分类： science

Skywatchers across Australia are preparing for a once-in-a-generation celestial treat this coming Sunday, May 31, as two rare lunar phenomena align to create a unique blue micromoon visible to the naked eye across the entire country.

This extraordinary event marks the rare convergence of two distinct astronomical occurrences: a blue moon and a micromoon. Unlike common misconceptions, a blue moon does not refer to a change in the moon’s color; instead, it describes the second full moon that occurs within a single calendar month. This quirk of astronomy arises because the moon’s 29.5-day orbital cycle does not perfectly align with the 30- or 31-day structure of the Gregorian calendar, creating an extra full moon roughly once every two to three years. This May will play host to two full moons, with Sunday’s event earning it the blue moon title.

Compounding the rarity of the event, this blue moon coincides with a micromoon, a phenomenon that takes place when a full moon falls close to the apogee – the farthest point of the moon’s elliptical orbit around Earth. Data from astronomy tracking site Time and Date notes that micromoons appear roughly 6% smaller than an average full moon, and more than 12% smaller than their counterpart, the supermoon, which occurs when a full moon falls near the closest orbital point, the perigee.

Laura Driessen, a postdoctoral researcher at the Sydney Institute for Astronomy, explained that while the size difference is subtle to the untrained eye, the brightness of the event will be unmistakable. “It’s tens of thousands of times brighter than the brightest star in the night sky,” Driessen told SBS News. She added that the human eye cannot pick up the small size difference between a micromoon and a typical full moon – the change is only noticeable when side-by-side photographs of the two events are compared. “It will look like a beautiful full moon to us,” she confirmed.

Unlike many rare celestial events that require specific viewing locations or specialized equipment, this blue micromoon will be visible from every region of Australia, with no telescope required. The best viewing window is any time after dark on Sunday when the sky is clear of cloud cover. Peak fullness falls at slightly different times across Australia’s time zones: 6:45pm AEST for New South Wales, Queensland, Victoria, the Australian Capital Territory and Tasmania; 6:15pm ACST for South Australia and the Northern Territory; and 4:45pm AWST for Western Australia.

For the best viewing experience, astronomy enthusiasts recommend looking toward an unobstructed eastern horizon around moonrise or just after sunset, when the moon will often take on a soft golden-orange glow as it sits low in the sky. While no equipment is needed, a pair of binoculars can help bring out sharper details of the moon’s craters and surface features for interested observers.

For those who miss this weekend’s event, the next blue moon will not grace Earth’s skies until December 31, 2028, making this a rare opportunity that astronomy fans across Australia are not keen to miss.

As climate change continues to drive more frequent and severe heatwaves across the globe, new research has uncovered a sobering threat to one of Australia’s most iconic native species: even moderately warm sustained temperatures can drastically increase a koala’s risk of death or urgent medical intervention.

Published in the journal *Biology Letters* and led by researcher Valentina Mella from the University of Sydney, the study draws on more than two decades of koala rescue and mortality data from New South Wales (NSW), one of the species’ key remaining habitats. Analyzing nearly 12,000 records of koala admissions to care facilities and recorded deaths collected between 2000 and 2022 from local rescue groups and koala hospitals, the team built the first statistically verified link between long-term ambient temperature trends and koala mortality, adapting a methodology commonly used to study heat risk in human populations.

The research revealed a clear upward trend in danger as sustained average peak temperatures climb. When seven-day average maximum temperatures hit 27 degrees Celsius – a threshold most would consider mild rather than extreme – the odds of koalas being rescued or dying already began to climb. Once average peaks reached 30C or higher, those risks jumped to between 1.5 and 3.5 times the rate observed around 25C, according to Mella.

“Our findings suggest that even what might seem like moderate heat can become physiologically stressful when it is sustained over time,” Mella told AFP in an interview.

Koalas have evolved a suite of adaptations to survive Australia’s naturally warm climate. On short hot days, they cool off by hugging tree trunks to pull excess heat away from their bodies, retreat to dense foliage and lower tree branches away from direct sunlight, and conserve water by reabsorbing moisture from their colons and producing concentrated urine. They also use heterothermy, allowing their body temperatures to shift with surrounding conditions to reduce energy and water use. For short periods, the species can even survive temperatures above 40C.

But the study confirms that these adaptations are no match for prolonged heat, even at much lower, less alarming temperature thresholds. Mella explained that prolonged exposure to sustained moderate heat significantly undermines koalas’ health and ability to survive.

The species’ inherent biological traits and changing landscape make them uniquely vulnerable to rising temperatures compared to many other wild animals. Unlike creatures that can adapt to shifting conditions by changing their diets or moving to cooler habitats, koalas are largely sedentary, tied to specific forest ecosystems, and get most of their water from eucalyptus leaves. When high temperatures persist for days on end, koalas rapidly develop dangerous dehydration, and widespread habitat fragmentation often blocks their ability to travel to cooler, more shaded areas.

Koalas already fighting disease face even greater risk: the study found that individuals living with chlamydiosis, one of the most widespread and damaging diseases affecting wild koala populations, see their existing conditions worsened by heat stress, putting them at even higher risk of death.

These threats are growing worse by the year. As climate change pushes once-rare high temperatures to become a regular summertime occurrence, Mella noted that koalas will increasingly face prolonged periods of heat stress on an annual basis. The threat is particularly acute for already endangered inland northwest koala populations, which are exposed to more extreme heat and face the greatest risk of population collapse.

The study does offer clear pathways for intervention to reduce risk. Mella noted that protecting large, mature shade-producing trees and providing accessible water sources for koalas during heatwaves can cut rates of dehydration and death. Without targeted, proactive conservation action, however, the growing frequency of extreme heat events could push already vulnerable koala populations closer to permanent extinction.

The findings add to a growing body of evidence confirming that climate change does not only threaten human communities – it puts a wide range of wildlife species at growing risk of mortality and extinction, even through threats that may seem moderate at first glance.

Nearly 1,800 meters below the sunlit surface of the Pacific Ocean, off the rugged coast of the Galapagos Islands, a research submersible navigated the dark, unexplored abyssal plain and captured footage of a creature that would rewrite what we know about deep-sea cephalopod diversity. As the clear, blue-tinted image of the tiny animal beamed back to the research team on the surface, one excited researcher could not contain her awe, blurting out the simple, enthusiastic observation that has now become tied to the find: “He’s tiny! It’s blue!”

The discovery, formally published this week in the taxonomic journal *Zootaxa*, confirms the creature is a previously undocumented species of octopus, now officially named *Microeledone galapagensis*. The journey from first sighting to formal classification took nearly a decade, after the initial 2015 encounter near Darwin Island — the same Galapagos landmark that helped inspire Charles Darwin’s theory of evolution more than 180 years ago.

Octopus expert Janet Voight, a curator at Chicago’s Field Museum of Natural History, was brought on to identify the unusual specimen after the Charles Darwin Foundation research team captured it. Voight told Agence France-Presse that she recognized the creature was extraordinary from the first photographs she received. When the preserved specimen arrived in the mail weeks later, that initial excitement only grew: “When it arrived, I was like ‘Oh! My goodness! It’s beautiful,’” she said.

What struck Voight immediately was the strange geographic gap between this new octopus and its closest known relative. The most similar shaped octopus on record lives thousands of kilometers away off the coast of Uruguay, on the opposite side of the South American continent in a completely different ocean basin. This unexpected range separation adds new questions about the evolutionary history and dispersal of deep-sea octopus species.

Faced with only a single specimen, the research team refused to dissect the fragile animal for traditional anatomical study, a common step in describing new species. Instead, they turned to cutting-edge imaging technology: the Field Museum’s CT scanning lab captured thousands of high-resolution X-ray images, which were compiled into a detailed 3D model that revealed the octopus’s internal anatomy without damaging the irreplaceable specimen. “There’s nothing like spending the day looking at something no other human has ever seen,” said Stephanie Smith, head of the museum’s X-ray lab, in a public statement announcing the find.

Beyond its one-of-a-kind status as a new species, *Microeledone galapagensis* stands out for multiple unique traits. Most notably, its pale cerulean blue back is an extremely rare coloration in natural animal populations, while its underside is a striking deep purple. It is also the smallest known member of the Megaleledonidae family, a group of octopuses that typically grow to much larger sizes and are mostly found in the frigid Southern Ocean surrounding Antarctica.

Voight explained that the unusual two-tone color pattern likely serves an important defensive purpose. Deep-sea environments are home to many bioluminescent organisms that emit light when disturbed, and a glowing captured prey could draw the attention of larger predators. The octopus’s dark purple underside is used to cloak glowing prey it has captured, hiding the light and keeping the octopus concealed from larger hunters. Additional distinguishing features include its short, stubby arms that bear only a single row of suckers, and its uniquely smooth dorsal skin that sets it apart from other closely related species.

Despite the excitement of this new find, Voight emphasized that discoveries of new octopus species in the deep sea are far rarer than they should be — not because new species are uncommon, but because so little of the world’s deep ocean floor has been explored. To put that in perspective, Voight notes that if all of Earth’s landmasses were combined into a single continuous landmass, they would still not cover the area of the Pacific Ocean alone. The deep sea remains the largest and least explored ecosystem on the planet, meaning countless new species are still waiting to be discovered by researchers. Voight added that this is already the second new octopus species she has identified in just two years, following a 2023 discovery off the coast of Costa Rica.

China has successfully launched the Shenzhou-23 crewed spacecraft, marking another major milestone in its ambitious plan to land humans on the lunar surface by 2030, with the craft completing a smooth docking with the country’s Tiangong Space Station just hours after liftoff, according to official Chinese state media. This mission carries historic significance, as it includes the first ever astronaut from Hong Kong to travel to space, opening a new chapter in the region’s participation in China’s growing space exploration program.

The Long March 2-F carrier rocket lifted off on schedule at 11:08 pm Beijing Time Sunday (1508 GMT) from the Jiuquan Satellite Launch Center located in China’s arid northwestern Gobi Desert. Footage broadcast by China’s state-run CCTV captured the powerful launch, with the rocket ascending through the night sky, engulfed in bright orange flames and thick plumes of smoke. Roughly 10 minutes after liftoff, the Shenzhou-23 spacecraft successfully separated from the rocket and entered its planned orbit, the China Manned Space Agency (CMSA) confirmed in a social media statement shortly after launch. “All three astronauts are in good physical condition, and the launch mission has been declared a complete success,” the agency added.

Approximately 3.5 hours after entering orbit, the spacecraft completed an automated docking with the Tiangong Space Station, China’s permanent outpost in low-Earth orbit, state news agency Xinhua reported, citing CMSA updates. The three-member crew is led by 43-year-old Li Jiaying, a former Hong Kong police officer who makes history as the first Hong Kong-born astronaut to reach space. She is joined by two other crewmates: 39-year-old space engineer Zhu Yangzhu, and 39-year-old Zhang Zhiyuan, a former Chinese Air Force pilot who is making his first trip to space.

In pre-launch ceremonies held at the launch center, crowds of attendees waved national flags and cheered as the three crew members saluted from the stage, accompanied by a ceremonial performance from a military band. Once settled aboard Tiangong, the crew will conduct a wide range of scientific experiments across multiple disciplines, including life sciences, materials science, fluid physics, and biomedical research.

The centerpiece of the mission is a groundbreaking 12-month orbital stay for one crew member, a first for China’s manned space program that will generate critical data to support the country’s 2030 lunar landing goal. This long-duration mission is designed to study the physiological and psychological impacts of extended exposure to microgravity, a key area of research for any crewed deep space exploration effort, including future missions to Mars. CMSA has stated that the specific crew member selected for the full-year stay will be announced at a later date, based on the progress of the mission in its early phases.

Richard de Grijs, an astrophysicist and professor at Australia’s Macquarie University, outlined the unique challenges that this mission will address. Extended stays in space carry well-documented health risks for humans, including bone density loss, muscle atrophy, increased radiation exposure, sleep disruption, and cumulative mental and physical fatigue, he explained. Beyond human health, the mission will also test the reliability of critical life support systems, including closed-loop water and air recycling technologies, as well as protocols for managing potential medical emergencies thousands of kilometers from Earth.

De Grijs noted that the year-long mission represents a steady, deliberate step forward for China’s space program, building operational experience for long-term sustained occupation of the Tiangong Space Station and laying critical groundwork for future lunar and deep space exploration. “A 12-month orbital stay pushes both the program’s hardware and the astronauts themselves into a new operational domain, compared to the shorter six-month missions that have been standard for Shenzhou in earlier phases of the program,” he told Agence France-Presse. Prior to this mission, all crews rotating through Tiangong have served six-month tours of duty before being relieved by replacement crews.

Shenzhou-23 is a core part of China’s timeline to put astronauts on the Moon before 2030, a goal that puts Beijing in a friendly global space race with the United States, which is pursuing its own return to the Moon through the NASA-led Artemis program. China is already moving forward with testing the next-generation hardware needed for lunar missions, with an uncrewed orbital test flight of the new Mengzhou spacecraft planned for 2026. The Mengzhou craft will replace the current Shenzhou fleet, and is designed specifically to carry Chinese astronauts to the Moon. Beijing also aims to complete the first phase of its International Lunar Research Station, a permanent manned outpost on the lunar surface, by 2035.

Looking beyond its national program, China has plans to expand international collaboration in low-Earth orbit, with the first foreign astronaut – a Pakistani crew member – set to visit Tiangong by the end of 2024.

Over the past three decades, China has rapidly expanded its space exploration program, investing tens of billions of dollars into the sector to close the gap with long-established space powers including the United States, Russia, and Europe. The country has already notched multiple historic space firsts: in 2019, it became the first nation in the world to land a robotic probe, Chang’e-4, on the far side of the Moon, a feat no other space program had achieved. In 2021, China successfully landed a robotic rover on the surface of Mars, cementing its status as a major player in deep space exploration.

China’s development of an independent space station grew out of a political restriction: since 2011, the country has been excluded from participating in the U.S.-led International Space Station, after U.S. legislation banned NASA from any formal collaboration with Beijing. That restriction pushed China to pursue an entirely domestic space station program, which it completed with the construction of Tiangong in 2022.