Measuring the universe with star-shattering explosions

An international team of 23 researchers led by Maria Dainotti, Assistant Professor at the National Astronomical Observatory of Japan (NAOJ), has analyzed archive data for powerful cosmic explosions from the deaths of stars and found a new way to measure distances in the distant Universe.

With no landmarks in space, it is very difficult to get a sense of depth. One technique astronomers use is to look for "standard candles," objects or events where the underlying physics dictate that the absolute brightness (what you would see if you were right next to it) is always the same. By comparing this calculated absolute brightness to the apparent brightness (what is actually observed from Earth), it is possible to determine the distance to the standard candle, and by extension other objects in the same area. The lack of standard candles bright enough to be seen more than 11 billion light-years away has hindered research on the distance Universe. Gamma-Ray bursts (GRBs), bursts of radiation produced by the deaths of massive stars, are bright enough, but their brightness depends on the characteristics of the explosion.

Embracing the challenge of attempting to use these bright events as standard candles, the team analyzed archive data for the visible light observations of 500 GRBs taken by world-leading telescopes such as the Subaru Telescope (owned and operated by NAOJ), RATIR, and satellites such as the Neil Gehrels Swift Observatory. Studying the light curve's pattern of how the GRB brightens and dims over time, the team identified a class of 179 GRBs which have common features and have likely been caused by similar phenomena. From the characteristics of the light curves, the team was able to calculate a unique brightness and distance for each GRB which can be used as a cosmological tool.

These findings will provide new insights into the mechanics behind this class of GRBs, and provide a new standard candle for observing the distant Universe. Lead author Dainotti had previously found a similar pattern in X-ray observations of GRBs, but visible light observations have been revealed to be more accurate in determining cosmological parameters.

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Study finds why many IVF embryos fail to develop

In humans, a fertilized egg is no guarantee of reproductive success. Most embryos stop developing and perish within days of fertilization, usually because they have an abnormal number of chromosomes. Now, researchers at Columbia University Vagelos College of Physicians and Surgeons have found that most of these mistakes are due to spontaneous errors in DNA replication in the earliest phase of cell division.

The findings provide new insights into the basic biology of human reproduction and in the long term could lead to improvements in the success rate of in vitro fertilization (IVF). The study was published online July 19 in the journal Cell.

Challenging task for early embryos

Approximately 24 hours after a human egg is fertilized, the process of cell division begins. During cell division, the entire genome -- 46 chromosomes containing more than 3 billion base pairs of DNA -- must be faithfully duplicated. The duplicate sets of chromosomes must then be separated so that each daughter cell receives a complete set.

In many human embryos created for IVF, something goes wrong and some cells within the embryo have too few or too many chromosomes.

"Duplicating the genome is a challenging task for the early embryo," says study leader Dieter Egli, PhD, the Maimonides Assistant Professor of Developmental Cell Biology (in pediatrics) at Columbia University Vagelos College of Physicians and Surgeons.

Researchers have long theorized that errors occur during the final phase of cell division, when the duplicate sets of chromosomes separate into two identical daughter cells. Most of these failures were attributed to issues with the microtubule spindle, the apparatus that pulls the two sets of chromosomes apart.

But Egli's studies found that chromosomal abnormalities stem from errors that occur much earlier in the process of cell division when the genome's DNA is duplicated. If the DNA is not copied precisely, his studies found, the spindle malfunctions and places the wrong number of chromosomes into each daughter cell. When DNA duplication is abnormal, the spindle does not function normally. "This has largely been overlooked in previous studies -- because why would the embryo allow the integrity of the genome to be compromised when this is such a critical requirement for normal development?" Egli says.

Though the studies were conducted with embryos created in a petri dish -- including from individuals undergoing IVF and egg donors who were not seeking fertility treatment -- the same problems may contribute to the failure of embryos created in natural human reproduction.

Clues to source of DNA errors

The source of DNA copying errors in embryos appears to spring from obstacles within the DNA's double helix. Though the precise reason for these obstacles is not yet known, they cause duplication of the DNA to pause, or even stop, which results in DNA breakage and an abnormal number of chromosomes.

Spontaneous DNA errors can occur as early as the first cycle of cell division in human embryos, the researchers found, as well as in subsequent cell divisions. If too many cells in the early embryo are affected by chromosomal abnormalities, the embryo cannot develop further.

IVF

Most human embryos created for IVF stop developing within days after fertilization. This inefficiency of human development is an obstacle to successful fertility treatments.

"Many women undergoing fertility treatment require multiple IVF cycles in order to get pregnant, and some never get pregnant at all. Not only is this enormously expensive, it's emotionally taxing," says Jenna Turocy, MD, a fertility specialist at Columbia University Fertility Center and a co-author of the study.

The researchers are planning additional studies looking at DNA damage during replication in the hope of understanding normal and disease-causing variations in the human germ line. In the long term, these studies may lead to methods to reduce the risk of genetic abnormalities and embryo attrition for patients undergoing IVF.

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Supermassive blackhole influences star formation

A European team of astronomers led by Professor Kalliopi Dasyra of the National and Kapodistrian University of Athens, Greece, under participation of Dr. Thomas Bisbas, University of Cologne modelled several emission lines in Atacama Large Millimeter Array (ALMA) and Very Large Telescope (VLT) observations to measure the gas pressure in both jet-impacted clouds and ambient clouds. With these unprecedented measurements, published recently in Nature Astronomy, they discovered that the jets significantly change the internal and external pressure of molecular clouds in their path. Depending on which of the two pressures changes the most, both compression of clouds and triggering of star formation and dissipation of clouds and delaying of star formation are possible in the same galaxy. "Our results show that supermassive black holes, even though they are located at the centers of galaxies, could affect star formation in a galaxy-wide manner" said Professor Dasyra, adding that "studying the impact of pressure changes in the stability of clouds was key to the success of this project. Once few stars actually form in a wind, it is usually very hard to detect their signal on top of the signal of all other stars in the galaxy hosting the wind."

It is believed that supermassive black holes lie at the centers of most galaxies in our Universe. When particles that were infalling onto these black holes are trapped by magnetic fields, they can be ejected outwards and travel far inside galaxies in the form of enormous and powerful jets of plasma. These jets are often perpendicular to galactic disks. In IC 5063 however, a galaxy 156 million light years away, the jets are actually propagating within the disk, interacting with cold and dense molecular gas clouds. From this interaction, compression of jet-impacted clouds is theorized to be possible, leading to gravitational instabilities and eventually star formation due to the gas condensation.

For the experiment, the team used the emission of carbon monoxide (CO) and formyl cation (HCO+) provided by ALMA, and the emission of ionized sulfur and ionized nitrogen provided by VLT. They then used advanced and innovative astrochemical algorithms to pinpoint the environmental conditions in the outflow and in the surrounding medium. These environmental conditions contain information about the strength of the far-ultraviolet radiation of stars, the rate at which relativistic charged particles ionize the gas, and the mechanical energy deposited on the gas by the jets. Narrowing down these conditions revealed the densities and gas temperatures descriptive of different parts of this galaxy, which were then used to provide pressures.

"We have performed many thousands of astrochemical simulations to cover a wide range of possibilities that may exist in IC 5063" said co-author Dr. Thomas Bisbas, DFG Fellow of the University of Cologne and former postdoctoral researcher at the National Observatory of Athens. A challenging part of the work was to meticulously identify as many physical constraints as possible to the examined range that each parameter could have. "This way, we could get the optimal combination of physical parameters of clouds at different locations of the galaxy," said co-author Mr. Georgios Filippos Paraschos, Ph.D. student at the Max Planck Institute for Radio Astronomy in Bonn and former Master's student at the National and Kapodistrian University of Athens.

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How the intestine replaces and repairs itself

To act as a robust barrier against pathogens while also absorbing needed nutrients, the lining of the intestines must regenerate on a daily basis to remain equal to the task. The intestine's resident stem cells are responsible for meeting this need for constant repair and replenishment, but each stem cell faces decisions that depend on the overall conditions of the intestine and the needs of the moment. Bad decisions and poor coordination could result in intestinal diseases or cancer.

A new study suggests that stem cells are able to integrate cues from their surroundings and coordinate their behavior across the tissue through networks of vasculature in their close vicinity.

Rockefeller scientists found that lymphatic capillaries -- fine vessels that transport immune cells and drain fluids from tissues -- represent a signaling hub that communicates with stem cells to regulate their activity. With molecular guidance from the lymphatics, the stem cells produce daughter cells to repopulate the intestinal lining or self-renew to restock the stem cell reserve.

The findings, published in the journal Cell Stem Cell, provide new insights about primary intestinal components whose disrupted communication may contribute to intestinal disorders, such as inflammatory bowel disease. "The key to treating these diseases will be to figure out who talks to whom in this ecosystem and how we can reset the communication networks," says Rachel Niec, a clinical scholar in the laboratory of Elaine Fuchs.

Communications in the crypt

The intestinal stem cells reside in so-called crypts, found at the base of densely packed indentations in the intestinal lining. The stem cells may renew and stay in the crypt, or differentiate into specialized cells, which then migrate out of the crypt to replenish the gut lining. "To understand how stem cells balance self-renewal with differentiation, we needed a more complete picture of crypt niches," says Marina Schernthanner, a graduate student in the Fuchs lab.

To zoom in on the crypt, the team used a suite of techniques, including single-cell and spatial transcriptomics, which allowed them to identify cell types at specific locations and study their signaling molecules. The results showed that lymphatic capillaries, which form an intimate connection with the stem cells in the crypt, produce a number of proteins known to be important for stem cell functioning.

One previously underappreciated protein, REELIN, emerged as a top candidate for mediating communications between lymphatics and stem cells. By manipulating the amount of REELIN in lab-grown intestinal organoid cultures in some experiments and genetically suppressing it in mice in others, the researchers found that REELIN directly governs the regenerative behavior of intestinal stem cells.

The involvement of the lymphatic system in stem cell functioning is a relatively new concept. A previous study by the Fuchs team revealed that lymphatics are also closely involved with stem cells of the skin and play a key role in hair regeneration. There, however, it is the hair follicle stem cells that signal to lymphatic capillaries. By controlling their interactions with lymphatics, the stem cells synchronize hair regeneration across the tissue. "This suggests that lymphatics may be a conserved feature of stem cell niches, but their relationship to stem cells are likely tailored around the needs of each tissue," Niec says.

From Science Daily

New method to map the surface of the moon increases accuracy to unprecedented levels

Topography: The surface of the moon and rocky planets, Mars in particular, are of huge interest to anyone trying to explore our solar system. The surface must be known in as much detail as possible, for missions to land safely, or for any robotic vessel to drive across the surface. But until now, the methods to analyze images from e.g. orbiting spacecraft have entailed a huge work load and immense computer power -- with limited results. A project from now former PHD student at the Niels Bohr Institute, University of Copenhagen, Iris Fernandes, has changed that. Studying the limestone formation Stevns Klint in Denmark, she developed a method to interpret shadows in images, so the exact topography can be extracted.The method is even much quicker and less work-intensive. The result is now published Planetary and Space Science 218.

Human space exploration entails high levels of safety -- so precise images of the terrain are adamant

The topography of any surface will create shades, when the sunlight hits it. We can clearly see the shades in the pictures of e.g. the Moon, but we don't know the elevation of the terrain. So we can see the topography changes, but not how much! It is necessary to be able to see even very small features to ensure safe landing or movement of e.g. a rover. Not to mention the safety of astronauts.

If a rover can't see details, it could get stuck in sand surfaces or hit rocks -- and being able to see interesting geological formations to find rich geological environments for research purposes is also of great importance.

Former limitations in topography assessment have now been largely eradicated

When satellites orbit a planet, they can take pictures in reasonable quality of the surface. But in order to establish an interpretation of the exact topography, good enough for landing the hugely expensive equipment or perhaps even astronauts, a lot of ad hoc information still needs to be processed.

The method of using the shades existed before, but it was computationally inefficient, and still had to rely on assumptions. The new method uses a much more direct and precise calculation, it doesn't rely on a whole set of parameters to be fed into the computer, and it can even calculate the uncertainties and the accuracy.

"This method is fast, it is precise and it doesn't have to rely on any assumptions. Previously," Iris Fernandes says, "if you posed the question: How precise is the assessment of the topography -- there really wasn't a satisfactory answer.

Now the precise topography is revealed, and we can even quantify the uncertainties."

Scientific curiosity can lead you to surprising places

"I was involved in a project where we wanted to use pictures from Stevns Klint to model patterns in the surface. I even presented this method in a conference in L.A. But the shades presented a challenge, because the algorithm "saw" the shades as geological features.

It created a bias in the model. We needed to find ways to remove the shades, in order to remove the bias.

I was always interested in planets, and I knew the surface of the moon was being studied. There aren't many disturbing features on the Moon, so it was ideal for removing the bias.

When we filtered away the shades, we could see what they were "hiding," so to speak -- the surface shapes," Iris Fernandes explains.

Resolution of existing images presented a new problem -- and a new approach

When work on the Moon started, the discrepancy of the different resolutions in images and the topography data turned out to be tremendous. A new problem appeared, in other words. "How could we combine different sources of data in different resolutions?

It presented a huge mathematical problem -- and this is really what the study is about.

This is where former research had come to a stop. What we did differently than former attempts to solve this, was that we focused on the mathematics and narrowed it down to a challenging mathematical equation. Basically, to see if this equation could solve the problem.

And it did," Iris Fernandes smiles. "You could say that we, my supervisor, Professor Klaus Mosegaard and I, found the mathematical key to a door that had remained closed for many years."

The way forward

The focus now is improving the method even more. Wherever there are data available on rock-formation in the solar system, like the Moon, Mars, asteroids or the like, the method can be applied to extract precise topographic details.

The images used for this task, can be images from satellites or even the rovers themselves, presently on the ground on Mars -- or any mobile robot in the future.

The purposes for achieving correct topographic analysis can be different, it could be the safety of the equipment or astronauts or finding geologically interesting sites.

There is a wide array of possible applications, in other words. "It is a sort of computer vision thing," Iris Fernandes says: "When, for instance, a robot has some form of machinery to interact with the environment, the method can help in navigation or the "eye-hand coordination," because it is less computational "heavy" and thus faster.

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Plant study hints evolution may be predictable

Evolution has long been viewed as a rather random process, with the traits of species shaped by chance mutations and environmental events -- and therefore largely unpredictable.

But an international team of scientists led by researchers from Yale University and Columbia University has found that a particular plant lineage independently evolved three similar leaf types over and over again in mountainous regions scattered throughout the neotropics.

The findings provided the first examples in plants of a phenomenon known as "replicated radiation," in which similar forms evolve repeatedly within different regions, suggesting that evolution is not always such a random process but can be predicted.

The study is published July 18 in the journal Nature Ecology & Evolution.

"The findings demonstrate how predictable evolution can actually be, with organismal development and natural selection combining to produce the same forms again and again under certain circumstances," said Yale's Michael Donoghue, Sterling Professor Emeritus of Ecology & Evolutionary Biology and co-corresponding author. "Maybe evolutionary biology can become much more of a predictive science than we ever imagined in the past."

For the study, the research team studied the genetics and morphology of the plant lineage Viburnum, a genus of flowering plants that began to spread south from Mexico into Central and South America some 10 million years ago. Donoghue studied this same plant group for his Ph.D. dissertation at Harvard 40 years ago. At the time, he argued in favor of an alternative theory in which large, hair-covered leaves and small smooth leaves evolved early in the evolution of the group and then both forms migrated separately, being dispersed by birds, through the various mountain ranges.

The new genetic analyses reported in the paper, however, show that the two different leaf types evolved independently, in parallel, in each of a number of mountain regions.

"I came to the wrong conclusion because I lacked the relevant genomic data back in the 1970s," Donoghue said.

The team found that a very similar set of leaf types evolved in nine of 11 regions studied. However, the full array of leaf types may have yet to evolve in places where Viburnum has only more recently migrated. For instance, the mountains of Bolivia lack the large hairy leaf types found in other wetter areas with little sunshine in the cloud forest in Mexico, Central America, and northern South America.

"These plants arrived in Bolivia less than a million years ago, so we predict that the large, hairy leaf form will eventually evolve in Bolivia as well," Donoghue said.

Several examples of replicated radiation have been found in animals, such as Anolis lizards in the Caribbean. In that case, the same set of body forms, or "ectomorphs," evolved independently on several different islands. With a plant example now in hand, evolutionary biologists will try to discover the general circumstances under which solid predictions can be made about evolutionary trajectories.

"This collaborative work, spanning decades, has revealed a wonderful new system to study evolutionary adaptation," said Ericka Edwards, professor of ecology and evolutionary biology at Yale and co-corresponding author of the paper. "Now that we have established the pattern, our next challenges are to better understand the functional significance of these leaf types and the underlying genetic architecture that enables their repeated emergence."

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Just 10 financial actors hold the key to climate change

A new report has identified the 10 financial actors with the most influence on the fossil fuel economy and outlines the decisive role they can play in helping de-carbonize our future.

The study found that the top 10 most influential actors, including investment advisors, governments, and sovereign wealth funds from around the world, own 49.5 per cent of potential emissions from the world's largest energy firms.

"This shows us that both investors and governments can be at the forefront of change if citizens and clients urge them to de-carbonize," said Truzaar Dordi, lead researcher from the University of Waterloo. "A concentrated number of investors with the potential to influence the trajectory of the fossil fuel industry is either a problem, or an opportunity, depending on how you see things."

To arrive at their list, the researchers used a novel scoring mechanism blending the financial actor's fossil fuel holdings and investment in the world's 200 largest fossil fuel firms.

"If they're serious, capital markets can enable a low-carbon transition within the top coal, oil and gas reserve owners in the world," said Dordi. "Recent pledges to reduce carbon exposure in investment portfolios and engagement with the fossil fuel industry indicate we may already be moving in that direction."

The paper outlines specific ways these 10 governments and private investment advisors can make changes that will have a transformative impact in the fight against climate change. Some recommendations include public disclosure of a scheduled phase-out of fossil fuel financing, an assessment of a portfolio's exposure to climate risk in a 2°C world, and an alignment of investment portfolios with a 1.5°C scenario.

"Individually, reducing the demand for fossil fuels by driving and flying less and turning off the air-conditioner are great. We should keep doing that. But we also need to reduce our production of fossil fuels, which these 10 actors can lead. Without them, we simply won't have what it takes to meet our emissions targets and avoid catastrophe."

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Paper wasps form abstract concept of 'same' and 'different'

In a series of studies over more than 20 years, University of Michigan evolutionary biologist Elizabeth Tibbetts and her colleagues have demonstrated that paper wasps, despite their tiny brains, have an impressive capacity to learn, remember and make social distinctions about others.

The researchers showed that paper wasps recognize individuals of their species by variations in their facial markings and that they behave more aggressively toward wasps with unfamiliar markings.

They established that paper wasps have surprisingly long memories and base their actions on what they remember of previous social interactions with other wasps. And they provided the first evidence of transitive inference -- a behavior that resembles logical reasoning -- in a nonvertebrate animal, the lowly paper wasp.

Now, Tibbetts and her students are reporting the first evidence that paper wasps can form abstract concepts. Strikingly, the wasps were also able to transfer what they learned through visual training into a different sensory modality: the sense of smell.

The study used laboratory tasks to test whether paper wasps (Polistes fuscatus) could learn and apply one of the most basic abstract concepts: the idea of sameness and difference.

The wasps were trained to distinguish between pairs of visual or olfactory stimuli (two colored bits of paper, two photos of wasp faces, or two chemical odors) that were either identical or different. One pair of stimuli was associated with a mild but unpleasant electrical shock, the other was not.

Then the stinging insects were exposed to novel pairs of stimuli (either identical or different) and tested on their ability to avoid an electric shock by selecting the "correct" pair -- the one associated with safety.

The previously trained wasps made the correct choice more than 80% of the time, according to the researchers. The team's findings were published online July 20 in the journal Proceedings of the Royal Society B.

"Our findings show the wasps learned the general concept of sameness and difference and applied it to new samples and new types of stimuli," said Tibbetts, a professor in the U-M Department of Ecology and Evolutionary Biology.

"Abstract concepts are thought to be associated with high levels of cognitive sophistication, so there has been much interest in which species can form and use them. This is the first time anyone has shown that wasps can form abstract concepts."

Historically, only primates were thought to be capable of same-different concept learning. But subsequent research found evidence of same-different concepts in many animals, including crows, pigeons, parrots, dolphins, ducklings and honeybees.

Now, the U-M researchers are adding paper wasps to the list. The first author of the Proceedings of the Royal Society B study is Chloe Weise, a former U-M master's student who graduated this spring.

"Concept learning is a cornerstone of challenging tasks like language, analogy and consciousness," Weise said. "Our results add to a growing body of evidence that the miniature nervous systems of insects do not limit sophisticated behaviors."

For the study, female paper wasps were collected on their nests in areas surrounding Ann Arbor, Michigan. The wasps and their nests were housed in the lab and were given water, sugar and waxworms for food.

During training and testing, individual wasps were placed inside a small balsa wood-and-plexiglass chamber to determine whether they could learn and apply same-different concepts.

The wasps were trained and tested using a method called the simultaneous two-item same-different task. Three types of stimuli were used in the study: colored paper, images of wasp faces and the scents of chemicals called alkenes, which resemble the odors that wasps use to identify nestmates.

The laboratory tests showed that wasps trained with visual stimuli were able to apply the concept of sameness and difference to olfactory stimuli.

"Remarkably, wasps applied the concept of sameness and difference across sensory modalities, as they transferred concepts learned in the visual domain to the odor domain," Weise said. "Therefore, our results illustrate that Polistes are able to master abstract interrelationships between stimuli."

Paper wasps are the second invertebrate shown to form same-different concepts, after honeybees. Paper wasps and honeybees have considerably smaller brains (fewer than 1 million neurons) than vertebrates known to form same-different concepts. Pigeons, for example, have brains with 310 million neurons, and macaque brains have 6 billion neurons.

Interestingly, paper wasps in this study achieved more than 80% correct choices after training involving just eight trials with eight stimulus pairs, while pigeons require 100 unique stimuli and thousands of trials to learn same-different concepts, according to Tibbetts.

The paper wasps used in the current study may have been more adept than pigeons at forming concepts because they were trained with different methods, including the use of biologically relevant stimuli, Tibbetts said.

"We trained and tested wasps using wasp face images, colors and odors," she said. "All three types of stimuli are important in wild wasp behavior."

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Astronomers develop novel way to 'see' the first stars through the fog of the early Universe

A team of astronomers has developed a method that will allow them to 'see' through the fog of the early Universe and detect light from the first stars and galaxies.

The researchers, led by the University of Cambridge, have developed a methodology that will allow them to observe and study the first stars through the clouds of hydrogen that filled the Universe about 378,000 years after the Big Bang.

Observing the birth of the first stars and galaxies has been a goal of astronomers for decades, as it will help explain how the Universe evolved from the emptiness after the Big Bang to the complex realm of celestial objects we observe today, 13.8 billion years later.

The Square Kilometre Array (SKA) -- a next-generation telescope due to be completed by the end of the decade -- will likely be able to make images of the earliest light in the Universe, but for current telescopes the challenge is to detect the cosmological signal of the stars through the thick hydrogen clouds.

The signal that astronomers aim to detect is expected to be approximately one hundred thousand times weaker than other radio signals coming also from the sky -- for example, radio signals originating in our own galaxy.

Using a radio telescope itself introduces distortions to the signal received, which can completely obscure the cosmological signal of interest. This is considered an extreme observational challenge in modern radio cosmology. Such instrument-related distortions are commonly blamed as the major bottleneck in this type of observation.

Now the Cambridge-led team has developed a methodology to see through the primordial clouds and other sky noise signals, avoiding the detrimental effect of the distortions introduced by the radio telescope. Their methodology, part of the REACH (Radio Experiment for the Analysis of Cosmic Hydrogen) experiment, will allow astronomers to observe the earliest stars through their interaction with the hydrogen clouds, in the same way we would infer a landscape by looking at shadows in the fog.

Their method will improve the quality and reliability of observations from radio telescopes looking at this unexplored key time in the development of the Universe. The first observations from REACH are expected later this year.

The results are reported today in the journal Nature Astronomy.

"At the time when the first stars formed, the Universe was mostly empty and composed mostly of hydrogen and helium," said Dr Eloy de Lera Acedo from Cambridge's Cavendish Laboratory, the paper's lead author.

He added: "Because of gravity, the elements eventually came together and the conditions were right for nuclear fusion, which is what formed the first stars. But they were surrounded by clouds of so-called neutral hydrogen, which absorb light really well, so it's hard to detect or observe the light behind the clouds directly."

In 2018, another research group (running the 'Experiment to Detect the Global Epoch of Reioniozation Signature' -- or EDGES) published a result that hinted at a possible detection of this earliest light, but astronomers have been unable to repeat the result -- leading them to believe that the original result may have been due to interference from the telescope being used.

"The original result would require new physics to explain it, due to the temperature of the hydrogen gas, which should be much cooler than our current understanding of the Universe would allow. Alternatively, an unexplained higher temperature of the background radiation -- typically assumed to be the well-known Cosmic Microwave Background -- could be the cause" said de Lera Acedo.

He added: "If we can confirm that the signal found in that earlier experiment really was from the first stars, the implications would be huge."

In order to study this period in the Universe's development, often referred to as the Cosmic Dawn, astronomers study the 21-centimetre line -- an electromagnetic radiation signature from hydrogen in the early Universe. They look for a radio signal that measures the contrast between the radiation from the hydrogen and the radiation behind the hydrogen fog.

The methodology developed by de Lera Acedo and his colleagues uses Bayesian statistics to detect a cosmological signal in the presence of interference from the telescope and general noise from the sky, so that the signals can be separated.

To do this, state-of-the-art techniques and technologies from different fields have been required.

The researchers used simulations to mimic a real observation using multiple antennas, which improves the reliability of the data -- earlier observations have relied on a single antenna.

"Our method jointly analyses data from multiple antennas and across a wider frequency band than equivalent current instruments. This approach will give us the necessary information for our Bayesian data analysis," said de Lera Acedo.

He added: "In essence, we forgot about traditional design strategies and instead focused on designing a telescope suited to the way we plan to analyse the data -- something like an inverse design. This could help us measure things from the Cosmic Dawn and into the epoch of reionisation, when hydrogen in the Universe was reionised."

The telescope's construction is currently being finalised at the Karoo radio reserve in South Africa, a location chosen for its excellent conditions for radio observations of the sky. It is far away from human-made radio frequency interference, for example television and FM radio signals.

The REACH team of over 30 researchers is multidisciplinary and distributed worldwide, with experts in fields such as theoretical and observational cosmology, antenna design, radio frequency instrumentation, numerical modelling, digital processing, big data and Bayesian statistics. REACH is co-led by the University of Stellenbosch in South Africa.

Professor de Villiers, co-lead of the project at the University of Stellenbosch in South Africa said: "Although the antenna technology used for this instrument is rather simple, the harsh and remote deployment environment, and the strict tolerances required in the manufacturing, make this a very challenging project to work on."

He added: "We are extremely excited to see how well the system will perform, and have full confidence we'll make that elusive detection."

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Why Jupiter doesn't have rings like Saturn

Because it's bigger, Jupiter ought to have larger, more spectacular rings than Saturn has. But new UC Riverside research shows Jupiter's massive moons prevent that vision from lighting up the night sky.

"It's long bothered me why Jupiter doesn't have even more amazing rings that would put Saturn's to shame," said UCR astrophysicist Stephen Kane, who led the research.

"If Jupiter did have them, they'd appear even brighter to us, because the planet is so much closer than Saturn." Kane also had questions about whether Jupiter once had fantastic rings and lost them. It is possible for ring structures to be temporary.

To understand the reason Jupiter currently looks the way it does, Kane and his graduate student Zhexing Li ran a dynamic computer simulation accounting for the orbits of Jupiter's four main moons, as well as the orbit of the planet itself, and information about the time it takes for rings to form. Their results are now online, soon to be published in the Planetary Science journal.

Saturn's rings are largely made of ice, some of which may have come from comets, which are also largely made of ice. If moons are massive enough, their gravity can toss the ice out of a planet's orbit, or change the orbit of the ice enough so that it collides with the moons.

"We found that the Galilean moons of Jupiter, one of which is the largest moon in our solar system, would very quickly destroy any large rings that might form," Kane said. As a result, it is unlikely that Jupiter had large rings at any point in its past.

"Massive planets form massive moons, which prevents them from having substantial rings," Kane said.

All four giant planets in our solar system -- Saturn, Neptune, Uranus and also Jupiter -- do in fact have rings. However, both Neptune and Jupiter's rings are so flimsy they're difficult to view with traditional stargazing instruments.

Coincidentally, some of the recent images from the newly commissioned James Webb Space Telescope included pictures of Jupiter, in which the faint rings are visible.

"We didn't know these ephemeral rings existed until the Voyager spacecraft went past because we couldn't see them," Kane said.

Uranus has rings that are aren't as large but are more substantial than Saturn's. Going forward, Kane intends to run simulations of the conditions on Uranus to see what the lifetime of that planet's rings might be.

Some astronomers believe Uranus is tipped over on its side as the result of a collision the planet had with another celestial body. Its rings could be the remains of that impact.

Beyond their beauty, rings help astronomers understand the history of a planet, because they offer evidence of collisions with moons or comets that may have happened in the past. The shape and size of the rings, as well as the composition of the material, offers an indication about the type of event that formed them.

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