Why can zebrafish regenerate damaged heart tissue, while other fish species cannot?

University of Utah biologists discover that tiny tropical fish's "superpower" lies in an immune response to heart injuries

UNIVERSITY OF UTAH

 

IMAGE: 

CLAYTON CAREY HANDLES A TANK CONTAINING MEDAKA FISH IN THE GAGNON LAB.

view more 

CREDIT: BRIAN MAFFLY, UNIVERSITY OF UTAH

A heart attack will leave a permanent scar on a human heart, yet other animals, including some fish and amphibians, can clear cardiac scar tissue and regrow damaged muscle as adults.

Scientists have sought to figure out how special power works in hopes of advancing medical treatments for human cardiac patients, but the great physiological differences between fish and mammals make such inquiries difficult.

So University of Utah biologists, led by assistant professor Jamie Gagnon, tackled the problem by comparing two fish species: zebrafish, which can regenerate its heart, and medaka, which cannot.

A tale of two fish

The team identified a few possible explanations, mostly associated with the immune system, for how zebrafish fix cardiac tissue, according to newly published research.

“We thought by comparing these two fish that have similar heart morphology and live in similar habitats, we could have a better chance of actually finding what the main differences are,” said Clayton Carey, a postdoctoral researcher in the Gagnon lab and lead author on the new study.

Gagnon’s team wasn’t able to solve the mystery—yet—but their study shed new light on the molecular and cellular mechanisms at play in zebrafish’s heart regeneration.

“It told us these two hearts that look very similar are actually very different,” Gagnon said.

Both members of the teleost family of ray-finned fish, zebrafish (Danio rerio) and medaka (Oryzias latipes) descended from a common ancestor that lived millions of years ago. Both are about 1.5 inches long, inhabit freshwater and are equipped with two-chamber hearts. Medaka are native to Japan and zebrafish are native to the Ganges River basin.

According to the study, the existence of non-regenerating fish presents an opportunity to contrast the differing responses to injury to identify the cellular features unique to regenerating species. Gagnon suspects heart regeneration is an ancestral trait common to all teleosts.

Understanding the evolutionary path that led to the loss of this ability in some teleost species could offer parallel insights into why mammals cannot regenerate as adults.

With their distinctive horizontal stripes, zebrafish have long been popular as pets in the United States. In the 1970s zebrafish were embraced by biologists as a model organism for studying embryonic development of vertebrates.

Scientists like zebrafish because they can be propagated by the thousands quickly in labs, are easy to study and proved to be extremely hardy.

Cold shock to the heart

To conduct their experiments, the Gagnon lab used a device called a cryoprobe to injure the fish hearts in ways that mimic heart attacks in humans, then extracted the hearts after certain time frames to learn how the two species responded differently.

Carey made the cryoprobe from a piece of copper wire, which was cooled in liquid nitrogen to about minus 170 degrees Celsius. Team members cut tiny incisions in the fish’s bellies to expose their hearts, then applied the probe for 23 seconds to the edge of the heart.

In 95% of the cases, the fish survived the procedure, although not for long. After three days or 14 days, their hearts were extracted and dissolved into a single-cell solution, which was then subjected to RNA sequencing in search of markers indicating how the fish responded to the injury.

“Zebrafish have this immune response that is typical of what you might see during a viral infection, called an interferon response,” Carey said. “That response is completely absent in medaka.”

The study documented differences in immune cell recruitment and behavior, epicardial and endothelial cell signaling, and alterations in the structure and makeup of the heart. For example, medaka lack a certain type of muscle cells that are present in zebrafish.

How zebrafish heal damaged cardiac tissue

“My hunch is the ancestor of all animals could regenerate its heart after an injury, and then that’s been repeatedly lost in different types of animals,” Gagnon said. “I would like to understand why. Why would you lose this great feature that allows you to regenerate your heart after an injury?”

The study indicates the zebrafish’s ability to regenerate has something to do with its immune system, but understanding exactly how would take more research. For example, far more macrophages, specialized immune cells, migrated into the wound site in zebrafish than in medaka.

Unlike medaka, the zebrafish form a transient scar that doesn’t calcify into rigid tissue.

“What you do with that scar is what matters,” Gagnon said. “We think that the interferon response causes these specialized macrophage cells to come into that wound site and start to promote the growth of new blood vessels.”

Over time new muscle replaces the damaged cardiac tissue and the heart heals.

“The more we learn about how animals can regenerate tissues, how those features have been lost in us and other animals, that’s going to help us think about our limitations and how we might engineer strategies to help us overcome those,” Gagnon said. “Our hope is that we build this knowledge base in animals that are really accessible and can be studied in incredible detail, then use that knowledge to generate more focused experiments in mammals, and then maybe someday in human patients.”

Zebrafish used in research at the University of Utah.

CREDIT

Brian Maffly, University of Utah

The study titled, “Distinct features of the regenerating heart uncovered through comparative single-cell profiling,” appears in the April 2024 edition of the journal Biology Open and was funded by the National Institutes of Health. Gagnon Lab members Hailey Hollins and Alexis Schmid are listed co-authors.

---

JOURNAL

Biology Open

DOI

10.1242/bio.060156 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Distinct features of the regenerating heart uncovered through comparative single-cell profiling

 

New research finds electric vehicles depreciate faster than gas cars, but the trend is changing

GEORGE WASHINGTON UNIVERSITY

WASHINGTON (April 18, 2024) – Thinking of buying an electric vehicle but unsure about its resale value? New research finds that while older electric vehicle models depreciate in value faster than conventional gas cars, newer electric vehicle models with longer driving ranges are holding their value better and approaching the retention rates of many gas cars.

The study examined more than nine million car listings at over 60,000 dealerships between 2016 and 2022. It found that older battery electric vehicles and plug-in hybrid electric vehicles with shorter driving ranges depreciated at faster rates than conventional cars and hybrid electric cars; the one exception being Tesla, whose older battery electric vehicle model held its value better. However, the study also showed the trend is changing–as newer model electric vehicles with higher driving ranges come online, they are retaining their value better than the older models with smaller driving ranges. The research also found that the COVID-19 pandemic significantly affected vehicle affordability, with mean listing prices for gas cars and battery electric vehicles rising 37% and 39%, respectively, in inflation-adjusted 2019 dollars from January 2020 to March 2022.

John Paul Helveston, an Assistant Professor of Engineering Management and Systems Engineering at the George Washington University and the study’s corresponding author, says this is a double-edged sword.

“While a higher resale value in future is better for new car buyers, it also means the end of lower cost used electric vehicles, which was an important source of affordable electric vehicles,” Helveston explains. He notes that the new $4,000 subsidy for used electric vehicles provided by the Inflation Reduction Act (IRA) might offset some of the burden in the used market.

Helveston is the doctoral advisor of GW Ph.D. student Laura Roberson, who led the study and recently defended her dissertation. The paper, "Battery-Powered Bargains? Assessing Electric Vehicle Resale Value in the United States," was published in the journal Environmental Research Letter. The Department of Energy Vehicle Technologies Office supported the research. If you would like to speak with Prof. Helveston, please contact GW Senior Media Relations Specialist Cate Douglass at cdouglass@gwu.edu.

-GW-

---

JOURNAL

Environmental Research Letters

DOI

10.1088/1748-9326/ad3fce 

ARTICLE TITLE

Battery-powered bargains? Assessing electric vehicle resale value in the United States

ARTICLE PUBLICATION DATE

17-Apr-2024

 

Problem in microscopy solved after decades

DELFT UNIVERSITY OF TECHNOLOGY

Flattened sample

When viewing biological samples with a microscope, the light beam is disturbed if the lens of the objective is in a different medium than the sample. For example, when looking at a watery sample with a lens surrounded by air, the light rays bend more sharply in the air around the lens than in the water. This disturbance leads to the measured depth in the sample being smaller than the actual depth. As a result, the sample appears flattened. "This problem has been known for a long time, and since the 80s, theories have been developed to determine a corrective factor for determining the depth. However, all these theories assumed that this factor was constant, regardless of the depth in the sample. This happened despite the fact that the later Nobel laureate Stefan Hell pointed out in the 90s that this scaling could be depth-dependent", explains Associate Professor Jacob Hoogenboom.

Calculations, experiments, and web tool

Sergey Loginov, a former postdoc at Delft University of Technology, has shown with calculations and a mathematical model that the sample indeed appears more strongly flattened closer to the lens than farther away. PhD candidate Daan Boltje and postdoc Ernest van der Wee subsequently confirmed in the lab that the corrective factor is depth-dependent. Van der Wee: "We have compiled our results into a web tool and software provided with the article. With these tools, anyone can determine the precise corrective factor for their experiment."

Understanding abnormalities and diseases

"Partly thanks to our calculation tool, we can now very precisely cut out a protein and its surroundings from a biological system to determine the structure with electron microscopy. This type of microscopy is very complex, time-consuming, and incredibly expensive. Ensuring that you are looking at the right structure is therefore very important", says Boltje. "With our more precise depth determination, we need to spend much less time and money on samples that have missed the biological target. Ultimately, we can study more relevant proteins and biological structures. And determining the precise structure of a protein in a biological system is crucial for understanding and ultimately combating abnormalities and diseases."

About the web tool

In the web tool, you can fill in the relevant details of your experiment, such as the refractive indices, the aperture angle of the objective, and the wavelength of the light used. The tool then displays the curve for the depth-dependent scaling factor. You can also export this data for your own use. Additionally, you can plot the result in combination with the result of each of the existing theories.

---

JOURNAL

Optica

DOI

10.1364/OPTICA.520595 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Depth-dependent scaling of axial distances in light microscopy

ARTICLE PUBLICATION DATE

18-Apr-2024

Drawing a line back to the origin of life

UNIVERSITY OF CAMBRIDGE

 

IMAGE: 

A SCHEMATIC REPRESENTATION OF THE SCENARIO WE PROPOSE HERE FOR CLEAN, HIGH-YIELD PRODUCTION OF PREBIOTIC FEEDSTOCK. EVENTS MOVE AROUND CLOCKWISE FROM THE TOP LEFT: FIRST, THE EARTH HAS A NEUTRAL ATMOSPHERE. THIS IS REDUCED FOLLOWING A GIANT IMPACT AT 4.3 GA BY OXIDATION OF THE IMPACTOR’S METAL CORE TO PRODUCE A MASSIVE H2 ATMOSPHERE WITH SIGNIFICANT METHANE AND AMMONIA. THIS ATMOSPHERE QUICKLY COOLS (IN <1 KYR), WITH PHOTOCHEMISTRY PRODUCING A THOLIN-RICH HAZE THAT DEPOSITS COMPLEX NITROGEN-RICH ORGANICS. THESE ORGANICS BECOME PROGRESSIVELY BURIED AND GRAPHITIZED BY INTERACTION WITH MAGMA. THE ATMOSPHERE CLEARS AS H2 IS LOST TO SPACE AND BECOMES NEUTRAL AGAIN. FINALLY, MAGMATIC GASES INTERACT WITH THE GRAPHITE AND ARE SCRUBBED TO PRODUCE HIGH YIELDS OF CLEAN HCN, HC3N, AND ISONITRILES.

view more 

CREDIT: OLIVER SHORTTLE

Scientists in Cambridge University suggest molecules, vital to the development of life, could have formed from a process known as graphitisation. Once verified in the laboratory, it could allow us to try and recreate plausible conditions for life's emergence. 

How did the chemicals required for life get there?  

It has long been debated how the seemingly fortuitous conditions for life arose in nature, with many hypothesises reaching dead ends. However, researchers at the University of Cambridge have now modelled how these conditions could occur, producing the necessary ingredients for life in substantial quantities.  

Life is governed by molecules called proteins, phospholipids and nucleotides. Past research suggests that useful molecules containing nitrogen like nitriles - cyanoacetylene(HC3N) and hydrogen cyanide(HCN) – and isonitriles - isocyanide(HNC) and methyl isocyanide(CH3NC) – could be used to make these building blocks of life. As of yet though, there has been no clear way to make all of these in the same environment in substantial amounts. 

In a recent study published in Life, the group have now found that through a process known as graphitisation, significant quantities of these useful molecules can be theoretically made. If the model can be verified experimentally, this suggests that the process was a likely step for early Earth on its journey towards life.  

Why is this process more likely to have occurred than others? 

Much of the problem with previous models, is that a range of other products are created along with the nitriles. This makes a messy system which hinders the formation of life. 

‘A big part of life is simplicity,’ said Dr Paul Rimmer, Assistant Professor of Experimental Astrophysics at the Cavendish Laboratory, and co-author of the study. ‘It’s order. It’s coming up with a way to get rid of some of the complexity by controlling what chemistry can happen.’  

We don’t expect life to be produced in a messy environment. So, what is fascinating is how graphitisation itself cleans the environment, since the process exclusively creates these nitriles and isonitriles, with mostly inert side-products.  

‘At first, we thought this would spoil everything, but actually, it makes everything so much better. It cleans the chemistry,’ said Rimmer. 

This means graphitisation could provide the simplicity scientists are looking for, and the clean environment required for life. 

How does the process work? 

The Hadean eon was the earliest period in Earth’s history, when the Earth was very different to our modern Earth. Impacts with debris, sometimes the size of planets, were not unheard of. The study theorises that when the early Earth was hit with an object roughly the size of the moon, around 4.3 billion years ago, the iron that it contained reacted with water on Earth.  

‘Something the size of the moon hit early Earth, and it would have deposited a large amount of iron and other metals’ said co-author Dr Oliver Shorttle, Professor of natural philosophy at the Institute of Astronomy and Department of Earth Sciences in Cambridge.  

The products of the iron-water reaction condense into a tar on the surface of the Earth. The tar then reacts with magma at over 1500°C and the carbon in the tar becomes graphite- a highly stable form of carbon- and what we use in modern pencil leads!  

‘Once the iron reacts with the water, a mist forms that would have condensed and mixed with the Earth’s crust. Upon heating, what’s left is, lo and behold, the useful nitrogen containing compounds,’ said Shorttle.   

What evidence exists to support this idea? 

The evidence to support this theory partly comes from the presence of komatiitic rocks. Komatiite is a type of volcanic rock which are formed when very hot magma(>1500°C) cools.  

‘Komatiite was originally found in South Africa. The rocks date back to around 3.5 billion years ago,’ said Shorttle. ‘Crucially, we know that these rocks only form at scorching temperatures, around 1700°C! That means the magma would already have been hot enough to heat the tar and create our useful nitriles.’ 

With the link confirmed, the authors suggest that nitrogen containing compounds would be made via this method- since we see komatiite, we know the temperature of magma on early Earth sometimes must have been in excess of 1500°C.  

What next? 

Now experiments must try to recreate these conditions in the lab, and study whether the water, which is inevitably in the system, eats up the nitrogen compounds, breaking them apart.  

‘Though we don’t know for sure that these molecules started out life on Earth, we do know that life’s building blocks must be made from molecules that survived in water,’ said Rimmer. ‘If future experiments show that the nitriles all fall apart, then we’ll have to look for a different way.’ 

---

JOURNAL

Life

DOI

10.3390/life14040498 

METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

A Surface Hydrothermal Source of Nitriles and Isonitriles

SPACE

Hubble goes hunting for small main belt asteroids

NASA/GODDARD SPACE FLIGHT CENTER

 

IMAGE: 

THIS HUBBLE SPACE TELESCOPE IMAGE OF THE BARRED SPIRAL GALAXY UGC 12158 LOOKS LIKE SOMEONE TOOK A WHITE MARKING PEN TO IT. IN REALITY IT IS A COMBINATION OF TIME EXPOSURES OF A FOREGROUND ASTEROID MOVING THROUGH HUBBLE'S FIELD-OF-VIEW, PHOTOBOMBING THE OBSERVATION OF THE GALAXY. SEVERAL EXPOSURES OF THE GALAXY WERE TAKEN, WHAT IS EVIDENCE IN THE DASHED PATTERN. THE ASTEROID APPEARS AS A CURVED TRAIL DUE TO PARALLAX: BECAUSE HUBBLE IS NOT STATIONARY, BUT ORBITING EARTH, AND THIS GIVES THE ILLUSION THAT THE FAINT ASTEROID IS SWIMMING ALONG A CURVED TRAJECTORY. THE UNCHARTED ASTEROID IS IN INSIDE THE ASTEROID BELT IN OUR SOLAR SYSTEM, AND HENCE IS 10 TRILLION TIMES CLOSER TO HUBBLE THAN THE BACKGROUND GALAXY. RATHER THAN A NUISANCE, THIS TYPE OF DATA ARE USEFUL TO ASTRONOMERS FOR DOING A CENSUS OF THE ASTEROID POPULATION IN OUR SOLAR SYSTEM.

view more 

CREDIT: NASA, ESA, PABLO GARCÍA MARTÍN (UAM); IMAGE PROCESSING: JOSEPH DEPASQUALE (STSCI); ACKNOWLEDGMENT: ALEX FILIPPENKO (UC BERKELEY)

Like boulders, rocks, and pebbles scattered across a landscape, asteroids come in a wide range of sizes. Cataloging asteroids in space is tricky because they are faint and they don't stop to be photographed as they zip along their orbits around the Sun.

Astronomers recently used a trove of archived images taken by NASA's Hubble Space Telescope to visually snag a largely unseen population of smaller asteroids in their tracks. The treasure hunt required perusing 37,000 Hubble images spanning 19 years. The payoff was finding 1,701 asteroid trails, with 1,031 of the asteroids previously uncatalogued. About 400 of these uncatalogued asteroids are below 1 kilometer in size.

Volunteers from around the world known as "citizen scientists" contributed to the identification of this asteroid bounty. Professional scientists combined the volunteers' efforts with machine learning algorithm to identify the asteroids. It represents a new approach to finding asteroids in astronomical archives spanning decades, which may be effectively applied to other datasets, say the researchers.

"We are getting deeper into seeing the smaller population of main belt asteroids. We were surprised with seeing such a large number of candidate objects," said lead author Pablo García Martín of the Autonomous University of Madrid, Spain. "There was some hint of this population existing, but now we are confirming it with a random asteroid population sample obtained using the whole Hubble archive. This is important for providing insights into the evolutionary models of our solar system."

The large, random sample offers new insights into the formation and evolution of the asteroid belt. Finding a lot of small asteroids favors the idea that they are fragments of larger asteroids that have collided and broken apart, like smashed pottery. This is a grinding-down process spanning billions of years.

An alternative theory for the existence of smaller fragments is that they formed that way billions of years ago. But there is no conceivable mechanism that would keep them from snowballing up to larger sizes as they agglomerated dust from the planet-forming circumstellar disk around our Sun. "Collisions would have a certain signature that we can use to test the current main belt population," said co-author Bruno Merín of the European Space Astronomy Centre, in Madrid, Spain .

Amateur Astronomers Teach AI to Find Asteroids

Because of Hubble's fast orbit around the Earth, it can capture wandering asteroids through their telltale trails in the Hubble exposures. As viewed from an Earth-based telescope, an asteroid leaves a streak across the picture. Asteroids "photobomb" Hubble exposures by appearing as unmistakable, curved trails in Hubble photographs.

As Hubble moves around the Earth, it changes its point of view while observing an asteroid, which also moves along its own orbit. By knowing the position of Hubble during the observation and measuring the curvature of the streaks, scientists can determine the distances to the asteroids and estimate the shapes of their orbits.

The asteroids snagged mostly dwell in the main belt, which lies between the orbits of Mars and Jupiter. Their brightness is measured by Hubble's sensitive cameras. And comparing their brightness to their distance allows for a size estimate. The faintest asteroids in the survey are roughly one forty-millionth the brightness of the faintest star that can be seen by the human eye.

"Asteroid positions change with time, and therefore you cannot find them just by entering coordinates, because at different times, they might not be there," said Merín. "As astronomers we don't have time to go looking through all the asteroid images. So we got the idea to collaborate with over 10,000 citizen-science volunteers to peruse the huge Hubble archives."

In 2019 an international group of astronomers launched the Hubble Asteroid Hunter, a citizen-science project to identify asteroids in archival Hubble data. The initiative was developed by researchers and engineers at the European Science and Technology Centre (ESTEC) and the European Space Astronomy Centre's science data center (ESDC), in collaboration with the Zooniverse platform, the world's largest and most popular citizen-science platform, and Google.

A total of 11,482 citizen-science volunteers, who provided nearly 2 million identifications, were then given a training set for an automated algorithm to identify asteroids based on artificial intelligence. This pioneering approach may be effectively applied to other datasets.

The project will next explore the streaks of previously unknown asteroids to characterize their orbits and study their properties, such as rotation periods. Because most of these asteroid streaks were captured by Hubble many years ago, it is not possible to follow them up now to determine their orbits.

The findings are published in the journal Astronomy and Astrophysics.

To learn how you can participate in citizen science projects related to NASA, visit https://science.nasa.gov/citizen-science/. Participation is open to everyone around the world, not limited to U.S. citizens or residents.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Learn More:

Hubble Sees Nearby Asteroids Photobombing Distant Galaxies

Tracking Evolution in the Asteroid Belt

Uncovering Icy Objects in the Kuiper Belt

Media Contact:

Claire Andreoli
NASA's Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov

Ray Villard
Space Telescope Science Institute, Baltimore, MD

Science Contact:
Pablo García Martín
Autonomous University of Madrid, Madrid, Spain

---

JOURNAL

Astronomy and Astrophysics

DOI

10.1051/0004-6361/202346771 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Hubble Asteroid Hunter

 

Peptides on Interstellar Ice

International research team led by physicists at Friedrich Schiller University Jena observes formation of biomolecules under space conditions

FRIEDRICH-SCHILLER-UNIVERSITAET JENA

 

IMAGE: 

DR SERGE KRASNOKUTSKI FROM UNIVERSITY OF JENA, GERMANY USES A VACUUM CHAMBER TO INVESTIGATE THE FORMATION OF BIOMOLECULES IN SPACE.

view more 

CREDIT: IMAGE: JENS MEYER/UNIVERSITY OF JENA

Peptides are organic compounds that play a crucial role in many biological processes, for example, as enzymes. A research team led by Dr Serge Krasnokutski from the Astrophysics Laboratory at the Max Planck Institute for Astronomy at the University of Jena had already demonstrated that simple peptides can form on cosmic dust particles. However, it was previously assumed that this would not be possible if molecular ice, which covers the dust particle, contains water – which is usually the case. Now, the team, in collaboration with the University of Poitiers, France, has discovered that the presence of water molecules is not a major obstacle for the formation of peptides on such dust particles. The researchers report on their finding in the journal “Science Advances”.

Chemistry in the Icy Vacuum

“We have replicated conditions similar to those in outer space in a vacuum chamber, also adding substances that occur in so-called molecular clouds,” explains Krasnokutski. These substances include ammonia, atomic carbon, and carbon monoxide. “Thus, all the chemical elements needed for simple peptides are present,” adds the physicist.

These raw materials, Krasnokutski describes, initially form chemical precursors to amino acids known as aminoketenes. These then combine to form chains, resulting in polypeptides. “It was previously suspected that the individual aminoketenes would bond to form peptides,” the scientist explains. “However, for this step, the absence of water might be crucial as it could hinder the reaction. At the same time, most interstellar dust particles are covered with water-containing molecular ice,” says Krasnokutski. Hence, the assumption until now has been that if peptides form in space, they do so only to a limited extent.

Precise Analysis in France

“The highly precise mass spectrometric analyses now possible at the University of Poitiers, however, showed that the presence of water in the molecular ice slows down the formation of peptides by fifty percent, but they still form,” he explains. “When you consider the time scales on which astronomical processes occur, this slowdown is practically negligible.”

The question of whether the first biomolecules on our planet are of terrestrial or extraterrestrial origin – or both – will likely remain unresolved for the foreseeable future. However, outer space as a source of our life cannot be ruled out, as this discovery indicates.

---

JOURNAL

Science Advances

DOI

10.1126/sciadv.adj7179 

METHOD OF RESEARCH

Experimental study

ARTICLE TITLE

Formation of extraterrestrial peptides and their derivatives

ARTICLE PUBLICATION DATE

17-Apr-2024

‘Tube map’ around planets and moons made possible by knot theory

UNIVERSITY OF SURREY

Just as sat-nav did away with the need to argue over the best route home, scientists from the University of Surrey have developed a new method to find the optimal routes for future space missions without the need to waste fuel.  

The new method uses mathematics to reveal all possible routes from one orbit to another without guesswork or using enormous computer power.  

Danny Owen, who developed the technique at the Surrey Space Centre, said:

“Previously, when the likes of NASA wanted to plot a route, their calculations relied on either brute force or guesswork.

"Our new technique neatly reveals all possible routes a spacecraft could take from A to B, as long as both orbits share a common energy level.

"This makes the task of planning missions much simpler. We think of it as a tube map for space.”   

In recent decades, space missions have increasingly relied on the ability to change the course of a satellite’s path through space without using fuel.  

One way of doing this is to find ‘heteroclinic connections’ - the paths that allow spacecraft to transfer from one orbit to another without using fuel.  

The mathematics for finding these paths is complex – usually calculated by using vast computing power to churn through one option after another or by making an ‘intelligent guess’ and then investigating it further.  

This new technique uses an area of maths called knot theory to quickly generate rough trajectories – which can then be refined. By doing so, space agencies can gain a full list of all possible routes from a designated orbit. They can then choose the one that best suits their mission – much as you might choose a route by studying the tube map.  

The technique was tested successfully on various planetary systems - including the Moon, and the Galilean moons of Jupiter. Both of these are the focus of current and future missions.  

Dr Nicola Baresi, Lecturer in Orbital Mechanics at the University of Surrey, said:  

“Spurred on by NASA’s Artemis programme, the new Moon race is inspiring mission designers around the world to research fuel-efficient routes that can better and more efficiently explore the vicinity of the Moon.  

“Not only does our technique make that cumbersome task more straightforward, but it can also be applied to other planetary systems, such as the icy moons of Saturn and Jupiter.” 

The paper is published in the journal Astrodynamics.  

---

JOURNAL

Astrodynamics

DOI

10.1007/s42064-024-0201-0 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Applications of knot theory to the detection of heteroclinic connections between quasi-periodic orbits

ARTICLE PUBLICATION DATE

17-Apr-2024

Atmospheric isotopes reveal 4.5 billion years of volcanism on Jupiter’s moon Io

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Sulfur and chlorine isotopes in the atmosphere of Jupiter’s moon Io indicate that it has been volcanically active for the entire 4.57 billion-year history of the Solar System, according to a new study. The findings offer new insights into the moon’s history. Io is the most volcanically active body in the Solar System. This extreme level of volcanic activity is the result of tidal heating from friction generated within the moon’s interior as it is pulled between Jupiter and its neighboring moons of Europa and Ganymede. However, how long Io has hosted such extensive volcanism isn’t fully understood. Due to the moon’s current level of volcanic activity, the surface of Io is constantly being reworked, leaving a geological record of only the most recent million years of its history. Stable isotopic measurements of volatile elements in Io’s atmosphere could provide information on the history of volcanism on Io. Katherine de Kleer and colleagues used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the gasses in Io’s tenuous atmosphere and determine the stable isotopic radios of sulfer- and chlorine-bearing molecules. de Kleer et al. found that both elements are highly enriched in heavy isotopes compared to average Solar System values due to the loss of lighter isotopes from the upper atmosphere as material is continuously recycled between Io’s interior and atmosphere. The findings indicate that Io has lost 94% to 99% of the sulfur that undergoes this outgassing and recycling process. According to the authors, this would require Io to have had its current level of volcanic activity for its entire lifetime.

---

JOURNAL

Science

DOI

10.1126/science.adj0625 

ARTICLE TITLE

Isotopic evidence of long-lived volcanism on Io

ARTICLE PUBLICATION DATE

18-Apr-2024

The CTAO enters a new phase of growth

CHERENKOV TELESCOPE ARRAY

 

VIDEO: 

ON THURSDAY, 18 APRIL, DURING THE CLOSING SESSION OF THE CTAO SCIENCE SYMPOSIUM AT TEATRO DUSE IN BOLOGNA, THE DIRECTOR GENERAL OF THE CTAO, DR. STUART MCMULDROCH, OFFICIALLY ANNOUNCED THE OBSERVATORY’S NEW PHASE OF GROWTH. SUPPORTED BY THE 30M EURO ENDORSEMENT BY THE CTAO’S GOVERNING BODIES IN SEPTEMBER 2023, THIS NEW PERIOD PUTS AN END TO THE DESIGN PHASE OF THE OBSERVATORY, AS IT EMBARKS ON MAJOR INFRASTRUCTURE DEVELOPMENT TO OPERATE INTERMEDIATE TELESCOPE ARRAY CONFIGURATIONS IN THE UPCOMING YEARS. TO SHOWCASE THIS MILESTONE, STUART ALSO LAUNCHED THE CTAO’S NEW VISUAL IDENTITY AND WEBSITE DURING HIS TALK. #CTAOisGrowing

view more 

CREDIT: CTAO

Bologna, Italy – On Thursday, 18 April, during the closing session of the CTAO Science Symposium at Teatro Duse in Bologna, the Managing Director of the CTAO, Dr. Stuart McMuldroch, officially announced the Observatory’s new phase of growth. Supported by the 30M Euro endorsement by the CTAO’s governing bodies in September 2023, this new period puts an end to the design phase of the Observatory, as it embarks on major infrastructure development to operate intermediate telescope array configurations in the upcoming years.

“We are moving from individual prototype telescopes to building intermediate array configurations on both sites in Spain and Chile,” explained Dr. McMuldroch during his presentation. “While our goal is to reach the Alpha Configuration, these subsets will already be more powerful than any existing instrument.”

“The intermediate array configurations will have a performance two to three times better than the current generation of ground-based instruments, allowing the CTAO to detect fainter sources and minute-scale variability from gamma-ray signals,” says Roberta Zanin, CTAO Project Scientist.

The growth of the CTAO will not only be apparent in terms of hardware, but also software and personnel. Firstly, the Observatory will start applying advanced software packages, moving from testing to integrating key systems that control the telescopes and process data. Additionally, the CTAO Central Organisation will double its staff to support the advancement of the Observatory on all fronts, from science and engineering to computing and administration.

To showcase this milestone, Stuart also launched the CTAO’s new visual identity and website during his talk. An important update is that the "CTAO" will now define the Observatory and international project, discontinuing the term "CTA."

“The CTAO is built thanks to a growing international partnership composed of various teams with different tasks, scopes and even management, but who share a common goal: to build the world’s largest gamma-ray observatory to achieve transformational science,” says Stuart. “The "CTAO" encompasses that joint effort, representing all the groups involved.”

The CTAO’s new logo and brand reflect this fresh phase of growth and collaboration with a clean, modern aesthetic that clearly positions the Observatory for its current and future status in the field. The website is the most visible manifestation of this transition, providing an immersive and engaging interface for the general public and scientists to interact with the science, technology and partners behind the CTAO.