NASA's Spitzer, TESS find potentially volcano-covered Earth-size world

 Astronomers have discovered an Earth-size exoplanet, or world beyond our solar system, that may be carpeted with volcanoes. Called LP 791-18 d, the planet could undergo volcanic outbursts as often as Jupiter's moon Io, the most volcanically active body in our solar system.

They found and studied the planet using data from NASA's TESS (Transiting Exoplanet Survey Satellite) and retired Spitzer Space Telescope, as well as a suite of ground-based observatories.

A paper about the planet -- led by Merrin Peterson, a graduate of the Trottier Institute for Research on Exoplanets (iREx) based at the University of Montreal -- appears in the May 17 edition of the scientific journal Nature.

"LP 791-18 d is tidally locked, which means the same side constantly faces its star," said Björn Benneke, a co-author and astronomy professor at iREx who planned and supervised the study. "The day side would probably be too hot for liquid water to exist on the surface. But the amount of volcanic activity we suspect occurs all over the planet could sustain an atmosphere, which may allow water to condense on the night side."

LP 791-18 d orbits a small red dwarf star about 90 light-years away in the southern constellation Crater. The team estimates it's only slightly larger and more massive than Earth.

Astronomers already knew about two other worlds in the system before this discovery, called LP 791-18 b and c. The inner planet b is about 20% bigger than Earth. The outer planet c is about 2.5 times Earth's size and more than seven times its mass.

During each orbit, planets d and c pass very close to each other. Each close pass by the more massive planet c produces a gravitational tug on planet d, making its orbit somewhat elliptical. On this elliptical path, planet d is slightly deformed every time it goes around the star. These deformations can create enough internal friction to substantially heat the planet's interior and produce volcanic activity at its surface. Jupiter and some of its moons affect Io in a similar way.

Planet d sits on the inner edge of the habitable zone, the traditional range of distances from a star where scientists hypothesize liquid water could exist on a planet's surface. If the planet is as geologically active as the research team suspects, it could maintain an atmosphere. Temperatures could drop enough on the planet's night side for water to condense on the surface.

Planet c has already been approved for observing time on the James Webb Space Telescope, and the team thinks planet d is also an exceptional candidate for atmospheric studies by the mission.

"A big question in astrobiology, the field that broadly studies the origins of life on Earth and beyond, is if tectonic or volcanic activity is necessary for life," said co-author Jessie Christiansen, a research scientist at NASA's Exoplanet Science Institute at the California Institute of Technology in Pasadena. "In addition to potentially providing an atmosphere, these processes could churn up materials that would otherwise sink down and get trapped in the crust, including those we think are important for life, like carbon."

Spitzer's observations of the system were among the last the satellite collected before it was decommissioned in January 2020.

"It is incredible to read about the continuation of discoveries and publications years beyond Spitzer's end of mission," said Joseph Hunt, Spitzer project manager at NASA's Jet Propulsion Laboratory in Southern California. "That really shows the success of our first-class engineers and scientists. Together they built not only a spacecraft but also a data set that continues to be an asset for the astrophysics community."

TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA's Ames Research Center in California's Silicon Valley; the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts; MIT's Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.

Source: ScienceDaily

Researchers find new approach to explore earliest universe dynamics with gravitational waves

 Researchers have discovered a new generic production mechanism of gravitational waves generated by a phenomenon known as oscillons, which can originate in many cosmological theories from the fragmentation into solitonic "lumps" of the inflaton field that drove the early Universe's rapid expansion, reports a new study published in Physical Review Letters.

The results have set the stage for revealing exciting novel insights about the Universe's earliest moments.

The inflationary period, which occurred just after the Big Bang, is believed to have caused the Universe to expand exponentially. In many cosmological theories, the rapid expansion period is followed by the formation of oscillons. Oscillons are a type of localized non-linear massive structure that can form from fields, such as the inflaton field, which are oscillating at high frequencies. These structures can persist for long periods, and as the researchers found, their eventual decay can generate a significant amount of gravitational waves, which are ripples in space-time.

In their study, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) Project Researcher Kaloian D. Lozanov, and Kavli IPMU Visiting Associate Scientist, International Center for Quantum-field Measurement Systems for Studies of the Universe and Particles (QUP) Senior Scientist, and High Energy Accelerator Research Organization (KEK) Theory Center Assistant Professor Volodymyr Takhistov, simulated the evolution of the inflaton field during the early Universe and found that oscillons were indeed present. They then found that oscillon decay was able to generate gravitational waves that would be detectable by upcoming gravitational wave observatories.

The findings provide a novel test of the early Universe dynamics independent of the conventionally studied cosmic microwave background radiation. The discovery of these gravitational waves would establish a new window into the Universe's earliest moments, and could help shed light on some of the pressing fundamental questions in cosmology.

With the ongoing development of gravitational wave detectors and supercomputing resources, we can expect to gain even more insights into the Universe's early moments in the coming years. Overall, the new study demonstrates the power of combining theoretical models with advanced computational techniques and observations to uncover new insights into the Universe's evolution.['

sources : science daily

Astronomers reveal the largest cosmic explosion ever seen

 A team of astronomers led by the University of Southampton have uncovered the largest cosmic explosion ever witnessed.

The explosion is more than ten times brighter than any known supernova (exploding star) and three times brighter than the brightest tidal disruption event, where a star falls into a supermassive black hole.

The explosion, known as AT2021lwx, has currently lasted over three years, compared to most supernovae which are only visibly bright for a few months. It took place nearly 8 billion light years away, when the universe was around 6 billion years old, and is still being detected by a network of telescopes.

The researchers believe that the explosion is a result of a vast cloud of gas, possibly thousands of times larger than our sun, that has been violently disrupted by a supermassive black hole. Fragments of the cloud would be swallowed up, sending shockwaves through its remnants, as well as into a large dusty 'doughnut' surrounding the black hole. Such events are very rare and nothing on this scale has been witnessed before.

Last year, astronomers witnessed the brightest explosion on record -- a gamma-ray burst known as GRB 221009A. While this was brighter than AT2021lwx, it lasted for just a fraction of the time, meaning the overall energy released by the AT2021lwx explosion is far greater.

The findings of the research have been published today [Friday, 12 May 2023] in Monthly Notices of the Royal Astronomical Society.

Discovery

AT2021lwx was first detected in 2020 by the Zwicky Transient Facility in California, and subsequently picked up by the Asteroid Terrestrial-impact Last Alert System (ATLAS) based in Hawaii. These facilities survey the night sky to detect transient objects that rapidly change in brightness indicating cosmic events such as supernovae, as well as finding asteroids and comets. Until now the scale of the explosion has been unknown.

"We came upon this by chance, as it was flagged by our search algorithm when we were searching for a type of supernova," says Dr Philip Wiseman, Research Fellow at the University of Southampton, who led the research. "Most supernovae and tidal disruption events only last for a couple of months before fading away. For something to be bright for two plus years was immediately very unusual."

The team investigated the object further with several different telescopes: the Neil Gehrels Swift Telescope (a collaboration between NASA, the UK and Italy), the New Technology Telescope (operated by the European Southern Observatory) in Chile, and the Gran Telescopio Canarias in La Palma, Spain.

Measuring the explosion

By analysing the spectrum of the light, splitting it up into different wavelengths and measuring the different absorption and emission features of the spectrum, the team were able to measure the distance to the object.

"Once you know the distance to the object and how bright it appears to us, you can calculate the brightness of the object at its source. Once we'd performed those calculations, we realised this is extremely bright," says Professor Sebastian Hönig from the University of Southampton, a co-author of the research.

The only things in the universe that are as bright as AT2021lwx are quasars -- supermassive black holes with a constant flow of gas falling onto them at high velocity.

Professor Mark Sullivan, also of the University of Southampton and another co-author of the paper, explains: "With a quasar, we see the brightness flickering up and down over time. But looking back over a decade there was no detection of AT2021lwx, then suddenly it appears with the brightness of the brightest things in the universe, which is unprecedented."

What caused the explosion?

There are different theories as to what could have caused such an explosion, but the Southampton-led team believe the most feasible explanation is an extremely large cloud of gas (mostly hydrogen) or dust that has come off course from its orbit around the black hole and been sent flying in.

The team are now setting out to collect more data on the explosion -- measuring different wavelengths, including X-rays which could reveal the object's surface and temperature, and what underlying processes are taking place. They will also carry out upgraded computational simulations to test if these match their theory of what caused the explosion.

Dr Philip Wiseman added: "With new facilities, like the Vera Rubin Observatory's Legacy Survey of Space and Time, coming online in the next few years, we are hoping to discover more events like this and learn more about them. It could be that these events, although extremely rare, are so energetic that they are key processes to how the centres of galaxies change over time."

sources: science daily

New study puts a definitive age on Saturn's rings -- they're really young

 A new study led by physicist Sascha Kempf at the University of Colorado Boulder has delivered the strongest evidence yet that Saturn's rings are remarkably young -- potentially answering a question that has boggled scientists for well over a century.

The research, to be published May 12 in the journal Science Advances, pegs the age of Saturn's rings at no more than 400 million years old. That makes the rings much younger than Saturn itself, which is about 4.5 billion years old.

"In a way, we've gotten closure on a question that started with James Clerk Maxwell," said Kempf, associate professor in the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder.

The researchers arrived at that closure by studying what might seem like an unusual subject: dust.

Kempf explained that tiny grains of rocky material wash through Earth's solar system on an almost constant basis. In some cases, this flux can leave behind a thin layer of dust on planetary bodies, including on the ice that makes up Saturn's rings.

In the new study, he and his colleagues set out to put a date on Saturn's rings by studying how rapidly this layer of dust builds up -- a bit like telling how old a house is by running your finger along its surfaces.

"Think about the rings like the carpet in your house," Kempf said. "If you have a clean carpet laid out, you just have to wait. Dust will settle on your carpet. The same is true for the rings."

It was an arduous process: From 2004 to 2017, the team used an instrument called the Cosmic Dust Analyzer aboard NASA's late Cassini spacecraft to analyze specks of dust flying around Saturn. Over those 13 years, the researchers collected just 163 grains that had originated from beyond the planet's close neighborhood. But it was enough. Based on their calculations, Saturn's rings have likely been gathering dust for only a few hundred million years.

The planet's rings, in other words, are new phenomena, arising (and potentially even disappearing) in what amounts to a blink of an eye in cosmic terms.

"We know approximately how old the rings are, but it doesn't solve any of our other problems," Kempf said. "We still don't know how these rings formed in the first place."

From Galileo to Cassini

Researchers have been captivated by these seemingly-translucent rings for more than 400 years. In 1610, Italian astronomer Galileo Galilei first observed the features through a telescope, although he didn't know what they were. (Galileo's original drawings make the rings look a bit like the handles on a water jug). In the 1800s, Maxwell, a scientist from Scotland, concluded that Saturn's rings couldn't be solid but were, instead, made up of many individual pieces.

Today, scientists know that Saturn hosts seven rings comprised of countless chunks of ice, most no bigger than a boulder on Earth. Altogether, this ice weighs about half as much as Saturn's moon Mimas and stretches nearly 175,000 miles from the planet's surface.

Kempf added that for most of the 20th Century, scientists assumed that the rings likely formed at the same time as Saturn.

But that idea raised a few issues -- namely, Saturn's rings are sparkling clean. Observations suggest that these features are made up of roughly 98% pure water ice by volume, with only a tiny amount of rocky matter.

"It's almost impossible to end up with something so clean," Kempf said.

Cassini offered an opportunity to put a definitive age on Saturn's rings. The spacecraft first arrived at Saturn in 2004 and collected data until it purposefully crashed into the planet's atmosphere in 2017. The Cosmic Dust Analyzer, which was shaped a bit like a bucket, scooped up small particles as they whizzed by.

Engineers and scientists at LASP designed and built a much more sophisticated dust analyzer for NASA's upcoming Europa Clipper mission, which is scheduled to launch in 2024.

The team estimated that this interplanetary grime would contribute far less than a gram of dust to each square foot of Saturn's rings every year -- a light sprinkle, but enough to add up over time. Previous studies had also suggested that the rings could be young but didn't include definitive measures of dust accumulation.

Stroke of luck

The rings might already be vanishing. In a previous study, NASA scientists reported that the ice is slowly raining down onto the planet and could disappear entirely in another 100 million years.

That these ephemeral features existed at a time when Galileo and the Cassini spacecraft could observe them seems almost too good to be true, Kempf said -- and it begs an explanation for how the rings formed in the first place. Some scientists, for example, have posited that Saturn's rings may have formed when the planet's gravity tore apart one of its moons.

"If the rings are short lived and dynamical, why are we seeing them now?" he said. "It's too much luck."

Co-authors on the new study include Nicolas Altobelli of the European Space Agency; Jürgen Schmidt of the Freie Universität Berlin; Jeffrey Cuzzi and Paul Estrada of the NASA Ames Research Center; and Ralf Srama of the Universität Stuttgart.

sources : science daily

Dark clouds on the horizon

 Our industrialized society releases many and various pollutants into the world. Combustion in particular produces aerosol mass including black carbon. Although this only accounts for a few percent of aerosol particles, black carbon is especially problematic due to its ability to absorb heat and impede the heat reflection capabilities of surfaces such as snow. So, it's essential to know how black carbon interacts with sunlight. Researchers have quantified the refractive index of black carbon to the most accurate degree yet which might impact climate models.

There are many factors driving climate change; some are very familiar, such as carbon dioxide emissions from burning fossil fuels, sulfur dioxide from cement manufacture or methane emissions from animal agriculture. Black carbon aerosol particles, also from combustion, are less covered in the news but are particularly important. Essentially soot, black carbon is very good at absorbing heat from sunlight and storing it, adding to atmospheric heat. At the same time, given dark colors are less effective at reflecting light and therefore heat, as black carbon covers lighter surfaces including snow, it reduces the potential of those surfaces to reflect heat back into space.

"Understanding the interaction between black carbon and sunlight is of fundamental importance in climate research," said Assistant Professor Nobuhiro Moteki from the Department of Earth and Planetary Science at the University of Tokyo. "The most critical property of black carbon in this regard is its refractive index, basically how it redirects and disperses incoming light rays. However, existing measurements of black carbon's refractive index were inaccurate. My team and I undertook detailed experiments to improve this. With our improved measurements, we now estimate that current climate models may be underestimating the absorption of solar radiation due to black carbon by a significant 16%."

Previous measurements of the optical properties of black carbon were often confounded by factors such as lack of pure samples, or difficulties in measuring light interactions with particles of differing complex shapes. Moteki and his team improved this situation by capturing the black carbon particles in water, then isolating them with sulfates or other water-soluble chemicals. By isolating the particles, the team was better able to shine light on them and analyze the way they scatter, which gave researchers the data to calculate the value of refractive index.

"We measured the amplitude, or strength, and phase, or step, of the light scattered from black carbon samples isolated in water," said Moteki. "This allowed us to calculate what is known as the complex refractive index of black carbon. Complex because rather than being a single number, it's a value that contains two parts, one of which is 'imaginary' (concerned with absorption), though its impact is very, very real. Such complex numbers with imaginary components are actually very common in the field of optical science and beyond."

As the new optical measurements of black carbon imply that current climate models are underestimating its contribution to atmospheric warming, the team hopes that other climate researchers and policymakers can make use of their findings. The method developed by the team to ascertain the complex refractive index of particles can be applied to materials other than black carbon. This allows for the optical identification of unknown particles in the atmosphere, ocean or ice cores, and the evaluation of optical properties of powdered materials, not just those related to the ongoing problem of climate change.

sources: science daily

Global warming puts whales in the Southern Ocean on a diet

 In the month of June, when winter bites in the southern hemisphere and the sea around the Antarctic freezes over, right whales swim north. Many of them gather in the bay outside the town of Hermanus in South Africa.

Here, the warmer South African water is perfect for mating or raising newborn calves. However, there is no food for the whales, and all winter long the right whale mothers use up their fat reserves to produce milk for their calves.

It is therefore extremely important that the whales eat a lot and fatten up in the cold waters around the Antarctic throughout the summer. But it seems there is not enough food. The whales arriving at the coasts of South Africa are thinner than they used to be.

This is the result of new research from Aarhus University. Since the researchers started to measure right whales in the 1980s, the whales have become increasingly thinner. This is explained by Fredrik Christiansen, a senior researcher at the Department of Ecoscience at Aarhus University, who is behind the new results.

"Right whales are 25 per cent thinner than they were in the 1980s. This is bad for the whale population, because it means that the newborn whale calves have a higher risk of dying. Fortunately, the right whales in the Southern Ocean are not endangered, but if this continues, they could become so," he says.

When the ice melts, food disappears

When winter comes, and the cows leave the Antarctic and swim north, they have to cope for several months without food. Several months in which they eat into the fat reserves they have built up through the warm and light summer season.

Throughout the summer, right whales swim around beneath the sea ice, open their mouths to take in seawater, krill and water fleas. The baleen inside their mouth is a sort of a giant filter and it filters the small animals from the salt water. This allows the whales to eat huge amounts of food without using a lot of energy.

But the large shoals of krill are shrinking -- and this means that the whales can't fatten up before winter as they used to," explains Fredrik Christiansen.

"The shoals of krill live on phytoplankton, which thrive best in the cold waters around the Antarctic. Here -- like plants on land -- they transform sunlight into energy. Rising sea temperatures mean there is less phytoplankton, fewer krill and thus less food for the whales.

Instead, the whales forage for food further north, where there is another and less energy-rich form of krill.

"Further north, there's less food for these small crustaceans. Therefore, they're not as big and fat as the animals living beneath the Antarctic sea ice," he says.

How to weigh a whale

How exactly do scientists know that the whales have become thinner? Do Fredrik Christiansen and his colleagues lift the huge animals out of the water with oversized weighing scales? No, he explains. Instead, the researchers have invented a method to work out the weight of the whales based on photographs taken by drones.

"Right whales like to lie flat on the sea surface. This makes them easy to photograph from above. When the drone has taken some photographs -- and we know the height of the drone -- we can calculate the size of the animal," he explains.

However, in order to know the weight of the whale, it is necessary to know the volume of the whale -- not just the length and width. But because scientists like Fredrik Christiansen have observed many right whales rolling around on the sea surface over the years -- and thereby have been able to measure their size -- the scientists now know the relationship between length, width and volume of the whales.

"We calculate the volume using the drone photographs -- and when we know the volume, we more or less know the weight. In this way, we can see that the whales have become thinner over the past 30 years -- and that's serious. The weight of the mothers has a huge impact on their calves," he says.

Small and weak whale calves

Thirty to forty years ago, the southern right whale had calves every three years on average. But this is no longer true, explains Fredrik Oscar Christiansen.

"In the 1980s, researchers observed that the right whales off the coast of South Africa gave birth to a new calf every three years. But because it's now difficult for them to fatten up during summer, this has fallen to every five years. This means that the population is growing significantly more slowly.

And not only do the whale calves come more rarely. The calves born today are smaller and grow more slowly.

"The amount of fat on the whale mother is directly linked to how much energy she can give to her calf through her milk. When the mother is thin, the calf gets less energy and grows more slowly," he says.

The researchers have discovered that the northern right whales in the waters off Canada and the northern US are not growing quite as big as before. This is possibly because the calves are born smaller. According to the researchers' calculations, a whale born in 2019 will be one metre shorter on average when it is fully grown than a whale born in 1981.

"Small calves have a higher risk of dying. They're more vulnerable if a killer whale attacks."

Hunted close to extinction

Right whales were given their name because they were considered the "right" whales to catch. People began hunting the large whales as early as in the 14th century, and for hundreds of years, they were hunted fiercely in both northern and southern parts of the Atlantic.

Oil from the whales' fat was one of the most important sources of energy. Train oil, which the oil used to be called, became a fuel in lamps -- both for indoors and for street lights. The demand for train oil was also one of the most important reasons why Denmark colonised Greenland in the 18th century.

Around 1900, train oil was replaced by another more efficient energy source: crude oil. The black gold pumped up from the underground meant that whale hunting was no longer profitable.

The southern right whale is one of the species that benefitted from the end of whaling. For more than 100 years, the population has been allowed to grow large and healthy again. And this is not just good for the whales, but also for the entire Southern Ocean ecosystem.

Because the whales bring nourishment to areas of the sea with little food.

Extremely important for the marine ecosystem

The sea around the Antarctic where the right whales come to eat has more life than any other sea on the planet. Despite the fact that the area only contains five per cent of the Earth's sea water, 20 per cent of all marine life lives in the area.

The many hours of sunshine in the summer, turbulent sea currents and the low temperature are perfect for teeming life.

The light makes marine algae grow explosively. The sea currents swirl the algae and nourishment around so that krill and plankton can gorge themselves. When full, the small crustaceans reproduce and form gigantic swarms. In some places, there may be as many as 35,000 krill in one cubic metre of water.

The right whales -- and many other animals -- stuff themselves with the abundance of krill, but unlike many other species, the whales migrate thousands of kilometres north to overwinter.

"The whales are extremely important for the parts of the sea where there is not much food. When the whales die, their huge bodies sink to the bottom. In the depths, they become food for a whole ecosystem of eel, sharks, crabs, lobsters, worms and microorganisms," says Fredrik Christiansen.

So, if the whales disappear, it will have major consequences for many other animals.

"The whales are an apex predator. When an animal at the top of the food chain disappears, it has a cascade effect. Animals throughout the food chain will be affected if the whales are no longer there. From sharks to bacteria," he concludes.

sources;science daily

Hammerhead sharks hold their breath on deep water hunts to stay warm

 Scalloped hammerhead sharks hold their breath to keep their bodies warm during deep dives into cold water where they hunt prey such as deep sea squids. This discovery, published today in Science by University of Hawai'i at Manoa researchers, provides important new insights into the physiology and ecology of a species that serves as an important link between the deep and shallow water habitats.

"This was a complete surprise!" said Mark Royer, lead author and researcher with the Shark Research Group at the Hawai'i Institute of Marine Biology (HIMB) in the UH Manoa School of Ocean and Earth Science and Technology. "It was unexpected for sharks to hold their breath to hunt like a diving marine mammal. It is an extraordinary behavior from an incredible animal."

Shark gills are natural radiators that would rapidly cool the blood, muscles, and organs if scalloped hammerhead sharks did not close their gill slits during deep dives into cold water. These sharks are warm water animals but feed at depths where seawater temperatures are similar to those found in Kodiak Alaska (around 5ºC/ 40ºF), yet they need to keep their bodies warm in order to hunt effectively.

"Although it is obvious that air-breathing marine mammals hold their breath while diving, we did not expect to see sharks exhibiting similar behavior," said Royer. "This previously unobserved behavior reveals that scalloped hammerhead sharks have feeding strategies that are broadly similar to those of some marine mammals, like pilot whales. Both have evolved to exploit deep dwelling prey and do so by holding their breath to access these physically challenging environments for short periods."

The research team discovered this unexpected phenomenon by equipping deep-diving scalloped hammerhead sharks with devices that simultaneously measured their muscle temperature, depth, body orientation, and activity levels. They saw that their muscles stayed warm throughout their dive into deep cold water but suddenly cooled as the sharks approached the surface toward the end of each dive. Computer modeling suggested that hammerhead sharks must be preventing heat loss from their gills to keep their bodies warm during these deep-dives into cold water.

Additionally, video of a scalloped hammerhead shark swimming along the seabed at a depth of 1,044 meters (more than 3,400 feet) showed its gill slits tightly closed, whereas similar images from surface waters show these sharks swimming with their gill slits wide open. A sudden cooling in muscle temperature as scalloped hammerhead sharks approach the surface at the end of each dive suggests that they opened their gill slits to resume breathing while still in relatively cool water.

"Holding their breath keeps scalloped hammerhead sharks warm but also shuts off their oxygen supply," said Royer. "So, although these sharks hold their breath for an average of 17 minutes, they only spend an average of four minutes at the bottom of their dives at extreme depths before quickly returning to warmer, well-oxygenated surface waters where breathing resumes."

"This discovery fundamentally advances our understanding of how scalloped hammerhead sharks are able to dive to great depths and withstand frigid temperatures in order to capture prey," said Royer. "It also demonstrates the delicate physiological balance that scalloped hammerhead sharks must strike in order to forage successfully."

Scalloped hammerhead sharks are not listed as threatened in Hawaii but are regionally endangered in other parts of the world due to overfishing, bycatch, and nursery habitat loss.

"This new and detailed understanding of scalloped hammerhead physiology and ecology enhances our ability to effectively manage and conserve this iconic species by revealing potential vulnerabilities associated with changing ocean conditions or future human exploitation of these deep foraging habitats, such as deep-sea mining or large-scale fishing in the mesopelagic "twilight zone," both of which might make it harder or more dangerous for these sharks to hunt their natural prey," said Royer. "This extraordinary physiological feat that allows scalloped hammerhead sharks to expand their ecological niche into the deep sea could very well make them vulnerable to additional human impacts."

sources:science daily