scientificamerican--2020-12-15--The Real Dilophosaurus Would Have Eaten the Jurassic Park Version for Breakfast

The fading sun beat down on our backs after an already long day in the field .
Exhausted , we toiled over shovels and dug with our bare hands to clear away the sand .
We were in the heart of dinosaur country on the Colorado Plateau of northern Arizona , working in the middle of the Navajo Nation to determine the ages of two skeletons of Dilophosaurus wetherilli that had been unearthed there previously .
We had spent this hot June day in 2014 hiking up and down the badlands to measure the rock beds and fill our backpacks @ @ @ @ @ @ @ had to excavate—not a new dinosaur but rather our truck , which had gotten bogged down in the sand dunes and was buried up to the axles .
The life of a globe-trotting field scientist is rooted in the mundane—applying for permits , taking notes , cooking meals and washing dishes in camp , reviewing the day 's data by light of the campfire—rather than the swashbuckling of the movies .
We never see Indiana Jones or Alan Grant digging out a stuck pickup truck .
In the summer of 1993 dinosaurs and @ @ @ @ @ @ @ world .
Adapted from the 1990 Michael Crichton novel , Jurassic Park made instant stars , and villains , of several little-known species .
Names such as Velociraptor and Dilophosaurus joined Tyrannosaurus and Triceratops in the public lexicon .
The dinosaurs of action movies are typically not the animals that scientists know from nature .
Yet one of the elements that made the Jurassic Park franchise so successful ( it broke box office records in 1993 and topped the charts again in the summer of 2020 ) was its narrative reliance on the @ @ @ @ @ @ @ genetics .
Author Crichton and director Steven Spielberg brought a modern look at dinosaur science to audiences for the first time , and the image they portrayed of active , intelligent animals still resonates today .
Of course , Crichton and Spielberg took artistic liberties to tell a compelling story , dramatizing not only the scientists but also the dinosaurs .
The animal that departed most from the fossil evidence was Dilophosaurus .
In the movie , it takes the form of a golden retriever–sized creature with a rattling frill and venomous spit @ @ @ @ @ @ @ , Dennis Nedry .
What was Dilophosaurus really like ?
In truth , scientists did not have a complete picture of this animal back when it entered pop culture .
But in the nearly three decades since Dilophosaurus got the Hollywood treatment , researchers have recovered significant new fossil specimens of this dinosaur and analyzed all of the remains with increasingly sophisticated methods .
As a result , we can now reconstruct this dinosaur—its appearance and behavior , how it evolved , the world it inhabited—in detail .
The findings show that the @ @ @ @ @ @ @ big-screen counterpart .
They also provide the most detailed portrait yet of a dinosaur from the Early Jurassic epoch .
Today we know Dilophosaurus as a bipedal , meat-eating dinosaur more than 20 feet long with two distinctive parallel crests of very thin bone along the top of its head ( its name derives from the Greek words for “ two-crested reptile ” ) .
But in 1954 , when the animal first appeared in the scientific literature , it had a different name : in a series of papers , Samuel Welles @ @ @ @ @ @ @ , paleontologist , presented his research on two skeletons found by Jesse Williams , a Navajo man who lived near Tuba City , Ariz .
The crest had not been identified among the fragmentary remains , and Welles called the creature Megalosaurus wetherilli , believing it to be a new species in the previously known genus Megalosaurus .
When Welles found an additional specimen in 1964 that preserved the top of the skull , with its dual crests , he realized that the original find represented a new genus , so he renamed @ @ @ @ @ @ @ body plan of the dinosaur in Jurassic Park was patterned on Welles 's 1984 anatomical description and sculpted reconstructions of the bones in museum exhibits , as well as artwork by paleontologist Gregory Paul in the 1988 book Predatory Dinosaurs of the World .
But the Jurassic Park Dilophosaurus departed from the scientific record of the time in several key details .
Most obviously , it was depicted as half the size of the real animal .
The filmmakers did this deliberately to avoid any confusion with another saurian antagonist , the Velociraptor @ @ @ @ @ @ @ , its venomous saliva and collapsible frill—were also fictional traits added for dramatic effect .
But these embellishments resembled the biology of other real animals , which made them believable .
When Welles described the fossils of Dilophosaurus , he interpreted some of the joints between the tooth-bearing bones at the end of the snout as “ weak ” and suggested that the animals may have been scavengers or that they did most of their killing with claws on their hands and feet .
When writing the story , Crichton invented a dramatic @ @ @ @ @ @ @ a blinding venom , based on some modern species of cobras , which can spit two meters .
Inspiration for the frill , meanwhile , came from the modern-day frilled agamid lizard that lives in Australia and New Guinea .
The lizard has a structure made of bone and cartilage originating from the throat that supports the frill .
No evidence of such a trait has turned up in the fossil record of Dilophosaurus .
Other aspects of Jurassic Park drew from the latest science .
In the early 1980s paleontologists were just @ @ @ @ @ @ @ birds descended from dinosaurs and are , in fact , the last surviving dinosaur lineage .
The filmmakers threw out early test animations of sinuous , snakelike velociraptors in preference of recommendations from their science adviser , dinosaur paleontologist Jack Horner , to make the animals more birdlike in their movements .
The film , with its depiction of dinosaurs as quick , clever animals rather than the sluggish , more lizardlike creatures that 19th-century scholars thought them to be , was the first time many members of the general public encountered the @ @ @ @ @ @ @ scientific understanding of Dilophosaurus was bound to change in the years after Jurassic Park 's release .
In the lead-up to the book and film , the field of paleontology was undergoing tremendous change .
Advances in computing were revolutionizing the study of fossils , enabling researchers to process enormous data sets in ways unimaginable when Dilophosaurus was first discovered .
Take , for instance , cladistic analysis , which identifies discrete , heritable anatomical features that can be compared between animals and that provide a statistical basis for testing hypotheses about the @ @ @ @ @ @ @ Researchers can now analyze many more characteristics much more quickly than ever before and thus develop better-supported hypotheses about how dinosaurs are related and how they evolved .
Increased computing power and developments in medical and industrial CT scanning also created a nondestructive way to look inside bones and rocks at hidden anatomy .
Not only did the analytical tools available to paleontologists evolve , but in 1998 teams at the University of Texas at Austin began recovering more Dilophosaurus remains in the same region of northern Arizona that yielded the first finds @ @ @ @ @ @ @ or refute prior thinking about long-vanished organisms .
In this case , the new fossils preserved parts of the Dilophosaurus anatomy that were missing or distorted in previously collected specimens .
Fossils are typically collected in large blocks of rock and encased in plaster to protect them during their journey from the field to the laboratory .
When they arrive in the museum , paleontologists use dental picks , chisels and miniature handheld jackhammers to carefully remove the rock and expose the fossils .
After millions of years of exposure to geologic processes @ @ @ @ @ @ @ fossils we find are most often distorted and incomplete elements .
We sometimes disassemble and reconstruct broken fragments to better approximate their original condition , sculpting and adding missing material based on closely related animals .
When Wann Langston , Jr. , and his colleagues prepared the first Dilophosaurus skeletons at U.C .
Berkeley around 1950 , they filled in missing skull parts with casts from the skull of a more complete carnivorous dinosaur from the Jurassic , and they sculpted missing parts of the pelvis out of plaster .
No one really @ @ @ @ @ @ @ ; the reconstructions represented a hypothesis of the real form of Dilophosaurus—one that could be tested with new fossils .
The Dilophosaurus material discovered since Welles 's initial description and Langston 's reconstruction shows that the animal 's snout and jaw were much more substantial than originally recognized .
The upper jaw bones do not have the weak interface that the fragmentary first finds suggested .
Instead these bones indicate a strong skull capable of biting into prey .
Likewise , newly identified features of bones from the animal 's lower jaw show @ @ @ @ @ @ @ modern reptiles , these ridges provide surface area for the attachment of large muscles .
And the skeleton of a different dinosaur found at the U.T .
Austin dig site—the plant-eating Sarahsaurus—features bite marks , attesting to the presence of a large meat-eating animal with jaws strong enough to puncture bone .
Together this evidence supports the idea that Dilophosaurus was probably a predator with a deadly bite rather than a creature that had to scavenge or use its claws to kill , as Welles supposed .
Dilophosaurus was a large dinosaur , @ @ @ @ @ @ @ the dinosaurs of the Late Triassic of western North America , just 20 million years earlier , were animals the size of turkeys or eagles , but Dilophosaurus would have towered over a human , standing up to eight feet tall and measuring up to 25 feet long when fully grown .
It had much longer and stronger arms than other larger meat-eating dinosaurs such as Allosaurus and Ceratosaurus , and its legs were relatively longer as well .
When the first skeletons of Dilophosaurus were found , scientists thought the species was @ @ @ @ @ @ @ Streptospondylus , so they reconstructed the missing parts of the pelvis to look like they did in those animals .
The better-preserved Dilophosaurus skeletons found later show more intermediate pelvis anatomy between Coelophysis-like and Allosaurus-like animals from the Late Triassic and Late Jurassic , respectively .
Like many early dinosaurs and all modern birds , Dilophosaurus had fleshy air pockets from its respiratory system growing into its vertebrae , which provided strength while simultaneously lightening the skeleton .
These air sacs allowed for the unidirectional flow of air through the lungs—in other words @ @ @ @ @ @ @ breath , as it does in birds and crocodilians .
This type of respiration provides the animal with more oxygen than does the bidirectional respiratory system that mammals have , in which air flows both in and out of the lungs .
Animals that breathe unidirectionally tend to have relatively high rates of metabolism and thus high activity levels , so Dilophosaurus was probably a fast , agile hunter .
CT imaging has revealed that these air sacs are also present in the bones surrounding the dinosaur 's brain and were continuous with @ @ @ @ @ @ @ the skull .
In most meat-eating dinosaurs , a ridge of bone provides a roof over an opening in the skull in front of the eye sockets known as the antorbital fenestra .
But in Dilophosaurus , this opening is continuous with the side of the dinosaur 's unique crests , suggesting that the crests , too , had air sacs .
The crests were almost certainly covered by keratin , the same material that forms horns , claws and hair , and may have played a role in helping members of this @ @ @ @ @ @ @ .
But how the air sacs might have supported these or other functions of the crests is unclear .
One of the challenges of studying the evolutionary history of any species is understanding physical variation within and among taxonomic groups .
Welles thought the various skeletons we now categorize as Dilophosaurus actually represented multiple genera .
Taking advantage of the latest cladistics tools , one of us ( Marsh ) tested that hypothesis by identifying hundreds of anatomical features present on each individual skeleton and comparing them with one another .
The results @ @ @ @ @ @ @ contrary to what Welles surmised , all of the animals are so similar that they must represent not only one genus but one species .
Marsh also incorporated these anatomical characteristics into a much larger data set that compares Dilophosaurus with other specimens from around the world .
This process elucidates the early evolutionary history and biogeographical distribution of dinosaur groups and has more precisely located Dilophosaurus on the tree of life .
We now know that the evolutionary gap between Dilophosaurus and its closest known relatives is significant , implying that many @ @ @ @ @ @ @ be discovered .
Just as our conception of Dilophosaurus the animal has grown more detailed , so , too , has our understanding of the world it lived in .
The hike down the Adeii Eichii Cliffs to the Dilophosaurus quarry is a journey back through 183 million years to the Early Jurassic .
Back then , dinosaurs roamed the landscape , leaving footprints in what is now sandstone across the Colorado Plateau .
Paved surfaces end miles from the rock outcrop , so we drive on overgrown rutted two-tracks that cross the @ @ @ @ @ @ @ on our geologic maps as “ QAL ” —Quaternary alluvium .
This windblown sand is what stranded our field vehicles in 2014 .
The bedrock under these modern dunes is the Navajo Sandstone , the lithified remains of a 180-million-year-old desert .
The red rock badlands of Ward Terrace , as this area is known , spill out to the western horizon , where they meet the much younger volcanic San Francisco Peaks of Flagstaff , Ariz. To the northwest is the mouth of one of the world 's most visited geologic features @ @ @ @ @ @ @ sands that trapped our pickup atop Ward Terrace to the Vishnu schist—the black rock at the bottom of the canyon that is being carved away by the Colorado River—these landscapes preserve much of the past 1.8 billion years of the rock record .
As paleontologists , we work to understand the life entombed in those rocks , and we use lines of geologic and biological evidence preserved within them to reconstruct the environments of deep time .
One of our objectives was to more precisely determine the age of the rock in which @ @ @ @ @ @ @ Kayenta Formation .
This rock was laid down by rivers , lakes and streams east of a volcanic arc that was depositing ash and fine-grained particles into the area .
The ash helped to both preserve the bones of Dilophosaurus and aid early efforts to date the Kayenta Formation .
We collected new rock samples to date using radiometric methods .
We processed the samples by grinding and extracting zircon crystals , which can preserve unstable isotopes of uranium .
The uranium isotope decays into lead at a constant rate , and when @ @ @ @ @ @ @ and analyze them with a mass spectrometer , the relative quantities of uranium and lead we measure indicate when the rock layers were laid down .
In the case of this Dilophosaurus site , it was around 183 million years ago , plus or minus a few million years .
Dilophosaurus thus lived during the Early Jurassic epoch , approximately five million to 15 million years after the end-Triassic mass extinction that resulted in the loss of roughly three quarters of life on Earth , including most of the large reptiles that competed @ @ @ @ @ @ @ The mass extinction was probably triggered by the initial breakup of the supercontinent Pangaea as the northern Atlantic Ocean opened up like a volcanic zipper .
Throughout the Late Triassic and Early Jurassic , the North American tectonic plate traveled northward from a subtropical climate belt into an arid climate belt , so the location that Dilophosaurus lived in moved from the approximate latitude of modern-day Costa Rica to modern-day northern Mexico .
As such , the environment that deposited the Kayenta Formation was seasonally dry , with sand dunes migrating in and @ @ @ @ @ @ @ .
Fossils of other organisms found in the Kayenta Formation reveal how Dilophosaurus fit into the ecosystem .
It was the apex predator in the river oasis it inhabited , a conifer-lined waterway through a sea of sand .
One specimen housed at U.T .
Austin was found in the same quarry as two individuals of the long-necked herbivore Sarahsaurus .
These dinosaurs lived alongside a smaller meat-eating dinosaur called Megapnosaurus and a small armored dinosaur called Scutellosaurus .
The most common animal found in the Kayenta Formation is the early turtle Kayentachelys @ @ @ @ @ @ @ fish , freshwater coelacanths and lungfish .
Early mammal relatives , including the beaverlike tritylodontids and ratlike morganucodontids , were also potential prey for Dilophosaurus .
In the fossil excavation depicted in Jurassic Park , a complete Velociraptor skeleton comes to light with some gentle brushing .
In the real world , dinosaur fossils are typically found as broken , barely identifiable fragments .
On a lucky day , a mostly complete bone might turn up .
With the publication last summer of Marsh 's comprehensive anatomical study , Dilophosaurus has become the @ @ @ @ @ @ @ the world .
But it took decades to find additional remains that filled in the unknown anatomy of the animal .
And it took successive generations of paleontologists to interpret the bones .
Museums play a vital role in facilitating such efforts .
The public 's conception of museums is a dramatically lit exhibit gallery , but the major function of a natural history museum is to conduct research into the natural world .
To that end , these institutions build large collections of specimens to serve as the evidence for scientific research @ @ @ @ @ @ @ archivists and collection managers carefully document and preserve the specimens , with the goal of making the collections accessible to researchers in perpetuity .
Repeatability is a cornerstone principle of scientific research ; other scientists must be able to corroborate our findings .
In paleontology , that means that the fossils themselves must be preserved in a museum , so that future generations of scientists can revisit the specimens and double-check observations .
The Navajo Nation has partnered with museums that care for those fossils to preserve not just the bones themselves but @ @ @ @ @ @ @ them .
In 2015 , when we went to relocate the original Dilophosaurus discovery site for this research , we were lucky to meet John Willie , a relative of Jesse Williams , the Navajo man who found the first bones in 1940 .
Willie walked us to the site and explained that the natural resources unique to the Navajo Nation are extremely important to the Diné ( Navajo People ) .
The Navajo Nation is one of the best places in the world to see terrestrial rocks from the Early Mesozoic era @ @ @ @ @ @ @ active in facilitating scientific research , including approving permits for fieldwork and loans of fossils and reviewing scientific manuscripts .
Scientific understanding comes from building on and reevaluating prior knowledge and sometimes overturning old notions .
It is exciting when this hard-won information filters into pop culture .
Paleontology has close ties with cinema going to the dawn of animation .
Winsor McCay 's 1914 Gertie the Dinosaur opens with the animator and a group of friends visiting the American Museum of Natural History in New York City , looking at the skeleton @ @ @ @ @ @ @ his party that he can bring the animal to life ; the result is the first dinosaur to appear on film .
McCay consulted with paleontologists at the museum for guidance on his reconstruction of Gertie .
Later Barnum Brown , the discoverer of Tyrannosaurus rex , provided expertise to Walt Disney during the production of its 1940 animated film Fantasia .
And the studio behind the 1954 Godzilla found inspiration for the design of its monster in the dinosaurs that appeared in a 1947 mural by Rudolph Zallinger entitled The Age of @ @ @ @ @ @ @ Museum .
With the Jurassic Park film franchise set to release its sixth installment in 2022 , we look forward to seeing how paleontology is represented .
Incidentally , the reverse is also true .
Pop culture filters into science , sometimes literally .
Langston once recounted that while repairing fossils at U.C .
Berkeley in the 1930s and 1940s , the paleontologists would dissolve cellulose acetate film strips in acetone to make glue rather than buy the more expensive Duco Cement .
So , yes , Dilophosaurus is in the movies .
@ @ @ @ @ @ @ of the movies in Dilophosaurus , too .
AUTHORS ' NOTE : Fieldwork on the Navajo Nation was conducted under a permit from the Navajo Nation Minerals Department .
Any persons wishing to conduct geologic investigations on the Navajo Nation must first apply for and receive a permit from the Navajo Nation Minerals Department , P.O .
Box 1910 , Window Rock , Arizona 86515 , and telephone no .
: ( 928 ) 871-6587 .

The fading sun beat down on our backs after an already long day in the field. Exhausted, we toiled over shovels and dug with our bare hands to clear away the sand. We were in the heart of dinosaur country on the Colorado Plateau of northern Arizona, working in the middle of the Navajo Nation to determine the ages of two skeletons of Dilophosaurus wetherilli that had been unearthed there previously. We had spent this hot June day in 2014 hiking up and down the badlands to measure the rock beds and fill our backpacks with geologic samples. And now we had to excavate—not a new dinosaur but rather our truck, which had gotten bogged down in the sand dunes and was buried up to the axles. The life of a globe-trotting field scientist is rooted in the mundane—applying for permits, taking notes, cooking meals and washing dishes in camp, reviewing the day's data by light of the campfire—rather than the swashbuckling of the movies. We never see Indiana Jones or Alan Grant digging out a stuck pickup truck.
In the summer of 1993 dinosaurs and paleontologists exploded onto movie screens around the world. Adapted from the 1990 Michael Crichton novel, Jurassic Park made instant stars, and villains, of several little-known species. Names such as Velociraptor and Dilophosaurus joined Tyrannosaurus and Triceratops in the public lexicon. The dinosaurs of action movies are typically not the animals that scientists know from nature. Yet one of the elements that made the Jurassic Park franchise so successful (it broke box office records in 1993 and topped the charts again in the summer of 2020) was its narrative reliance on the state of the art in paleontology and genetics. Author Crichton and director Steven Spielberg brought a modern look at dinosaur science to audiences for the first time, and the image they portrayed of active, intelligent animals still resonates today.
Of course, Crichton and Spielberg took artistic liberties to tell a compelling story, dramatizing not only the scientists but also the dinosaurs. The animal that departed most from the fossil evidence was Dilophosaurus. In the movie, it takes the form of a golden retriever–sized creature with a rattling frill and venomous spit that kills the computer programmer–turned–dinosaur embryo smuggler, Dennis Nedry. What was Dilophosaurus really like?
In truth, scientists did not have a complete picture of this animal back when it entered pop culture. But in the nearly three decades since Dilophosaurus got the Hollywood treatment, researchers have recovered significant new fossil specimens of this dinosaur and analyzed all of the remains with increasingly sophisticated methods. As a result, we can now reconstruct this dinosaur—its appearance and behavior, how it evolved, the world it inhabited—in detail. The findings show that the real Dilophosaurus bore little resemblance to its big-screen counterpart. They also provide the most detailed portrait yet of a dinosaur from the Early Jurassic epoch.
A Star is Born
Today we know Dilophosaurus as a bipedal, meat-eating dinosaur more than 20 feet long with two distinctive parallel crests of very thin bone along the top of its head (its name derives from the Greek words for “two-crested reptile”). But in 1954, when the animal first appeared in the scientific literature, it had a different name: in a series of papers, Samuel Welles, a University of California, Berkeley, paleontologist, presented his research on two skeletons found by Jesse Williams, a Navajo man who lived near Tuba City, Ariz. The crest had not been identified among the fragmentary remains, and Welles called the creature Megalosaurus wetherilli, believing it to be a new species in the previously known genus Megalosaurus. When Welles found an additional specimen in 1964 that preserved the top of the skull, with its dual crests, he realized that the original find represented a new genus, so he renamed the animal Dilophosaurus wetherilli.
The basic body plan of the dinosaur in Jurassic Park was patterned on Welles's 1984 anatomical description and sculpted reconstructions of the bones in museum exhibits, as well as artwork by paleontologist Gregory Paul in the 1988 book Predatory Dinosaurs of the World. But the Jurassic Park Dilophosaurus departed from the scientific record of the time in several key details. Most obviously, it was depicted as half the size of the real animal. The filmmakers did this deliberately to avoid any confusion with another saurian antagonist, the Velociraptor.
The hallmarks of the cinematic Dilophosaurus—namely, its venomous saliva and collapsible frill—were also fictional traits added for dramatic effect. But these embellishments resembled the biology of other real animals, which made them believable. When Welles described the fossils of Dilophosaurus, he interpreted some of the joints between the tooth-bearing bones at the end of the snout as “weak” and suggested that the animals may have been scavengers or that they did most of their killing with claws on their hands and feet. When writing the story, Crichton invented a dramatic mechanism by which the animals could spit a blinding venom, based on some modern species of cobras, which can spit two meters. Inspiration for the frill, meanwhile, came from the modern-day frilled agamid lizard that lives in Australia and New Guinea. The lizard has a structure made of bone and cartilage originating from the throat that supports the frill. No evidence of such a trait has turned up in the fossil record of Dilophosaurus.
Other aspects of Jurassic Park drew from the latest science. In the early 1980s paleontologists were just starting to reach broad agreement that modern birds descended from dinosaurs and are, in fact, the last surviving dinosaur lineage. The filmmakers threw out early test animations of sinuous, snakelike velociraptors in preference of recommendations from their science adviser, dinosaur paleontologist Jack Horner, to make the animals more birdlike in their movements. The film, with its depiction of dinosaurs as quick, clever animals rather than the sluggish, more lizardlike creatures that 19th-century scholars thought them to be, was the first time many members of the general public encountered the bird-dinosaur connection.
New and Improved
Artistic choices aside, scientific understanding of Dilophosaurus was bound to change in the years after Jurassic Park's release. In the lead-up to the book and film, the field of paleontology was undergoing tremendous change. Advances in computing were revolutionizing the study of fossils, enabling researchers to process enormous data sets in ways unimaginable when Dilophosaurus was first discovered. Take, for instance, cladistic analysis, which identifies discrete, heritable anatomical features that can be compared between animals and that provide a statistical basis for testing hypotheses about the relationships of animals to one another. Researchers can now analyze many more characteristics much more quickly than ever before and thus develop better-supported hypotheses about how dinosaurs are related and how they evolved. Increased computing power and developments in medical and industrial CT scanning also created a nondestructive way to look inside bones and rocks at hidden anatomy.
Not only did the analytical tools available to paleontologists evolve, but in 1998 teams at the University of Texas at Austin began recovering more Dilophosaurus remains in the same region of northern Arizona that yielded the first finds. Every new fossil discovery can support or refute prior thinking about long-vanished organisms. In this case, the new fossils preserved parts of the Dilophosaurus anatomy that were missing or distorted in previously collected specimens.
Fossils are typically collected in large blocks of rock and encased in plaster to protect them during their journey from the field to the laboratory. When they arrive in the museum, paleontologists use dental picks, chisels and miniature handheld jackhammers to carefully remove the rock and expose the fossils. After millions of years of exposure to geologic processes such as crushing and weathering, the fossils we find are most often distorted and incomplete elements. We sometimes disassemble and reconstruct broken fragments to better approximate their original condition, sculpting and adding missing material based on closely related animals.
When Wann Langston, Jr., and his colleagues prepared the first Dilophosaurus skeletons at U.C. Berkeley around 1950, they filled in missing skull parts with casts from the skull of a more complete carnivorous dinosaur from the Jurassic, and they sculpted missing parts of the pelvis out of plaster. No one really knew what those missing parts looked like; the reconstructions represented a hypothesis of the real form of Dilophosaurus—one that could be tested with new fossils.
The Dilophosaurus material discovered since Welles's initial description and Langston's reconstruction shows that the animal's snout and jaw were much more substantial than originally recognized. The upper jaw bones do not have the weak interface that the fragmentary first finds suggested. Instead these bones indicate a strong skull capable of biting into prey. Likewise, newly identified features of bones from the animal's lower jaw show stout ridges for muscle attachments. In modern reptiles, these ridges provide surface area for the attachment of large muscles. And the skeleton of a different dinosaur found at the U.T. Austin dig site—the plant-eating Sarahsaurus—features bite marks, attesting to the presence of a large meat-eating animal with jaws strong enough to puncture bone. Together this evidence supports the idea that Dilophosaurus was probably a predator with a deadly bite rather than a creature that had to scavenge or use its claws to kill, as Welles supposed.
Dilophosaurus was a large dinosaur, especially for its time. Most of the dinosaurs of the Late Triassic of western North America, just 20 million years earlier, were animals the size of turkeys or eagles, but Dilophosaurus would have towered over a human, standing up to eight feet tall and measuring up to 25 feet long when fully grown. It had much longer and stronger arms than other larger meat-eating dinosaurs such as Allosaurus and Ceratosaurus, and its legs were relatively longer as well. When the first skeletons of Dilophosaurus were found, scientists thought the species was related to the so-called carnosaurs Allosaurus and Streptospondylus, so they reconstructed the missing parts of the pelvis to look like they did in those animals. The better-preserved Dilophosaurus skeletons found later show more intermediate pelvis anatomy between Coelophysis-like and Allosaurus-like animals from the Late Triassic and Late Jurassic, respectively.
Like many early dinosaurs and all modern birds, Dilophosaurus had fleshy air pockets from its respiratory system growing into its vertebrae, which provided strength while simultaneously lightening the skeleton. These air sacs allowed for the unidirectional flow of air through the lungs—in other words, the entire cycle occurs in one breath, as it does in birds and crocodilians. This type of respiration provides the animal with more oxygen than does the bidirectional respiratory system that mammals have, in which air flows both in and out of the lungs. Animals that breathe unidirectionally tend to have relatively high rates of metabolism and thus high activity levels, so Dilophosaurus was probably a fast, agile hunter.
CT imaging has revealed that these air sacs are also present in the bones surrounding the dinosaur's brain and were continuous with the sinus cavities in the front of the skull. In most meat-eating dinosaurs, a ridge of bone provides a roof over an opening in the skull in front of the eye sockets known as the antorbital fenestra. But in Dilophosaurus, this opening is continuous with the side of the dinosaur's unique crests, suggesting that the crests, too, had air sacs. The crests were almost certainly covered by keratin, the same material that forms horns, claws and hair, and may have played a role in helping members of this species identify one another or attract mates. But how the air sacs might have supported these or other functions of the crests is unclear.
One of the challenges of studying the evolutionary history of any species is understanding physical variation within and among taxonomic groups. Welles thought the various skeletons we now categorize as Dilophosaurus actually represented multiple genera. Taking advantage of the latest cladistics tools, one of us (Marsh) tested that hypothesis by identifying hundreds of anatomical features present on each individual skeleton and comparing them with one another. The results of this statistical analysis show that, contrary to what Welles surmised, all of the animals are so similar that they must represent not only one genus but one species.
Marsh also incorporated these anatomical characteristics into a much larger data set that compares Dilophosaurus with other specimens from around the world. This process elucidates the early evolutionary history and biogeographical distribution of dinosaur groups and has more precisely located Dilophosaurus on the tree of life. We now know that the evolutionary gap between Dilophosaurus and its closest known relatives is significant, implying that many other, closer, relatives remain to be discovered.
Context Clues
Just as our conception of Dilophosaurus the animal has grown more detailed, so, too, has our understanding of the world it lived in. The hike down the Adeii Eichii Cliffs to the Dilophosaurus quarry is a journey back through 183 million years to the Early Jurassic. Back then, dinosaurs roamed the landscape, leaving footprints in what is now sandstone across the Colorado Plateau. Paved surfaces end miles from the rock outcrop, so we drive on overgrown rutted two-tracks that cross the loose sandy dune fields that show up on our geologic maps as “QAL”—Quaternary alluvium. This windblown sand is what stranded our field vehicles in 2014. The bedrock under these modern dunes is the Navajo Sandstone, the lithified remains of a 180-million-year-old desert. The red rock badlands of Ward Terrace, as this area is known, spill out to the western horizon, where they meet the much younger volcanic San Francisco Peaks of Flagstaff, Ariz. To the northwest is the mouth of one of the world's most visited geologic features, the Grand Canyon.
Credit: Daisy Chung; Source: Christopher R. Scotese (paleogeographic map reference)
From the sands that trapped our pickup atop Ward Terrace to the Vishnu schist—the black rock at the bottom of the canyon that is being carved away by the Colorado River—these landscapes preserve much of the past 1.8 billion years of the rock record. As paleontologists, we work to understand the life entombed in those rocks, and we use lines of geologic and biological evidence preserved within them to reconstruct the environments of deep time.
One of our objectives was to more precisely determine the age of the rock in which Dilophosaurus is found, known as the Kayenta Formation. This rock was laid down by rivers, lakes and streams east of a volcanic arc that was depositing ash and fine-grained particles into the area. The ash helped to both preserve the bones of Dilophosaurus and aid early efforts to date the Kayenta Formation. We collected new rock samples to date using radiometric methods. We processed the samples by grinding and extracting zircon crystals, which can preserve unstable isotopes of uranium. The uranium isotope decays into lead at a constant rate, and when we vaporize the crystals with a laser and analyze them with a mass spectrometer, the relative quantities of uranium and lead we measure indicate when the rock layers were laid down. In the case of this Dilophosaurus site, it was around 183 million years ago, plus or minus a few million years.
Dilophosaurus thus lived during the Early Jurassic epoch, approximately five million to 15 million years after the end-Triassic mass extinction that resulted in the loss of roughly three quarters of life on Earth, including most of the large reptiles that competed for resources with the early dinosaurs. The mass extinction was probably triggered by the initial breakup of the supercontinent Pangaea as the northern Atlantic Ocean opened up like a volcanic zipper. Throughout the Late Triassic and Early Jurassic, the North American tectonic plate traveled northward from a subtropical climate belt into an arid climate belt, so the location that Dilophosaurus lived in moved from the approximate latitude of modern-day Costa Rica to modern-day northern Mexico. As such, the environment that deposited the Kayenta Formation was seasonally dry, with sand dunes migrating in and out of wetter environments where animals flourished.
Fossils of other organisms found in the Kayenta Formation reveal how Dilophosaurus fit into the ecosystem. It was the apex predator in the river oasis it inhabited, a conifer-lined waterway through a sea of sand. One specimen housed at U.T. Austin was found in the same quarry as two individuals of the long-necked herbivore Sarahsaurus. These dinosaurs lived alongside a smaller meat-eating dinosaur called Megapnosaurus and a small armored dinosaur called Scutellosaurus. The most common animal found in the Kayenta Formation is the early turtle Kayentachelys, which swam alongside heavily scaled bony fish, freshwater coelacanths and lungfish. Early mammal relatives, including the beaverlike tritylodontids and ratlike morganucodontids, were also potential prey for Dilophosaurus.
Fossils for All
In the fossil excavation depicted in Jurassic Park, a complete Velociraptor skeleton comes to light with some gentle brushing. In the real world, dinosaur fossils are typically found as broken, barely identifiable fragments. On a lucky day, a mostly complete bone might turn up. With the publication last summer of Marsh's comprehensive anatomical study, Dilophosaurus has become the best-documented Early Jurassic dinosaur from anywhere in the world. But it took decades to find additional remains that filled in the unknown anatomy of the animal. And it took successive generations of paleontologists to interpret the bones.
Museums play a vital role in facilitating such efforts. The public's conception of museums is a dramatically lit exhibit gallery, but the major function of a natural history museum is to conduct research into the natural world. To that end, these institutions build large collections of specimens to serve as the evidence for scientific research. Teams of specially trained conservators, archivists and collection managers carefully document and preserve the specimens, with the goal of making the collections accessible to researchers in perpetuity. Repeatability is a cornerstone principle of scientific research; other scientists must be able to corroborate our findings. In paleontology, that means that the fossils themselves must be preserved in a museum, so that future generations of scientists can revisit the specimens and double-check observations.
The Navajo Nation has partnered with museums that care for those fossils to preserve not just the bones themselves but all the archives and data associated with them. In 2015, when we went to relocate the original Dilophosaurus discovery site for this research, we were lucky to meet John Willie, a relative of Jesse Williams, the Navajo man who found the first bones in 1940. Willie walked us to the site and explained that the natural resources unique to the Navajo Nation are extremely important to the Diné (Navajo People). The Navajo Nation is one of the best places in the world to see terrestrial rocks from the Early Mesozoic era, and its Minerals Department has been active in facilitating scientific research, including approving permits for fieldwork and loans of fossils and reviewing scientific manuscripts.
Scientific understanding comes from building on and reevaluating prior knowledge and sometimes overturning old notions. It is exciting when this hard-won information filters into pop culture. Paleontology has close ties with cinema going to the dawn of animation. Winsor McCay's 1914 Gertie the Dinosaur opens with the animator and a group of friends visiting the American Museum of Natural History in New York City, looking at the skeleton of a sauropod dinosaur. McCay bets his party that he can bring the animal to life; the result is the first dinosaur to appear on film. McCay consulted with paleontologists at the museum for guidance on his reconstruction of Gertie. Later Barnum Brown, the discoverer of Tyrannosaurus rex, provided expertise to Walt Disney during the production of its 1940 animated film Fantasia. And the studio behind the 1954 Godzilla found inspiration for the design of its monster in the dinosaurs that appeared in a 1947 mural by Rudolph Zallinger entitled The Age of Reptiles, housed at the Yale Peabody Museum. With the Jurassic Park film franchise set to release its sixth installment in 2022, we look forward to seeing how paleontology is represented.
Incidentally, the reverse is also true. Pop culture filters into science, sometimes literally. Langston once recounted that while repairing fossils at U.C. Berkeley in the 1930s and 1940s, the paleontologists would dissolve cellulose acetate film strips in acetone to make glue rather than buy the more expensive Duco Cement. So, yes, Dilophosaurus is in the movies. But perhaps there is a little bit of the movies in Dilophosaurus, too.
AUTHORS' NOTE: Fieldwork on the Navajo Nation was conducted under a permit from the Navajo Nation Minerals Department. Any persons wishing to conduct geologic investigations on the Navajo Nation must first apply for and receive a permit from the Navajo Nation Minerals Department, P.O. Box 1910, Window Rock, Arizona 86515, and telephone no.: (928) 871-6587.


scientificamerican--2020-12-15--2020 Has Been a Huge Year for Understanding the Process of Science

The heroes of the COVID-19 pandemic are legion : nurses , doctors and others who care for the sick ; epidemiologists and public health experts who track the disease and offer clear lifesaving guidance ; and everyone who masks up and avoids crowds and protects their own health and the health of their communities .
And around the world many scientists are working practically nonstop to understand the virus , how it spreads and what it does to the body .
We learned more about the immune system in 2020 than in any year in history .
Akiko Iwasaki heads @ @ @ @ @ @ @ effort to save people from COVID-19 .
She and grad student Patrick Wong explain how the immune system reacts to the new virus and how that knowledge might lead to new treatments .
They describe how their team took on the urgent challenge and how the process of science changed in 2020 .
Understanding the process of science can protect people against misinformation—or at least we hope so .
One of the outrageous myths about the pandemic is that the death toll is exaggerated .
It 's not .
More than a quarter @ @ @ @ @ @ @ have died of COVID-19 as of November .
Journalist Christie Aschwanden details how we know the disease has become the third leading cause of death in the U.S. One of the most intriguing stages in the process of science is noticing when something is ... weird .
Astronomers using new tools to see parts of space that had been shrouded by dust have observed that galaxy clusters formed much faster than anyone expected and that they seem to be too big for our universe .
Grad student Arianna S. Long recounts the excitement @ @ @ @ @ @ @ early universe and how any unusual discovery is first assumed to be a software bug before it is accepted .
Turn here .
We 're in a great age of dinosaur discoveries .
Starting here , fossil experts Matthew A .
Brown and Adam D. Marsh show how much has been learned about Dilophosaurus , our cover Dino Star , since it appeared in the film Jurassic Park in 1993 .
They point out that paleontology is more tedious and less glamorous than how it 's depicted in movies , but understanding the @ @ @ @ @ @ @ 183-million-year-old dinosaur is the next best thing to bringing it back to life .
Some data are harder to gather than others .
To understand the water cycle that sustains billions of people , mountain hydrologist Walter Immerzeel and his colleagues camp at 5,300 meters elevation ( about 17,400 feet ) and go higher to set up monitoring stations that have been twisted by winds and knocked over by avalanches .
As he reports here , climate change is disrupting ice melt , monsoons and river flows , and the consequences could be @ @ @ @ @ @ @ well-functioning cellular civilizations , according to psychologist and evolutionary biologist Athena Aktipis .
Multicellularity has a lot of advantages , and it has led to exquisite cooperation .
But when some cells cheat , they can threaten the entire organism .
Thinking of cancer cells as cheaters has led to new approaches to treatment .
When things get tumultuous on our planet , it 's a nice escape to look at another one .
The Mars Reconnaissance Orbiter has been photographing the Red Planet for 15 years now , and senior editor Clara @ @ @ @ @ @ @ views .
They reveal that Mars has dust devils , landslides and asteroid impacts just like Earth does .
All of us at Scientific American wish you a Happy New Year .
We hope your 2021 is healthy and full of pleasant discoveries .
And may science keep showing us more ways to save lives .

The heroes of the COVID-19 pandemic are legion: nurses, doctors and others who care for the sick; epidemiologists and public health experts who track the disease and offer clear lifesaving guidance; and everyone who masks up and avoids crowds and protects their own health and the health of their communities. And around the world many scientists are working practically nonstop to understand the virus, how it spreads and what it does to the body.
We learned more about the immune system in 2020 than in any year in history. Akiko Iwasaki heads one of the labs leading the global effort to save people from COVID-19. She and grad student Patrick Wong explain how the immune system reacts to the new virus and how that knowledge might lead to new treatments. They describe how their team took on the urgent challenge and how the process of science changed in 2020.
Understanding the process of science can protect people against misinformation—or at least we hope so. One of the outrageous myths about the pandemic is that the death toll is exaggerated. It's not. More than a quarter of a million people in the U.S. have died of COVID-19 as of November. Journalist Christie Aschwanden details how we know the disease has become the third leading cause of death in the U.S.
One of the most intriguing stages in the process of science is noticing when something is ... weird. Astronomers using new tools to see parts of space that had been shrouded by dust have observed that galaxy clusters formed much faster than anyone expected and that they seem to be too big for our universe. Grad student Arianna S. Long recounts the excitement of rethinking the time line of the early universe and how any unusual discovery is first assumed to be a software bug before it is accepted. Turn here.
We're in a great age of dinosaur discoveries. Starting here, fossil experts Matthew A. Brown and Adam D. Marsh show how much has been learned about Dilophosaurus, our cover Dino Star, since it appeared in the film Jurassic Park in 1993. They point out that paleontology is more tedious and less glamorous than how it's depicted in movies, but understanding the bodies and habitats and behaviors of a 183-million-year-old dinosaur is the next best thing to bringing it back to life.
Some data are harder to gather than others. To understand the water cycle that sustains billions of people, mountain hydrologist Walter Immerzeel and his colleagues camp at 5,300 meters elevation (about 17,400 feet) and go higher to set up monitoring stations that have been twisted by winds and knocked over by avalanches. As he reports here, climate change is disrupting ice melt, monsoons and river flows, and the consequences could be catastrophic.
Evolutionarily, we are all well-functioning cellular civilizations, according to psychologist and evolutionary biologist Athena Aktipis. Multicellularity has a lot of advantages, and it has led to exquisite cooperation. But when some cells cheat, they can threaten the entire organism. Thinking of cancer cells as cheaters has led to new approaches to treatment.
When things get tumultuous on our planet, it's a nice escape to look at another one. The Mars Reconnaissance Orbiter has been photographing the Red Planet for 15 years now, and senior editor Clara Moskowitz shares some of the most gorgeous views. They reveal that Mars has dust devils, landslides and asteroid impacts just like Earth does.
All of us at Scientific American wish you a Happy New Year. We hope your 2021 is healthy and full of pleasant discoveries. And may science keep showing us more ways to save lives.


scientificamerican--2020-12-15--For a Better Connection, Talk instead of Typing

Throughout the COVID-19 pandemic , the term “ social distancing ” has been at the center of public conversation , but this phrase is a bit of a misnomer .
Taken literally , the phrase seems to endorse social separation .
But it ’ s not “ social ” distance we are trying to promote .
It ’ s physical separation .
In fact , preserving social ties—even at a distance—is essential for both mental and physical health .
The results of epidemiological meta-analyses , for example , indicate that a lack of social support is on par with smoking @ @ @ @ @ @ @ and mortality and is even more harmful than other stressors , such as obesity and air pollution .
Given this empirical fact , how might we best stay connected to others while maintaining physical distance ?
Would we better off e-mailing a friend ?
Making a phone call ?
Setting up a video chat ?
Modern technology has provided us with many tools at our disposal .
Not all tools foster social connection equally , however .
And often such seemingly small choices can make a big difference between cultivating stronger social connections @ @ @ @ @ @ @ .
In a paper soon to be published in the Journal of Experimental Psychology : General , Nick Epley and I tested whether the media through which people interact affects their sense of connection—and how expectations about certain technologies impact the communication media they choose to use .
Note that these expectations can be misguided .
Although voice-based interactions ( such as phone calls ) can produce stronger connections , text-based media ( such as e-mails ) are often preferred because of mistaken beliefs about how social interactions will unfold .
Any interaction @ @ @ @ @ @ @ disadvantages , and decisions about how to connect tend to be based on expectations of these potential costs and benefits .
When people overestimate the cost , or underestimate the benefit , of voice-based communication , it can create a misplaced bias for text-based media .
In one experiment , for instance , we asked participants to reconnect with someone that they hadn ’ t interacted with recently , either through e-mail or over the phone .
Participants first made predictions about what it would be like to get in touch if they @ @ @ @ @ @ @ More specifically , these participants predicted how connected and how awkward they would feel in each situation .
In this experiment , they did generally intuit that they ’ d feel more connected when interacting via the phone than over e-mail .
But they also predicted that talking on the phone could be more uncomfortable than dashing off an e-mail .
Participants additionally indicated which option they preferred .
Although these participants believed that talking encouraged stronger bonds , most of them said they ’ d rather send an e-mail than call the @ @ @ @ @ @ @ it seems , push individuals toward text-based methods for communicating .
Our results demonstrated that , contrary to participants ’ expectations , worries about awkwardness are largely unwarranted .
In the next part of the experiment , we had participants actually reconnect using one randomly determined mode of communication—either e-mail or phone—and then followed up with them after they had done so .
As expected , we found that people do form meaningfully stronger bonds when interacting over the phone than over e-mail .
Importantly , though , there was no difference in @ @ @ @ @ @ @ the phone .
The human voice appears to provide benefits for connection without the expected costs .
In another experiment , we had individuals connect with each other by asking and answering a series of relatively personal questions ( for example , “ Is there something you ’ ve dreamed of doing for a long time ?
Why haven ’ t you done it ?
” ) .
These conversations took place by texting in real time during a live chat , using only audio , or engaging in a video chat .
@ @ @ @ @ @ @ about how they believed they would feel and then actually had a discussion with someone else .
We again measured awkwardness and connection , in this case using statements such as how much they would get to know their conversation partner , how much they would like that person , and how strong of a bond they would feel .
Here , participants didn ’ t expect that the media through which they communicated would matter .
But when they actually interacted , people again felt significantly more connected—and notably , no more @ @ @ @ @ @ @ typing .
Interestingly , visual cues didn ’ t add more to what voice-based media already provided .
Media containing only audio , as in a phone call , created as strong a sense of connection as audiovisual media , and both produced higher-quality social interactions than text-based media .
Our work suggests that these miscalibrated expectations can affect how people choose to connect with others and therefore how well they do so .
Misunderstanding the costs and benefits of different interactions can lead individuals to choose inferior methods for connecting , leading @ @ @ @ @ @ @ send a message on Slack instead of picking up the phone , which results in a more positive interaction .
In light of this evidence , it is critical that we not only focus on the content we are trying to convey but also the context in which it is conveyed .
The next time you think about how best to connect , consider calling or setting up a video chat .
You ’ re likely to feel better as a result .
E-mail or text messaging can sometimes be useful for sending @ @ @ @ @ @ @ , to be sure .
Feelings of social connection , however , are optimally facilitated by one ’ s voice rather than their keyboard .

Throughout the COVID-19 pandemic, the term “social distancing” has been at the center of public conversation, but this phrase is a bit of a misnomer. Taken literally, the phrase seems to endorse social separation. But it’s not “social” distance we are trying to promote. It’s physical separation. In fact, preserving social ties—even at a distance—is essential for both mental and physical health. The results of epidemiological meta-analyses, for example, indicate that a lack of social support is on par with smoking cigarettes as a risk factor for morbidity and mortality and is even more harmful than other stressors, such as obesity and air pollution. Given this empirical fact, how might we best stay connected to others while maintaining physical distance? Would we better off e-mailing a friend? Making a phone call? Setting up a video chat? Modern technology has provided us with many tools at our disposal. Not all tools foster social connection equally, however. And often such seemingly small choices can make a big difference between cultivating stronger social connections and giving in to growing social distance.
In a paper soon to be published in the Journal of Experimental Psychology: General, Nick Epley and I tested whether the media through which people interact affects their sense of connection—and how expectations about certain technologies impact the communication media they choose to use. Note that these expectations can be misguided. Although voice-based interactions (such as phone calls) can produce stronger connections, text-based media (such as e-mails) are often preferred because of mistaken beliefs about how social interactions will unfold. Any interaction we have can come with advantages and disadvantages, and decisions about how to connect tend to be based on expectations of these potential costs and benefits. When people overestimate the cost, or underestimate the benefit, of voice-based communication, it can create a misplaced bias for text-based media.
In one experiment, for instance, we asked participants to reconnect with someone that they hadn’t interacted with recently, either through e-mail or over the phone. Participants first made predictions about what it would be like to get in touch if they reached out in these two ways. More specifically, these participants predicted how connected and how awkward they would feel in each situation. In this experiment, they did generally intuit that they’d feel more connected when interacting via the phone than over e-mail. But they also predicted that talking on the phone could be more uncomfortable than dashing off an e-mail. Participants additionally indicated which option they preferred. Although these participants believed that talking encouraged stronger bonds, most of them said they’d rather send an e-mail than call the person up. Fears about awkwardness, it seems, push individuals toward text-based methods for communicating.
Our results demonstrated that, contrary to participants’ expectations, worries about awkwardness are largely unwarranted. In the next part of the experiment, we had participants actually reconnect using one randomly determined mode of communication—either e-mail or phone—and then followed up with them after they had done so. As expected, we found that people do form meaningfully stronger bonds when interacting over the phone than over e-mail. Importantly, though, there was no difference in the amount of discomfort when reconnecting on the phone. The human voice appears to provide benefits for connection without the expected costs.
In another experiment, we had individuals connect with each other by asking and answering a series of relatively personal questions (for example, “Is there something you’ve dreamed of doing for a long time? Why haven’t you done it?”). These conversations took place by texting in real time during a live chat, using only audio, or engaging in a video chat. Once again, participants first made predictions about how they believed they would feel and then actually had a discussion with someone else. We again measured awkwardness and connection, in this case using statements such as how much they would get to know their conversation partner, how much they would like that person, and how strong of a bond they would feel. Here, participants didn’t expect that the media through which they communicated would matter. But when they actually interacted, people again felt significantly more connected—and notably, no more awkward—when they communicated by talking rather than typing. Interestingly, visual cues didn’t add more to what voice-based media already provided. Media containing only audio, as in a phone call, created as strong a sense of connection as audiovisual media, and both produced higher-quality social interactions than text-based media.
Our work suggests that these miscalibrated expectations can affect how people choose to connect with others and therefore how well they do so. Misunderstanding the costs and benefits of different interactions can lead individuals to choose inferior methods for connecting, leading them to text, e-mail, or send a message on Slack instead of picking up the phone, which results in a more positive interaction. In light of this evidence, it is critical that we not only focus on the content we are trying to convey but also the context in which it is conveyed. The next time you think about how best to connect, consider calling or setting up a video chat. You’re likely to feel better as a result. E-mail or text messaging can sometimes be useful for sending attachments or scheduling a time to talk, to be sure. Feelings of social connection, however, are optimally facilitated by one’s voice rather than their keyboard.


scientificamerican--2020-12-15--Quantum Mechanics, the Mind-Body Problem and Negative Theology

Here ’ s how I distinguish science from philosophy .
Science addresses questions that can be answered , potentially , through empirical investigation .
Examples : What ’ s the best way to defeat COVID-19 ?
What causes schizophrenia , and how should it be treated ?
Can nuclear power help us overcome climate change ?
What are the causes of war , and how can we end it ?
Philosophy addresses questions that probably can ’ t be solved , now or ever .
Examples ( and these are of course debatable , some philosophers and scientists insist that @ @ @ @ @ @ @ ) : Why is there something rather than nothing ?
Does free will exist ?
How does matter make a mind ?
What does quantum mechanics mean ?
This final question has absorbed me lately because of my ongoing effort to learn quantum mechanics .
Quantum mechanics represents reality at its most fundamental level , that of particles darting through space .
Supposedly .
That ’ s why science writer and astrophysicist Adam Becker calls his recent book about quantum mechanics What Is Real ?
I suspect we ’ ll never have final @ @ @ @ @ @ @ means and what is real .
My reasoning is primarily inductive .
For more than a century , experts have sought to “ interpret ” quantum mechanics , to specify what it tells us about matter and energy , time and space , the infrastructure of existence .
Physicists and philosophers have come up with lots of possibilities , notably the Copenhagen interpretation , the many-worlds hypothesis and the Bohmian pilot-wave model .
I ’ ve just become aware of a hypothesis called quantum Bayesianism , or QBism ( pronounced “ cubism ” @ @ @ @ @ @ @ out yourself .
Unfortunately , most interpretations don ’ t offer testable predictions to distinguish them from rivals .
( An exception is a quantum model proposed by Nobel laureate Roger Penrose , certain versions of which are reportedly ruled out by a recent experiment . )
Hence adherents favor one interpretation over others for largely subjective , aesthetic reasons .
You dig the austere minimalism of the Copenhagen interpretation .
I favor the pilot-wave model , which insists that particles are … particles , and not probabilistic blurs .
If I ’ @ @ @ @ @ @ @ with John Wheeler ’ s metaphysically extravagant “ it from bit ” proposal , which fuses quantum mechanics and information theory .
Arguments about which interpretation is “ true ” can not be resolved , because our preferences are matters of taste , not truth .
When I say a problem is unsolvable , I don ’ t mean we should abandon it .
Far from it .
I love reading , writing and arguing about intractable puzzles .
For example , I don ’ t believe in God , certainly not the @ @ @ @ @ @ @ I enjoy smart , imaginative theology ( defined as the study of God ) in the same way that I enjoy good science fiction .
Two of my favorite theologians are physicist Freeman Dyson and psychedelic adventurer Terence McKenna .
I ’ m especially fond of what is known as negative theology .
Negative theology assumes that God exists but insists that He/She/It/They transcends human language and concepts .
Negative theologians try to say—over and over again , and sometimes with great eloquence—what they acknowledge can not be said .
Negative theology is @ @ @ @ @ @ @ , as defined by William James in The Varieties of Religious Experience , possess two seemingly contradictory properties .
They are on the one hand “ noetic , ” that is , you feel you are gaining profound insight into and knowledge of reality .
They are on the other hand “ ineffable , ” meaning you can not convey your revelation in words .
Mystical aphorisms often emphasize ineffability .
“ He who knows , does not speak , ” the ancient Chinese sage Lao Tzu says , violating his own dictum @ @ @ @ @ @ @ not know.
” Pseudo-Dionysius the Areopagite , a medieval monk , describes mystical knowledge as being “ at one with Him Who is indescribable.
” I suspect Wittgenstein had his own mystical experiences in mind when he wrote at the end of his cryptic prose-poem Tractatus Logico-Philosophicus , “ Whereof one can not speak , thereof one must remain silent.
” ( After a friend , a philosopher , quoted that line to me , I replied : Then why are you still speaking ?
The friend hasn ’ t spoken to me @ @ @ @ @ @ @ doing research for my book Rational Mysticism , I attended a symposium on mysticism at the University of Chicago .
At a session on negative theology , a speaker said he ’ d arrived by mistake a day early .
Upon entering the empty auditorium , he thought , “ This is taking negative theology too far.
” Another speaker described mystical literature as “ that which contests its own possibility.
” Negative theology can serve as a model for scientists and philosophers trying to solve quantum mechanics and another enigma I posed @ @ @ @ @ @ @ mind ?
This is the mind-body problem , which investigates , as I argue in a recent book , what we really are , can be and should be , collectively and as individuals .
Are we really matter , mind , some combination of the two or , perhaps , none of the above ?
When we wrestle with quantum mechanics , we ’ re also taking on the mind-body problem .
Quantum paradoxes like Schrödinger ’ s cat and the measurement problem raise questions about the connection between matter and mind @ @ @ @ @ @ @ other .
Is matter self-sufficient , as materialists insist , or does reality require mind too ?
Mind is essential , according to QBism , it from bit and other quantum hypotheses .
I have disparaged these mind-centric frameworks as neo-geocentrism , throwbacks to the ancient assumption that the universe revolves around us .
But I enjoy mulling them over , just as I enjoy thinking about theodicies , which seek to explain why a loving , all-powerful God would create such a painful , unfair world .
( I ’ ve even @ @ @ @ @ @ @ my own . )
Many , most , scientists and philosophers who dwell on quantum mechanics and the mind-body problem have faith that these conundrums can and will be solved , eventually .
They crave answers , they want to know .
If they can not know during their lifetime , they want at least to feel that their efforts are taking us closer to the truth .
Philosopher David Chalmers , who has rejected strictly materialist solutions of what he calls “ the hard problem ” of consciousness , nonetheless insists that @ @ @ @ @ @ @ .
So does another thinker I admire , philosopher-novelist Rebecca Goldstein .
They and other seekers will probably dismiss negative theology as a model for inquiry , and I understand why .
I share their craving for a revelation so profound that it dissipates the weirdness of the world .
But I ’ ve also become increasingly wary of our craving for absolute knowledge , and absolute certainty , especially when it comes to riddles like what is reality and what are we .
People convinced that they possess ultimate knowledge can become @ @ @ @ @ @ @ exterminating others in the name of truth .
Negative theology helps us avoid fanaticism by keeping us humble .
We acknowledge , as an axiom , that ultimate truth will always elude us .
Those who have a hard time accepting this anti-truth—and hence the premise of negative theology—should keep two points in mind .
First , if we can not grasp ultimate truth , we can pursue it forever , never losing sight of the mystery at the heart of things .
Second , I ’ m not proposing negative theology as @ @ @ @ @ @ @ .
Science has answered , conclusively , many questions , and it will answer many more , including , I hope , those listed at the beginning of this column .
Problems related to infectious disease , mental illness , climate change and war will surely yield to dogged empirical inquiry .
Although science will never entirely explain reality , it can make it more bearable .
For more ruminations on quantum mechanics , the mind-body problem and mysticism , see my new book Pay Attention : Sex , Death , and Science @

Here’s how I distinguish science from philosophy. Science addresses questions that can be answered, potentially, through empirical investigation. Examples: What’s the best way to defeat COVID-19? What causes schizophrenia, and how should it be treated? Can nuclear power help us overcome climate change? What are the causes of war, and how can we end it?
Philosophy addresses questions that probably can’t be solved, now or ever. Examples (and these are of course debatable, some philosophers and scientists insist that science can answer all questions worth asking): Why is there something rather than nothing? Does free will exist? How does matter make a mind? What does quantum mechanics mean?
This final question has absorbed me lately because of my ongoing effort to learn quantum mechanics. Quantum mechanics represents reality at its most fundamental level, that of particles darting through space. Supposedly. That’s why science writer and astrophysicist Adam Becker calls his recent book about quantum mechanics What Is Real?
I suspect we’ll never have final, definitive answers to what quantum mechanics means and what is real. My reasoning is primarily inductive. For more than a century, experts have sought to “interpret” quantum mechanics, to specify what it tells us about matter and energy, time and space, the infrastructure of existence.
Physicists and philosophers have come up with lots of possibilities, notably the Copenhagen interpretation, the many-worlds hypothesis and the Bohmian pilot-wave model. I’ve just become aware of a hypothesis called quantum Bayesianism, or QBism (pronounced “cubism”), which proposes—well, check it out yourself.
Unfortunately, most interpretations don’t offer testable predictions to distinguish them from rivals. (An exception is a quantum model proposed by Nobel laureate Roger Penrose, certain versions of which are reportedly ruled out by a recent experiment.) Hence adherents favor one interpretation over others for largely subjective, aesthetic reasons.
You dig the austere minimalism of the Copenhagen interpretation. I favor the pilot-wave model, which insists that particles are … particles, and not probabilistic blurs. If I’m feeling frisky, I might go with John Wheeler’s metaphysically extravagant “it from bit” proposal, which fuses quantum mechanics and information theory. Arguments about which interpretation is “true” cannot be resolved, because our preferences are matters of taste, not truth.
When I say a problem is unsolvable, I don’t mean we should abandon it. Far from it. I love reading, writing and arguing about intractable puzzles. For example, I don’t believe in God, certainly not the God of my Catholic childhood. But I enjoy smart, imaginative theology (defined as the study of God) in the same way that I enjoy good science fiction. Two of my favorite theologians are physicist Freeman Dyson and psychedelic adventurer Terence McKenna.
I’m especially fond of what is known as negative theology. Negative theology assumes that God exists but insists that He/She/It/They transcends human language and concepts. Negative theologians try to say—over and over again, and sometimes with great eloquence—what they acknowledge cannot be said.
Negative theology is an outgrowth of mysticism. Mystical experiences, as defined by William James in The Varieties of Religious Experience, possess two seemingly contradictory properties. They are on the one hand “noetic,” that is, you feel you are gaining profound insight into and knowledge of reality. They are on the other hand “ineffable,” meaning you cannot convey your revelation in words.
Mystical aphorisms often emphasize ineffability. “He who knows, does not speak,” the ancient Chinese sage Lao Tzu says, violating his own dictum. “He who speaks, does not know.” Pseudo-Dionysius the Areopagite, a medieval monk, describes mystical knowledge as being “at one with Him Who is indescribable.”
I suspect Wittgenstein had his own mystical experiences in mind when he wrote at the end of his cryptic prose-poem Tractatus Logico-Philosophicus, “Whereof one cannot speak, thereof one must remain silent.” (After a friend, a philosopher, quoted that line to me, I replied: Then why are you still speaking? The friend hasn’t spoken to me since.)
In 1999, while doing research for my book Rational Mysticism, I attended a symposium on mysticism at the University of Chicago. At a session on negative theology, a speaker said he’d arrived by mistake a day early. Upon entering the empty auditorium, he thought, “This is taking negative theology too far.” Another speaker described mystical literature as “that which contests its own possibility.”
Negative theology can serve as a model for scientists and philosophers trying to solve quantum mechanics and another enigma I posed above: How does matter make a mind? This is the mind-body problem, which investigates, as I argue in a recent book, what we really are, can be and should be, collectively and as individuals. Are we really matter, mind, some combination of the two or, perhaps, none of the above?
When we wrestle with quantum mechanics, we’re also taking on the mind-body problem. Quantum paradoxes like Schrödinger’s cat and the measurement problem raise questions about the connection between matter and mind, and their status relative to each other. Is matter self-sufficient, as materialists insist, or does reality require mind too?
Mind is essential, according to QBism, it from bit and other quantum hypotheses. I have disparaged these mind-centric frameworks as neo-geocentrism, throwbacks to the ancient assumption that the universe revolves around us. But I enjoy mulling them over, just as I enjoy thinking about theodicies, which seek to explain why a loving, all-powerful God would create such a painful, unfair world. (I’ve even come up with a drug-inspired theodicy of my own.)
Many, most, scientists and philosophers who dwell on quantum mechanics and the mind-body problem have faith that these conundrums can and will be solved, eventually. They crave answers, they want to know. If they cannot know during their lifetime, they want at least to feel that their efforts are taking us closer to the truth.
Philosopher David Chalmers, who has rejected strictly materialist solutions of what he calls “the hard problem” of consciousness, nonetheless insists that one day we’ll crack it. So does another thinker I admire, philosopher-novelist Rebecca Goldstein. They and other seekers will probably dismiss negative theology as a model for inquiry, and I understand why. I share their craving for a revelation so profound that it dissipates the weirdness of the world.
But I’ve also become increasingly wary of our craving for absolute knowledge, and absolute certainty, especially when it comes to riddles like what is reality and what are we. People convinced that they possess ultimate knowledge can become self-righteous fanatics, capable of enslaving and exterminating others in the name of truth.
Negative theology helps us avoid fanaticism by keeping us humble. We acknowledge, as an axiom, that ultimate truth will always elude us. Those who have a hard time accepting this anti-truth—and hence the premise of negative theology—should keep two points in mind. First, if we cannot grasp ultimate truth, we can pursue it forever, never losing sight of the mystery at the heart of things.
Second, I’m not proposing negative theology as a model for science as a whole. Science has answered, conclusively, many questions, and it will answer many more, including, I hope, those listed at the beginning of this column. Problems related to infectious disease, mental illness, climate change and war will surely yield to dogged empirical inquiry. Although science will never entirely explain reality, it can make it more bearable.
Further Reading:
For more ruminations on quantum mechanics, the mind-body problem and mysticism, see my new book Pay Attention: Sex, Death, and Science.


scientificamerican--2020-12-15--Light Pollution Is Causing Birds to Nest Earlier--Which Might Not Be a Bad Thing

Birds exposed to artificial lights at night nest up to a month earlier than those dwelling away from humanity ’ s glow , according to a study published recently in Nature .
But , perhaps counterintuitively , this disruption may actually benefit some birds—in part by helping them adjust as global warming alters the rhythms of the natural world .
The new paper offers a continent-wide , multispecies look at the impact of light and noise pollution on birds ’ reproductive success , with the hope of giving land managers more concrete information to make conservation decisions .
Using data @ @ @ @ @ @ @ Lab of Ornithology ’ s NestWatch program , the study ’ s authors analyzed more than 58,000 nest observations for 142 species in the contiguous U.S. between 2000 and 2014 .
For birds living in temperate climates , lengthening days provide the chief cue that it is time to nest .
Street lamps and other artificial lighting may trick avian brains into thinking days are longer than they are , so the researchers were not surprised to see birds nest earlier in areas with light pollution .
Because nesting is timed to coincide @ @ @ @ @ @ @ scientists had anticipated that light-driven early nesting would disrupt this delicate synchrony and disadvantage the species involved .
But “ we ended up finding the opposite , ” says study co-author Clinton Francis , an ecologist at California Polytechnic State University .
“ For those nests that were exposed to light , they ended up having higher reproductive success.
” The answer to this puzzle may be linked to another human-caused disturbance : climate change .
In a warming world of premature springs , birds must somehow adjust to corresponding shifts in food @ @ @ @ @ @ @ light cues have “ allowed these birds to catch up to the effects of climate change , which has caused their resources to essentially emerge earlier in the spring , ” Francis says .
There could be other explanations , though , says Jacob Socolar , a postdoctoral researcher at the Norwegian University of Life Sciences , who has studied birds and climate change but was not involved with the new research .
“ The one that ’ s most obvious to me is that we know that some species are capable of @ @ @ @ @ @ @ ” he says .
The illumination could create a kind of 24-hour buffet for birds , better nourishing these species for breeding .
None of these hypotheses mean that light pollution is a good thing overall , though .
“ Light might be ‘ helping ’ birds in this one respect , ” Francis says , but “ we need to look at the bigger pictures of the lives of these animals and the ecological systems they live in.
” For example , light pollution has been shown to disrupt hormones and sleep @ @ @ @ @ @ @ disorient migrating birds and to contribute to declines in insects that birds eat .
“ Light pollution and noise pollution are these pervasive , previously overlooked facets of global change , whose effects , we are increasingly learning , are big , ” Socolar says .
Global light emissions are escalating at a rate of roughly 2 percent a year .
Even in national parks , the glow of artificial lights has been detected from sources 200 miles away .
Similarly , a 2017 paper in Science found that 63 percent of national @ @ @ @ @ @ @ .
Noise had a clearly negative impact on birds in the new study , particularly for those living in forests .
When exposed to the rumble of airplanes or cars , for example , birds delayed nesting , and their clutch size—the number of eggs in a nest—shrank by 12 percent .
One explanation is that noise pollution and the songs and calls of forest-dwelling birds tend to be low-frequency , so resulting interference could disrupt communication that is essential to mating .
With bird populations having declined by 29 percent in North @ @ @ @ @ @ @ study published last year in Science , understanding how humans impact bird reproduction is crucial to conservation .
Most research findings on the effects of noise and light pollution on birds involve behavioral changes , such as how the creatures alter their song in response to noise .
These results can be difficult to translate to on-the-ground policy decisions , though , because it is not always clear how a changed behavior may affect a species ’ survival prospects .
One of the larger goals of the new research , which was partially @ @ @ @ @ @ @ National Park Service , is to create a sensitivity index .
This index could help park managers understand how new noise or light disturbances affect the breeding success of specific avian species of concern .
Compared with climate change , Francis believes the solutions to excessive noise and light are simpler .
Technologies such as lights that turn off when not in use and low-tread , quiet tires are tools that individuals and local governments can employ to hush and darken our environment .
“ It ’ s certainly worth people thinking about @ @ @ @ @ @ @ impacts , ” he says .
“ They can actually make a big difference for wildlife populations .
”

Birds exposed to artificial lights at night nest up to a month earlier than those dwelling away from humanity’s glow, according to a study published recently in Nature. But, perhaps counterintuitively, this disruption may actually benefit some birds—in part by helping them adjust as global warming alters the rhythms of the natural world.
The new paper offers a continent-wide, multispecies look at the impact of light and noise pollution on birds’ reproductive success, with the hope of giving land managers more concrete information to make conservation decisions. Using data gathered by citizen scientists through the Cornell Lab of Ornithology’s NestWatch program, the study’s authors analyzed more than 58,000 nest observations for 142 species in the contiguous U.S. between 2000 and 2014.
For birds living in temperate climates, lengthening days provide the chief cue that it is time to nest. Street lamps and other artificial lighting may trick avian brains into thinking days are longer than they are, so the researchers were not surprised to see birds nest earlier in areas with light pollution. Because nesting is timed to coincide with peak spring food availability, the scientists had anticipated that light-driven early nesting would disrupt this delicate synchrony and disadvantage the species involved. But “we ended up finding the opposite,” says study co-author Clinton Francis, an ecologist at California Polytechnic State University. “For those nests that were exposed to light, they ended up having higher reproductive success.”
The answer to this puzzle may be linked to another human-caused disturbance: climate change. In a warming world of premature springs, birds must somehow adjust to corresponding shifts in food availability. It is possible the artificial light cues have “allowed these birds to catch up to the effects of climate change, which has caused their resources to essentially emerge earlier in the spring,” Francis says.
There could be other explanations, though, says Jacob Socolar, a postdoctoral researcher at the Norwegian University of Life Sciences, who has studied birds and climate change but was not involved with the new research. “The one that’s most obvious to me is that we know that some species are capable of foraging at night by artificial light,” he says. The illumination could create a kind of 24-hour buffet for birds, better nourishing these species for breeding.
None of these hypotheses mean that light pollution is a good thing overall, though. “Light might be ‘helping’ birds in this one respect,” Francis says, but “we need to look at the bigger pictures of the lives of these animals and the ecological systems they live in.” For example, light pollution has been shown to disrupt hormones and sleep in birds and other wildlife, to disorient migrating birds and to contribute to declines in insects that birds eat.
“Light pollution and noise pollution are these pervasive, previously overlooked facets of global change, whose effects, we are increasingly learning, are big,” Socolar says. Global light emissions are escalating at a rate of roughly 2 percent a year. Even in national parks, the glow of artificial lights has been detected from sources 200 miles away. Similarly, a 2017 paper in Science found that 63 percent of national parklands were exposed to significant human-caused noise.
Noise had a clearly negative impact on birds in the new study, particularly for those living in forests. When exposed to the rumble of airplanes or cars, for example, birds delayed nesting, and their clutch size—the number of eggs in a nest—shrank by 12 percent. One explanation is that noise pollution and the songs and calls of forest-dwelling birds tend to be low-frequency, so resulting interference could disrupt communication that is essential to mating.
With bird populations having declined by 29 percent in North America since 1970, according to a study published last year in Science, understanding how humans impact bird reproduction is crucial to conservation. Most research findings on the effects of noise and light pollution on birds involve behavioral changes, such as how the creatures alter their song in response to noise. These results can be difficult to translate to on-the-ground policy decisions, though, because it is not always clear how a changed behavior may affect a species’ survival prospects. One of the larger goals of the new research, which was partially funded by NASA and affiliated with the National Park Service, is to create a sensitivity index. This index could help park managers understand how new noise or light disturbances affect the breeding success of specific avian species of concern.
Compared with climate change, Francis believes the solutions to excessive noise and light are simpler. Technologies such as lights that turn off when not in use and low-tread, quiet tires are tools that individuals and local governments can employ to hush and darken our environment. “It’s certainly worth people thinking about these small changes that have collectively big impacts,” he says. “They can actually make a big difference for wildlife populations.”


scientificamerican--2020-12-15--Asteroid Dust Recovered from Japan's Daring Hayabusa2 Mission

Japan ’ s mission to bring asteroid dust back to Earth has succeeded .
The Japan Aerospace Exploration Agency ( JAXA ) confirmed on 14 December that a capsule from spacecraft Hayabusa2 , which landed in an Australian desert last week , contained black grains from asteroid Ryugu .
“ The confirmation of sample is a very important milestone for us and for JAXA , ” says Yuichi Tsuda , project manager for the mission at JAXA , in Sagamihara .
JAXA said in a statement that they observed the sandy material at the entrance of the collection chamber , @ @ @ @ @ @ @ see whether more asteroid dust is lurking there .
It is only the second time that scientists have returned material from an asteroid .
The samples from Ryugu could give researchers important insights into the early evolution of planets , and help to explain the origins of water on Earth .
“ The samples containing precious asteroid material will provide scientists with key information about the formation of the Solar System , ” says Ed Kruzins , director of the Canberra Deep Space Communication Complex at the Commonwealth Scientific and Industrial Research Organisation @ @ @ @ @ @ @ and its encounter with Ryugu .
In the early hours of 6 December , a brilliant fireball streaked through the southern skies and landed in the desert in South Australia , setting off a race to locate the capsule that scientists hoped contained material from Ryugu .
“ Images that Hayabusa2 took during its landing operations made us confident that the spacecraft collected Ryugu samples , ” wrote Satoru Nakazawa , deputy manager of the mission , in an e-mail while in Woomera , Australia .
But the team couldn ’ t know @ @ @ @ @ @ @ and saw the dark dust .
Some 57 hours after the capsule was located , the team delivered it back to Japan .
The swift shipment “ means that the samples we got from Ryugu are very pure without contamination from the Earth ’ s atmosphere and we confirmed that there was no leakage ” , says Tsuda .
Once the capsule is fully unsealed , possibly later today , JAXA scientists will measure the material ’ s mass and study its composition and structure .
They hope to have collected at least @ @ @ @ @ @ @ Makoto , mission manager for Hayabusa2 at JAXA .
Some 10 % of the material will be sent to NASA in December 2021 in exchange for samples from asteroid Bennu , which spacecraft OSIRIS-REx collected in October and should arrive on Earth by late 2023 .
Another 15 % will be made available to international researchers , and about 40 % will be stored for future scientists to investigate .
Hayabusa2 collected the samples over a year and a half of poking and prodding Ryugu—a small asteroid shaped like a squashed sphere , @ @ @ @ @ @ @ a C-type , or carbon-rich , asteroid , which scientists think contains organic and hydrated minerals preserved from as far back as 4.6 billion years ago .
The samples could help to explain how Earth became covered with water .
Scientists think it came on asteroids or similar planetary bodies from the outer regions of the Solar System .
Tsuda is interested in finding out whether the samples contain more complex organic material , similar to those found on Earth .
“ If we find very complicated organics on Ryugu , that is @ @ @ @ @ @ @ now begun its 11-year journey to its next destination : a fast-rotating asteroid known as 1998 KY26 .
To reach it , the spacecraft will fly by another asteroid—2001 CC21—and swing past Earth another two times .
This article is reproduced with permission and was first published on December 15 2020 .

Japan’s mission to bring asteroid dust back to Earth has succeeded. The Japan Aerospace Exploration Agency (JAXA) confirmed on 14 December that a capsule from spacecraft Hayabusa2, which landed in an Australian desert last week, contained black grains from asteroid Ryugu.
“The confirmation of sample is a very important milestone for us and for JAXA,” says Yuichi Tsuda, project manager for the mission at JAXA, in Sagamihara.
JAXA said in a statement that they observed the sandy material at the entrance of the collection chamber, but have yet to look inside to see whether more asteroid dust is lurking there. It is only the second time that scientists have returned material from an asteroid.
The samples from Ryugu could give researchers important insights into the early evolution of planets, and help to explain the origins of water on Earth.
“The samples containing precious asteroid material will provide scientists with key information about the formation of the Solar System,” says Ed Kruzins, director of the Canberra Deep Space Communication Complex at the Commonwealth Scientific and Industrial Research Organisation, which helped to track the spacecraft and its encounter with Ryugu.
The capsule’s journey
In the early hours of 6 December, a brilliant fireball streaked through the southern skies and landed in the desert in South Australia, setting off a race to locate the capsule that scientists hoped contained material from Ryugu.
“Images that Hayabusa2 took during its landing operations made us confident that the spacecraft collected Ryugu samples,” wrote Satoru Nakazawa, deputy manager of the mission, in an e-mail while in Woomera, Australia. But the team couldn’t know for sure until they disassembled the capsule and saw the dark dust.
Some 57 hours after the capsule was located, the team delivered it back to Japan. The swift shipment “means that the samples we got from Ryugu are very pure without contamination from the Earth’s atmosphere and we confirmed that there was no leakage”, says Tsuda.
Plans for the samples
Once the capsule is fully unsealed, possibly later today, JAXA scientists will measure the material’s mass and study its composition and structure. They hope to have collected at least 0.1 grams of material, says Yoshikawa Makoto, mission manager for Hayabusa2 at JAXA.
Some 10% of the material will be sent to NASA in December 2021 in exchange for samples from asteroid Bennu, which spacecraft OSIRIS-REx collected in October and should arrive on Earth by late 2023. Another 15% will be made available to international researchers, and about 40% will be stored for future scientists to investigate.
Hayabusa2 collected the samples over a year and a half of poking and prodding Ryugu—a small asteroid shaped like a squashed sphere, peppered with giant boulders. Ryugu is a C-type, or carbon-rich, asteroid, which scientists think contains organic and hydrated minerals preserved from as far back as 4.6 billion years ago. The samples could help to explain how Earth became covered with water. Scientists think it came on asteroids or similar planetary bodies from the outer regions of the Solar System.
Tsuda is interested in finding out whether the samples contain more complex organic material, similar to those found on Earth. “If we find very complicated organics on Ryugu, that is a very big finding.”
Hayabusa2 has now begun its 11-year journey to its next destination: a fast-rotating asteroid known as 1998 KY26. To reach it, the spacecraft will fly by another asteroid—2001 CC21—and swing past Earth another two times.
This article is reproduced with permission and was first published on December 15 2020.