This is a Simulation of a gravitationally unstable circumstellar disk by
means of hydrodynamic calculations. Protoplanetary 'embryo' form in the
disc thanks to gravitational fragmentation. The three small pictures
show the successive 'disappearance' of the lump by the star.
Stars are born inside a rotating cloud of interstellar gas and dust, which contracts to stellar densities thanks to its own gravity. Before finding itself on the star, however, most of the cloud lands onto a circumstellar disk forming around the star owing to conservation of angular momentum. The manner in which the material is transported through the disk onto the star, causing the star to grow in mass, has recently become a major research topic in astrophysics.
It turned out that stars may not accumulate their final mass steadily, as was previously thought, but in a series of violent events manifesting themselves as sharp stellar brightening. The young FU Orionis star in the constellation of Orion is the prototype example, which showed an increase in brightness by a factor of 250 over a time period of just one year, staying in this high-luminosity state now for almost a century.
One possible mechanism that can explain these brightening events was put forward 10 years ago by Eduard Vorobyov, now working at the Astrophysical Department of the Vienna University, in collaboration with Shantanu Basu from the University of Western Ontario, Canada.
According to their theory, stellar brightening can be caused by fragmentation due to gravitational instabilities in massive gaseous disks surrounding young stars, followed by migration of dense gaseous clumps onto the star. Like the process of throwing logs into a fireplace, these episodes of clump consumption release excess energy which causes the young star to brighten by a factor of hundreds to thousands. During each episode, the star is consuming the equivalent of one Earth mass every ten days. After this, it may take another several thousand years before another event occurs.
Eduard Vorobyov describes the process of clump formation in circumstellar disks followed by their migration onto the star as "cannibalism on astronomical scales." These clumps could have matured into giant planets such as Jupiter, but instead they were swallowed by the parental star. This invokes an interesting analogy with the Greek mythology, wherein Cronus, the leader of the first generation of Titans, ate up his newborn children (though failing to gobble up Zeus, who finally brought death upon his father).
With the advent of advanced observational instruments, such as SUBARU 8.2 meter optical-infrared telescope installed in Mauna Kea (Hawaii), it has become possible for the first time to test the model predictions. Using high-resolution, adaptive optics observations in the polarized light, an international group of astronomers led by Hauyu Liu from European Space Observatory (Garching, Germany) has verified the presence of the key features associated with the disk fragmentation model -- large-scale arms and arcs surrounding four young stars undergoing luminous outbursts, including the prototype FU Orionis star itself. The results of this study were accepted for publication in Science Advances -- a peer-review, open-access journal belonging to the Science publishing group.
US astronaut Edgar Mitchell, one of just 12 people to have walked on the moon, has died aged 85, his family and NASA said Friday, calling him a "pioneer."
NASA paid glowing tribute to Mitchell, who died in Florida after a brief illness late Thursday, the eve of the 45th anniversary of his lunar landing.
The late astronaut was a member of the 1971 Apollo 14 mission along with Alan Shepard Jr. and Stuart Roosa.
Mitchell was the last Apollo 14 survivor: Roosa died in 1994 and Shepard in 1998.
Speaking in a 1997 interview for NASA's oral history program, Mitchell said that he was drawn to spaceflight after president John F. Kennedy's call to send astronauts to the Moon.
"That's what I wanted because it was the bear going over the mountain to see what he could see, and what could you learn, and I've been devoted to that, to exploration, education and discovery since my earliest years, and that's what kept me going," Mitchell said.
NASA Administrator Charles Bolden recalled Mitchell marveling at the stunning view of Earth from space.
"Edgar spoke poetically about seeing our home planet from the Moon saying, 'Suddenly, from behind the rim of the Moon, in long, slow-motion moments of immense majesty, there emerges a sparkling blue and white jewel, a light, delicate sky-blue sphere laced with slowly swirling veils of white, rising gradually like a small pearl in a thick sea of black mystery.
"'It takes more than a moment to fully realize this is Earth... home.’"
Bolden added: "He is one of the pioneers in space exploration on whose shoulders we now stand."
Buzz Aldrin, the second person on the Moon, echoed that on Twitter, calling Mitchell a "lunar pioneer."
The Apollo 14 mission -- Mitchell's only spaceflight -- began when the trio blasted off from Cape Canaveral, Florida, on January 31, 1971.
Mitchell was in charge of piloting the Antares lunar module, which landed in the Fra Mauro region of the Moon.
It was the third manned mission to the Moon and Mitchell became the sixth human to walk on the lunar surface.
During the mission the astronauts collected 100 pounds (40 kilos) of lunar rock samples and carried out a series of experiments.
The mission ended when the astronauts, traveling aboard a space capsule, splashed down in the Pacific Ocean on February 9, 1971.
DNA evidence lifted from the ancient bones and teeth of people who lived in Europe from the Late Pleistocene to the early Holocene -- spanning almost 30,000 years of European prehistory -- has offered some surprises, according to researchers who report their findings in the Cell Press journal Current Biology on Feb. 4, 2016. Perhaps most notably, the evidence shows a major shift in the population around 14,500 years ago, during a period of severe climatic instability.
"We uncovered a completely unknown chapter of human history: a major population turnover in Europe at the end of the last Ice Age," says leading author Johannes Krause of the Max Planck Institute for the Science of Human History in Germany.
The researchers pieced this missing history together by reconstructing the mitochondrial genomes of 35 hunter-gatherer individuals who lived in Italy, Germany, Belgium, France, the Czech Republic, and Romania from 35,000 to 7,000 years ago. Mitochondria are organelles within cells that carry their own DNA and can be used to infer patterns of maternal ancestry.
"There has been a real lack of genetic data from this time period, so consequently we knew very little about the population structure or dynamics of the first modern humans in Europe," Krause says.
The new data show that the mitochondrial DNA of three individuals who lived in present-day Belgium and France before the coldest period in the last Ice Age -- the Last Glacial Maximum -- belonged to haplogroup M. This is remarkable because the M haplogroup is effectively absent in modern Europeans but is extremely common in modern Asian, Australasian, and Native American populations.
The absence of the M haplogroup and its presence in other parts of the world had previously led to the argument that non-African people dispersed on multiple occasions to spread across Eurasia and Australasia. The researchers say the discovery of this maternal lineage in Europe in the ancient past now suggests instead that all non-Africans dispersed rapidly from a single population, at a time they place around 50,000 years ago. Then, at some later stage, the M haplogroup was apparently lost from Europe.
"When the Last Glacial Maximum began around 25,000 years ago, hunter-gatherer populations retreated south to a number of putative refugia, and the consequent genetic bottleneck probably resulted in the loss of this haplogroup," explains first author of the study Cosimo Posth of Germany's University of Tübingen.
The researchers say their biggest surprise, however, was evidence of a major turnover of the population in Europe around 14,500 years ago, as the climate began to warm. "Our model suggests that during this period of climatic upheaval, the descendants of the hunter-gatherers who survived through the Last Glacial Maximum were largely replaced by a population from another source," says Adam Powell, another senior author at the Max Planck Institute for the Science of Human History.
Fourteen new species of tarantula have just been discovered in the southwestern U.S., including one named after the popular late singer-songwriter Johnny Cash.
The newfound spiders double the number of known tarantula species from the region, according to a study published in the journal ZooKeys.
“We often hear about how new species are being discovered from remote corners of the earth, but what is remarkable is that these spiders are in our own backyard,” Chris Hamilton, lead author of the study, said in a press release. “With the earth in the midst of a sixth mass extinction, it is astonishing how little we know about our planet’s biodiversity, even for charismatic groups such as tarantulas.”
Hamilton, a researcher at the Florida Museum of Natural History, and his team spent more than a decade searching for tarantulas throughout scorching deserts, frigid mountains, and other locations in the American Southwest, sometimes literally in the backyards of homeowners. The scientists also looked at specimens in museums.
Overall, the researchers studied nearly 3,000 specimens, undertaking what they say is the most comprehensive taxonomic study ever performed on a group of tarantulas.
Many of the leggy spiders look alike, so the researchers had to employ a combination of anatomical, behavioral, distributional, and genetic data to tell the different species apart from one another.
The results indicate there are 29 tarantula species in the United States, 14 of which are new to science. All belong to the genus Aphonopelma, but sizes can widely vary. Some reach 6 inches or more in leg span, while others are about the size of a quarter.
Johnny Cash the tarantula (Aphonopelma johnnycashi) was found near Folsom Prison, the subject of singer Cash’s song “Folsom Prison Blues.” The music star’s nickname, based on his distinctive dressing style, was the “man in black,” which led to another connection with his namesake spider. Mature males of the species are generally solid black in coloration.
Most of the newly discovered species are abundant and have relatively large distributions, but others have highly restricted distributions and could require conservation efforts to save them.
“Two of the new species are confined to single mountain ranges in southeastern Arizona, one of the United States’ biodiversity hotspots,” explained co-author Brent Hendrixson. “These fragile habitats are threatened by increased urbanization, recreation, and climate change. There is also some concern that these spiders will become popular in the pet trade due to their rarity, so we need to consider the impact that collectors may have on populations as well.”
The Internet loves conspiracy theories. Last December, silly claims that archaeologists in Austria unearthed a clay tablet with a cuneiform writing perfectly resembling a modern-day mobile phone went viral.
Now it’s time for another crazy theory.
Reports this week have resurrected a 2014 video from the YouTube channel “Still Speaking Out” which maintains that a modern-day laptop, complete with USB ports, is depicted on an ancient Greek grave marker.
Paranormal fans and conspiracy theorists went nuts: this is could be proof of time travel. The laptop would link in with none other than the Oracle of Delphi, they claimed.
“When I look at the sculpture I can’t help but think about the Oracle of Delphi, which was supposed to allow the priests to connect with the gods to retrieve advanced information and various aspects,” StillSpeakingOut said in the video.
Currently on display at the J. Paul Getty Museum in Malibu, Calif., the marble carving is titled “Grave Naiskos of an Enthroned Woman with an Attendant” and dates to about 100 B.C.
The relief, which is a little over 37 inches tall, depicts a woman sitting on a cushioned throne while a servant girl holds open a small box.
According to the museum, the rectangular object held by the servant is “the lid of a shallow chest.”
“The depiction of the deceased reaching out for an item held by a servant has a long history in Greek funerary art and probably alludes to the hope of continuing earthly pleasures in the afterlife,” the museum stated.
The dead woman must have come from a wealthy family, as revealed by the snake-bracelets on her upper and lower arms and the elaborate chair showing a leg decorated with lions’ paws and an eagle arm-support.
As for the young attendant, her clothes and hairstyle indicate she was a slave.
But according to StillSpeakingOut the earthly pleasures the deceased woman hoped to continue in the afterlife included the laptop she appears to reach toward, her eyes focused on the screen.
He noted that another picture taken by a random tourist from a better angle reveals the object is wide with a structure too narrow to be a jewel box.
“The claim is ridiculous as it is clearly a box,” classical archaeologist Dorothy Lobel King told Discovery News.
According to Janet Burnett Grossman, author of “Greek Funerary Sculpture: Catalogue of the Collections at the Getty Villa,” the relief was formerly in the collection of British statesman Sir William Fitzmaurice Petty, second Earl of Shelburne and first Marquess of Lansdowne, and most likely came from the Greek island of Delos.
Burnett Grossman described the woman in the relief as reaching out to touch “the lid of an open flat box or mirror held by a girl standing in front of her.”
You’re a mammal, so pat yourself on the back—no, not you, lizard people from outer space posing as high-ranking members of the US government. Mammals have got it made: Fur to keep you warm, milk to nourish your young, relatively big brains to keep you not dumb.
What you don’t have, though, is a venomous bite … unless you are in fact a lizard person from outer space. Or, better yet, a mysterious mammal called the solenodon. They’re one of just a handful of mammals with venom glands that deliver a powerful toxin. But wait, there’s more: The solenodon’s nose has a ball-and-socket joint like the human hip, making it crazy flexible. And a lady solenodon’s teats are … oddly placed. Let’s just leave it at that for now.
If you find yourself in the forests of Cuba or Hispaniola, take a deep breath. It might smell kind of like a goat: musky, earthy, maybe a bit like wet dog, definitely pungent. Now look at your feet. You might find strange conical holes in the dirt, with scratch marks ringing the edges.
Chances are you’re not far behind the aromatic wonder that is the solenodon. Foraging typically at night, it jams its long, highly mobile ball-and-socket schnoz into the soil to root around for invertebrates, things like worms and insects. Its many sensitive whiskers help it feel around the dirt, which is just as well because the solenodon ain’t got much going on in the eyesight department.
“They’ve got tiny little eyes and they don’t seem to have particularly good vision, although they’re really sensitive to light,” says ecologist Joe Nunez-Mino. While not many solenodons live in captivity, the ones Nunez-Mino has come across run like hell if you switch a light on. Clearly, this is an animal most comfortable dancing in the dark.
But should you be lucky enough to bump into a solenodon in the wild, you’re in for a treat. Mildly put, this is a singular mammal. It’s about as big as a large rat with a tail to match. (Looks kind of like a Rodent of Unusual Size, don’t it?) It’s got long, sharp nails and ambles with a wobbly, I’m-just-coming-off-anesthesia gait. Females with their young are particularly awkward. “The teats are sort of in the armpit of the rear legs, and sometimes the females will kind of run around dragging the babies,” Nunez-Mino says.
An adult solenodon at right with a juvenile at left. Between them are rocks of indeterminate age.
All laughing at the expense of the solenodon aside, please no touchy this animal if you happen to find one. Not just because solenodon is endangered, but because it has a venomous bite, an extreme rarity for a mammal. (Shrews have a venomous bite too, and male platypuses have venomous spurs on their hind legs, though the males only use these to fight each other.) Sitting underneath the solenodon’s lower incisors are salivary glands that send venom along grooves in its teeth. All the solenodon has to do is break the victim’s skin—or cuticle, in the case of insects—for the venom to get in there and work its magic.
From the few reports of human envenomations, it sounds like the experience is no picnic. Symptoms are similar to a snake bite, including localized swelling and severe pain, perhaps lasting several days. (Ask your doctor if solenodon venom is right for you!)
If you’re lucky, though, you’ll get what’s known as a dry bite—that is, the critter will nip you without producing venom. And that makes good sense from an energy perspective. Snakes know what’s up here: “Snakes quite often will bite and not inject venom because using venom is actually quite wasteful unless you really have to,” says Nunez-Mino.
Check out the solenodon’s tiny eyes. It’s pretty much the Howard Moon of the forest.
Even if you do get a dose of solenodon venom, you’re getting off easy. The venom incapacitates other victims like lizards, and in laboratory tests, scientists dosed mice with the venom and recorded breathing problems, convulsions, and paralysis. And the solenodon doesn’t stop at prey smaller than it. “There’s one report of a solenodon kept in captivity in London that ate an entire chicken,” says molecular biologist Rodrigo Ligabue Braun of Brazil’s Federal University of Rio Grande do Sul. “He bit a chicken and then ate all the parts he wanted.”
If the also-venomous shrews are any indication, the solenodon may not always be killing and consuming its prey outright. Shrews will often bite and incapacitate their victims, then drag them to their dens and come back later and gnaw on the comatose things. The solenodon may well do the same. (Oh relax—it’s not that bad in the grand scheme of things. The tarantula hawk is a wasp that stings, well, tarantulas, then drags them back to a den for its larva to devour it alive over the course of several weeks.)
Now the why. Why would the solenodon evolve venomousness while pretty much every mammal on Earth gets along fine without it? Well, it may not be the case of the solenodon evolving venomousness, as much as other mammals losing it.
Mammals have it made right now. But for tens of millions of years, puny little mammals spent the bulk of their time running away from dinosaurs. Many ancient mammals may have enlisted venom so they could better defend themselves.
But the game changed big time when the dinosaurs died out. “From an evolutionary point of view,” says Braun, “you’d be expending too much of your resources producing venom in an environment that did not have the same kind of prey or predators that it had before.” So it might have made sense for mammal lineages to evolve away from venomousness.
For whatever reason, though, solenodon held onto it. Indeed, solenodon is a truly ancient mammal, having diverged some 76 million years ago—not long (in evolutionary time, that is) before the dinos met their match in the form of an asteroid punching Earth right in the face. (Braun notes, though, that debate still swirls around the evolution of venom in mammals. It may be that venomousness was rare in early mammals, as it is today, and solenodon has just always been an oddity.)
While venom can land solenodon a meal and protect it from its natural enemies, it won’t do a lick of good against humans. Habitat destruction on Cuba and Hispaniola has hit the solenodon hard. Add to that the invasive species that humans have brought along and you’ve got a massacre.
Dogs in particular are a problem on Hispaniola, “although we’ve also recorded or heard of cases where the solenodon has bitten a dog and the dog has died from presumably the venom,” Nunez-Mino says. Feral cats, too, aren’t just a potential executioner, but competition: The felines target the lizards and large insects and such that the solenodon relies on to survive.
Scientists have discovered an insect that went extinct for more than 120 million years and featured many of the traits associated with modern butterflies including markings on the wing called eye spots.
Known as Kalligrammatid lacewings, paleobotanists for the past century have known they lived in Eurasia during the Mesozoic. But it’s taken recent discoveries of well-preserved fossils from two sites in northeastern China to demonstrate how similar they were to modern butterflies. Thanks to extensive lakes that limited oxygen exposure in these areas during mid-Jurassic through early Cretaceous time, paleontologists have been able to recover exquisitely preserved fossils that retain much of their original structure.
“Poor preservation of lacewing fossils had always stymied attempts to conduct a detailed morphological and ecological examination of the kalligrammatid,” Indiana University’s David Dilcher, who was part of the team that made the discovery published in the journal Proceedings of the Royal Society B, said in a statement. “Upon examining these new fossils, however, we’ve unraveled a surprisingly wide array of physical and ecological similarities between the fossil species and modern butterflies, which shared a common ancestor 320 million years ago.”
Dilcher, who also discovered the first flower last year, found that this insect from the Jurassic period survived in a manner similar their modern sister insects by visiting plants with “flower-like” reproductive organs producing nectar and pollen. They probably used their long tongues to probe nectar deep within the plant and also possessed hairy legs that allowed for carrying pollen from the male flower-like reproductive organs of one plant to the flower-like female reproductive organs of another.
Eventually, this system of pollination by long-tongued lacewings traveling between plants with exposed reproductive parts - called gymnosperms – gave way to more familiar system of insect pollinators and modern flowers, or angiosperms, in which the reproductive parts of the plants are contained with a protective seed.
This butterfly-like behavior is striking considering that modern butterflies didn’t appear on Earth for another 50 million years.
It is an example of what scientists call convergent evolution where two distantly related animals develop similar characteristics independently. In this case, the butterfly-like insect is an extinct “lacewing” of the genus kalligrammatid called Oregramma illecebrosa. Another genus of this insect – of the order Neuroptera – live on today and are commonly known as fishflies, owlflies or snakeflies.
“Here, we’ve got coevolution of plants with these animals due to their feeding behavior, and we’ve got coevolution of the lacewings and their predators,” Dilcher said. It’s building a web of life that is more and more complex.”
The researchers, which also included Conrad Labandeira, a curator at the Smithsonian Institution’s National Museum of Natural History, and Dong Ren of Capital Normal University in Beijing, China, where the fossils are housed, found that the Kalligrammatid lacewings probably were important pollinators during mid-Mesozoic times.
“Various features of the mouthparts all indicate that these things were sucking fluids from the reproductive structures of gymnosperm plants,” Labandeira said in a statement, of a finding that was confirmed by an analysis of material lingering within the food tube of one fossil, which was found to contain only carbon. Had the insect been feeding on blood, its final meal would have left traces of iron.
Researchers were also able to find the presence of scales on wings and mouthparts, which, like the scales on modern butterflies, likely contained pigments that gave the insects vibrant colors. Based on similarities between Kalligrammatid wing patterns and those found on modern nymphalid butterflies (a group that includes red admirals and painted ladies), Labandeira said Kalligrammatids might have been decorated with red or orange hues.
From there, researchers did a chemical composition of various regions of the Kalligrammatid’s patterned wings including the eyespots. In modern butterflies with eyespots such as the modern owl butterfly, the dark center of the mark is formed by a concentration of the pigment melanin. It seems the Kalligrammatids, too, had melanin at the center of their eyespots.
Four new species of deep-sea flatwormlike animals that look like deflated whoopee cushions and lack complex organs have helped solve a complicated puzzle about their group’s placement on the tree of life, scientists found.
The new study, representing 12 years of specimen collection and analysis, adds the new species to a group previously known by only a single species, and in doing so, provides a clearer picture of the evolutionary position these animals hold.
When describing the physical characteristics of these baggy marine creatures, “simple” doesn’t begin to do justice to how simple they are, as animals go. They have no recognizable face or limbs. Their bodies are blobs that look more like empty socks than animals, and are wrinkled by muscular folds and propelled by cilia. A mouth opening at one end leads to a gut sack, but there is no anal opening in the back end. They have no digestive system, no excretory system, no reproductive organs, but they probably don’t worry about that too much because they don’t have brains, either — just a neural network.
Surface appearances aside, this genus — Xenoturbella — has proved surprisingly difficult to position on the tree of life, ever since the first species, Xenoturbella bocki, was discovered in 1950, according to the study researchers. Scientists first classified it as a flatworm, and then, in the 1990s, suggested that it was a type of mollusk that had “degenerated,” losing its more developed features over time to reach a simpler form. This explanation placed Xenoturbella closer to vertebrates andechinoderms — the group of marine life that includes starfish and sea urchins — rather than in an earlier evolutionary location on a more distant branch from these more complex animals.
But new genetic data, with more than 1,000 genes sequenced from just one of the new species, disproves that Xenoturbellawas once complex, according to study lead author Greg Rouse, a marine biologist with the Scripps Institution of Oceanography, at the University of California at San Diego. “Our new analysis and that of another paper in the same issue of Nature using much more data overturns this idea, and supports the idea that Xenoturbella is simple,” Rouse told Live Science in an email. “Sequencing more than 1,000 genes of one of the species gave a large amount of data that could be directly compared with other animals,” he said.
The new species — X. hollanduram, X. monstrosa, X. profunda, and X. churro (named after the fried-dough dessert)—were found in diverse and remote deep-sea locations off the coasts of California and Mexico, the deepest of which, where X. produnda hugged the seafloor, was a hydrothermal vent 12,139 feet (3,700 meters) below the surface of the Gulf of California. The biggest species, X. monstrosa, measured 8 inches (20 centimeters) long, while tiny X. hollandorum was a mere 1 inch (2.5 centimeters) in length.
A prehistoric animal similar in appearance to a modern wildebeest had a "trumpet-like nasal passage" that enabled it to produce a unique array of calls, a new study has found.
The animal’s internal trumpet nasal passage has only been seen once before, in another beast that would seem to have little in common with this now-extinct hoofed mammal, Rusingoryx atopocranion.
"The nasal dome is a completely new structure for mammals — it doesn’t look like anything you could see in an animal that’s alive today," co-author Haley O’Brien of Ohio University, Athens, said in a press release. "The closest example would be hadrosaur dinosaurs with half-circle shaped crests that enclose the nasal passages themselves."
For the study, O’Brien, co-author Tyler Faith of the University of Queensland and colleagues analyzed the remains of Rusingoryx. The fossils were unearthed on Kenya’s Rusinga Island and date to the Late Pleistocene.
Faith explained that their curiosity was piqued in 2009, after they were told about a site called Bovid Hill. The hill had been so named because of an abundance of fossil Bovidae, the group including antelopes and buffaloes, eroding from its surface.
"After several years of collecting fossils from Bovid Hill, it became very clear that most of the fossils belonged to the poorly known species Rusingoryx atopocranion, described from the same site in 1983, and that we may be dealing with an entire herd that was somehow wiped out and buried at the site," Faith said.
The researchers also uncovered stone tools and butchered bone, strongly raising the possibility that early modern humans were responsible for the concentration of Rusingoryx skeletons. In 2011, study co-author Kirsten Jenkins of the University of Minnesota took charge of excavations, hoping to find more complete fossils and to establish why so many skeletons had ended up in that spot. Along the way, she found several intact skulls.
"I was astonished to see that [the skulls] looked unlike any antelope that I had ever seen–the only thing more surprising would have been fossil zebras with horns growing from their heads!" Faith said. "The anatomy was clearly remarkable."
Faith and O'Brien CT-scanned the remains, which revealed their inner structures. They immediately noticed the similarity to hadrosaur anatomy around the nose area.
The little-known hoofed mammals turned out to have a very unusual, trumpet-like nasal passage similar only to the nasal crests of lambeosaurine hadrosaur dinosaurs. These were duck-billed dinos that sported such prominent crests.
At first the scientists thought the hollow nasal dome might have had something to do with thermoregulation. After anatomical investigations and acoustical modeling, however, they now think the trumpet-like nasal tube may have allowed Rusingoryx to deepen its normal vocal calls.
Their calculations even suggest that the animals might have been able to call at levels very close to infrasound, such that other animals may not have been able to hear individuals in the herd calling back and forth to each other.
A rarely seen volcanic eruption on a sub-Antarctic island has been captured by a team of scientists sailing near the remote area.
Heard Island, about 2,500 miles (4,000 kilometers) southwest of Australia and just 600 miles (1,000 kilometers) north of the coast of Antarctica, is about 25 miles (40 kilometers) long and is dominated by an active volcano known as Big Ben. Volcanic activity at the spot has been known since 1881, and satellites recorded eruptions there in the 1990s and 2000s. However, because the island is remote and rarely visited, eye-witness accounts of such eruptions are few and far between.
Researchers and crew on board the Commonwealth Science and Industrial Research Organisation (CSIRO) ship Investigator witnessed the eruption during a University of Tasmania-led expedition to investigate whether iron from underwater volcanoes in the region exerts control on the dynamics of phytoplankton blooms and fertilization of the Southern Ocean.
“We saw vapor being emitted from the top of the volcano and we saw lava flows coming down the flank of Big Ben,” Professor Mike Coffin of the University of Tasmania’s Institute of Marine and Antarctic Studies, the voyage’s chief scientist, said. “This was a very exciting observation. There are very few ships that come to this part of the world and in fact the last geological expedition that landed on Heard Island was in 1987.”
