For ten years, China and Central Asian countries have been more tightly bonded together through cooperation in the traditional energy section under the Belt and Road Initiative (BRI). However, the rise of Chinese companies specializing in renewable energy and scientific institutes equipped with technology on ecological preservation has been greening the BRI in the past decade. 

By using Chinese technology and experience to monitor and improve the ecology of Central Asia countries, imparting local people the expertise to build a hydropower station, and kick starting a cutting-edge photovoltaic power plant to help generate substantial renewable energy in the region, Chinese institutes and companies are helping turn the dream of a "Green Silk Road" into reality, while also making China-Central Asia cooperation in the green sector a paragon for other countries. 

Ecological cooperation 

The Aral Sea, located between Kazakhstan and Uzbekistan, was once the world's fourth-largest lake. Farmland expansion, rising temperatures and a lack of water-saving technology caused the sea to shrink to just 10 percent of its original surface by the end of the 1990s. Large areas of the lake bed have become bare and covered with salt or salt crust. The health of local residents has also been affected, with a significant increase in the proportion of people suffering from leukemia, kidney disease, bronchitis, and asthma.

In recent years, scientists from the Xinjiang Institute of Ecology and Geography (XIEG) with the Chinese Academy of Sciences and Uzbekistan have been actively cooperating on the treatment of the Aral Sea. 

"The Aral Sea crisis is essentially a problem of an inland lake drying up due to excessive water extraction for agricultural irrigation," Li Yaoming, the director of the Research Center for Green Development of Silk Road at XIEG, told the Global Times. 

"China's Xinjiang region has also faced similar problems in the past, such as the management of the Tarim River. China has been implementing ecological water transfer from the Tarim River for many years and has relatively mature water resource management techniques, which can provide a reference for Uzbekistan," said Li. 

In the suburb of Tashkent, capital of Uzbekistan, stood a 5-hectare demonstration field for drip irrigation water-saving technology. XIEG participated in the project, established an observation station for plants, brought cotton and wheat seeds from China and used drip irrigation to improve plant productivity. 

The drip irrigation technology equipment and supporting farming machinery here are all from China, Shakhzod Saitjanov, a research fellow from the Institute of Genetics and Plant Experimental Biology of the Academy of Science of Uzbekistan, told the Global Times. He believes this project will elevate the quality of Uzbekistan's agriculture and boost the country's economy. 

"Traditionally, Uzbeks tended to use flood irrigation in cotton cultivation, which requires the use of a large amount of water to wash away the salt content in the soil. We have introduced new drip irrigation technology, which will help save a significant amount of water resources," said Li. 

In addition, Chinese scientists also helped in improving and managing saline-alkali land. They use salt-tolerant plants to reduce the salt content in the soil, creating conditions for growing other crops. Artificial forests are also planted on the sandy desert that formed after the drying up of part of the Aral Sea. All of these efforts play an important role in the protection of the Aral Sea.

Since the launch of the BRI, XIEG has conducted vast fundamental cooperation with regional countries in terms of improving the region's ecology. For example, the institute helped developed an integrated water-saving irrigation system for cotton in the Aral Sea region and a 25-hectare technology demonstration base has been established. The technology has been across a 200-hectare area. In 2021 and 2022, Uzbekistan found out that yields reached 404 kilograms and 414 kilograms per mu (0.06 hectare), respectively, while the water-saving rate reached 70 percent. Both yield and water-saving efficiency were more than double that of local cotton fields.

In Kazakhstan, XIEG introduced 32 species of plants with a total of 15,600 plants, and conducted training on planting techniques and irrigation measures. The institute completed the establishment of a 20-hectare protective forest belt demonstration zone, established a comprehensive health assessment system for man-made forests, and evaluated the ecological service functions of ecological barriers.

As the Earth is becoming hotter from global warming, inland and hydropenic Central Asian countries are facing severe environmental challenges. Such challenges are pushing China and Central Asia closer in cooperation in improving the region's ecological problems after the BRI was launched.  Ten years ago, people in Central Asia had little understanding of China's in water-saving and ecological protection technology. However, climate change has made them feel the urgency of environmental protection in recent years, said Li, noting that more and more research institutes and government departments in Central Asian countries have been approaching them, seeking cooperation.

He said that ecological protection has been gradually emphasized under the framework of the BRI and that he expects the governments of Central Asian countries to endow more support to relevant projects. 

Environmental protection was highlighted during the Xi'an Declaration of the China-Central Asia Summit, which concluded in Xi'an in May. As noted in the declaration, the Parties reaffirm the need for concerted efforts to ensure food security in a changing climate, and also note the importance of farming in the most environmentally friendly ways that support biodiversity, with the optimal use of water and land resources.

Li believes that the summit, as well as development of the BRI will be a turning point for China's environmental cooperation with Central Asian countries, as "collaboration in this field has been put in a higher position ever since."    

Teach a man to fish

The Tuyabuguz Hydropower Plant in Uzbekistan was the first project completed after leaders of China and Uzbekistan signed government-to-government energy cooperation during the Belt and Road Forum held in 2017 in Beijing. 

The project, contracted by Dongfang Electric Corporation (DEC), was completed within 14 months and put into operation in April 2019. As of August, a total of 109 million kilowatt-hours of electricity has been generated by the project. The station can achieve uninterrupted power generation for 11 months in a year, with an annual electricity output sufficient to meet the power needs of 1,600 households in Uzbekistan. It will become profitable within four years.  

Sun Jianfeng, a DEC project manager in charge of the station, told the Global Times on August 18 that "all power generation equipment in the project was manufactured in China, and the key technologies for the water turbines and generators were independently developed using Chinese intellectual property rights."

Sun introduced that the project was located downstream from the Akhangaran River's Tuyabuguz reservoir in the Tashkent region, which was originally used for irrigation. It was built at the location with the highest potential energy, which it fully utilizes to generate electricity, making it highly economical.

"The hydropower station maximized the utilization of energy during the irrigation process. Moreover, the project takes measures to prevent the flow of water from damaging crops or facilities," said Sun. 

The project's environmental friendliness not only embodies the generation of green energy, it also does not cause environmental problems like the construction of traditional dams, as it was built under an existing reservoir, introduced Sun.

Uzbekistan has shown enormous interest in renewable energy in recent years. The country has set an ambitious goal - generate 30 percent of its electricity from renewable energy sources by 2030.

Sun said that Uzbekistan government has been encouraging foreign investment into the renewable energy sector in recent years, which has created a friendly environment for Chinese companies. Meanwhile, Chinese companies' advanced technology in green energy also made them highly competitive in Uzbekistan. Thus, Sun believes cooperation between the two countries has great potential. 

In May 2022, Uzbekistan's investment committee and China's Ministry of Commerce reached an agreement to build a series of small and medium-sized hydroelectric power facilities worth a total of $2.7 billion, media reported.

Apart from exporting equipment, DEC is devoted to training local experts in the hydropower industry. Sun said his company held large-scale training sessions in 2018 and 2019. More than 60 Uzbeks took part in the sessions. 

"We taught them how to operate and maintain our equipment. The locals completed installation and debugging of our facilities during the final stage. The equipment has been functioning well and been well maintained during the past three years of operation," said Sun. 

"We did not send our people to the site for maintenance, we just provided guidance online. We sold our equipment and offered them our technology at the same time. There's an old idiom called 'give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.' We taught them how to keep the project running for the next four or five decades, so the Uzbeks are going to operate it independently in the future," said Sun.

Meet local demands

Aziz, who works at the Zarafshan 500MW Wind Power Project, is always enthusiastic about her work. Whenever she encounters a problem, she relentlessly seeks answers from her Chinese colleagues. 

Aziz considers herself fortunate to have witnessed the installation of the first wind turbine at the Zarafshan wind power project in early June. This marks the first-ever wind turbine installation in Uzbekistan.

Constructed and run by SEPCOIII Electric Power Construction Co., Ltd. (SEPCOIII) in Zarafshan, Navoi Region, Uzbekistan, the Zarafshan wind power project is the first megawatt-scale wind power project implemented in Uzbekistan. With a total installed capacity of 500MW, it will also be the largest operational wind power project in Central Asia upon completion. 

Currently, the project is in its peak construction phase. Once completed, the project will provide sufficient green electricity for 500,000 households and save 1.1 million tons of carbon dioxide emissions annually, making a significant contribution to Uzbekistan's energy transition and sustainable economic development goals.

Uzbekistan's President Shavkat Mirziyoyev has implemented a series of reforms since taking office, of which new energy reform is an important part. According to the government plan, by 2030, the share of renewables in Uzbekistan's energy will reach 25 percent of the energy mix.

Aziz still vividly remembers the nationwide power shortage that occurred in early 2023. Despite the overall stability of the political situation and the upward trajectory of the economy in Uzbekistan, the country still faces challenges in meeting its growing electricity demand. 

However, Aziz feels optimistic about the future of energy development in Uzbekistan. Aziz's confidence in the future of energy development in Uzbekistan is shared by many. The government's commitment to addressing the power shortage issue and its efforts to attract investments in the energy sector have instilled hope among the population.  

"Uzbekistan is an important country along the BRI route, and the production and construction of photovoltaic, wind power and other new energy fields are the strengths of Chinese enterprises, so the prospects for cooperation between the two sides are promising," Ji Jun, manager of the project from SEPCOIII, told the Global Times.

'Green Silk Road' realized

A power station located in Kapchagay, Kazakhstan, co-invested and constructed by Universal Energy, a Chinese renewable energy company based in Shanghai and its Kazakhstan partners, marked the largest single photovoltaic power plant in Kazakhstan. Starting operation in 2019, the station is also the region's first large-scale new energy power station. 

With the model of "100 percent Made in China, 100 percent Construction in Kazakhstan," the project is able to generate electricity at a much lower cost than other similar power stations, and has substantially reduced carbon emissions. Wu Xiaoliang, deputy manager of the Universal Energy told the Global Times that "the station can generate 160 million kilowatt-hours on annual basis, equivalent to the electricity consumption of 50,000 households in Kazakhstan for one year. The project can reduce carbon emissions by 160,000 tons annually."

Wu also pointed out that in 2023, the company completed an international green certificate transaction with a large international trader, selling carbon assets generated from the 7,000 megawatt-hours of electricity generated by the Kapchagay power station, offsetting approximately 5,950 tons of carbon dioxide emissions. 

"The company has six newly built renewable energy power stations in Kazakhstan that have provided a total of 1.7 billion kilowatt-hours of green electricity to the local area, reducing carbon emissions by a total of 1.7 million tons."

In recent years, China and Central Asian countries have accelerated cooperation in the field of new energy such as wind power, solar power, and hydropower. According to data from China Power International (Kazakhstan) Investment Limited, by the end of 2022, the total installed capacity of a series of renewable energy projects invested and constructed by Chinese companies in Kazakhstan, including the Zhanatas wind power station and Turgusun hydropower plant, has exceeded 1,000 megawatts.

The accelerated cooperation is also aimed to cater for Central Asian countries' rising ambition in exploring usage of new energy. For example, Kazakhstan has made ambitious commitments to reduce the country's greenhouse gas emissions to 15 percent below their 1990 levels by 2030 and of reaching carbon neutrality by 2060.

Wu explained that Kazakhstan can realize self-sufficiency in providing electricity at the current stage, yet the country is facing the problem of an outmoded electricity infrastructure. 

"Most of the electricity-generation infrastructure was built during the Soviet era, which means their service time is reaching the limit. Insufficient maintenance and reinvestment in certain facilities are also evident. This means that if investment in the power sector is not increased soon, Kazakhstan may face significant power shortages in the coming years," said Wu.

Compared with companies from other countries such as Germany and Japan, Chinese companies' advantages are visible: Its leading photovoltaic technology, its deep connection with Central Asian countries and China-Europe freight train services have given such cooperation a better edge.

Wu said that the Kapchagay power station alone has more than 300,000 photovoltaic modules that were transported from China through China-Europe freight trains. The time and cost advantages brought by the China-Europe freight trains enabled the project to be completed and connected to the grid within only nine months.

China-Europe freight train services are helping China-invested wind power and photovoltaic power stations successfully land in Kazakhstan, which has accelerated exports of relevant Chinese equipment, and broken Europe's monopoly over Kazakhstan's new energy equipment, said Wu.

"The 'Green Silk Road' is becoming a reality," he said.

Over the ground lies a mantle of white — on Pluto. Snow-capped peaks on the dwarf planet dot an otherwise ruddy terrain. But these snowy summits appear to be composed of methane, not water, researchers report online March 3.

Mountain tops in Pluto’s Cthulhu Regio, a dark landscape abutting the planet’s famous heart, reflect more light than the surrounding area. The New Horizons spacecraft, which flew past Pluto on July 14, found that the bright regions correspond to surface deposits of methane. Mission scientists speculate that perhaps methane in the atmosphere on Pluto behaves like water in the air on Earth, building up on the ground as frost at the highest (and coldest) elevations.

Three Earth-sized planets orbiting a star practically next-door might be a good place to hunt for alien life — or at least check out some worlds that are different from anything in our solar system.

The planets orbit a dim, cool star just 39 light-years away in the constellation Aquarius. Each is outside or possibly on the edge of the star’s habitable zone — where average temperatures are just right for liquid water. But there could be niche locales on these worlds where alien life might thrive, Michaël Gillon, an astrophysicist at University of Liège in Belgium, and colleagues report online May 2 in Nature.
A year on the two inner planets lasts just a couple of days. Data on the third world are sparse; it could take anywhere between 4.5 and 72.8 days to trek around its sun. The star, designated 2MASS J23062928−0502285, is roughly the size of Jupiter — about one-tenth as wide as our sun — and about 3,200 degrees Celsius cooler than the sun. Such runts make up about 15 percent of the stars in the galaxy, though astronomers had not found planets around one before. All three planets were discovered as periodic dips in starlight in late 2015 using TRAPPIST, a telescope at La Silla Observatory in Chile.

If anything does crawl or grow on these worlds, it bathes in mostly infrared light. The innermost planets receive several times as much energy from their star as Earth does from our sun, which technically puts them outside the star’s habitable zone (SN: 4/30/16, p. 36). But the planets are huddled up so close to the star that gravity might keep them from spinning, creating a temperate zone along the line where day turns to night, the researchers suggest.

Faint red stars such as this one are the best place to look for warm rocky planets, says Nicolas Cowan, an astronomer at McGill University in Montreal. Planets, even small ones, are easier to see around these dim bulbs rather than sunlike stars. NASA’s planet-hunting Kepler space telescope has already shown that planets exist around similar stars, but those are too far away to investigate further. “This [study] finds a nearby example,” says Cowan.

Being nearby is important for studying the atmospheres of such worlds, or learning whether they have atmospheres at all. They may not. Red dwarf stars take a long time to form; planets arise while their sun is still a puffy, temperamental ball of contracting gas. “That might bake off all the water and the atmosphere,” Cowan says. Astronomers won’t know, though, until they point some big telescopes toward these worlds.

The Hubble Space Telescope might be able to get a crude look. But NASA’s James Webb Space Telescope, scheduled to launch in 2018, could gaze at these planets and measure how much starlight is being absorbed by molecules in their atmospheres. If there is an atmosphere, James Webb could look for such gases as oxygen and methane (SN: 4/30/16, p. 32). On Earth, at least, those gases are produced by plants and microbes.

Whether or not life has found a home on these worlds, all offer a peek at unfamiliar environments. The two planets closest to the star, for example, are bombarded with more energy than Venus, notes Lisa Kaltenegger, an astronomer at Cornell University. “How would Venus evolve if you heat it up even more?” she asks. “We don’t have such planets in our own solar system, so it is really interesting to find out what such planets can be like.”

New sperm-catching beads could someday help prevent pregnancy — or enable it.

Researchers created microscopic polymer beads that mimic unfertilized eggs and trap passing sperm. The beads are coated in the sperm-binding section of a protein called ZP2. In mammals, ZP2 is found in membranes around unfertilized eggs; sperm must bind to the protein before entering the egg.

The beads could be used as short-term contraceptives, Jurrien Dean of the National Institutes of Health in Bethesda, Md., and colleagues report in the April 27 Science Translational Medicine. In the laboratory, human sperm attached to the beads within five minutes. The researchers then mixed 100,000 human sperm with 1.5 million beads and 28 mouse eggs containing human ZP2 proteins. After 16 hours, only one sperm reached an egg.
In another experiment, beads coated with mouse ZP2 delayed pregnancy when injected into the uteruses of mating female mice. Bead-free mice took just over 28 days, on average, to conceive and give birth; bead-treated mice didn’t have babies for nearly 73 days on average. The beads didn’t appear to cause swelling or damage, and treated mice were able to give birth again within five months.

The beads could also help combat infertility. In an egg-penetration test, researchers gently detached bead-captured sperm and pitted those sperm against a control batch of sperm that had not been exposed to the beads. More than half of eggs (mouse eggs with human ZP2) exposed to the bead-selected sperm ended up with three or more sperm attached to them; none of the eggs exposed to the control group snagged three or more sperm. In fact, the control group failed to penetrate 38 out of 50 eggs. So the beads could someday be used to select healthy sperm for assisted reproduction, the researchers say.

But it’s not clear if the ability to bind to ZP2 necessarily indicates a healthy sperm, says Andrew La Barbera, chief scientific officer of the American Society for Reproductive Medicine in Birmingham, Ala. “Sperm selection is a very complex undertaking because of the fact that sperm are very complex,” he says. “We don’t know what makes a good sperm.”

Contraception might be a more reasonable future use for the beads, although allowing fertilization of one in 28 eggs is underwhelming, La Barbera says. Birth control should be closer to 99.9 percent effective. “It only takes one sperm to fertilize an egg,” he says. Still, the beads’ performance at blocking pregnancy in mice seems promising, La Barbera says. Future experiments would need to determine if the beads are safe and effective in women, and how many beads are needed to prevent conception.

Dean notes that the study is a proof of principle. Many unknowns must be evaluated before using the beads for birth control, including the side effects of long-term use, he says. “Although promising, we are a long way from translating these basic laboratory observations into useful clinical applications that provide people with better reproductive choices.”

During the rainy season in the Orinoco Llanos of Columbia and Venezuela, an odd landscape feature appears in places: mounds of grassy plants, as big as five meters across and two meters tall, surrounded by water. Traversing this landscape, called surales, requires either hopping from mound to mound or trudging through the boggy bits in between.

Locals and scientists have generally agreed that some kind of earthworm creates the mounds, but what species and how it does so has been a mystery. Now Anne Zangerlé of the Braunschweig University of Technology in Germany and colleagues report that they’ve found the culprit — giant Andiorrhinus earthworms, which can grow to a meter in length as juveniles. And the mounds themselves, the team reports May 11 in PLOS ONE, are actually made mostly of earthworm poop.

Zangerlé and her colleagues used Google Earth images to locate surales landscapes, finding that they come in the shape of both mounds and labyrinths. Leaving the complex labyrinths for a future study, the team studied the mounds and the lands on which they were found in both the rainy and dry seasons. They characterized the soil and the plants and worms living in and on the mounds. And then they pieced all of that information together to come up with a scenario that they think explains the construction of the mounds.
Andiorrhinus earthworms deposit feces, or casts, in towers that give the worms access to the air so they can breathe. The worms then return to the tower, depositing more and more material, building the tower into a mound. These young mounds, the researchers found, are dominated by Andiorrhinus earthworms. But over time, as the mounds get even bigger, other worm species begin to make their home there, as well as plants and, eventually, if the mounds get big enough, trees.

The Andiorrhinus earthworms tend to stay around the same mound because, as they build, they excavate soil from the region around the mound. That moat gets deeper and deeper until it becomes a barrier to the giant earthworm that created it.

The researchers don’t quite understand everything that is happening in the system. For example, there could be an as-yet-unknown end stage to mound development, or some kind of equilibrium state for the landscape. But they note that “these ecosystems are under threat from industrial agriculture, and are being leveled to make way for highly intensified commercial production of rice.” Because of that, they say, there is a risk that these wonderfully complex and mysterious systems could disappear before anyone fully understands what made them in the first place.

Earth’s plate tectonics could be a passing phase. After simulating rock and heat flow throughout a planet’s lifetime, researchers have proposed that plate tectonics is just one stage of a planet’s life cycle.

In the simulation, the Earth’s interior was too hot and runny at first to push around the giant chunks of crust, researchers report in the June Physics of the Earth and Planetary Interiors. After the interior cooled for around 400 million years, tectonic plates began shifting and sinking, though the process was stop-and-go for about 2 billion years. The simulation suggests that Earth now is nearly halfway through its tectonic life cycle, says study coauthor Craig O’Neill, a planetary scientist at Macquarie University in Sydney. In around 5 billion years, plate tectonics will grind to a halt as the planet chills.

The long delay before full-blown plate tectonics hints that the process could one day begin on currently stagnant planets, says Julian Lowman, a geodynamicist at the University of Toronto who was not involved in the research. “There is a possibility that plate tectonics could start up on Venus if conditions were right,” he says.
Plate tectonics regulates a planet’s climate by adding and removing carbon dioxide from the atmosphere. This climate control helps maintain Earth’s habitability. Plate movement is driven by heat flow through the planet’s interior. Simulating that heat flow requires complex calculations. Previous simulations were simplified and typically considered only snapshots of Earth’s history and missed how plate tectonics evolves over time.

O’Neill and colleagues simulated Earth’s full tectonic life span, starting with the planet’s formation around 4.5 billion years ago and looking ahead to around 10 billion years in the future. Even using a supercomputer and simulating only a two-dimensional cross section of the planet, the calculations took weeks.

The new timeline suggests that Earth’s plate tectonics is just a midpoint in the planet’s evolution between two stagnant states. Planets with different starting temperatures than Earth’s follow different trajectories, the team found. Colder planets may exhibit plate tectonics throughout their history while hotter planets could go for billions of years without plate tectonics.

Just because a planet currently lacks plate tectonics doesn’t make it uninhabitable, O’Neill says. Life potentially appeared on Earth as early as around 4.1 billion years ago (SN Online: 10/19/2015), a time when the new simulation suggests that Earth lacked full-blown plate tectonics. “Stagnant planets, depending on when they are in their history, can be equally likely of supporting habitable conditions” as planets with plate tectonics, O’Neill says.

A radio signal detected last year has sparked speculation that an advanced alien civilization is broadcasting from a relatively nearby planet. But recent scans have turned up nothing, suggesting the blip was a false alarm and nothing more than earthly interference.

In May 2015, astronomers detected a blast of radio waves coming from the direction of HD 164595, a sunlike star about 94 light-years away in the constellation Hercules. The signal, reported online August 27 on the blog Centauri Dreams, lasted just a few seconds and reached a peak power of about 750 millijansky — fairly strong by radio astronomy standards (1 jansky equals 10-26 watts per square meter per hertz). The researchers aren’t claiming that they found E.T., but they are asking other astronomers to monitor the star — home to a planet at least 16 times as massive as Earth — in case the signal repeats.
So far, all is quiet.

Scientists with the SETI Institute, whose mission is to seek out signs of extraterrestrial intelligence, turned the Green Bank Telescope in West Virginia toward HD 164595 on August 28 to scan for signals. “There was nothing there,” says Dan Werthimer, a SETI astronomer at the University of California, Berkeley. The original claim, however, “is consistent with someone pushing the button on a CB radio for a couple of seconds.”

Radio telescopes have to contend with interference from the civilization on this planet before picking out transmissions from our galactic neighbors. Earth-based satellites, power lines and cellphones all emit radio waves that can overwhelm cosmic signals. One type of radio chirp whose origin had eluded astronomers for years recently turned out to be coming from microwave ovens, a fact discovered when researchers at the Parkes observatory in Australia who were tracking the signal prematurely opened an oven door without waiting for the ding signal (SN: 5/16/15, p. 5).

“We see strong signals like this all the time,” says Werthimer. With enough information, such as frequency and location, researchers can usually figure out the cause of an incoming signal. But this latest finding, recorded at the RATAN-600 radio observatory near the Caucasus Mountains in Russia, is missing a lot of details that could help astronomers assess its origin. Without precise frequency measurements or statistics on how often the observatory detects comparable events, says Werthimer, it’s hard to tell how unusual this signal is.

The signal was detected around a frequency of 11 gigahertz. That suggests interference from telecommunication devices, says Italian astronomer Claudio Maccone, who was part of the discovery team. “This is precisely why many countries have to watch the star with different technologies,” he says. “By comparing results, we may be able to find the answer.” The long delay in sharing the results, he says, comes from a reluctance among his Russian colleagues to interact with Western researchers. “They are a closed community,” he says. “It’s an unfortunate circumstance.” The team will present the findings September 27 at a meeting of the International Academy of Astronautics in Guadalajara, Mexico.
If the signal didn’t originate on Earth, there are also plenty of natural cosmic sources. Jean Schneider, an astrophysicist at the Paris Observatory in Meudon, France, contends that a gravitational microlens might be responsible. Gravity from an object, such as a star or planet, can temporarily amplify light — including radio waves — received on Earth from other more distant bodies that the interloper passes in front of. Testing that idea would require meticulously tracking the movement of stars that lie in the direction of the radio signal, says Schneider, and seeing if anything could have lined up on the day of the detection.

The discovery is reminiscent of an infamous — and still unexplained — detection known as the “Wow!” signal, named after what astronomer Jerry Ehman wrote on a printout of the signal. Detected in 1977 at the Big Ear radio telescope in Delaware, Ohio, the Wow! signal was at least 70 times as powerful as the one at RATAN-600, lasted for about 72 seconds and appeared to originate in the constellation Sagittarius. Many ideas have been put forth about the signal’s origin, including comets in our solar system, Earth-orbiting space debris and, of course, extraterrestrials.

If aliens do reside around HD 164595, and they are trying to get our attention, they could do so with precisely aimed transmitters no more powerful than anything on Earth, Werthimer says. But if we eavesdropped on a signal that was blasting in all directions into space, then our neighbors are far more advanced than us; such a device would require tapping into the entire power output of their sun.

Anna Frebel can’t explain her fascination with the stars. It’d be like explaining why “berry purple-pink” is one of her favorite colors. “They are just a part of me,” says Frebel, an astronomer at MIT. “What’s going on with them and what they can tell us — there is something magical.”

Frebel’s fascination has led to the discovery of at least three record-breaking stars. Dating back roughly 13 billion years, the stars — all within the Milky Way galaxy — might be elders from the second generation of stars ever formed in the universe. She has also found that one of the tiny galaxies flitting around outside the Milky Way might be a fossil that has survived from not long after the Big Bang. The light from these ancient relics encodes stories about the birth of the first stars, the assembling of galaxies and the origin of elements essential to creating planets and life as we know i
“Anna has a really good track record of finding these amazing things,” says Alexander Ji, one of the three graduate students Frebel mentors at MIT. “She’s always finding things that change our understanding of the universe.”
As a young girl living in Germany, Frebel wanted to be an astronaut, but she passed on that dream when she learned about the centrifuge that whips trainees around to simulate launch acceleration. Not for her. She instead studied physics and astronomy, first at the University of Freiburg in Germany and then at the Australian National University in Canberra. Since then, Frebel, now 36, has earned a reputation as a “stellar archaeologist,” with the patience and perseverance to search through the universe’s most ancient debris.

Only someone with a galaxy’s worth of patience could sift through the tiny rainbows of light, the spectra, produced by thousands of stars, handpicking the specimens that might preserve clues to the conditions shortly after the first stars lit up the universe. And only a persistent person would spend more than two years pointing Australia’s 2.3-meter-wide Advanced Technology Telescope at 1,200 of the most promising candidates (“105 stars per night was my record,” she says) and eventually, with observations from other telescopes too, land on one star that was, for a while, among the oldest known.

She was first drawn to this research after hearing astronomer Norbert Christlieb, then a visiting researcher at the Australian National University, talk about his work on old stars. “It hit me: Oh my God, this project combines all my interests,” Frebel says. There were stars, chemistry, nuclear physics and the periodic table. “There are so many, for me, cool topics that come together.”

In combing through her stars, Frebel was looking for ones that contained hydrogen and helium — but little else. Most heavier elements up to iron are forged in the cores of stars, where atomic nuclei smash together. As the universe aged, its inventory of atoms such as carbon, silicon and iron steadily increased. The earliest stars, however, came on the scene when there were far fewer of these pollutants floating around.
Her efforts paid off in 2005 with a star branded HE 1327-2326, reported in

Nature

asthe most pristine star known at the time

. “She found one that took us closer back to the beginning of time as we know it,” says Frebel’s Ph.D. adviser, astronomer John Norris of Australian National. “It became clear to us early on that she was quite gifted.”

Her gifts netted her the Charlene Heisler Prize in 2007, given by the Astronomical Society of Australia for outstanding Ph.D. thesis. She has since won several recognitions, including the Annie Jump Cannon Award in 2010, given to notable young female researchers by the American Astronomical Society, for her “pioneering work in advancing our understanding of the earliest epochs of the Milky Way galaxy through the study of its oldest stars.”

Carbon seeding
The geriatric stars that Frebel finds are not perfectly pristine; they preserve in their atmospheres the chemical makeup of interstellar gas that had been seeded with a smidgen of heavy elements from the explosions of stars that came before. Chemical abundances in many of these stellar fossils are out of balance compared with modern stars. The fossil stars have much more carbon relative to iron, for example — carbon that had to have come from the debris of that very first crop of stars.

Frebel worked with theorists to show that excess carbon could have allowed successive generations of stars (and planets) to form, reporting the work in 2007 in Monthly Notices of the Royal Astronomical Society Letters. “I’ve always been interested in understanding the main message of the data,” she says, which leads her away from the telescope to computer simulations and theory. In this case, the message is that carbon “might have been the most important element in the universe.”

Gas needs to be cold, around –270° Celsius, just a few degrees above absolute zero, to clump and form stars. And carbon is an excellent coolant; its electrons are arranged in such a way to let it efficiently radiate energy. The first generation of stars didn’t have carbon’s help. They were probably slow to form and ended up as gargantuan fluffy orbs hundreds of times as massive as the sun. But once those stars exploded and seeded the cosmos with carbon, Frebel’s data suggest, subsequent generations of stars formed that would have looked more like the stars we see today.

Frebel likens her studies to watching her young son learn to walk and talk. “My overall interpretation is that the universe was still trialing things.”

Before she became a parent, she regularly went to one of the twin Magellan telescopes, 2,380 meters above sea level in the Chilean Atacama Desert. On long nights, while waiting for the telescope to soak up light from a star tens of thousands of light-years away, Frebel would feel the pull of the night sky. “I just lie on the ground and stare into the sky and get lost in the universe,” she says.

In recent years, Frebel has expanded her repertoire to include a horde of teeny galaxies that orbit the Milky Way and also serve as archaeological sites. “Now we can use not just one star,” she says. “We can use the entire galaxy as a fossil record.” One of these runts, called Segue 1, appears to be a remnant from the cosmic dawn and might be typical of the pieces that assembled into large galaxies like the Milky Way.

Frebel and her student Ji discovered that another dwarf galaxy, dubbed Reticulum II, contains clues about one of the mechanisms responsible for creating most of the elements heavier than iron. A long-ago smashup between two neutron stars once bombarded the gas in Reticulum II with neutrons, producing atoms, such as uranium, that can’t be formed in stellar cores. Similar run-ins in other galaxies might have helped build up the universe’s stockpile of heavy elements.

Frebel plans to continue her quest to understand the origin of atoms, stars and galaxies. Though the celestial bodies she studies are ancient, “my days never get old,” she says.

DENVER — Barnacles can tell a whale of a tale. Chemical clues inside barnacles that hitched rides on baleen whales millions of years ago could divulge ancient whale migration routes, new research suggests.

Modern baleen whales migrate thousands of kilometers annually between breeding and feeding grounds, but almost nothing is known about how these epic journeys have changed over time. Scientists can glean where an aquatic animal has lived based on its teeth. The mix of oxygen isotopes embedded inside newly formed tooth material depends on the region and local temperature, with more oxygen-18 used near the poles than near the equator. That oxygen provides a timeline of the animal’s travels. Baleen whales don’t have teeth, though. So paleobiologists Larry Taylor and Seth Finnegan, both of the University of California, Berkeley, looked at something else growing on whales: barnacles. Like teeth, barnacle shells take in oxygen as they grow.
Patterns of oxygen isotopes in layers of barnacle shells collected from modern beached whales matched known whale migration routes, Taylor said September 25 at the Geological Society of America’s annual meeting. Roughly 2-million-year-old barnacle fossils have analogous oxygen isotope changes, preliminary results suggest. Converting those changes into migration maps, however, will require reconstructing how oxygen isotopes were distributed long ago, Taylor said.

VANCOUVER — Traces of long-lost human cousins may be hiding in modern people’s DNA, a new computer analysis suggests.

People from Melanesia, a region in the South Pacific encompassing Papua New Guinea and surrounding islands, may carry genetic evidence of a previously unknown extinct hominid species, Ryan Bohlender reported October 20 at the annual meeting of the American Society of Human Genetics. That species is probably not Neandertal or Denisovan, but a different, related hominid group, said Bohlender, a statistical geneticist at the University of Texas MD Anderson Cancer Center in Houston. “We’re missing a population or we’re misunderstanding something about the relationships,” he said.
This mysterious relative was probably from a third branch of the hominid family tree that produced Neandertals and Denisovans, an extinct distant cousin of Neandertals. While many Neandertal fossils have been found in Europe and Asia, Denisovans are known only from DNA from a finger bone and a couple of teeth found in a Siberian cave (SN: 12/12/15, p. 14).

Bohlender isn’t the first to suggest that remnants of archaic human relatives may have been preserved in human DNA even though no fossil remains have been found. In 2012, another group of researchers suggested that some people in Africa carry DNA heirlooms from an extinct hominid species (SN: 9/8/12, p. 9).

Less than a decade ago, scientists discovered that human ancestors mixed with Neandertals. People outside of Africa still carry a small amount of Neandertal DNA, some of which may cause health problems (SN: 3/5/16, p. 18). Bohlender and colleagues calculate that Europeans and Chinese people carry a similar amount of Neandertal ancestry: about 2.8 percent. Europeans have no hint of Denisovan ancestry, and people in China have a tiny amount — 0.1 percent, according to Bohlender’s calculations. But 2.74 percent of the DNA in people in Papua New Guinea comes from Neandertals. And Bohlender estimates the amount of Denisovan DNA in Melanesians is about 1.11 percent, not the 3 to 6 percent estimated by other researchers.

While investigating the Denisovan discrepancy, Bohlender and colleagues came to the conclusion that a third group of hominids may have bred with the ancestors of Melanesians. “Human history is a lot more complicated than we thought it was,” Bohlender said.

Another group of researchers, led by Eske Willerslev, an evolutionary geneticist at the Natural History Museum of Denmark in Copenhagen, recently came to a similar conclusion. Willerslev’s group examined DNA from 83 aboriginal Australians and 25 people from native populations in the Papua New Guinea highlands (SN: 10/15/16, p. 6). The researchers found Denisovan-like DNA in the study volunteers, the group reported October 13 in Nature. But the DNA is genetically distinct from Denisovans and may be from another extinct hominid. “Who this group is we don’t know,” Willerslev says. They could be Homo erectus or the extinct hominids found in Indonesia known as Hobbits (SN: 4/30/16, p. 7), he speculates.
But researchers don’t know how genetically diverse Denisovans were, says Mattias Jakobsson, an evolutionary geneticist at Uppsala University in Sweden. A different branch of Denisovans could be the group that mated with ancestors of Australians and Papuans.

Researchers know so little about the genetic makeup of extinct groups that it’s hard to say whether the extinct hominid DNA actually came from an undiscovered species, said statistical geneticist Elizabeth Blue of the University of Washington in Seattle. DNA has been examined from few Neandertal fossils, and Denisovan remains have been found only in that single cave in Siberia. Denisovans may have been widespread and genetically diverse. If that were the case, said Blue, the Papuan’s DNA could have come from a Denisovan population that had been separated from the Siberian Denisovans for long enough that they looked like distinct groups, much as Europeans and Asians today are genetically different from each other. But if Denisovans were not genetically diverse, the mysterious extinct ancestor could well be another species, she said.

Jakobsson says he wouldn’t be surprised if there were other groups of extinct hominids that mingled with humans. “Modern humans and archaic humans have met many times and had many children together,” he said.