forming regions in the future, and hopes to clarify whether chemically-rich systems, as seen in our Solar System, are ubiquitous through the history of the Universe.

Reference: “The Detection of a Hot Molecular Core in the Extreme Outer Galaxy” by Takashi Shimonishi, Natsuko Izumi, Kenji Furuya and Chikako Yasui, 1 December 2021, The Astrophysical Journal.
DOI: 10.3847/1538-4357/ac289b

This work is supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (19H05067, 21H00037, 21H01145).

Mysterious Dusty Object Discovered by Astronomers Using NASA’s TESS Planet Hunter

By HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS JANUARY 3, 2022

Artist’s concept of a dark and mysterious object.

The Transiting Exoplanet Survey Satellite, TESS, was launched in 2018 with the goal of discovering small planets around the Sun’s nearest neighbor stars. TESS has so far discovered 172 confirmed exoplanets and compiled a list of 4703 candidate exoplanets. Its sensitive camera takes images that span a huge field of view, more than twice the area of the constellation of Orion, and TESS has also assembled a TESS Input Catalog (TIC) with over 1 billion objects. Follow-up studies of TIC objects have found they result from stellar pulsations, shocks from supernovae, disintegrating planets, gravitational self-lensed binary stars, eclipsing triple star systems, disk occultations, and more.

CfA astronomer Karen Collins was a member of a large team that discovered the mysterious variable object TIC 400799224. They searched the Catalog using machine-learning-based computational tools developed from the observed behaviors of hundreds of thousands of known variable objects; the method has previously found disintegrating planets and bodies that are emitting dust, for example. The unusual source TIC 400799224 was spotted serendipitously because of its rapid drop in brightness, by nearly 25% in just a few four hours, followed by several sharp brightness variations that could each be interpreted as an eclipse.

An optical/near-infrared image of the sky around the TESS Input Catalog (TIC) object TIC 400799224 (the crosshair marks the location of the object, and the width of the field of view is given in arcminutes). Astronomers have concluded that the mysterious periodic variations in the light from this object are caused by an orbiting body that periodically emits clouds of dust that occult the star. Credit: Powell et al., 2021

The astronomers studied TIC 400799224 with a variety of facilities including some that have been mapping the sky for longer than TESS has been operating. They found that the object is probably a binary star system, and that one of the stars pulsates with a 19.77 day period, probably from an orbiting body that periodically emits clouds of dust that occult the star. But while the periodicity is strict, the dust occultations of the star are erratic in their shapes, depths, and durations, and are detectable (at least from the ground) only about one-third of the time or less.

The nature of the orbiting body itself is puzzling because the quantity of dust emitted is large; if it were produced by the disintegration of an object like the asteroid Ceres in our solar system, it would survive only about eight thousand years before disappearing. Yet remarkably, over the six years that this object has been observed, the periodicity has remained strict and the object emitting the dust apparently has remained intact.

The team plans to continue monitoring the object and to incorporate historical observations of the sky to try to determine its variations over many decades.

Reference: “Mysterious Dust-emitting Object Orbiting TIC 400799224” by Brian P. Powell, Veselin B. Kostov, Saul A. Rappaport, Andrei Tokovinin, Avi Shporer, Karen A. Collins, Hank Corbett, Tamás Borkovits, Bruce L. Gary, Eugene Chiang, Joseph E. Rodriguez, Nicholas M. Law, Thomas Barclay, Robert Gagliano, Andrew Vanderburg, Greg Olmschenk, Ethan Kruse, Joshua E. Schlieder, Alan Vasquez Soto, Erin Goeke, Thomas L. Jacobs, Martti H. Kristiansen, Daryll M. LaCourse, Mark Omohundro, Hans M. Schwengeler, Ivan A. Terentev and Allan R. Schmitt, 8 December 2021, The Astronomical Journal.
DOI: 10.3847/1538-3881/ac2c81

Astronomers Explore Cosmic Ray Influences on Star Formation in Galaxies

By HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS JANUARY 2, 2022

An image of a galaxy seen face-on in a simulation. It shows the distribution of gas over the galaxy (red is higher density and blue is lower density); the clumpiness of the gas is apparent. When cosmic ray transport is suppressed, the simulations show that this clumpiness is reduced, in turn reducing the star formation activity. Astronomers modeling cosmic-ray influences on star formation have motivated their simulations with gamma-ray observations to investigate cosmic ray transport. Credit: Semenov et al., 2021

The triggering of star formation, and also its quenching, is regulated by young massive stars in galaxies which inject energy and momentum into the interstellar medium. Feedback from the supermassive black holes at galaxies’ nuclei plays a similarly important role. These processes drive the massive gas outflows observed in galaxies, for example. However, the details including how they work and the relative roles of the different feedback processes are actively debated.

Cosmic rays in particular are accelerated in strong shocks formed by supernova explosions and stellar winds (both aspects of star formation), and generate considerable pressure in the interstellar medium. They play a central role in regulating thermal balance in dense molecular clouds where most stars form and may play an important role in regulating star formation, driving galactic winds, and even in determining the character of the intergalactic medium.

Astronomers believe that a key property limiting cosmic ray influence is the ability to propagate out of the sites where they are produced into the interstellar medium and beyond the disk, but the details are not very well understood.

CfA astronomer Vadim Semenov and two collaborators used computer simulations to explore how such a variation of cosmic ray propagation can affect star formation in galaxies, motivated by recent observations of gamma-ray emission from nearby sources of cosmic rays including star clusters and supernova remnants. The observations probe the propagation of cosmic rays because a significant fraction of gamma-ray emission is believed to be produced when cosmic rays interact with interstellar gas. The observed gamma-ray fluxes suggest that cosmic ray propagation near such sources can be locally suppressed by a significant factor, up to several orders of magnitude. Theoretical works suggest that such suppression can result from nonlinear interactions of cosmic rays with magnetic fields and turbulence.

The scientists used the simulations to probe the effects of suppressing the transport of cosmic rays near the sources. They find that suppression causes a local pressure buildup and produces strong pressure gradients that prevent the formation of the massive clumps of molecular gas that make new stars, qualitatively changing the global distribution of star formation, especially in massive, gas-rich galaxies which are prone to clump formation. They conclude that this cosmic-ray effect regulates the development of the structure of the galaxy’s disk and is an important complement to the other processes active in shaping the galaxy.

Reference: “Cosmic-Ray Diffusion Suppression in Star-forming Regions Inhibits Clump Formation in Gas-rich Galaxies” by Vadim A. Semenov, Andrey V. Kravtsov and Damiano Caprioli, 5 April 2021, The Astrophysical Journal.
DOI: 10.3847/1538-4357/abe2a6

Hubble Space Telescope Captures Galactic Conjunction

By ESA/HUBBLE JANUARY 2, 2022

Hubble Space Telescope image of spiral galaxy NGC 105. Credit: ESA/Hubble & NASA, D. Jones, A. Riess et al., Acknowledgement: R. Colombari

This image from the NASA/ESA Hubble Space Telescope captures the spiral galaxy NGC 105, which lies roughly 215 million light-years away in the constellation Pisces. While it looks like NGC 105 is plunging edge-on into a collision with a neighboring galaxy, this is just the result of the chance alignment of the two objects in the night sky. NGC 105’s elongated neighbor is actually far more distant and remains relatively unknown to astronomers. These misleading conjunctions occur frequently in astronomy — for example, the stars in constellations are at vastly different distances from Earth, and only appear to form patterns thanks to the chance alignment of their component stars.

The Wide Field Camera 3 observations in this image are from a vast collection of Hubble measurements examining nearby galaxies which contain two fascinating astronomical phenomena — Cepheid variables and cataclysmic supernova explosions. Whilst these two phenomena may appear to be unrelated — one is a peculiar class of pulsating stars and the other is the explosion caused by the catastrophic final throes of a massive star’s life — they are both used by astronomers for a very particular purpose: measuring the vast distances to astronomical objects. Both Cepheids and supernovae have very predictable luminosities, meaning that astronomers can tell precisely how bright they are. By measuring how bright they appear when observed from Earth, these “standard candles” can provide reliable distance measurements. NGC 105 contains both supernovae and Cepheid variables, giving astronomers a valuable opportunity to calibrate the two distance measurement techniques against one another.

Astronomers recently carefully analyzed the distances to a sample of galaxies including NGC 105 to measure how fast the Universe is expanding — a value known as the Hubble constant. Their results don’t agree with the predictions of the most widely-accepted cosmological model, and their analysis shows that there is only a 1-in-a-million chance that this discrepancy was caused by measurement errors. This discrepancy between galaxy measurements and cosmological predictions has been a long-standing source of consternation for astronomers, and these recent findings provide persuasive new evidence that something is either wrong or lacking in our standard model of cosmology.

Off-Earth Manufacturing: Using Local Resources To Build a New Home on Another World

By EUROPEAN SPACE AGENCY (ESA) JANUARY 3, 2022

A vision of a future Moon base that could be produced and maintained using 3D printing. Credit: RegoLight, visualisation: Liquifer Systems Group, 2018

Humanity is heading back to the Moon, and this time, we’re planning to stay. But for long-term space missions, astronauts would need infrastructure to live and work, to move around, to communicate with Earth, and to produce oxygen and water vital for survival. Taking all this infrastructure from Earth would likely be prohibitively expensive. Instead, we need to figure out how to make it on site. ESA Discovery & Preparation has supported many studies to explore how we can do this.

Using local materials to build infrastructure and produce amenities is known as in-situ resource utilization (ISRU). Past research in this area has explored and demonstrated fundamental ISRU concepts using a combination of resources found on the exploration site and materials brought from Earth.

By testing the market for transport services to the Moon, ESA aims to push the limits of technology and create new models of space business. Credit: ESA

ISRU is needed to build a habitat that shields astronauts from harsh environments including thin or non-existent atmospheres, extreme temperatures, intense radiation, and even micrometeoroids. It would enable us to build roads to move around the surface, and launch and landing pads for traveling to and from Earth. It could be used to produce equipment that can generate and store energy for producing electricity, as well as antenna towers for communication. And it could produce huge amounts of water and oxygen for keeping astronauts alive and creating propellants for traveling around and eventually coming back to Earth.

Discovery & Preparation activities

In 1999, one of the first ISRU-related Discovery & Preparation studies focused on propulsion and power systems, assessing the needs for advanced propulsion in the current century. The study concluded that ISRU could reduce the costs of missions to Mars whilst increasing our capabilities, but that research and development in ISRU technologies should begin right away.

And so, in coordination with all ESA programs, research continued. A study completed in 2000 focused on the power systems required for future space exploration, including designing an ISRU chemical plant to produce propellant, chemicals for life support, and fuel for surface activities.

A close-up view of GOCE’s ion-propulsion assembly. Credit: ESA /AOES Medialab

Other studies happening at the same time took a broader look at long-term space exploration, with one considering what architectures and technologies would be required for Mars exploration. The study investigated the possibility of producing propellant and fluids necessary for crew survival – including nitrogen, oxygen, hydrogen and water – from the Martian atmosphere and soil. Another study on the survivability and adaptability of humans to long-duration interplanetary and planetary environments also found that ISRU could be particularly useful for producing propellants and life support consumables.

Fast forwarding 13 years, the technology had developed enough to explore more specific ISRU concepts, including a system to collect and store carbon dioxide from the Martian atmosphere and deliver it to a propulsion system. The study, carried out by Airbus, suggested ways in which dust and water could be removed from the carbon dioxide, as well as how it could be liquified for storage.

Over the last few years, Discovery & Preparation has supported more research into building infrastructure using lunar soil and more specific methods of energy generation and storage; a recent study explored how lunar regolith could be used to store heat and provide electricity for astronauts, rovers, and landers.

Setting up a future lunar base could be made much simpler by using a 3D printer to build it from local materials. Industrial partners including renowned architects Foster+Partners joined ESA to test the feasibility of 3D printing using lunar soil. Credit: ESA/Foster + Partners

One study explored how lunar analog facilities could support the development of ISRU technologies, including testing the excavation and processing of local materials, as well as how these materials could be used to build structures using processes like 3D printing.

Another confirmed the suitability of lunar soil as a building material, selected a suitable process for printing structures from it, and even designed a printable habitat. And a third recently went one step further and explored how any necessary structures, equipment, and spare parts could be 3D printed using lunar regolith, even selecting which specific printing processes would work best.

As an alternative to existing 3D printing technologies, a 2019 study looked into turning lunar soil into fibers to build strong structures. The researchers produced a sample of material to show that it is possible to use this process to make structures that are locally impermeable.

A set of Discover & Preparation studies recently explored and defined ESA’s lunar IRSU demonstration mission, which aims to prove by 2025 that producing water or oxygen on the Moon is possible. These studies looked into the system that would actually produce the water and oxygen, proposing a package that extracts oxygen from the soil and uses it to produce water, using a ‘carbo-thermal reactor’. Another explored how the system could rely on a lander as a power supply and a third investigated how it could communicate with Earth.

What else is ESA doing?

To implement the lunar ISRU demonstration mission, ESA intends to procure mission-enabling services from the commercial sector, including payload delivery, communication, and operations services. In doing so, ESA will both leverage on and further nurture existing commercial initiatives that may find widespread applications in a future lunar exploration scenario.

A computer model of Luna-27, which will fly to the Moon’s south pole. Credit: Roscosmos

ESA is also currently working on the PROSPECT mission, which will access and assess potential resources on the Moon to prepare for the technologies that may be used to extract these resources in the future. PROSPECT will drill beneath the Moon’s surface near its South Pole and extract samples expected to contain frozen water and other chemicals that can become trapped at extremely low temperatures. The drill will then pass the samples to a chemical laboratory where they will be heated to extract these chemicals. The mission will operate as part of the Russian-led Luna-27 mission and will test processes that could be applied to resource extraction in the future.

To support the ambition to have a human presence on the Moon sustained by local resources by 2040, in May 2019, ESA published its Space Resources Strategy. The strategy considers what we need to discover and develop to support sustainable space exploration. The strategy covers the period up to 2030, by which time the potential of lunar resources will have been established through measurements at the Moon, key technologies will have been developed and demonstrated and a plan for their introduction into international mission architectures will have been defined. Following the publication of the strategy, ESA hosted a workshop to identify the next steps needed to make space resource utilization a reality.

Producing oxygen and metal out of simulated moondust inside ESA’s Materials and Electrical Components Laboratory. Credit: ESA–A. Conigili

In 2020, ESA set up a prototype plant to produce oxygen out of simulated moondust. Removing the oxygen from lunar soil leaves various metals; another line of research, therefore, is to see what are the most useful alloys that could be produced from them, and how they could be used on the Moon. The ultimate aim would be to design a ‘pilot plant’ that could operate sustainably on the Moon, with the first technology demonstration targeted for the mid-2020s.

What are other space agencies doing in this area?

NASA’s Lunar Reconnaissance Orbiter already indicated the presence of water ice buried under the lunar soil at certain locations. The orbiter launched with the Lunar CRater Observation and Sensing Satellite that was released from the orbiter and impacted the Moon; observations of the resulting 16-kilometer-high plume showed the chemical make-up of the lunar surface.

The US Agency is also developing several CubeSat orbital missions that will visit the Moon. Lunar Flashlight, LunaH-MAP, and Lunar IceCube will aim to find out how much water ice there is and where exactly it can be found.

Artist’s impression of NASA’s Mars Perseverance rover. Credit: NASA/JPL-Caltech

NASA’s first Mars lander, Viking, returned important data about the Martian atmosphere, revealing that it is made up of 95.9 percent carbon dioxide. Based on this discovery and information returned by subsequent robotic missions, the Agency has developed technologies to convert Mars’ atmospheric carbon dioxide into oxygen to benefit human missions to the red planet. Recently, NASA selected the Mars Oxygen In-Situ Resource Utilization Experiment, or MOXIE, as one of seven instruments on the Mars Perseverance rover.

Volatiles are substances that vaporize easily and could be a source of water on the Moon. Together with other space agencies, NASA is conducting an international coordination of lunar polar volatiles exploration to increase scientific knowledge, determine the viability of volatiles as potential resources, and to use the Moon as a proving ground for Mars ISRU technologies.

Future China National Space Administration missions are also expected to target lunar polar volatiles as potential resources. China’s vision of an international lunar research station, to be established initially as a robotic facility for science and research during the late 2020s and early 2030s may provide an early opportunity for lunar resources to be utilized.

The Russian space agency, Roscosmos, is working with ESA on the series of three Luna missions, including Luna-27, which will host ESA’s PROSPECT package. The mission will target measurements in the polar region of the Moon, focusing on cold trapped volatiles that may be found there.

What’s next at ESA?

Through its Open Space Innovation Platform (OSIP), ESA sought ideas on enabling technologies for in-situ construction, manufacturing, and maintenance of infrastructure and hardware to support long-term exploration of a planetary body.

The proposed ideas support the construction of habitats, mobility infrastructure (e.g. roads and landing pads), ancillary infrastructure (e.g. for communication and energy generation and storage), and hardware (e.g. tools, interior equipment, machinery and clothing).

An idea submitted to the Open Space Innovation Platform (OSIP) proposed that orbital debris could be used for in-situ resource manufacturing on the Moon. Credit: ESA/Orbit Recycling

Ideas include many novel methods for melting and 3D printing lunar soil, making solar cells from lunar soil, optimizing energy storage, finding methods to grow plants from organic waste without needing soil, using lunar soil to build crop-friendly greenhouses, and building infrastructure using space debris. Many of the ideas are now being implemented by ESA as studies, co-funded research projects or early technology development projects. To find out more, visit the results section of this call for ideas.

The use of space resources for exploration is now within reach thanks to advances in our knowledge and understanding of the Moon and asteroids, increased international and private sector engagement in space technologies, and the emergence of new technologies.

Developing technologies and methods to use local resources to support future astronauts remains a challenge, but in doing so we are stimulating innovation on Earth through technology needs as well as new approaches to managing limited resources. This will hopefully help us find new ways to address global challenges and generate near to mid-term economic returns for terrestrial industries.

Extinct species of fish reintroduced into its native habitat in Mexico

Locals and international organizations worked together to make it happen.

 by Alexandru Micu
January 3, 2022


A little river in Mexico is the site of one of 2021’s most heartwarming tales — the reintroduction of a species that had gone extinct in the wild.

Tequila splitfin (Zoogoneticus tequila). Image via Wikimedia.

We often hear stories about animals going extinct, and they’re always heartbreaking. But, every so often, we get to hear of the reverse: a species that had gone extinct, being reintroduced into the wild. The waters of the Teuchitlán, a river in Mexico that flows near a town bearing the same name, can now boast the same tale.

Efforts by local researchers, conservationists, and citizens, with international support, have successfully reintroduced the tequila splitfin (Zoogoneticus tequila), a tiny fish that only lived in the Teuchitlán river but had gone extinct during the 1990s, to the wild.

Re-fishing

In the 1990s, populations of the tequila splitfin began to dwindle in the Teuchitlán river. Eventually, it vanished completely.

Omar Domínguez, one of the researchers behind the program that reintroduced the species, and a co-authored of the paper describing the process, was a university student at the time and worried about the fish’s future. Pollution, human activity, and invasive, non-native species were placing great pressure on the tequila splitfin.

Now a 47-year-old researcher at the University of Michoacán, he recounts that then only the elderly in Teuchitlán remembered the fish — which they called gallito (“little rooster”) because of its brightly-colored, orange tail.

Conservation efforts started in 1998 when a team from the Chester Zoo in England, alongside members from other European institutions, arrived with several pairs of tequila splitfin from the aquariums of collectors and set up a lab to help preserve the species.

The first few years were spent reproducing the fish in aquariums. Reintroducing these to the river directly was deemed to be too risky. So Domínguez and his colleagues built an artificial pond on-site, in which the fish could breed in semi-captivity. The then-40 pairs of tequila splitfins were placed in this pond in 2012, and by 2014 they had multiplied to around 10,000 individuals.

By now, their results gave all the organizations involved in the effort (various zoos and wildlife conservation groups from Europe, the United States, and the United Arab Emirates) enough confidence to fund further experimentation. So the team set their sights on the river itself. Here, they studied the species’ interactions with local predators, parasites, microorganisms, and how they fit into the wider ecosystem of the area.

Then, they placed some of the tequila splitfins back into the river — inside floating cages. This step, too, was a marked success, and the fish multiplied quickly inside the cages. When their numbers grew large enough, around late 2017, the researchers marked the individual fish and set them free. In the next six months, their population increased by 55%, the authors report. The fish are still going strong, they add: in December 2021, they were seen inhabiting a new area of the river, where they were completely extinct in the past.

It’s not just about giving a species a new lease on life, the team explains. Their larger goal was to restore the natural equilibrium of the river’s ecosystem. Although there is no hard data on environmental factors in the past to compare with, Domínguez is confident that the river’s overall health has improved. Its waters are cleaner, the number of invasive species has declined, and cattle are no longer allowed to drink directly from the river in some areas.

Local communities were instrumental in the conservation effort.

“When I started the environmental education program I thought they were going to turn a deaf ear to us — and at first that happened,” Domínguez said.

However, the conservationists made sustained efforts to educate the locals through puppet shows, games, and educational materials, and presentations about zoogoneticus tequila. Among others, citizens were told about the ecological role of the species, and the part it plays in controlling dengue-spreading mosquitoes.

The tequila splitfin is currently listed as endangered on the IUCN’s red list.

The paper “Progress in the reintroduction program of the tequila splitfin in the springs of Teuchitlán, Jalisco, Mexico” has been published online by the IUCN CTSG (Conservation Translocation Specialist Group). An update on the project has been published in the magazine Amazonas.




Alexandru Micu
Stunningly charming pun connoisseur, I have been fascinated by the world around me since I first laid eyes on it. Always curious, I'm just having a little fun with some very serious science.

© 2007-2019 ZME Science - Not exactly rocket science. All Rights Reserved.

A starfish-shaped soft robot that creeps, changes its color, and self-heals broken parts

by Wiley

Credit: Wiley

Natural camouflage is one of nature's most interesting traits. Materials scientists have now developed a material that can mimic the camouflage capabilities of marine mollusks. They created a starfish-shaped soft robot that responds to heat and pressure with deformation, movement, and color changes. Cut-off tentacles can be welded together, and the material can be fully recycled, they write in the journal Angewandte Chemie.

Octopuses, jellyfish, and starfish are capable of natural camouflage; that is, they can quickly change their colors or shapes to match the background. A research team led by Quan Li from Southeast University, China, has now created a soft material that can mimic such traits. As an underlying material, they chose a liquid crystal elastomer that changes phases at different temperatures. When heated up, the oriented liquid crystal molecules of the elastomer lose ordering, causing the material part to shrink.

The researchers used this shrinking effect to enable a soft robot to "crawl." For this purpose, they molded the polymer material in the shape of a starfish and added an infrared-sensitive dye to the underside of one of the tentacles. This modified site contracted when heated up by a photothermal effect resulting from near-infrared irradiation, and expanded when cooled down. Since only one arm received the light stimulus, the starfish robot slowly moved over the surface, pushed by the contracting–expanding tentacle like a caterpillar.

The starfish soft robot was capable of changing its color. The researchers integrated a cross-linker in the material—a molecular dye linking polymer strands. However, the dynamic covalent cross-linking system used here was made to break easily. During heating and under pressure, its molecular parts separated, and the previously yellowish dye molecule turned red. "Similar to the natural camouflage effect of a starfish," the authors said.

Finally, the starfish robot also demonstrated self-healing and even recycling qualities. When the researchers cut off a tentacle, it healed seamlessly after the parts were heated up again. The same thing occurred when the whole robot was cut to pieces. Molding it again into a starfish shape, the researchers regained a new, soft robot with properties that were intact.

According to the authors, the key to this multiple adaptation capability was the integration of the cross-linking dye molecule, tetraarylsuccinonitrile, which could perform several functions simultaneously. It acted as a light-absorbing chromophore, and it provided dynamic covalent bonding to the elastomeric network. The authors suggest use of such biomimetic soft materials with thermal and mechanochromic properties (color change due to heat and pressure) in biomimetic robots, sensors, and for artificial camouflage.Watch these tube-shaped robots roll up stairs, carry carts, and race one another

More information: Zhongcheng Liu et al, Thermo‐ and Mechanochromic Camouflage and Self‐Healing in Biomimetic Soft Actuators Based on Liquid Crystal Elastomers, Angewandte Chemie International Edition (2021). DOI: 10.1002/anie.20211575

Provided by Wiley