EXPLAINER: Veteran Hubble vs. new Webb space telescope

by Marcia Dunn

This combination of images made available by NASA shows the Hubble Space Telescope 

orbiting the Earth and an illustration of the James Webb Space Telescope. With NASA and

 the European Space Agency's Hubble pushing 32 years in orbit, the bigger, 100 times 

more powerful Webb is widely viewed as its successor even though the two are vastly 

different. Credit: NASA via AP

Don't ask astronomers to choose between the Hubble Space Telescope and the new kid on the cosmic block, the James Webb Space Telescope.

"Comparing Hubble and Webb is like asking if you will love your second child as much as your first," said Susan Mullally, Webb's deputy project scientist at the Space Telescope Science Institute in Baltimore.

"Hubble will always be loved for its awe-inspiring images of our universe and will continue to collect important data for astronomers. Webb gives us new and unique eyes of places that we have never been able to reach."

With NASA and the European Space Agency's Hubble pushing 32 years in orbit, the bigger, 100 times more powerful Webb is widely viewed as its successor even though the two are vastly different. Its liftoff is slated for Saturday morning from the coast of South America.

The lowdown on Hubble versus Webb:

ROCKET RIDES

Hubble caught a lift to orbit tucked inside NASA's space shuttle Discovery in 1990. It quickly ran into trouble: one of the telescope's solar wings jammed as it was unfurling. Astronauts suited up for an emergency spacewalk, but commands from Earth freed the panel. Within weeks, Hubble's blurry vision was detected. Spacewalking astronauts fixed it three years later. Soaring from South America on a European Ariane rocket, Webb won't be reachable by astronauts at its destination 1 million miles (1.6 million kilometers) away. Bigger and more intricate than Hubble, Webb will be a goner if its foldout mirror and sunshield snarl.

In this image released by NASA, Arianespace's Ariane 5 rocket with NASA's James Webb

 Space Telescope onboard, is rolled out to the launch pad, Thursday, Dec. 23, 2021, at 

Europe's Spaceport, the Guiana Space Center in Kourou, French Guiana. Set to soar after 

years of delay, the James Webb Space Telescope will seek out the faint, twinkling light 

from the first stars and galaxies, providing a glimpse into cosmic creation.

 Credit: Bill Ingalls/NASA via AP

LET THERE BE LIGHT

Webb is expected to behold light from the universe's first stars and galaxies, beyond Hubble's range. This light will reveal how the original stars looked 13.7 billion years ago. Hubble has stared as far back as 13.4 billion years, disclosing a clumpy runt of a galaxy that is currently the oldest and farthest object ever observed. Astronomers are eager to close the 300 million year gap with Webb and draw ever closer in time to the Big Bang, the moment the universe formed 13.8 billion years ago. "It's like looking at the picture book of my kids and missing the first two years, right? Trying to figure out where they come from," said NASA science chief Thomas Zurbuchen.

INFRARED VISION

Hubble sees what we see—visible light—with a little ultraviolet and infrared thrown in. Webb has infrared vision, allowing it to pierce cosmic clouds of dust. The shorter visible and ultraviolet wavelengths emitted by the first stars and galaxies have been stretched as the universe expands, so Webb will see them in their elongated, heat-emitting infrared form. That's why Webb's detectors need to run at minus 400 degrees Fahrenheit (minus 240 degrees Celsius). To stay chilled, Webb carries a parasol the size of a tennis court. Between each of the sunshield's five layers is a gap so heat can escape out the sides. Multiple layers also better protect against micrometeorite hits.

Arianespace's Ariane 5 rocket with NASA's James Webb Space Telescope onboard, is

seen in the final assembly building ahead of the planned roll to the launch pad, Thursday, 

Dec. 23, 2021, at Europe's Spaceport, the Guiana Space Center in Kourou, French Guiana. 

(Chris Gunn/NASA via AP

SIZE MATTERS

To discern the universe's first, faint stars, Webb requires the largest mirror ever launched for astronomy. The mirror spans more than 21 feet (6.5 meters), yet is lighter than Hubble's, which is 8 feet (2.4 meters) across. That's because Webb's mirror is made of beryllium, a strong but lightweight metal. It's also segmented, allowing it to fold like a drop-leaf table for launch. Each of the 18 hexagonal segments are the size of a coffee table and coated with ultra-thin gold, an ideal reflector of infrared light.

LOCATION, LOCATION, LOCATION

Hubble circles 330 miles (530 kilometers) overhead. The altitude was dictated by the capabilities of NASA's space shuttles, which delivered Hubble to orbit and then made five service calls. Webb is bound for more a more distant spot—1 million miles (1.6 million kilometers) away at what's called the second Lagrange point. This is where the gravitational forces of the Earth and sun balance, requiring minimal fuel for a spacecraft to stay put. Webb will constantly face the nightside of Earth as the spacecraft and planet swoop around the sun in unison.

In this image released by NASA, Arianespace's Ariane 5 rocket with NASA's James Webb 

Space Telescope onboard, is rolled out to the launch pad, Thursday, Dec. 23, 2021, at

 Europe's Spaceport, the Guiana Space Center in Kourou, French Guiana. Set to soar 

after years of delay, the James Webb Space Telescope will seek out the faint, twinkling 

light from the first stars and galaxies, providing a glimpse into cosmic creation. 

Credit: Bill Ingalls/NASA via AP

GROWING PAINS

Hubble was years late and millions over budget by the time it rocketed into orbit in 1990. Webb also is years late with huge cost overruns. NASA's tab for Hubble from its 1970s development until now: $16 billion, adjusted for inflation. That doesn't include all the shuttle flights for launch and repairs. Webb's price tag is an estimated $10 billion; that includes the first five years of operation. The European Space Agency is picking up the launch costs, with a French-built Ariane rocket providing Webb's lift from French Guiana.

Arianespace's Ariane 5 rocket with NASA's James Webb Space Telescope onboard, is 

seen in the final assembly building ahead of the planned roll to the launch pad, Thursday, 

Dec. 23, 2021, at Europe's Spaceport, the Guiana Space Center in Kourou, French Guiana. 

Credit: Bill Ingalls/NASA via AP

HUBBLE AND WEBB NAMESAKES:

Astronomer Edwin Hubble confirmed a century ago that countless galaxies exist beyond our Milky Way and the universe is constantly expanding. James Webb led NASA from 1961 to 1968, presiding over Projects Mercury and Gemini, and the early phase of Apollo's moon-landing program. In 2002, a decade after Webb's death, NASA chose his name for the new telescope. But now some scientists and others want a new name, given Webb's State Department and NASA leadership during the Truman administration, when government workers were fired for being gay. NASA's historian conducted an archival search of Webb this year, but found no evidence warranting a name change, said Administrator Bill Nelson 

NASA: Webb telescope launch delayed by communication problem

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© 2021 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.

The earliest atmosphere on Mercury

by David Appell , Phys.org

A schematic of Mercury's early magma surface and atmospheric constituents in its lower, nonhomogeneous atmosphere and exosphere where the upper atmosphere merges with space. Credit: NASA

Mercury is a most unusual planet. The smallest planet in the solar system, and the closest planet to the sun, it is in a 3:2 spin resonance, slowly turning and experiencing scorching heat up to 430 degrees Celsius, and the night side frigid, down to -170 degrees Celsius. Due to its much larger iron-rich core compared to Earth, it has the second-highest average density in the solar system, just 1.5 percent below Earth's. Despite its proximity to the sun, the surface of Mercury was, surprisingly, found to be rich in volatile elements such as sodium and sulfur.

Notably, the planet's separation into an iron-rich core and rocky mantle (the geological region between the core and the crust) suggests Mercury had a magma ocean early in its formation. Like any liquid, this ocean would have evaporated, but in the case of Mercury, the temperatures were likely to have been so high that the vapor was not composed of water, but rock. In a new study published in The Planetary Science Journal, Noah Jäggi and colleagues modeled how the evaporation of the surface of this magma ocean would form an atmosphere and determined whether losses from the atmosphere could alter Mercury's composition, addressing an open question of why moderately volatile elements like sodium have accumulated on Mercury's surface. Their results were surprising, Jäggi, a graduate student at the University of Bern, told Phys.org.

Early planetary magma oceans aren't unusual, explained Lindy Elkins-Tanton, director of the School of Earth and Space Exploration at Arizona State University. "We think all rocky planets have one or more—maybe several—magma oceans as they form. The impacts of accretion toward the end of planet formation are just that energetic; they will melt the planets to some depth."

The early solar system was a rough and active place, full of flying rocks, massive collisions and heavy bombardments. The heat these events generated, in addition to radioactive decay and heat produced by gravitational setting of Mercury's iron-rich core, kept the planet's surface and interior molten. Models indicate these processes caused the temperature of the surface to rise to about 2,400 K (3,860 degrees Fahrenheit). Could evaporation and then atmospheric loss change the makeup of Mercury?

Jäggi and his team assumed two initial sizes for Mercury, one larger than today's, as some scientists hypothesize, and four possible magma ocean compositions. Volatile species like carbon dioxide, carbon monoxide, hydrogen (H2) and water dissolve in magma and can escape as a gas when pressure is released. Comparably nonvolatile, rock-forming elements such as silicon, sodium or iron can exist as gases such as silicon monoxide (SiO) only at the very high temperatures thought to have existed in the early magma ocean. The difference between the volatile and nonvolatile gaseous species is that, for a given temperature, volatile species have much larger equilibrium vapor pressures than do nonvolatiles. This is the pressure the atmosphere exerts at the atmosphere-magma surface when the two coexist.

The research team ran a coupled interior-atmospheric model to determine the effect of evaporation from the ocean into the atmosphere, and after accounting for atmospheric chemical and physical processes, the resulting mass loss from the atmosphere either to space or back to the planet. Meanwhile, the planet was cooling. Liquid magma begins to crystallize at 1,700 K (2,600 degrees Fahrenheit) which makes 1,500 K used by Jäggi a good approximation for the lifetime of the surface melt and sets the end point for mass loss sourced by the magma ocean of Mercury.

In both the volatile and nonvolatile case, the magma ocean evaporates to supply the atmosphere. Molecules can escape the atmosphere in one of four ways—plasma heating from the solar wind of charged particles; photoevaporation of atmospheric species from extremely high-energy solar photons such as X-rays and ultraviolet photons from the sun deep in the upper atmosphere creating an outflow of gas (also called hydrodynamic escape); Jeans escape, where especially high-altitude, high-velocity, low-mass molecules zip out the top of the atmosphere before encountering another molecular collision; and photoionization, where high-energy photons produce ions that escape via various means.

The team's model found that of the four potential escape mechanisms, Jeans escape was negligible, with the others leading to mass losses from 1 million to 4 billion kilograms per second, depending on the timing of Mercury's formation and assumptions about heating efficiencies, with the upper range coming from hydrodynamic escape—"from insignificant to predominant," said Jäggi, depending on how efficiently atmospheric species are heated and how much radiation was produced and delivered by the early sun.

But importantly, the total loss of mass from the two vastly differently atmospheres tested—volatile and nonvolatile—were found to be quite similar. Given the mass loss, the model's resulting timescale for efficient interior-atmosphere chemical exchange was less than 10,000 years, implying atmospheric escape processes only account for about 0.3 percent of Mercury's initial mass, or less than 2.3 kilometers of crust. (Mercury's present-day radius is 2,440 km.)

So cumulative mass loss seems not to have significantly modified Mercury's bulk mantle composition during the magma ocean stage. Thus, the cooling times, which depend on the greenhouse effect induced, determined how much material is lost over the lifespan of the magma ocean.

The insignificance of the total atmospheric mass loss from Mercury, hydrodynamic escape aside, was surprising, Jäggi said. "It tells us that there must be more to the high sodium measurements on Mercury's surface, as they cannot be accumulated nor lost in any significant amount given our modeled loss rates and magma ocean lifetimes." The results could be extended to the moon, an exoplanet or Earth-like planet that begins in a hot magma phase "with a volatile budget delivered by its building blocks."New research explains Earth's peculiar chemical composition

More information: Noah Jäggi et al, Evolution of Mercury's Earliest Atmosphere, The Planetary Science Journal (2021). DOI: 10.3847/PSJ/ac2dfb

Journal information: The Planetary Science Journal 

© 2021 Science X Network

The largest-ever flying animal behaved like a giant heron

by James Ashworth, Natural History Museum

Quetzalcoatlus northropi had a wingspan of around 11 metres, which meant it had to jump 

into the air to take off. Credit: James Kuether

The largest-ever flying animal acted like a giant heron, plucking prey from the water and launching itself into the air.

Quetzalcoatlus northropi was a pterosaur which ruled the skies for millions of years, alongside a newly discovered relative.

Some of the secrets of the largest animal to have ever taken to the air have been revealed, acting like a heron on the ground and a condor in the skies.

With the wingspan of a small airplane, Quetzalcoatlus northropi was a pterosaur living in the wetlands of what is now Texas, U.S. over 67 million years ago. Researchers have found that its 11-meter-long wings meant it would have had to jump up to 2.5 meters into the air, followed by powerful flaps to pull it into the sky.

The scientists also described a smaller relative, Quetzalcoatlus lawsoni, for the first time, which would have had a shorter wingspan, at around the length of a car. Together, these pterosaurs would have fed on a range of fish and small aquatic prey.

The co-editor of a series of recently published papers on the animals, Professor Brian Padian, says, "These ancient flying reptile are legendary, although most of the public conception of the animal is artistic, not scientific.

"This is the first real look at the entirety of the largest animal ever to fly, as far as we know. The results are revolutionary for the study of pterosaurs—the first animals, after insects, ever to evolve powered flight."

The papers were published together as a "memoir" in the Journal of Vertebrate Paleontology.

Quetzalcoatlus northropi was discovered in Big Bend National Park in Texas in the 1970s. 

Credit: Zack Frank/Shutterstock

The Texan titan

The largest ever pterosaur, Quetzalcoatlus northropi, was named in 1975 following the discovery of hundreds of bones in Big Bend National Park. The species was described from the large bones of the left wing, but many smaller bones were also found in other areas of the park in different layers of rock.

When these fossils were discovered, it was uncertain whether the smaller bones were simply young Q. northropi, or were from a different related species. In the end, scientists decided that they were probably a new species of Quetzalcoatlus, but did not carry out any further analysis to find an exact species.

Decades later, scientists have finally analyzed these smaller bones and found that they have a number of differences from the larger Q. northropi. These include changes in its skull structure and spine, suggesting that two other species of pterosaur were living side-by-side with the giant.

The majority of the finds are Quetzalcoatlus lawsoni, named in honor of Douglas Lawson, who first discovered the remains. As opposed to its larger relative, this species had a wingspan of around 4.5 meters long and was found in rocks dated to around 69 million years ago.

From around the same period researchers also found a few bones of a third species of pterosaur called Wellnhopterus brevirostris, which had a wingspan of three meters.

There is the potential for further species to be found at the site, but these will require further finds as the current unclassified bones lack the necessary detail to determine what they are.

The sky's the limit

By classifying the different bones by species, and investigating their unique features, the researchers were also able to find out how the different Quetzalcoatlus species would have behaved.

The researchers first turned to the 'chopstick-like' beak, and found it was probably too delicate to have eaten meat or scavenged from carcasses. Instead, they suggest the animals probably acted like a large heron, plucking fish, invertebrates, small amphibians and reptiles out of the water and gulping them down whole.

Unlike some previous studies which suggested Quetzalcoatlus would be unable to fly, researchers found that the species would have been very capable by using a jumping start. The scientists argue the size of its wings would have prevented it using a running start as they would have hit the ground.

"If they could jump twice their hip height, to eight feet, the wings would be able to clear the ground and they could execute a deeper flight stroke," Brian says. "This may be the best option for taking off, though it depends on sufficient power from the legs."

Once in the air, Quetzalcoatlus would have soared like modern condors and vultures, with suggestions its large head may have helped it to complete turns. Though historic drawings have compared pterosaurs to bats, the wings would have only been attached to the front limbs like those of a bird.

When it came to landing it would have acted like an airplane, slowing until it is about to fall out of the sky before touching down.

"The animal had to flap its wings to stall and slow its descent before it lands with its back feet and takes a little hop," Brian explains. "Then it puts down its front feet, assumes a four-legged posture, straightens itself out and walks away."

This four-legged posture saw Quetzalcoatlus walk in a way unlike any animal alive today. While vampire bats also use their wings to help them move forward, the bone structure of the pterosaur would have prevented this.

"To avoid tripping, the animal first raised its left arm, then advanced its left leg in a full step, then it placed the hand on the ground," Brian explains. "The process was then repeated with the right limb. It seems a cumbersome process to us, but the animal could execute the gait quickly and easily."

This suggestion ties in with fossilized tracks found in France, which are too oddly shaped for any terrestrial quadruped to have made them.

The researchers now hope to discover more about Quetzalcoatlus, such as the shape of its wing membranes and how they would have affected its flight.

While pterosaurs ruled the skies for millions of years, in the end it was another flying object that brought their time to an end. When the meteor which brought an end to the dinosaurs struck in Mexico 66 million years ago, it also spelled the end for their flying relatives.

Fleshing out the bones of Quetzalcoatlus, Earth's largest flier ever

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More information: Matthew A. Brown et al, Preface, Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2020.1853560

Matthew A. Brown et al, The discovery, local distribution, and curation of the giant azhdarchid pterosaurs from Big Bend National Park, Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2020.1780599

Brian Andres, Phylogenetic systematics of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea), Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2020.1801703

Brian Andres et al, Morphology and taxonomy of Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea), Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2021.1907587#_i8

Thomas M. Lehman, Habitat of the giant pterosaur Quetzalcoatlus Lawson 1975 (Pterodactyloidea: Azhdarchoidea): a paleoenvironmental reconstruction of the Javelina Formation (Upper Cretaceous) Big Bend National Park, Texas, Journal of Vertebrate Paleontology (2021). DOI: 10.1080/02724634.2019.1593184

Mark P. Witton et al, On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness, PLoS ONE (2010). DOI: 10.1371/journal.pone.0013982

Nicholas R. Longrich et al, Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary, PLOS Biology (2018). DOI: 10.1371/journal.pbio.2001663

Journal information: Journal of Vertebrate Paleontology , PLoS Biology , PLoS ONE 

Provided by Natural History Museum 

Sea level fall led to the decline of pre-Columbian societies 2,000 years ago

by Autonomous University of Barcelona

Sambaquis of Figueirinha, in southern Brazil. Credit: Joannis77

Sea level changes caused the decline of one of the longest pre-Columbian coastal societies of the Americas 2,000 years ago, known as Sambaqui. This is demonstrated in a study carried out in Brazil by researchers from the Institute of Environmental Science and Technology (ICTA-UAB) and the Department of Prehistory of the Universitat Autònoma de Barcelona, recently published in the journal Scientific Reports.

The study, funded by the European project ERC-CoG TRADITION, assessed the stable isotope composition of over 300 human individuals and more than 400 radiocarbon dates from archaeological sites on the southern Brazilian coast. Most of the sites are collective cemeteries built by fishing communities that flourished in the region between 7,000 and 1,000 years ago. Thousands of sites have already been recorded by archaeologists, who usually find hundreds of human burials, carefully deposited among enormous quantities of fish and shellfish that were consumed and used as grave goods in funerary rituals.

The researchers found a sharp decline in the frequency of archaeological sites from ca. 2,200 years ago, which coincided with a major reorganization of coastal environments in response to a fall in the relative sea level. According to Alice Toso, ICTA-UAB researcher and lead author of the study, "sea level change around 2,000 years ago possibly caused a turning point in the carrying capacity of coastal environments that for thousands of years had sustained large indigenous communities along the southern coast of Brazil. The shrinking of coastal ecosystems such as bays and lagoons caused aquatic resources to be less abundant and less predictable, forcing groups to disperse into smaller social units."

André Colonese, ICTA-UAB researcher and senior author of the paper, said, "The radiocarbon density distribution of these sites suggests the human population declined along Brazil's Atlantic Forest coast around 2,000 years ago. Interestingly, instead of abandoning fishing due to less predictable resource distribution, the remaining populations intensified fishing, exploiting in particular species of high trophic level, including sharks and rays. We believe that a fundamental shift in subsistence practices occurred at that time, from community-based (large sharing) to family-based (limited sharing) fishing." The study thus reveals that millennial-scale resilient coastal societies are vulnerable to the societal and economic impacts of environmental thresholds.

Diet of pre-Columbian societies in the Brazilian Amazon reconstructed

More information: Alice Toso et al, Fishing intensification as response to Late Holocene socio-ecological instability in southeastern South America, Scientific Reports (2021). DOI: 10.1038/s41598-021-02888-7

Journal information: Scientific Reports 

Provided by Autonomous University of Barcelona 

Humans reached remote North Atlantic islands centuries earlier than thought

by Earth Institute at Columbia University

The bed of this lake on the island of Eysturoy contains a sediment layer laid down around 

500 AD that documents the first arrival of sheep, and thus humans, on the archipelago. 

Credit: Raymond Bradley/UMass Amherst

New evidence from the bottom of a lake in the remote North Atlantic Faroe Islands indicates that an unknown band of humans settled there around 500 AD—some 350 years before the Vikings, who up until recently have been thought to have been the first human inhabitants. The settlers may have been Celts who crossed rough, unexplored seas from what are now Scotland or Ireland. The findings appear today in the journal Communications Earth & Environment.

The Faroes are a small, rugged archipelago about midway between Norway and Iceland, some 200 miles northwest of Scotland. Towering cliffs dominate the coasts; buffeted by strong winds and cloudy weather, the rocky landscape is mostly tundra. There is no evidence that indigenous people ever lived there, making it one of the planet's few lands that remained uninhabited until historical times. Past archaeological excavations have indicated that seafaring Vikings first reached them around 850 AD, soon after they developed long-distance sailing technology. The settlement may have formed a stepping stone for the Viking settlement of Iceland in 874, and their short-lived colonization of Greenland, around 980.

The new study, led by scientists at Columbia University's Lamont-Doherty Earth Observatory, is based on lake sediments containing signs that domestic sheep suddenly appeared around 500, well before the Norse occupation. Previously, the islands did not host any mammals, domestic or otherwise; the sheep could have arrived only with people. The study is not the first to assert that someone else got there first, but the researchers say it clinches the case.

In the 1980s, researchers determined that plantago lanceolata, a weed commonly associated with disturbed areas and pastures and often used as an indicator of early human presence in Europe, showed up in the Faroes around 2200 B.C. At the time, this was deemed possible evidence of human arrival. However, seeds could have arrived on the wind, and the plant does not need human presence to establish itself. Likewise, studies of pollen taken from lake beds and bogs show that some time before the Norse period, woody vegetation largely disappeared—possibly due to persistent chewing by sheep, but also possibly due to natural climatic changes.

Faroese sheep have been a staple of the culture for centuries, and are found nearly 

everywhere on the islands. Credit: William D’Andrea/Lamont-Doherty Earth Observatory

Some Medieval texts suggest that Irish monks reached the islands by around 500. For one, St. Brendan, a famous and far-traveled early Irish navigator, was said to have set out across the Atlantic with comrades from 512 to 530, and supposedly found a land dubbed the Isle of the Blessed. Later speculations and maps say that this was the Faroes—or the far southerly Azores, or the Canary Islands—or that Brendan actually reached North America. There is no proof for any of this. Centuries later, in 825, the Irish monk and geographer Dicuil wrote that he had learned that hermits had been living in some unidentified northern islands for at least 100 years. Again, later speculations landed on on the Faroes, but there was never any proof.

The first physical evidence of early occupation came with a 2013 study in the journal Quaternary Science Reviews, which documented two patches of burnt peat containing charred barley grains found underneath the floor of a Viking longhouse on the Faroese island of Sandoy. The researchers dated the grains to somewhere between 300 and 500 years before the Norse; barley was not previously found on the island, so someone must have brought it. For many archaeologists, this constituted firm evidence of pre-Viking habitation. However, others wanted to see some kind of corroboration before declaring the case closed.

The researchers in the new study employed a non-archaeological approach. In a small vessel, they sailed out onto a lake near the village of Eiði, site of an ancient Viking locale on the island of Eysturoy. Here, they dropped weighted open-ended tubes to the bottom to collect muck—sediments dropped year by year and built up over millennia, forming a long-term environmental record. The cores penetrated down about 9 feet, recording some 10,000 years of environmental history. The scientists had started out hoping to better understand the climate around the time of the Viking occupation, but came up with a surprise.

Starting at 51 centimeters (20 inches) down in the sediments, they found signs that large numbers of sheep had suddenly arrived, most likely some time between 492 and 512, but possibly as early as 370. The telltale signs: identifiable fragments of sheep DNA, and two distinctive types of lipids produced in sheep digestive systems—so-called fecal biomarkers. (The researchers also found bits of human DNA in the same layers, but suspect modern contamination during handling of the samples.) A layer of ash deposited from a known Icelandic volcano eruption in 877 helped them reliably date the sediment sequences below.

Researchers William D'Andrea (left) and Gregory de Wet load sediment cores taken from

 the lake bed. Credit: Nicholas Balascio/the College of William & Mary

"We see this as putting the nail in the coffin that people were there before the Vikings," said lead author Lorelei Curtin, who did the research as a grad student at Lamont-Doherty. She noted that while the Faroes look rugged and wild today, practically every square inch of vegetation has been chewed up by Faroese sheep, a staple of the Faroese diet that are found nearly everywhere.

Beyond the earlier discovery of barley grains, no one has yet found physical remains of pre-Norse people, but the researchers say this is unsurprising. The Faroes contain very few sites suitable for settlement, mainly flat areas at the heads of protected bays where the Norse would have built over earlier habitations. On the other hand, "You see the sheep DNA and the biomarkers start all at once. It's like an off-on switch," said Lamont-Doherty paleoclimatologist William D'Andrea, who co-led the study. He points out that the markers correspond well with the Irish monks' accounts. But, he said, "Those early writings are tenuous—it's all circumstantial."

So, who were these early settlers? D'Andrea and Curtin speculate that they could have been Celts, though not necessarily monks. For one, many Faroese place names derive from Celtic words, and ancient, though undated, Celtic grave markings dot the islands. Also, DNA studies of the modern Faroese show that their paternal lineages are mainly Scandinavian, while their maternal lineages are mainly Celtic. Other regions in the north Atlantic show this asymmetry—male Viking settlers are thought to have brought Celtic brides with them—but the Faroes have the highest level of maternal Celtic ancestry, suggesting an existing Celtic population that preceded the Vikings.

Kevin Edwards, an archaeologist and environment researcher at Scotland's University of Aberdeen, and coauthor of the 2013 barley-grains paper, said the new study "has produced convincing and exciting evidence from another island within the archipelago" of earlier human occupation. He added: "Is similar evidence to be found in Iceland, where similar arguments are made for a pre-Norse presence, and for which tantalizingly similar archaeological, pollen-analytical and human DNA are forthcoming?"

The other authors of the study are Nicholas Balascio of the College of William & Mary; Sabrina Shirazi and Beth Shapiro of the University of California, Santa Cruz; Gregory de Wet and Raymond Bradley of the University of Massachusetts, Amherst; and Jostein Bakke of the University of Bergen, Norway.Evidence of people on the Azores archipelago 700 years earlier than thought

More information: Lorelei Curtin, Sedimentary DNA and molecular evidence for early human occupation of the Faroe Islands, Communications Earth & Environment (2021). DOI: 10.1038/s43247-021-00318-0. www.nature.com/articles/s43247-021-00318-0

Journal information: Communications Earth & Environment , Quaternary Science Reviews 

Provided by Earth Institute at Columbia University 

Millet bread and pulse dough from Early Iron Age South India

by Seoul National University

Credit: Seoul National University

Prof. Jennifer Bates and her coworkers, Kelly Wilcox Black and Prof. Kathleen Morrison, published a new archaeobotanical article, "Millet Bread and Pulse Dough from Early Iron Age South India: Charred Food Lumps as Culinary Indicators, " in the Journal of Archaeological Science. Jennifer is a former Postdoc in the Penn Paleoecology Lab, now an Assistant Professor at Seoul National University, Kelly is a Ph.D. student at the University of Chicago, completing her dissertation. Kathleen is a Professor at the University of Pennsylvania.\

In the paper, the authors explore charred lumps from the site of Kadebakele, in southern India, where they have excavated for several years with the support of the Archaeological Survey of India and colleagues. The site dates from around 2,300 BCE to CE 1600 or so, but these data are from the Early Iron Age, about 800 BC. Charred lumps are usually seen as not identifiable, but using high-quality imaging, they were able to show that (some of) these are charred remains of dough or batter; these would have been used to make bread-like dishes. Comparing the data with experimental studies done another lab group, they identified two kinds of food lumps, along with cattle dung lumps (likely fuel).

They found a dough made primarily from millets which matches the experimental results of "flatbreads" most closely. Millet flatbreads are still made in this region. There was also a batter made primarily from pulses (beans, lentils, etc.). This highlights the great importance of pulses in the diet, something also seen in the overall botanical assemblage. As far as we know, there hasn't any previous understanding of how these foods might have been prepared, and this paper is the first glimpse at food making in South Asian prehistory.

The work contributes to our understanding of cooking, diet, and daily life in the South Indian Iron Age, a period without historical documents, and also establishes the value of a data source previously assumed to be too difficult to study on a routine basis (that is, without using SEM). Professor Bates, Ms Wilcox Black and Professor Morrison argue that work like this allows archaeologist to move beyond "taxa lists" (lists of plants and animals used—you could think of these as possible 'ingredients') to approach issues of culinary practice (combinations of ingredients as well as techniques).

Credit: Seoul National University

Archaeologists discover bread that predates agriculture by 4,000 years

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More information: Jennifer Bates et al, Millet bread and pulse dough from early Iron Age South India: Charred food lumps as culinary indicators, Journal of Archaeological Science (2021). DOI: 10.1016/j.jas.2021.105531

Journal information: Journal of Archaeological Science 

Provided by Seoul National University 

Swapping small talk with strangers for deeper dialogue offers surprising rewards

by University of Texas at Austin

Credit: Unsplash/CC0 Public Domain

People benefit from deep conversations, but we often stick to small talk with strangers because we underestimate how much they're interested in our lives, according to new research from The University of Texas at Austin.

The findings have important practical implications, especially as the pandemic wanes and people become more social again.

"We wrongly assume that other people are somewhat indifferent towards us, so we avoid more intimate conversation, thinking it would be awkward," said Amit Kumar, an assistant professor of marketing at UT Austin's McCombs School of Business and co-author of the study. "But we'd likely be happier if we dug deeper when we're interacting with others."

The findings appear in the Journal of Personality and Social Psychology.

Kumar and his colleagues, Michael Kardas of Northwestern University and Nicholas Epley of the University of Chicago, designed a series of 12 experiments with more than 1,800 total participants. The researchers asked pairs of people—mainly strangers—to discuss either relatively deep or shallow topics.

In some experiments, people received shallow or deep questions to discuss. Shallow questions included typical small-talk topics, such as, "What is the best TV show you've seen in the last month? Tell your partner about it," or "What do you think about the weather today?" Deep questions elicited more personal and intimate information, such as, "Can you describe a time you cried in front of another person?" or "If a crystal ball could tell you the truth about yourself, your life, your future or anything else, what would you want to know?" In other experiments, people generated their own deep and shallow conversation topics.

Credit: University of Texas at Austin

Before the conversations, participants predicted how awkward they thought the conversations would be, how connected they thought they would feel to their conversation partner, and how much they would enjoy the conversation. Afterward, they rated the awkwardness, connectedness and enjoyment they actually felt.

Overall, the researchers found that both deep and shallow conversations felt less awkward and led to greater feelings of connectedness and enjoyment than the participants had expected. That effect tended to be stronger for deep conversations. In one experiment, participants who had a deep conversation with one partner and a shallow conversation with another partner initially expected to prefer the shallow conversation but actually preferred the deep one.

If deep conversations are genuinely better and people in these experiments said they wanted to have deep conversations, then why aren't they having more of them? The researchers suspected it might be because people underestimate how interested strangers are in learning about their deeper thoughts and feelings. In some of the experiments, the researchers asked participants to predict how interested their conversation partner would be in the discussion, and then afterward to indicate how interested their partner actually was in the discussion. On average, people consistently underestimated how interested their partners would be in learning about them.

"People care about what we have to say, just as we care about what they have to say," Kumar said. "And these effects are quite robust. Our different experiments recruited students from around the world, online participants, and people who just happened to be at a public park. We even had older business executives at a financial services firm talking about the last time they cried in front of another person. Across all these different samples of participants, we find similar effects."

In the final experiments, the researchers examined whether having more accurate expectations about a conversation partner increased people's interest in having a deeper conversation. In one experiment, they told the participants to imagine that they would be speaking to a particularly caring and interested person, or to a particularly uncaring and uninterested one. Participants who expected they would be speaking to the caring person chose to discuss deeper questions.

In another experiment, the researchers told people about the results of the previous experiments—letting them know that most people underestimate the degree to which other people are interested in hearing about their personal and deeper thoughts. People given this information later chose to discuss deeper questions with strangers more often than people not given the information.

"In these social situations, the fear is largely in our heads—how we imagine these conversations going," Kumar said. "Reality suggests we might be better off if we opened up and dove a little deeper than we normally do."Getting beyond small talk: Study finds people enjoy deep conversations with strangers

More information: Michael Kardas et al, Overly shallow?: Miscalibrated expectations create a barrier to deeper conversation., Journal of Personality and Social Psychology (2021). DOI: 10.1037/pspa0000281

Journal information: Journal of Personality and Social Psychology 

Provided by University of Texas at Austin