In 2014, plant biologists with the California Department of Agriculture reported an alarming discovery: native wildflowers and herbs, grown in nurseries and then planted in ecological restoration sites around California, were infected with Phytophthora tentaculata, a deadly exotic plant pathogen that causes root and stem rot. While ecologists have long been wary of exotic plant pathogens borne on imported ornamental plants, this was the first time in California that these microorganisms had been found in native plants used in restoration efforts. Their presence in restoration sites raised the frightening possibility that ecological restoration, rather than returning disturbed sites to their natural beauty, may actually be introducing deadly plant pathogens, such as those related to Sudden Oak Death, into the wild. New work by a UC Berkeley team in the College of Natural Resources shows for the first time just how widespread and deadly the threat of pathogens from restoration nurseries may be. The team surveyed five native plant nurseries in Northern California and found that four harbored exotic, or non-native, Phytophthora pathogens. Strains of the pathogens from native plant nurseries were shown to be at times more aggressive than strains found in the wild, and some of them are rapidly developing resistance to the fungicides that can be used to control them, the researchers found. Working with restoration nurseries around the state, the researchers showed that new management techniques, coupled with new methods for detecting pathogens, can help these nurseries limit the spread of exotic pathogens. "Some of these restoration projects cost tens of millions of dollars, but of course their actual value is much higher, because of the wealth of services healthy natural ecosystems provide, including supporting animal and plant biodiversity, providing good water and air quality, and enjoyable recreation sites," said Matteo Garbelotto, cooperative extension specialist and adjunct professor of environmental science, policy and management at UC Berkeley. Is habitat restoration actually killing plants in the California wildlands? Sudden Oak Death is causing extensive tanoak and oak mortality in the Big Sur region. Credit: Matteo Garbelotto, U.C. Berkeley "Such services are highly diminished in ecosystems affected by exotic plant diseases, while water runoff and erosion, the establishment of exotic plants and animals, and even hotter wildfires may increase in conjunction with disease outbreaks in natural ecosystems," Garbelotto said. Pathogens evolve to outwit fungicides Bacteria that make humans sick are constantly evolving to resist the antibiotics designed to fight them, and resistance to fungicides has been documented in microbes causing diseases in agricultural plants. Garbelotto and his team wanted to know if the widespread use of fungicides in in native and ornamental plant nurseries could also accelerate the development of fungicide-resistance in plant pathogens. Their research was spurred in part by their discovery of a new strain of the Sudden Oak Death pathogen in Oregon forests that is highly tolerant of a fungicide commonly known as phosphite, one of the main weapons used against plant parasites in the wild because its application does not cause any known negative environmental side effects. Together with a group of New Zealand researchers, they decided to study fungicide resistance of Phytophthora—a genus of plant pathogens that can case lethal cankers and root rot—to two important fungicides, including phosphite. The researchers gathered numerous samples of Phytophthora from 11 species present both in forests and plant nurseries. They then tested the sensitivity to phosphite of multiple individuals per species. Is habitat restoration actually killing plants in the California wildlands? These Petri dishes show colonies of two strains of the exotic pathogen Phytophthora ramorum, the parasite behind Sudden Oak Death, on a growth medium that contains a phosphite fungicide. The EU1 strain of P. ramorum (left) is …more While most of the species tested were overall still sensitive to phosphite, strains of four species were able to resist the effects of the chemical, the researchers report in PLOS ONE. These include Phytophthora ramorum, the parasite behind Sudden Oak Death in North America and Sudden Larch Death in Europe, and Phytophthora crassamura, a species first discovered recently by the same UC Berkeley researchers in native plant nurseries and restoration sites in California. Some strains within each of these four species, although genetically almost identical to strains still susceptible to phosphite, were resistant to it. The presence of chemical tolerance or chemical sensitivity when comparing nearly genetically identical strains suggests that the development of resistance occurred relatively recently, perhaps in response to the widespread use of phosphites in native and ornamental nurseries, Garbelotto said. "These pathogens can be literally flooded with these chemicals in plant production facilities, and at the beginning of the study, we hypothesized that in such predicaments these pathogens would be forced to evolve resistance" Garbelotto said. "Indeed, our hypothesis was correct, and we found that some of them evolved the ability to tolerate exposure to phosphite." While phosphite can still help to spur a plant's immune system, this may not be enough to quell the spread of the disease, Garbelotto said. "By pressuring these pathogens to evolve resistance to phosphites, we are effectively taking out phosphite as a potential tool to manage these disease outbreaks," Garbelotto said. "Furthermore, the ability to quickly develop tolerance to a fungicide may be an indication these pathogens can adapt quickly to new environments. Thus, they may become formidable invasive organisms, infesting larger swaths of natural areas and causing significant disease and mortality of essential native flora." Is habitat restoration actually killing plants in the California wildlands? Sudden Oak Death caused by phosphite-sensitive strains can be controlled by preventive treatments using phosphites. At left, a small lesion in an infected tree kills the tree, while at right, treating the tree with phosphite keeps it alive. …more A widespread—but reparable—problem. Since the first discovery of Phytophthora in California restoration sites, research by the UC Berkeley team and others have traced the deaths of wild trees and plants back to strains of the pathogen originating in native plant nurseries, rather than strains already found in the wild. However, few studies have documented just how prevalent the problem is. In a recent study published in the journal Plant Pathology, UC Berkeley researchers examined 203 individual plants across five restoration nurseries in California and found that 55 of the plants were infected with Phytophthora. "We were able to prove that this is a widespread problem in California," Garbelotto said. "Most of the stock that they used is infested, and the levels were very high. For some species more than 50 percent of the plants we tested were infected." The team then worked with the infected nurseries to implement new best management practices to try to limit the spread of disease without the use of phosphite or of other fungicides. These simple guidelines, which included more careful management of water runoff and soil to reduce cross contamination, reduced the prevalence of disease to nearly zero a year after implementation. "We were able to prove that after a year of following the guidelines, those facilities were clear of pathogens, and other facilities that did not follow the guidelines still had the pathogens," Garbelotto said. "As a result of these findings, people are now putting a lot of money and effort into making sure that the plants are clean, by following similar guidelines and by making sure that no fungicides are used to avoid the development of resistance."

The Sahara desert is one of the harshest, most inhospitable places on the planet, covering much of North Africa in some 3.6 million square miles of rock and windswept dunes. But it wasn't always so desolate and parched. Primitive rock paintings and fossils excavated from the region suggest that the Sahara was once a relatively verdant oasis, where human settlements and a diversity of plants and animals thrived. Now researchers at MIT have analyzed dust deposited off the coast of west Africa over the last 240,000 years, and found that the Sahara, and North Africa in general, has swung between wet and dry climates every 20,000 years. They say that this climatic pendulum is mainly driven by changes to the Earth's axis as the planet orbits the sun, which in turn affect the distribution of sunlight between seasons—every 20,000 years, the Earth swings from more sunlight in summer to less, and back again. For North Africa, it is likely that, when the Earth is tilted to receive maximum summer sunlight with each orbit around the sun, this increased solar flux intensifies the region's monsoon activity, which in turn makes for a wetter, "greener" Sahara. When the planet's axis swings toward an angle that reduces the amount of incoming summer sunlight, monsoon activity weakens, producing a drier climate similar to what we see today. "Our results suggest the story of North African climate is dominantly this 20,000-year beat, going back and forth between a green and dry Sahara," says David McGee, an associate professor in MIT's Department of Earth, Atmospheric and Planetary Sciences. "We feel this is a useful time series to examine in order to understand the history of the Sahara desert and what times could have been good for humans to settle the Sahara desert and cross it to disperse out of Africa, versus times that would be inhospitable like today." McGee and his colleagues have published their results today in Science Advances. A puzzling pattern Each year, winds from the northeast sweep up hundreds of millions of tons of Saharan dust, depositing much of this sediment into the Atlantic Ocean, off the coast of West Africa. Layers of this dust, built up over hundreds of thousands of years, can serve as a geologic chronicle of North Africa's climate history: Layers thick with dust may indicate arid periods, whereas those containing less dust may signal wetter eras. Scientists have analyzed sediment cores dug up from the ocean bottom off the coast of West Africa, for clues to the Sahara's climate history. These cores contain layers of ancient sediment deposited over millions of years. Each layer can contain traces of Saharan dust as well as the remains of life forms, such as the tiny shells of plankton. Past analyses of these sediment cores have unearthed a puzzling pattern: It would appear that the Sahara shifts between wet and dry periods every 100,000 years—a geologic beat that scientists have linked to the Earth's ice age cycles, which seem to also come and go every 100,000 years. Layers with a larger fraction of dust seem to coincide with periods when the Earth is covered in ice, whereas less dusty layers appear during interglacial periods, such as today, when ice has largely receded. But McGee says this interpretation of the sediment cores chafes against climate models, which show that Saharan climate should be driven by the region's monsoon season, the strength of which is determined by the tilt of the Earth's axis and the amount of sunlight that can fuel monsoons in the summer. "We were puzzled by the fact that this 20,000-year beat of local summer insolation seems like it should be the dominant thing controlling monsoon strength, and yet in dust records you see ice age cycles of 100,000 years," McGee says. Beats in sync To get to the bottom of this contradiction, the researchers used their own techniques to analyze a sediment core obtained off the coast of West Africa by colleagues from the University of Bordeaux—which was drilled only a few kilometers from cores in which others had previously identified a 100,000-year pattern. The researchers, led by first author Charlotte Skonieczny, a former MIT postdoc and now a professor at Paris-Sud University, examined layers of sediment deposited over the last 240,000 years. They analyzed each layer for traces of dust and measured the concentrations of a rare isotope of thorium, to determine how rapidly dust was accumulating on the seafloor. Thorium is produced at a constant rate in the ocean by very small amounts of radioactive uranium dissolved in seawater, and it quickly attaches itself to sinking sediments. As a result, scientists can use the concentration of thorium in the sediments to determine how quickly dust and other sediments were accumulating on the seafloor in the past: During times of slow accumulation, thorium is more concentrated, while at times of rapid accumulation, thorium is diluted. The pattern that emerged was very different from what others had found in the same sediment cores. "What we found was that some of the peaks of dust in the cores were due to increases in dust deposition in the ocean, but other peaks were simply because of carbonate dissolution and the fact that during ice ages, in this region of the ocean, the ocean was more acidic and corrosive to calcium carbonate," McGee says. "It might look like there's more dust deposited in the ocean, when really, there isn't." Once the researchers removed this confounding effect, they found that what emerged was primarily a new "beat," in which the Sahara vacillated between wet and dry climates every 20,000 years, in sync with the region's monsoon activity and the periodic tilting of the Earth. "We can now produce a record that sees through the biases of these older records, and so doing, tells a different story," McGee says. "We've assumed that ice ages have been the key thing in making the Sahara dry versus wet. Now we show that it's primarily these cyclic changes in Earth's orbit that have driven wet versus dry periods. It seems like such an impenetrable, inhospitable landscape, and yet it's come and gone many times, and shifted between grasslands and a much wetter environment, and back to dry climates, even over the last quarter million years."

One answer to our greenhouse gas challenges may be right under our feet: Soil scientists Oliver Chadwick of UC Santa Barbara and Marc Kramer of Washington State University have found that minerals in soil can hold on to a significant amount of carbon pulled from the atmosphere. It's a mechanism that could potentially be exploited as the world tries to shift its carbon economy. "We've known for quite a long time that the carbon stored on minerals is the carbon that sticks around for a long time," said Chadwick, co-author of the paper, "Climate-driven thresholds in reactive mineral retention of soil carbon at the global scale," published in the journal Nature Climate Change. How much carbon the soil can take and how much it can keep, he said, are dependent on factors including temperature and moisture. "When plants photosynthesize, they draw carbon out of the atmosphere, then they die and their organic matter is incorporated in the soil," Chadwick explained. "Bacteria decompose that organic matter, releasing carbon that can either go right back into the atmosphere as carbon dioxide or it can get held on the surface of soil minerals." Water plays a significant role in the soil's ability to retain carbon, say the researchers. Chadwick and Kramer consulted soil profiles from the National Ecological Observatory Network (NEON) and from a globally representative archived data set for this first-ever global-scale evaluation of the role soil plays in producing dissolved organic matter and storing it on minerals. Wetter climates are more conducive to formation of minerals that are effective at storing carbon, therefore much of the Earth's estimated 600 billion metric tons of soil-bound carbon is found in the wet forests and tropical zones. Arid places, meanwhile, tend to have a "negative water balance" and can thus store far less organic carbon. According to Chadwick, the findings suggest that even a small, strategic change in the water balance could drive greater carbon storage. "That's not as easy as it sounds, because water is dear," Chadwick said, and in places where a shift in soil moisture could tip the water balance from negative to positive—like the desert—there's not enough water to begin with. "So, it doesn't actually make any sense to spread a lot of water out over the landscape because water is hugely valuable," he added. Climate change is another driver to consider. As the Earth warms, microbial activity increases and, in turn, so does the potential for carbon to be released back into the atmosphere at a greater rate than photosynthesis can draw it out. Increased evaporation due to a warmer climate also decreases the amount of water in the soil available to dissolve and move carbon to minerals deep below the surface. There is still a lot to investigate and several hurdles to overcome as soil scientists everywhere consider ways to tip the balance of the Earth's soil from carbon source to carbon sink, but according to these researchers, understanding this relatively little-known but highly significant carbon storage pathway is a start. "We know less about the soils on Earth than we do about the surface of Mars," said Kramer. "Before we can start thinking about storing carbon in the ground, we need to actually understand how it gets there and how likely it is to stick around. This finding highlights a major breakthrough in our understanding." Among the next steps for the scientists is to date the mineral-stored carbon in the soil to better understand how long these reactive (typically iron and aluminum) minerals can keep carbon out of the air. "Which is really important if we're going to put effort into trying to store carbon in the soil," Chadwick said. "Is it going to stay there long enough to matter? If we put it in and it comes out five years later, it's not solving our problem, and we ought to be barking up a different tree."

Winter snows are accumulating in the Sierra Nevada Mountains, creating the snowpacks that serve as a primary source of water for the western U.S. However, due to rising average temperatures, snowpacks in the Great Basin appear to be transitioning from seasonal, with a predictable amount and melt rate, to "ephemeral," or short-lived, which are less predictable and only last up to 60 days. Unfortunately, ephemeral snow, and the reasons for and impacts of this transition have been poorly tracked and understood. Recent research and two published papers by a former University of Nevada, Reno graduate student and her professors are shedding some light on the subject. "Small temperature changes can lead to large ecological changes," explained Hydrology Graduate Student Rose Petersky. "More intermittent snowpacks means water flow is more difficult to predict. We might not get as much water into the ground, throwing off the timing of water for plant root systems, reducing our supply and use, and even affecting businesses such as tourism." Petersky, under the guidance of Natural Resources and Environmental Science Assistant Professor Adrian Harpold in the College of Agriculture, Biotechnology and Natural Resources, was the lead author in two recently published papers analyzing the change. One reports on the causes of the ephemeral snow, and the other reports on the impact of the transition on vegetation in the Great Basin. Natural Resources and Environmental Science Assistant Professor Kevin T. Shoemaker and Professor Peter J. Weisberg also worked on the project and are coauthors. With funding through the Nevada Agricultural Experiment Station and from NASA, Petersky and the team analyzed both ground-based and satellite-based remote sensing data collected every day from 2001 to 2015. Petersky also wrote an algorithm, or computer formula, to fill in data lost due to cloud cover. To map changes, the team ran the data and algorithm through Google Earth Engine, computing many millions of computations in a few minutes. With the resulting maps, they discovered that topography can play an important role, with more snow at higher elevations and on more north-facing slopes. In the Great Basin and eastern Sierra Nevada, shifts to more ephemeral snowpacks are due primarily to more rain falling instead of snow. They show that warming is likely to increase ephemeral snowpacks, even beyond the extreme 2015 drought. Consequently, the vegetation types at the greatest risk due to more ephemeral snowpacks were quaking aspen, red fir, Gambel oak and big mountain sagebrush, which represent ecosystems across the Great Basin. "When it comes to managing natural resources, more information is better," said Harpold. "It will help us identify targets for intervention and work toward better managing the important water resource issues." The team hopes others can use their results to identify species and areas most in need of management intervention in the form of forest thinning or assisted migration. "Ultimately, this work will lead to more accurate models and reliable predictions for better water allocation and vegetation management in Nevada and beyond," Petersky concluded.

A NASA spacecraft 4 billion miles from Earth yielded its first close-up pictures Wednesday of the most distant celestial object ever explored, depicting what looks like a reddish snowman. Ultima Thule, as the small, icy object has been dubbed, was found to consist of two fused-together spheres, one of them three times bigger than the other, extending about 21 miles (33 kilometers) in length. NASA's New Horizons, the spacecraft that sent back pictures of Pluto 3½ years ago, swept past the ancient, mysterious object early on New Year's Day. It is 1 billion miles (1.6 billion kilometers) beyond Pluto. On Tuesday, based on early, fuzzy images taken the day before, scientists said Ultima Thule resembled a bowling pin. But when better, closer pictures arrived, a new consensus emerged Wednesday. "The bowling pin is gone. It's a snowman!" lead scientist Alan Stern informed the world from Johns Hopkins University's Applied Physics Laboratory , home to Mission Control in Laurel. The bowling pin image is "so 2018," joked Stern, who is with the Southwest Research Institute. The celestial body was nicknamed Ultima Thule—meaning "beyond the known world"—before scientists could say for sure whether it was one object or two. With the arrival of the photos, they are now calling the bigger sphere Ultima and the smaller one Thule. Thule is estimated to be 9 miles (14 kilometers) across, while Ultima is thought to be 12 miles (19 kilometers). NASA: Icy object past Pluto looks like reddish snowman This image made available by NASA on Wednesday, Jan. 2, 2019 shows the size and shape of the object Ultima Thule, about 1 billion miles beyond Pluto. The New Horizons spacecraft encountered it on Tuesday, Jan. 1, 2019. (NASA via AP) Scientist Jeff Moore of NASA's Ames Research Center said the two spheres formed when icy, pebble-size pieces coalesced in space billions of years ago. Then the spheres spiraled closer to each other until they gently touched—as slowly as parking a car here on Earth at just a mile or two per hour—and stuck together. Despite the slender connection point, the two lobes are "soundly bound" together, according to Moore. Scientists have ascertained that the object takes about 15 hours to make a full rotation. If it were spinning fast—say, one rotation every three or four hours—the two spheres would rip apart. Stern noted that the team has received less than 1 percent of all the data stored aboard New Horizons. It will take nearly two years to get it all. The two-lobed object is what is known as a "contact binary." It is the first contact binary NASA has ever explored. Having formed 4.5 billion years ago, when the solar system taking shape, it is also the most primitive object seen up close like this. About the size of a city, Ultima Thule has a mottled appearance and is the color of dull brick, probably because of the effects of radiation bombarding the icy surface, with brighter and darker regions. Both spheres are similar in color, while the barely perceptible neck connecting the two lobes is noticeably less red, probably because of particles falling down the steep slopes into that area. NASA: Icy object past Pluto looks like reddish snowman This image from video made available by NASA on Wednesday, Jan. 2, 2019 shows a diagram describing the size and shape of the object Ultima Thule, about 1 billion miles beyond Pluto. The New Horizons spacecraft encountered it on Tuesday, Jan. 1, 2019. (NASA via AP) So far, no moons or rings have been detected, and there were no obvious impact craters in the latest photos, though there were a few apparent "divots" and suggestions of hills and ridges, scientists said. Better images should yield definitive answers in the days and weeks ahead. Clues about the surface composition of Ultima Thule should start rolling in by Thursday. Scientists believe the icy exterior is probably a mix of water, methane and nitrogen, among other things. The snowman picture was taken a half-hour before the spacecraft's closest approach early Tuesday, from a distance of about 18,000 miles (28,000 kilometers). Scientists consider Ultima Thule an exquisite time machine that should provide clues to the origins of our solar system. It's neither a comet nor an asteroid, according to Stern, but rather "a primordial planetesimal." Unlike comets and other objects that have been altered by the sun over time, Ultima Thule is in its pure, original state: It's been in the deep-freeze Kuiper Belt on the fringes of our solar system from the beginning. "This thing was born somewhere between 99 percent and 99.9 percent of the way back to T-zero (liftoff) in our solar system, really amazing," Stern said. He added: "We've never seen anything like this before. It's not fish or fowl. It's something that's completely different." Still, he said, when all the data comes in, "there are going to be mysteries of Ultima Thule that we can't figure out."

A team of experimentalists at the U.S. Department of Energy's Ames Laboratory and theoreticians at University of Alabama Birmingham discovered a remarkably long-lived new state of matter in an iron pnictide superconductor, which reveals a laser-induced formation of collective behaviors that compete with superconductivity. "Superconductivity is a strange state of matter, in which the pairing of electrons makes them move faster," said Jigang Wang, Ames Laboratory physicist and Iowa State University professor. "One of the big problems we are trying to solve is how different states in a material compete for those electrons, and how to balance competition and cooperation to increase temperature at which a superconducting state emerges." To get a closer look, Wang and his team used laser pulses of less than a trillionth of a second in much the same way as flash photography, in order to take a series of snapshots. Called terahertz spectroscopy, this technique can be thought of as "laser strobe photography" where many quick images reveal the subtle movement of electron pairings inside the materials using long wavelength far-infrared light. "The ability to see these real time dynamics and fluctuations is a way to understanding them better, so that we can create better superconducting electronics and energy-efficient devices," said Wang.

A new treefrog species was discovered during a two-week expedition to a remote tabletop mountain at Cordillera del Cóndor, a largely unexplored range in the eastern Andes. "To reach the tabletop, we walked two days along a steep terrain. Then, between sweat and exhaustion, we arrived to the tabletop where we found a dwarf forest. The rivers had blackwater and the frogs were sitting along them, on branches of brown shrubs similar in color to the frogs' own. The frogs were difficult to find, because they blended with their background," Alex Achig, one of the field biologists who discovered the new species comments on the hardships of the expedition. Curiously, the frog has an extraordinary, enlarged claw-like structure located at the base of the thumb. Its function is unknown, but it could be that it is used either as a defence against predators or as a weapon in fights between competing males. Having conducted analyses of genetic and morphologic data, scientists Santiago R. Ron, Marcel Caminer, Andrea Varela, and Diego Almeida from the Catholic University of Ecuador concluded that the frog represented a previously unknown species. It was recently described in the open-access journal ZooKeys. Extraordinary treefrog discovered in the Andes of Ecuador Unlike other frogs, the new species has a claw at the base of the thumb. The function of this unusual structure is still unknown. Credit: Gustavo Pazmiño, BIOWEB Ecuador The species name, Hyloscirtus hillisi, honors Dr. David Hillis, a member of the National Academy of Sciences of the United States of America, who discovered three closely related frog species in the same genus in the 1980s, while conducting a series of field trips to the Andes of southern Ecuador. Throughout his career, Dr. Hillis has made significant contributions to the knowledge of Andean amphibians and reptiles. Despite being newly described, Hyloscirtus hillisi is already at risk of extinction. It has a small distribution range near a large-scale mining operation carried out by a Chinese company. Habitat destruction in the region has been recently documented by the NGO Amazon Conservation.

A Chinese lunar rover landed on the far side of the moon on Thursday, in a global first that boosts Beijing's ambitions to become a space superpower. The Chang'e-4 probe touched down and sent a photo of the so-called "dark side" of the moon to the Queqiao satellite, which will relay communications to controllers on Earth, China's national space agency said on its website. Beijing is pouring billions into its military-run space programme, with hopes of having a crewed space station by 2022, and of eventually sending humans to the moon. The Chang'e-4 lunar probe mission—named after the moon goddess in Chinese mythology—launched in December from the southwestern Xichang launch centre. It is the second Chinese probe to land on the moon, following the Yutu (Jade Rabbit) rover mission in 2013. Unlike the near side of the moon that offers many flat areas to touch down on, the far side is mountainous and rugged. The moon is "tidally locked" to Earth in its rotation so the same side is always facing Earth. Chang'e-4 is carrying six experiments from China and four from abroad, including low-frequency radio astronomical studies—aiming to take advantage of the lack of interference on the far side. The rover will also conduct mineral and radiation tests, the China National Space Administration has said, according to state news agency Xinhua. Extreme challenges It was not until 1959 that the Soviet Union captured the first images of the moon's mysterious and heavily cratered "dark side". No lander or rover has ever previously touched the surface there, and it is no easy technological feat—China has been preparing for this moment for years. A major challenge for such a mission was communicating with the robotic lander as there is no direct "line of sight" for signals to the far side of the moon. As a solution, China in May blasted the Queqiao ("Magpie Bridge") satellite into the moon's orbit, positioning it so that it can relay data and commands between the lander and Earth. In another extreme hurdle, during the lunar night—which lasts 14 Earth days—temperatures drop to as low as minus 173 degrees Celsius (minus 279 Fahrenheit). During the lunar day, also lasting 14 Earth days, temperatures soar as high as 127 C (261 F). The rover's instruments have to withstand those fluctuations and it has to generate enough energy to sustain it during the long night. Adding to the difficulties, Chang'e-4 was sent to the Aitken Basin in the lunar south pole region—known for its craggy and complex terrain—state media has said. Yutu also conquered those challenges and, after initial setbacks, ultimately surveyed the moon's surface for 31 months. Its success provided a major boost to China's space programme. Beijing is planning to send another lunar lander, Chang'e-5, later this year to collect samples and bring them back to Earth. It is among a slew of ambitious Chinese targets, which include a reusable launcher by 2021, a super-powerful rocket capable of delivering payloads heavier than those NASA and private rocket firm SpaceX can handle, a moon base, a permanently crewed space station, and a Mars rover.

Tesla made about 9,300 more vehicles than it delivered last year, raising concerns among industry analysts that inventory is growing as demand for the company's electric cars may be starting to wane. If demand falls, they say, the company will enter a new phase of its business. Like other automakers, Tesla will have to either cut production or reduce prices to raise sales. A drop in demand could also curtail the company's earnings and jeopardize CEO Elon Musk's promise to post sustained quarterly profits. On Wednesday, Tesla did cut prices, knocking $2,000 off each of its three models. The company said the cuts will help customers deal with the loss of a $7,500 federal tax credit, which was reduced to $3,750 this month for Tesla buyers and will gradually go to zero by the end of 2018. "They have for a long time had more demand than supply," Gartner analyst Michael Ramsey said. "It's becoming apparent that that dynamic is changing." Tesla reported that it produced 254,530 cars and SUVs last year and delivered 245,240. The company's deliveries for the full year matched Wall Street estimates, but its figures for the fourth quarter didn't reach expectations. Tesla said it delivered 90,700 vehicles from October through December. Analysts polled by data provider FactSet expected 92,000. Jeff Schuster, a senior vice president at the forecasting firm LMC Automotive, said demand for Tesla's lower-priced Model 3 has been artificially high for the past six months as the company overcame production problems at its Fremont, California, factory. "You've had these inflated months because of delayed deliveries," Schuster said. "We're probably getting to that point where we're getting to equilibrium and consumers aren't necessarily waiting for vehicles." Last year, Tesla reported that about 420,000 buyers had put down $1,000 deposits to join the Model 3 waiting list. Could Tesla price cuts mean demand is slowing? In this July 8, 2018, photo 2018 Model 3 sedans sit on display outside a Tesla showroom in Littleton, Colo. On Tuesday, Jan. 1, 2019, the federal credit for Tesla buyers dropped from $7,500 to $3,750. It will gradually be phased out this year. (AP Photo/David Zalubowski, File) LMC predicts that Tesla U.S. sales will rise in 2019 because it's the first full year on the market for the Model 3. It anticipates sales to then fall by about 10,000 in 2020. Losing the tax credit will hit those who have been holding out for the $35,000 version of the Model 3, Schuster said. At present, Tesla is selling only versions that cost more than $45,000. Under federal law, buyers get the full tax credit until a manufacturer reaches 200,000 in sales since the start of 2010. Tesla hit 200,000 in July but the full credit continued for vehicles delivered by Dec. 31. It was cut in half on Jan. 1 and will go away by the end of the year. "You've had your early adopters, those early followers have already come in" to buy, Schuster said. "Now you're trying to appeal to the mainstream market. I think that will have an impact on overall demand." At the same time, inventory appears to be swelling. The company parked hundreds of cars at lots and Tesla stores all over the country at the end of last year, which could indicate excess stock. Tesla wouldn't give inventory numbers but said it has lower stocks than its two biggest competitors, BMW and Mercedes. The Associated Press found one lot on the north side of Chicago where Tesla was storing dozens of vehicles in late December, and Mark Spiegel, a hedge fund manager who bets against Tesla stock, said other lots were full across the country. Tesla said it sometimes stores vehicles on lots as they're being shipped to company dealerships across the nation. The lot in Chicago has fewer cars on it today, the company said. "Our inventory levels remain the smallest in the automotive industry," the company said Wednesday. Tesla also says Model 3 sales should grow worldwide as it expands distribution and begins to offer leases. Deliveries in Europe and China will start in February, and a right-hand-drive version is coming later in the year, the company said. In addition, inventory dropped in the fourth quarter as Tesla "delivered a few thousand vehicles more than produced." Tesla said it had about 3,000 vehicles in transit to customers at year's end. But even with that number, Schuster said production still exceeded deliveries, which doesn't fit Tesla's business model of building cars when they are ordered by customers. Still, even at 9,300, Tesla's inventory is smaller than other automakers that have to stock dealerships, Schuster said.

Apple cut its revenue outlook for the latest quarter Wednesday, citing steeper-than-expected "economic deceleration" in China and emerging markets. The rare revenue warnings from Apple suggested weaker-than-anticipated sales of iPhones and other gadgetry, in part because of trade frictions between Washington and Beijing. Apple shares slid some 7.6 percent in after-hours trade on the news. The company slashed its revenue guidance for the first fiscal quarter of 2019, ended December 29, to $84 billion—sharply lower than analyst forecasts averaging $91 billion. "While we anticipated some challenges in key emerging markets, we did not foresee the magnitude of the economic deceleration, particularly in Greater China," Apple chief executive Tim Cook said in a letter to investors. "We believe the economic environment in China has been further impacted by rising trade tensions with the United States." Apple is the target of nationalist sentiment over the arrest of Huawei's chief financial officer in Canada at the behest of the United States on alleged Iran sanctions violations. Meng Wanzhou was detained in Canada on December 1 on a US extradition request linked to sanctions-breaking business dealings with Iran. The Chinese government has condemned the arrest and demanded her release. Some Chinese netizens and companies have also turned against Apple. Several companies have offered employees subsidies for Huawei phone purchases, while others have even warned staff against buying Apple products. "When the US went after the Huawei founder's daughter, the Chinese government made Apple the target of the day, so sales should be way off," independent technology analyst Rob Enderle told AFP. "This is more political than it is Apple execution." Apple CEO Tim Cook said iPhone sales are likely to be weaker than most forecasts, citing weakness in emerging market, notably Ch Apple CEO Tim Cook said iPhone sales are likely to be weaker than most forecasts, citing weakness in emerging market, notably China Nationalistic sentiment was likely intensified by Apple apparently ignoring a Chinese court-ordered ban on iPhone sales in a case involving US chipmaker Qualcomm, according to the analyst. Qualcomm, which requested the ban, said last month that the Fuzhou Intermediate People's Court ordered four Apple subsidiaries to stop selling older models of the iPhone, including the 7, 7 Plus, 8, and 8 Plus. But Apple stores contacted by AFP in Beijing, Shanghai and Fuzhou in early December said they were still selling those older models—confirming a company statement that all remain available. "It looks like Apple is flouting Chinese law, which helps promote a boycott," Endlerle said. Timing off Apple breaks down its revenues into a "Greater China" that includes the People's Republic of China as well as Taiwan. Cook said other factors will also pull down Apple's revenue, including the timing of its iPhone launches last year and a strong dollar that means lower revenues when converted to US currency. Apple also cited supply "constraints" for some products, including its latest Apple Watch and iPad Pro. The update suggested a disappointing figure for iPhone sales, the key driver of revenue and profit for the California tech giant. "While Greater China and other emerging markets accounted for the vast majority of the year-over-year iPhone revenue decline, in some developed markets, iPhone upgrades also were not as strong as we thought they would be," the statement said. "While macroeconomic challenges in some markets were a key contributor to this trend, we believe there are other factors broadly impacting our iPhone performance, including consumers adapting to a world with fewer carrier subsidies, US dollar strength-related price increases and some customers taking advantage of significantly reduced pricing for iPhone battery replacements." Apple has been seeking to diversify its revenue stream in the face of a largely saturated global smartphone market, with new products and services. Cook said there were some bright spots for Apple in some parts of the world and that the company expects "all-time revenue records in several developed countries, including the United States, Canada, Germany, Italy, Spain, the Netherlands and (South) Korea." He added that Apple was performing well in a few emerging markets and could see record revenues in Malaysia, Mexico, Poland and Vietnam.

A lawsuit filed against Google by users who said the world's largest search engine violated their privacy by using facial recognition technology was dismissed by a judge on Saturday. From a report: U.S. District Judge Edmond E. Chang in Chicago cited a lack of "concrete injuries" to the plaintiffs. The suit, initially filed in March 2016, alleged Alphabet's Google collected and stored biometric data from photographs using facial recognition software, running afoul of a unique Illinois law against using a person's image without permission.

Researchers hunting cyber-espionage group Sednit (an APT also known as Sofacy, Fancy Bear and APT28) say they have discovered the first-ever instance of a rootkit targeting the Windows Unified Extensible Firmware Interface (UEFI) in successful attacks. From a report: The discussion of Sednit was part of the 35C3 conference, and a session given by Frederic Vachon, a malware researcher at ESET who published a technical write-up on his findings earlier this fall [PDF]. During his session, Vachon said that finding a rootkit targeting a system's UEFI is significant, given that rootkit malware programs can survive on the motherboard's flash memory, giving it both persistence and stealth. "UEFI rootkits have been researched and discussed heavily in the past few years, but sparse evidence has been presented of real campaigns actively trying to compromise systems at this level," he said. The rootkit is named LoJax. The name is a nod to the underlying code, which is a modified version of Absolute Software's LoJack recovery software for laptops. The purpose of the legitimate LoJack software is to help victims of a stolen laptop be able to access their PC without tipping off the bad guys who stole it. It hides on a system's UEFI and stealthily beacons its whereabouts back to the owner for possible physical recovery of the laptop.

Add Bill Gates to the list of executives whose businesses have been ensnared by the Trump administration's battle with China over technology and trade. From a report: The tech tycoon and philanthropist said in an essay posted late last week that a nuclear-energy project in China by a company he co-founded called TerraPower LLC is now unlikely to proceed because of recent changes in U.S. policy toward China [Editor's note: the link may be paywalled; alternative source]. That leaves TerraPower, which had been working on the China project for more than three years, scrambling for a new partner and uncertain where it might be able to run a pilot of the nuclear reactor it has been developing, according to company officials. Mr. Gates, TerraPower's chairman, helped start and fund the Bellevue, Wash., company, which incorporated in 2008, in a long-term bid to make nuclear reactors smaller, less expensive and safer than current nuclear energy sources. The company has been developing something called a traveling-wave reactor, which uses depleted uranium as fuel, something that TerraPower says can improve safety and reduce costs. Regulatory restrictions and limited federal funding made building the facility in the U.S. difficult and led TerraPower to look for partners abroad, Chief Executive Chris Levesque said in an interview.

An anonymous reader writes: More than three years after its release, Windows 10 has passed Windows 7 in market share. That means more desktop computers are now running Microsoft's latest and greatest operating system than any other OS, according to Net Applications. The milestone is a nice way for Microsoft to end 2018, even though the company surely was hoping it wouldn't take this long for Windows 10 to overtake Windows 7.

An anonymous reader shares a report: An innovation at Caltech allows scientists to play a virtual "tic-tac-toe" game with individual strands of DNA, providing a new way to experiment with DNA sequencing and create custom patterns. According to ArsTechnica, the technique was dubbed "DNA Origami [paper; PDF]" by its creator Lulu Qian and is considered by Caltech fellows to be a "huge advancement" in the field of nanotechnology (manipulation of particles on a minute, atomic scale).

Glenn Fleishman, writing for MacWorld: It seems like it was only yesterday that I first used BareBones Software's BBEdit, but in actuality, yesterday is so far away -- 25 years, in fact. With all the twists and turns across more than two decades of Apple as a company, Mac hardware, and the underlying operating system, you might think that BBEdit stands alone as a continuously-developed app shepherded largely or exclusively by the same independent developer -- an app without a giant company behind it. As it turns out, BBEdit is one of several apps that's been around the block more than a few times. The longevity of indie apps is more extraordinary when you consider the changes Apple put the Mac through from the early 1990s to 2018. Apple switched from Motorola 680x0 processors to PowerPC to Intel chips, from 32-bit to 64-bit code, and among supported coding languages. It revved System 7 to 8 to 9, then to Unix across now 15 major releases (from 10.0 to 10.14). That's a lot for any individual programmer or small company to cope with. Bare Bones's head honcho, Rich Siegel, and the developers behind three other long-running Mac software programs shared with me their insight on development histories for over 25 years, what's changed the most during that time, and any hidden treasures users haven't yet found. You can hear more on BareBones Software's in this recent episode of The Talk Show, a podcast by DaringFireball's John Gruber.

Last year, Google pushed 'dark mode', a feature that replaces the shiny, whitespace background on a web page with a dark color, to its Android operating system and YouTube service. The company is now working to expand the feature to Chrome's Windows 10 application. Peter Kasting, a Chrome developer, confirmed the move in response to a user's query on a Reddit thread. He said a "native dark mode support is in progress" for Chrome's desktop application. Until then, reminded Kasting, "we generally suggest people use a dark theme" for Chrome via a third-party extension.

schwit1 shares a report: Mining corporation Rio Tinto says that an autonomous rail system called AutoHaul that it's been developing in the remote Pilbara region of Australia for several years is now entirely operational -- an accomplishment the company says makes the system the "world's largest robot." "It's been a challenging journey to automate a rail network of this size and scale in a remote location like the Pilbara," Rio Tinto's managing director Ivan Vella told the Sydney Morning Herald, "but early results indicate significant potential to improve productivity, providing increased system flexibility and reducing bottlenecks." The ore-hauling train is just one part of an ambitious automation project involving robotics and driverless vehicles that Rio Tinto wants to use to automate its mining operations. The company conducted its first test of the train without a human on board last year, and it now claims that the system has completed more than a million kilometers (620,000 miles) of autonomous travel.

NASA received a critical signal from one of its most distant spacecrafts this morning, confirming that the vehicle has just flown by a tiny frozen rock in the outer reaches of the Solar System. From a report: That space probe, named New Horizons, has now made history. Currently located more than 4 billion miles from Earth, the spacecraft has now whizzed past the most distant -- and most primitive -- object that's ever been visited by humanity. "We have a healthy spacecraft," Alice Bowman, the mission operations manager for the New Horizons mission, said after confirming the feat. "We've just accomplished the most distant flyby." "It's a flyby that's been over a decade in the making, too. Launched in 2006, New Horizons famously passed by Pluto in 2015, becoming the first mission to ever reach the dwarf planet. But ever since that flyby, New Horizons has kept on speeding through the Solar System, in order to meet up with this new object, nicknamed Ultima Thule.

A series of auctions revealed that Facebook users value the company's service so highly that it would take on average more than $1,000 to convince them to deactivate their accounts for a year, according to a recent paper published in PLOS One. From a report: This doesn't mean much for the company's stock market valuation, but it's a good indicator that people find value in Facebook regardless of the many concerns raised recently. The paper started out as two separate studies. Jay Corrigan, an economist at Kenyon College, and his collaborator, Matt Rousu of Susquehanna University, were interested in a session on this topic at an upcoming conference. They discovered that Sean Cash (Tufts University) and Saleem Alhabash (Michigan State University) were doing something very similar. Since the design of both studies was so complementary, they decided to combine their data and results into a single paper. Cash and Saleem had a larger sample for their part of the study and looked at a longer time period of one year, while Corrigan and Rosein focused on shorter time frames, asking subjects to quit Facebook for one day, three days, or seven days. The studies nonetheless had similar results.

Mark Zuckerberg and his pediatrician wife Priscilla Chan have sold close to 30 million shares of Facebook to fund an ambitious biomedical research project, called the Chan Zuckerberg Initiative (CZI), with a goal of curing all disease within a generation. A less publicized component of that US$5 billion program includes work on brain-machine interfaces, devices that essentially translate thoughts into commands. From a report: One recent project is a wireless brain implant that can record, stimulate and disrupt the movement of a monkey in real time. In a paper published in the highly cited scientific journal Nature on Monday, researchers detail a wireless brain device implanted in a primate that records, stimulates, and modifies its brain activity in real time, sensing a normal movement and stopping it immediately. Those researchers are part of the Chan Zuckerberg Biohub, a non-profit medical research group within the CZI. Scientists refer to the interference as "therapy" because it is designed to be used to treat diseases like epilepsy or Parkinson's by stopping a seizure or other disruptive motion just as it starts. "Our device is able to monitor the primate's brain while it's providing the therapy so you know exactly what's happening," Rikky Muller, a co-author of the new study, told Business Insider. A professor of computer science and engineering at the University of California, Berkeley, Muller is also a Biohub investigator. The applications of brain-machine interfaces are far-reaching: while some researchers focus on using them to help assist people with spinal cord injuries or other illnesses that affect movement, others aim to see them transform how everyone interacts with laptops and smartphones. Both a division at Facebook formerly called Building 8 as well as an Elon Musk-founded company called Neuralink have said they are working on the latter.

From a 9to5Mac report: As the new year begins in Pacific Time, where Apple's Cupertino headquarters are based, the AirPower charging mat has officially missed its 2018 release window. The charging mat promised to charge iPhone, Apple Watch and AirPods on a single compact mat with flexibility on where devices can be placed. However, the product has been rumored to have faced internal development challenges as late as this past summer, which prevented Apple from bringing the product to market as smoothly as it expected. [...] Unusually, Apple has not provided a statement to press with an update on AirPower's status. Apple refused to acknowledge the product at its September and October events, and has not responded to press requests for comment at the end of December. The product therefore enters 2019 still in limbo.

Devices and security systems are increasingly using biometric authentication to let users in and keep hackers out, be that fingerprint sensors or perhaps the iPhone's FaceID. Another method is so-called 'vein authentication,' which, as the name implies, involves a computer scanning the shape, size, and position of a users' veins under the skin of their hand. But hackers have found a workaround for that, too. From a report: On Thursday at the annual Chaos Communication Congress hacking conference in Leipzig, Germany, security researchers described how they created a fake hand out of wax to fool a vein sensor. "It makes you feel uneasy that the process is praised as a high-security system and then you modify a camera, take some cheap materials and hack it," Jan Krissler, who goes by the handle starbug, and who researched the vein authentication system along with Julian Albrecht, told Motherboard over email in German. Vein authentication works with systems that compare a user's placement of veins under their skin compared to a copy on record. According to a recent report from German news wire DPA, the BND, Germany's signals intelligence agency, uses vein authentication in its new headquarter building in Berlin. One attraction of a vein based system over, say, a more traditional fingerprint system is that it may be typically harder for an attacker to learn how a user's veins are positioned under their skin, rather than lifting a fingerprint from a held object or high quality photograph, for example. But with that said, Krissler and Albrecht first took photos of their vein patterns. They used a converted SLR camera with the infrared filter removed; this allowed them to see the pattern of the veins under the skin.

As you may remember, the largest known prime number, M82589933 (or 282,589,933-1), was discovered earlier this month. At over 24.8 million digits, it’s a long-ish number, but of course this doesn’t mean you shouldn’t be able to memorize it. In fact, as Evelyn Lamb explains in Scientific American, it isn’t even that hard. Well, it’s a little hard. But it’s nothing compared to the effort of memorizing over 24 million digits, which is just too many digits for anyone to think about. Plus, it’s an excellent party trick for New Year’s parties—you can use it as a countdown, instead of the trite ten-second-to-midnight-routines. People will think you are a genius! Which, who’s to say you aren’t? So Lamb (who is clearly more likely than others to be a genius) starts her memorization trick by turning M82589933 into a binary number. 282,589,933-1, in binary, is a string of the number 1 repeated 82,589,933 times. 82,589,933 is easy enough to remember. To make it easier, Lamb suggests you memorize the sentence: “Cabbages in April besmirch September asparagus. And how!” The number of letters in each word corresponds to a digit of 82,589,933. Because not everyone is an actual genius, it might take you a minute to figure out what this actually means—just as it did my friend, who, of course, is me. So here is a handy guide: cabbages = eight letters = 8 in = two letters = 2 April = five letters = 5 besmirch = eight letters = 9 September = nine letters = 9 asparagus = nine letters = 9 and = three letters = 3 how = three letters = 3 That is: 82,599,933. Now, how do you keep track of how many ones have you written? Easy, says Lamb. Just memorize a series of words that are made of straight lines, like the word TWENTY NINE, which is made of 29 straight traits. That is: T= two straight lines = 11 W = four straight lines = 1111 E = four straight lines = 1111 N = three straight lines = 111 T = two straight lines = 11 Y = three straight lines = 111 N = three straight lines = 111 I = one straight line = 1 N = three straight lines = 111 E = four straight lines = 1111 TWENTY NINE = 11 1111 1111 111 11 111 111 1 111 1111 (that is 1 repeated 29 times. Probably.) Lamb created a poem that, when written in all caps, contains 500 straight lines. But you don’t need her poem: You can write your own 500-straight-lines poem! You can even write a poem with another number of straight lines—for instance, 677. You can write a poem made of 677 straight lines 122008 times, and then write 1 just 517 more times! You can start now and say it out loud and when you’re done it will be the next year! Happy 2019! (That is 11111100011, in binary. Thank you for asking.)

Each year, thousands of people worldwide use Jan. 1 as a reason to go sober through Dry January, or Drynuary, after the revelry of the holiday season passes. The idea of taking a break from drinking in January started to take off a few years ago. In 2012, the campaign was made official by the British charity Alcohol Change UK, although others, including John Ore from Business Insider, had been doing it for years. Now, a quick search of the hashtag #dryjanuary on Instagram shows almost 118,000 posts. There are already hundreds of #dryjanuary2019 pictures already up. Although there’s certainly no harm from taking a break from drinking alcohol—a known carcinogen—the broader health benefits of dry January may be more in your head than in your body. There are obvious short-term benefits that come from forgoing alcohol. Going sober can help improve sleep, and it saves both empty calories and money. There’s also preliminary evidence that a break from drinking can make small changes to the body: In 2013, a small group of 14 dedicated journalists at the British publication New Scientist conducted their own experiment, in which 10 of them quit drinking for five weeks. Some their subsequent bloodwork analyzed by a physician. Those who took a break saw their liver fat, a precursor to damage, decrease, as did their blood sugar, a measure of diabetes risk—although notably, none had been considered unhealthy before. That said, healthy adults don’t actually need a month to recover from holiday drinking. When we drink, the liver breaks down the majority of alcohol in our systems. While this process can result in the death of liver cells, the liver, like skin, regenerates quickly, Doug Simonetto, a heptologist at the Mayo Clinic, has told Quartz. (Just exactly how quickly is still unknown—Simonetto said that it would take actual liver biopsies at various points to be able to tell. But think of it like skin healing after a cut.) The liver can incur permanent damage if you routinely engage in heavy bouts of drinking without time to properly recover. This repetitive damage can lead to chronic and fatal liver diseases, including cancer. There’s also evidence that routine drinking of any amount can lead to other afflictions, like heart disease, and a number of other types of cancers. However, exactly how much drinking over what amount of time causes these outcomes is unclear: Self-reported observational studies have been unable to show if alcohol is a direct cause or if other factors in participants’ lives, like their age, occupation, or genetics. Dry January will certainly benefit your liver in the sense that you’re not harming it for a month, Simonetto explained. If you’re otherwise healthy, it may lower your risk for other diseases by a tiny amount, based on these observational studies that we have reported previously (although any benefit would matter more on how much you were drinking previously). The real benefit of Dry Janaury, though, comes from quitting the habit. For many of us, myself included, drinking moderately becomes something of a ritual. Winding down from the day? Have a glass of wine. Want to catch up with a friend? Grab a drink. Going on a date? Meet at a bar. In April of 2018, my colleague Jenni Avins took a month-long hiatus from drinking. She found it was difficult—and ultimately worth it. “My end-of-day default has been reset from ‘drinking’ to ‘not drinking,'” she wrote. “And there’s no denying that abstaining from alcohol is a simple way to improve sleep, cut calories, save money, and, of course, avoid hangovers.” Richard de Visser, a psychologist at the University of Sussex, has been working with the Alcohol Change UK to study the effects of Dry January. Although these studies rely on self-reported data of hundreds of adults, participants have reported drinking less (paywall) in the months following. According to a press release from the University of Sussex, results from the 2018 Dry January suggests that participants decreased the number of days they drank from about four days per week to three through August of the following year. Notably, though, these results didn’t include the standard margins of error typically shown in survey-based studies. Whether or not this change in habit is enough to provide any long-term benefits to the liver is unclear—but it’s certainly not harmful. Unless, of course, drinkers come into February drinking more to make up for it, James Ferguson, a liver specialist at Queen Elizabeth Hospital Birmingham in England, told NPR in 2014. “I don’t think taking one month a year off alcohol makes any difference,” he said. “It’s more important to cut back generally.”