PASADENA, Calif. — The forecast on Pluto is clear with less than a 1 percent chance of clouds. Images from the New Horizons spacecraft show hints of what could be a few isolated clouds scattered around the dwarf planet, the first seen in otherwise clear skies.
Seven cloud candidates appear to hug the ground in images taken shortly after the probe buzzed by the planet in July 2015. Along the line where day turns to night, several isolated bright patches appear. These are consistent with clouds forming at sunset and sunrise, said mission head Alan Stern during an October 18 news conference at a meeting of the American Astronomical Society’s Division for Planetary Sciences.
If they are clouds, they’re probably made of ethane, acetylene or hydrogen cyanide, based on what researchers have learned about Pluto’s atmosphere — though they might not be clouds, just reflective splotches on the surface, Stern said. Without stereo imaging, it’s impossible to tell how high off the ground the patches are, or whether they’re in the sky at all. Since New Horizons isn’t returning to Pluto — it’s hurtling deep into the Kuiper belt — the spacecraft won’t be able to take another look at the cloud candidates and answer these questions. That will have to wait until another spacecraft goes back to orbit Pluto, Stern said.
The Schiaparelli Mars lander, missing in action since its October 19 descent, dinged the surface of the Red Planet. A black spot framed by dark rays of debris mark the lander’s final resting place, the European Space Agency reports online October 27. Its parachute, still attached to the rear heat shield, lies about 1.4 kilometers to the south, new images from the Mars Reconnaissance Orbiter show. The front heat shield, ejected about four minutes into the descent, sits roughly 1.4 kilometers to the east of the impact site.
Radio contact with Schiaparelli was lost about 50 seconds before its planned landing. Early analysis of data from the lander indicate that the parachute was jettisoned prematurely and that the landing rockets shut off just a few seconds after igniting. Engineers with ESA’s ExoMars mission are still analyzing that data to understand what went wrong.
Below most volcanoes, Earth packs some serious deep heat. Mount St. Helens is a standout exception, suggests a new study. Cold rock lurks under this active Washington volcano.
Using data from a seismic survey (that included setting off 23 explosions around the volcano), Steven Hansen, a geophysicist at the University of New Mexico, peeked 40 kilometers under Mount St. Helens. That’s where the Juan de Fuca tectonic plate releases fluids due to intense heat and pressure as it descends beneath the North American plate. Those fluids rise and trigger melting in the rock above, fueling an arc of volcanoes that line up like lights on a runway. All except for Mount St. Helens, which stands apart about 50 kilometers to the west. Still, Hansen and colleagues expected to see a heat source under Mount St. Helens, as seen at other volcanoes. Instead, thermal modeling revealed a wedge of a rock called serpentinite that’s too cool to be a volcano’s source of heat, the researchers report November 1 in Nature Communications. “This hasn’t really been seen below any active arc volcanoes before,” Hansen says.
This odd discovery helps show what the local crust-mantle boundary looks like, but raises another burning question: Where is Mount St. Helens’ heat source? Somewhere to the east, suggests Hansen. Exactly where, or how it reaches the volcano, remains a cold case.
Editor’s Note: this article was revised on January 4, 2017, to note how the Juan de Fuca tectonic plate fuels the chain of volcanoes.
It’s a familiar sight: Your mom or grandmother picks up a document and immediately holds it out at arm’s length to make out the small letters on the page, while simultaneously reaching for her reading glasses. As people age, their ability to see things close up often fades, a condition known as presbyopia. The eye can no longer focus light on the retina, focusing it instead just behind and causing poor close-up vision.
Many have thought that presbyopia was a consequence of living in an era in which people are overburdened by tasks that require frequently focusing in the near-field of vision. But perhaps not: A new study finds that if bonobos could read, they too would need glasses as they age.
Bonobos aren’t burdened with having to read tiny newsprint or letters on a mobile phone screen, but they do perform one task that regularly requires close focus: grooming. This behavior not only removes tiny bits of dirt and ectoparasites from the animals but also promotes social relationships. Most of the time, a bonobo grooms by putting its face within 20 centimeters of its partner and picking off the offending debris with its fingers. But older bonobos place their partner at arm’s length, probably because they can no longer see close up, researchers report November 7 in Current Biology.
For more than 40 years, researchers from Japan’s Kyoto University have studied wild bonobos in the Luo Scientific Reserve near a village called Wamba. Some researchers had noticed that older bonobos groomed differently than young ones, keeping their companions at arm’s length. Then in 2015, Heunglin Ryu of Kyoto University and colleagues decided to try to quantify this. Was it all older bonobos, or just some? They photographed 14 bonobos as they groomed, using the bonobos’ ear length and a ruler to determine grooming distance. Then they plotted out their data.
Grooming distance increased exponentially after a bonobo hit age 35, with the oldest bonobos, at age 45, keeping their partners around five times as far away as did young bonobos. A video of one bonobo taken in 2009 showed how her vision changed. When Ki was 29 years old, she placed his face 11.9 centimeters from her fingers as she plucked away at her partner. But at age 35, that had increased to 16.9 centimeters.
Scientists had reported anecdotes of older female chimpanzees (male chimps generally do not reach old age) that developed presbyopia. The bonobo finding combined with our own bad eyesight may indicate that presbyopia is a condition that dates to at least our most recent common ancestor.
As in humans, bad eyesight may come with a price for older bonobos. People who are farsighted often have trouble seeing in the dark. If that is also true for bonobos, they may have difficulty seeing in the low light of the rainforest canopy. Plus, if they are not able to groom others well, that may affect their social lives. Maybe they would benefit from reading glasses.
Global emissions of carbon dioxide won’t increase much in 2016 despite overall economic growth, newly released bookkeeping suggests. The result marks a three-year-long plateau in the amount of CO2 released by human activities, scientists from the Global Carbon Project report November 14 in Earth System Science Data.
The group’s projected rise in CO2 emissions of 0.2 percent for 2016 is far lower than the rapid emissions growth of around 2.3 percent annually on average from 2004 through 2013. Emissions increased by about 0.7 percent in 2014 over the previous year and remained largely flat in 2015.
China is largely responsible for the emissions slowdown, the researchers write. The country is the world’s largest carbon dioxide emitter and is projected to reduce its CO2 emissions by 0.5 percent this year.
SAN ANTONIO — The world’s earliest alphabet, inscribed on stone slabs at several Egyptian sites, was an early form of Hebrew, a controversial new analysis concludes.
Israelites living in Egypt transformed that civilization’s hieroglyphics into Hebrew 1.0 more than 3,800 years ago, at a time when the Old Testament describes Jews living in Egypt, says archaeologist and epigrapher Douglas Petrovich of Wilfrid Laurier University in Waterloo, Canada. Hebrew speakers seeking a way to communicate in writing with other Egyptian Jews simplified the pharaohs’ complex hieroglyphic writing system into 22 alphabetic letters, Petrovich proposed on November 17 at the annual meeting of the American Schools of Oriental Research. “There is a connection between ancient Egyptian texts and preserved alphabets,” Petrovich said.
That’s a highly controversial contention among scholars of the Bible and ancient civilizations. Many argue, despite what’s recounted in the Old Testament, that Israelites did not live in Egypt as long ago as proposed by Petrovich. Biblical dates for the Israelites’ stay in Egypt are unreliable, they say. Scholars have also generally assumed for more than 150 years that the oldest alphabetic script Petrovich studied could be based on any of a group of ancient Semitic languages. But not enough is known about those tongues to specify one language in particular. Petrovich’s Hebrew identification for the ancient inscriptions is starved for evidence, said biblical scholar and Semitic language specialist Christopher Rollston of George Washington University in Washington, D.C. There is no way to tell which of many Semitic languages are represented by the early alphabetic system, Rollston contended.
The origins of writing in different parts of the world — including that of the alphabet carved into the Egyptian slabs — have long stimulated scholarly debates (SN: 3/6/93, p. 152). A German scholar identified the ancient Egyptian writing as Hebrew in the 1920s. But he failed to identify many letters in the alphabet, leading to implausible translations that were rejected by researchers.
Petrovich says his big break came in January 2012. While conducting research at the Egyptian Museum in Cairo, he came across the word “Hebrews” in a text from 1874 B.C. that includes the earliest known alphabetic letter. According to the Old Testament, Israelites spent 434 years in Egypt, from 1876 B.C. to 1442 B.C. Petrovich then combined previous identifications of some letters in the ancient alphabet with his own identifications of disputed letters to peg the script as Hebrew. Armed with the entire fledgling alphabet, he translated 18 Hebrew inscriptions from three Egyptian sites.
Several biblical figures turn up in the translated inscriptions, including Joseph, who was sold into slavery by his half-brothers and then became a powerful political figure in Egypt, Joseph’s wife Asenath and Joseph’s son Manasseh, a leading figure in a turquoise-mining business that involved yearly trips to Egypt’s Sinai Peninsula. Moses, who led the Israelites out of Egypt, is also mentioned, Petrovich says.
One inscription, dated to 1834 B.C., translates as “Wine is more abundant than the daylight, than the baker, than a nobleman.” This statement probably meant that, at that time or shortly before, drink was plentiful, but food was scarce, Petrovich suspects. Israelites, including Joseph and his family, likely moved to Egypt during a time of famine, when Egyptians were building silos to store food, he suggests.
A book by Petrovich detailing his analyses of the ancient inscriptions will be published within the next few months. Petrovich says the book definitively shows that only an early version of Hebrew can make sense of the Egyptian inscriptions.
SAN ANTONIO — A roughly 3,000-year-old cemetery on Israel’s coast is providing an unprecedented look at burial practices of the Philistines, a mysterious population known from the Old Testament for having battled the Israelites.
Work at the Ashkelon cemetery from 2013 to 2016 has uncovered remains of at least 227 individuals, ranging from infants to older adults. Only a small section of the cemetery has been explored. Archaeologist and excavation director Adam Aja of the Harvard Semitic Museum estimates that approximately 1,200 people were interred there over a span of about 100 years. “For the first time, we have found a formal Philistine cemetery,” Aja said November 18 at the annual meeting of the American Schools of Oriental Research. Aja and his colleagues first announced having found the Philistine graveyard on July 10. He was among several researchers to present their latest findings about the cemetery at the meeting.
Despite the new discoveries, the geographic origins of the Philistines remain unknown, Aja said. It’s also unclear how early Philistines reached the Middle East or how much their culture changed by the time they started burying their dead at Ashkelon.
Philistine burial practices have been discussed and debated for about a century. Other ancient Philistine sites in Israel, also identified in ancient texts, have yielded individual graves and small-scale burial grounds.
At Ashkelon, the dead were interred in several ways. Most individuals were placed in shallow pits, often with pairs of jugs or storage containers near the bodies. Some pits contained a person’s remains that had been buried on top of one or more previously interred bodies. Bronze earrings, bracelets, rings and other jewelry adorn most skeletons of children and women. Several pit graves of male skeletons include ornamental beads or engraved stones.
One grave holds a set of iron arrows near a man’s hip. A quiver probably once held the arrows at the man’s side, Aja suggested. Researchers also uncovered ashes and bone fragments from six human cremations in sealed jars placed in pit graves.
At least eight stone burial chambers capped with stone slabs were also found. The largest chamber held skeletons of 23 individuals. These burial chambers were aligned in three rows that ran parallel to the coast, Aja said.
Tapered storage jars found in pit graves and burial chambers were influenced by pottery of the Canaanites, a nearby population along the Mediterranean coast, said team member Janling Fu of Harvard University.
Fu suspects the excavation is located at the cemetery’s edge. Considerable space between some burials suggests denser clusters of grave sites lie nearby, he proposed, raising the prospect of learning much more about how the Philistines treated their dead.
Although the excavation is in its early stages, it’s clear that Philistines buried at Ashkelon show signs of physiological stress, reported bioarchaeologist and team member Sherry Fox of Eastern Michigan University in Ypsilanti. Many individuals’ teeth have signs of growth interruptions caused by fever, malnutrition or a range of possible biological disorders, she said.
Relatively short average heights for people buried at Ashkelon — about 5 feet, 1 inch for men and 4 feet, 10 inches for women — also fit a scenario of biological stress, Fox said. Short stature and minimal height differences between men and women occur with population-wide stresses such as malnutrition, she said.
The Philistines were a famously combative crowd. Archaeologist Eric Meyers of Duke University, who was not a member of the Ashkelon team, wondered if at least some of those buried at Ashkelon had been killed in battles or fights. But no head injuries or other skeletal signs of violent encounters appeared among the dead at Ashkelon, Fox said. Neither did any skeletons contain evidence of tumors or cancers.
If DNA can be extracted from the Ashkelon skeletons, scientists may get a glimpse of where the Philistines originally came from. Evolutionary geneticist Johannes Krause of the Max Planck Institute for the Science of Human History in Jena, Germany, is currently directing efforts to retrieve genetic sequences from the Ashkelon bones.
Our grasp of food allergy science is as jumbled as a can of mixed nuts. While there are tantalizing clues on how food allergies emerge and might be prevented, misconceptions are plentiful and broad conclusions are lacking, concludes a new report by the National Academies of Sciences, Engineering and Medicine.
As a result, both the general public and medical community are confused and ill-informed about food allergies and what to do about them. Most prevention strategies and many tests used to diagnose a food allergy aren’t supported by scientific evidence and should be abandoned, the 562-page report concludes. “We are much more in the dark than we thought,” says Virginia Stallings, a coeditor of the new report, released November 30.
While solid data are hard to come by, the report notes, estimates suggest that 12 million to 15 million Americans suffer from food allergies. Common culprits include peanuts, milk, eggs, fish, shellfish, sesame, wheat and soy.
Food allergies should be distinguished from food intolerances; the two are often confused by the public and practitioners, says Stallings, a pediatrician and research director of the nutrition center at the Children’s Hospital of Philadelphia. Strictly defined food allergies, the primary focus of the report, arise from a specific immune response to even a small amount of the allergen; they produce effects such as hives, swelling, vomiting, diarrhea and, most crucially, anaphylaxis, a severe, potentially deadly allergic reaction. These effects reliably occur within two hours after every time a person ingests that food. Allergic reactions that fall outside this strict definition and food-related intolerances, such as a gastrointestinal distress after ingesting lactose, are a legitimate public health concern. But the mechanisms behind them are probably very different than the more strictly defined food allergies, as are the outcomes, says Stallings.
Anyone suspecting a food allergy should see a specialist. If medical history and preliminary results hint at problems, then the gold standard diagnostic test should be applied: the oral food challenge. This test exposes an individual to small amounts of the potentially offending food while under supervision. Doctors and others in health care should abandon many unproven tests, such as ones that analyze gastric juices or measure skin’s electrical resistance, the report concludes.
Regarding prevention, research has borne a little fruit: The authors recommend that parents should give infants foods that contain potential allergens. This recommendation is largely based on peanut allergy research suggesting early exposure is better than late (SN: 3/21/2015, p. 15). There’s little to no evidence supporting virtually all other behaviors thought to prevent food allergies, such as taking vitamin D supplements, or women avoiding allergens while pregnant or breastfeeding. While additional rigorous long-term studies are needed to better understand why food allergies arise, the report addresses many issues that society can confront in the meantime. Industry needs to develop a low-dose (0.075 milligrams) epinephrine injector to treat infants who experience food allergy anaphylaxis; the U.S. Food and Drug Administration, Department of Agriculture and the food manufacturing industry need to revamp food labeling so it reflects allergy risks; and relevant agencies should establish consistent guidelines for schools and airplanes that include first-aid training and on-site epinephrine supplies.
“This report is mammoth and very impressive,” says Anita Kozyrskyj, whose research focuses on the infant gut microbiome. Kozyrskyj, of the University of Alberta in Canada, presented research to the reports’ authors while they were gathering evidence. She says the report identifies issues that can help guide the research community. But its real value is in the recommendations for parents, schools, caregivers and health care providers who are dealing with food allergies in the here and now.
The first normally solitary spider to win Dad of the Year sets up housekeeping in a web above his offspring and often ends up as their sole defender and single parent.
Moms handle most parental care known in spiders, says Rafael Rios Moura at the Federal University of Uberlândia in Brazil. But either or both parents care for egg sacs and spiderlings in the small Manogea porracea species he and colleagues studied in a eucalyptus plantation. The dad builds a dome-shaped web above the mom’s web, and either parent will fight hungry invaders looking for baby-spider lunch. In webs with no parents, only about four spiderlings survived per egg sac. But with dad, mom or both on duty, survival more than doubled, the researchers report in the January 2017 Animal Behaviour. “To the best of my knowledge, there really aren’t other examples where male spiders step up to care for young or eggs,” says Linda Rayor of Cornell University, who has studied spider maternal care. In a group-living Stegodyphus species, some of the males in a communal web will attack intruders, but Manogea dads do much more. They switch from solitary life to a dad-web upstairs, brush rainwater off egg sacs and share defense, sometimes at the cost of their own lives. Many male web-building spiders stop feeding as adults because they’re out searching for mates instead of catching food with their web, Moura says. Manogea males, however, stick with a female they mated with and build a new food-catching web. Now Moura would like to know whether such commitment makes males unusually choosy about females, he says.
To predators, females “must be very delicious,” Moura says. In the wild he found that many females disappeared, probably eaten, by the end of the breeding season, leaving dads as the sole protector for 68 percent of the egg sacs.
That high female mortality could have been important for evolution of the dads’ care-taking, says behavioral ecologist Eric Yip of Penn State. Just why this species has such high female mortality puzzles him, though. Females, geared up for egg-laying, have rich nutrient stores. Yet, he says, “that’s generally true for all spiders — that females are going to be more nutritious and males are going to be mostly legs.”
To create a heavy black hole, it might help to start with a massive magnetic star.
Strong magnetic fields could help stem the flow of gas from a heavyweight star, leaving behind enough material to form hefty black holes, a new study suggests. A pair of such magnetic stars could be responsible for giving birth to the black hole duo that created recently detected gravitational waves, researchers report online December 1 in Monthly Notices of the Royal Astronomical Society. The shake-up in spacetime that was picked up the Advanced Laser Interferometric Gravitational-Wave Observatory, or LIGO, in 2015 came from a collision between two black holes weighing about 29 and 36 times the mass of the sun (SN: 3/5/16, p. 6). Such plump black holes were surprising. The creation of a big black hole requires the explosive death of a gargantuan star. But weighty stars are so bright that the light blows gas into space.
“These massive stars can lose up to half their mass to their dense stellar winds,” says study coauthor Véronique Petit, an astrophysicist at Florida Institute of Technology in Melbourne. That leaves only enough mass to make a more modest black hole.
Having a paucity of elements heavier than helium is one way a massive star might retain gas. Atoms such as carbon, oxygen and iron present large targets to the radiation streaming from a star. Photons nudge these atoms along, generating strong stellar winds. A lack of heavy elements could keep these winds in check.
Petit and colleagues have proposed another idea: intense magnetic fields that might redirect escaping gas back onto the star. Observations in recent years have led to the discovery that about 10 percent of stellar heavyweights have powerful magnetic fields, some exceeding 10,000 gauss (the sun’s magnetic field is, on average, closer to 1 gauss).
Computer simulations allowed researchers to see how much mass a star could retain if it were blanketed by magnetic fields. Magnetism is an effective levee, they found. A magnetic star that starts off with 80 times as much mass as the sun, for example, ends its life about 20 suns heavier than a similarly massive one that’s not magnetic. “This is an interesting alternative hypothesis for how stars can end up holding onto more of their mass, so they can form such heavy black holes,” says Vicky Kalogera, an astrophysicist at Northwestern University in Evanston, Ill. But, she cautions, “the mechanism is somewhat speculative.” Astronomers don’t have a good handle yet on how magnetic fields change as a star evolves, she says, particularly as the star approaches the end of its life.
“It’s going to be hard to test our hypothesis,” Petit says. Pinpointing the host galaxy of a future collision between obese black holes might help, but that’s fraught with ambiguity. If the galaxy is rich in heavy elements, then perhaps magnetic fields are needed to hold back the flow of gas from gigantic stars. But that doesn’t mean the black holes were born in that environment. They could also have formed early in the universe, says Petit, when their galaxy had fewer heavy elements, in which case magnetic fields might not be necessary.
