Artificial solar eclipses created by two European satellites
The European Space Agency released the eclipse pictures at the Paris Air Show yesterday. Launched late last year, the orbiting duo have churned out simulated solar eclipses since March while zooming tens of thousands of kilometres above Earth.
Flying 150 metres apart, one satellite blocks the sun like the moon does during a natural total solar eclipse as the other aims its telescope at the corona, the sun's outer atmosphere that forms a crown or halo of light.
It's an intricate, prolonged dance requiring extreme precision by the cube-shaped spacecraft, less than 1.5 metres in size. Their flying accuracy needs to be within a mere millimeter, the thickness of a fingernail. This meticulous positioning is achieved autonomously through GPS navigation, star trackers, lasers and radio links.
Dubbed Proba-3, the US$210 million (NZ$346.03 million) mission has generated 10 successful solar eclipses so far during the ongoing checkout phase. The longest eclipse lasted five hours, said the Royal Observatory of Belgium's Andrei Zhukov, the lead scientist for the orbiting corona-observing telescope. He and his team are aiming for a wondrous six hours of totality per eclipse once scientific observations begin in July.
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Scientists already are thrilled by the preliminary results that show the corona without the need for any special image processing, said Zhukov.
"We almost couldn't believe our eyes,' Zhukov said in an email. 'This was the first try, and it worked. It was so incredible.'
Two spacecraft of the Proba-3 mission aligning to create an eclipse to capture a coronagraph in space. (Source: Associated Press)
Zhukov anticipates an average of two solar eclipses per week being produced for a total of nearly 200 during the two-year mission, yielding more than 1000 hours of totality. That will be a scientific bonanza since full solar eclipses produce just a few minutes of totality when the moon lines up perfectly between Earth and the sun — on average just once every 18 months.
The sun continues to mystify scientists, especially its corona, which is hotter than the solar surface. Coronal mass ejections result in billions of tons of plasma and magnetic fields being hurled out into space. Geomagnetic storms can result, disrupting power and communication while lighting up the night sky with auroras in unexpected locales.
While previous satellites have generated imitation solar eclipses — including the European Space Agency and NASA's Solar Orbiter and Soho observatory — the sun-blocking disk was always on the same spacecraft as the corona-observing telescope. What makes this mission unique, Zhukov said, is that the sun-shrouding disk and telescope are on two different satellites and therefore far apart.
The distance between these two satellites will give scientists a better look at the part of the corona closest to the limb of the sun.
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"We are extremely satisfied by the quality of these images, and again this is really thanks to formation flying' with unprecedented accuracy, ESA's mission manager Damien Galano said from the Paris Air Show.
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The Spinoff
14-07-2025
- The Spinoff
Could we save the kererū by eating it?
Once so abundant they darkened the skies, kererū are now struggling to survive. Dr Madeline Shelling argues it's time to rethink our conservation model – and consider restoring tikanga-based harvesting to help save the bird. Prior to colonisation, native birds ruled the land of the long white cloud. Aotearoa was cloaked in dense, abundant forests, teeming with manu. Joseph Banks, the botanist aboard the Endeavour, even wrote the following in a diary entry dated January 1770, as they were parked offshore from Tōtaranui (Queen Charlotte Sound), Marlborough Sounds: 'This morn I was awakd by the singing of the birds ashore from whence we are distant not a quarter of a mile, the numbers of them were certainly very great.' But that's just one man's diary of a first encounter. It's a drop in the ocean compared to the vast mātauranga Māori and deep scientific ecological knowledge developed over hundreds of years of a sacred, symbiotic relationship. Kererū, also known as kūkū or kūkupa in Te Tai Tokerau, are an essential part of our forest ecosystem. With a slightly larger cousin on Rēkohu/Wharekauri (Chatham Island) called parea, these birds are the primary distributor of at least 11 of our biggest forest tree species; including karaka, miro, tawa, pūriri, and taraire. Deforestation and pest introduction have been the biggest drivers of their rapid decline since European arrival. They produce only one offspring per breeding season, and only breed on good fruiting seasons, making them even more vulnerable. While there are some success stories over decades of well-meaning efforts, kererū repopulation outside of pest-free sanctuaries is not fast enough to overcome predation and competition from cats, stoats, rats, possums and even myna birds. Once so plentiful they could block out the sun as they flocked in their hundreds, the protection of kererū requires a radical transformation. If they die out, our forest will forever struggle to regenerate itself. My solution? A carefully managed kererū repopulation programme that flips conventional conservation on its head. My goal is that through this programme, kererū once again become so abundant that it is no longer controversial to eat them. Phase one: Establish or partner with secure breeding facilities, large aviaries or pest-free sanctuaries dedicated to kererū reproduction. Phase two: Focus entirely on population recovery. Every single bird produced would be dedicated to boosting wild populations in predator-proof areas. Tree planting and pest eradication efforts will ramp up across the motu. Phase three: Once healthy population targets are met, introduce tightly regulated, tikanga-based quota systems allowing 1–2% of kererū to be harvested for ceremonial and customary use. Why eating kererū could save them Kererū were, and sometimes still are, a highly prized food source. By the 1860s, laws began to control hunting activities. From 1864, hunting seasons were set in certain areas for kererū and native ducks. In 1865, The Protection of Certain Animals Act prohibited using snares and traps to catch native birds – meaning that shooting became the only approved form of hunting. This restricted traditional methods that had ensured an ongoing food supply for whānau, but allowed Pākehā to continue hunting kererū as game. Disputes over the hunting season ensued, as Māori preferred late autumn and winter when the birds were fatter, while Pākehā preferred early autumn, when the birds were more agile, adding to the 'sport'. The law was repealed in 1866 but reinstated in 1907, when all hunting of native birds was outlawed. However, the reduction of the kererū population is not due to traditional harvesting, but the drastically destructive changes to their environment. Deforestation has stripped away the ancient forests that once provided abundant food and shelter. Introduced pests have decimated their numbers by preying on eggs and chicks, while also competing for food. These combined pressures have driven kererū populations into decline, despite hunting bans and conservation efforts. This raises a critical question: if the greatest threats to kererū are habitat loss and invasive species, where are our current conservation approaches falling short? Could a return to traditional practices – including consumption – be the key to saving them? Consumption as conservation Western conservation models are rooted in colonial ideas of European superiority, which promote 'preservationism' – building fences and restricting human activity. While effective in some contexts, this approach contradicts Indigenous active management strategies and undermines the rights and knowledge of Indigenous peoples, who have managed their lands sustainably for generations. As put by Catherine Delahunty: 'Pākehā environmental thinking is stuck in preservationism, as if the natural world was a museum or a magical depopulated Narnia where the plants and animals are waiting for the white ecologist rescuers to come and save them from evil.' On the other hand, indigenous management works in reciprocity with nature, emphasising stewardship, sustainable use, and co-existence – maintaining ecosystem health through active, place-based practices. Māori enactment of kaitiakitanga is not just for environmental and food security reasons – it also represents revitalisation of important cultural activities, allowing for the continuation and transmission of mātauranga Maori. In Tūhoe, generations have relied on a range of qualitative indicators, including visual (e.g. decreasing flock size), audible (e.g. less noise from kererū in the forest canopy), and harvest-related (e.g. steep decline in harvests since the 1950) indicators to monitor kererū abundance and condition in Te Urewera. They have consistently demonstrated that autonomy is vital, highlighting that the ability to make management decisions according to mātauranga is likely to yield more effective and sustainable outcomes, both ecologically and culturally. Mātauranga like this should guide transformational restoration efforts. However, Māori-led active management embedded in mātauranga and kaitiakitanga is a constant battle for recognition and meaningful integration in the conservation ideology of Aotearoa. This is certainly the case in Aotearoa, where Māori sovereignty and Te Tiriti-guaranteed rights to manage their own taonga species is often denied even at the highest level of government. While hunting kererū is illegal under the Wildlife Act 1953, te Tiriti o Waitangi guarantees full and undisturbed possession of taonga to Māori, which includes rights to harvesting. Hapū retain the right to enact kaitiakitanga, rangatiratanga and the responsibility to establish tikanga pertaining to the harvesting of kererū. Len Gillman, a biogeographer at Auckland University of Technology, also argues that sustainable harvesting of kererū could satisfy everyone's needs. Gillman suggests that careful management, including sustainable harvesting quotas based on kererū numbers and age distributions, holds great promise. Sustainable harvests would require robust monitoring and adaptive management, ensuring only surplus birds are taken and young birds have the opportunity to learn survival skills from older individuals. A kererū breeding programme with the end goal of reclaiming harvesting traditions would challenge preservationist ideals. However, it could strike the balance between conservation and Māori rights better than the Wildlife Act ever could. Active management based on tikanga, such as controlled harvests, quota systems, and qualitative environmental monitoring informed by mātauranga, can improve species resilience and restore ecological balance. The real question isn't whether we should eat kererū, but whether we can afford not to try radical solutions, because sometimes, saving a species might just mean putting it back on the menu.
Otago Daily Times
11-07-2025
- Otago Daily Times
Study casts magpies in new light
A bird now seen as an unwelcome Australian import may have much deeper roots in New Zealand than previously thought. Magpies, often regarded in Central Otago and elsewhere as aggressive invaders introduced from Australia in the 1860s, have long divided public opinion. But new research reveals their ancestors once lived in New Zealand — millions of years before European settlers arrived. Researchers from Canterbury Museum, the University of Canterbury, and Australian institutions, including Flinders and New South Wales universities, have spent more than 20 years studying fossils from the St Bathans area of Central Otago. Their work has now uncovered enough evidence to describe a new species of currawong — an ancient relative of the modern magpie. The newly identified species, named the St Bathans currawong, lived between 19 and 16 million years ago, during the Miocene era, in what was then a lush, forested landscape surrounding a large prehistoric lake. The bird, likely similar in size to today's Australian magpie but probably all black, appears to have gone extinct before the end of the Miocene period. Dr Paul Scofield, senior curator of natural history at Canterbury Museum and a co-author of the study, said the findings challenged the widespread belief magpies were foreign intruders with no historical place in New Zealand's environment. "We persecute the magpie as an Australian that has no place in the New Zealand ecosystem, but its close relatives lived here in the past," he said. "We've probably been without a member of the magpie's extended family for only five million years." Co-author Associate Prof Trevor Worthy of Flinders University said New Zealand's ecosystems had been constantly evolving for millions of years, waves of extinctions and new arrivals shaping biodiversity long before human settlement. "There's an idea that we should return New Zealand to a pre-European ecological state," he said. "But that ignores the fact that Aotearoa's ecosystems were already dramatically different by the time humans arrived." The fossil record shows species such as currawong and native pigeons disappeared as the country's floral diversity declined. Other groups of animals and plants have arrived during the past few thousand years, both naturally and through human influence. Dr Scofield said during the Miocene period, New Zealand forests would have looked more like Australian bushland, eucalypts, laurels and she-oaks ( Casuarina ) being common. A major climate cooling event around 13 million years ago led to the extinction of many warm-climate species, reshaping the ecosystem into the one seen today. Fossil evidence from St Bathans suggests a greater diversity of songbirds once filled the bush with birdsong. Together the findings suggest New Zealand's natural history is far more complex and dynamic than the idea of a static, untouched ecosystem. So instead of striving to recreate a specific past state, these scientists are saying we should embrace and protect the biodiversity we have. — APL
Otago Daily Times
08-07-2025
- Otago Daily Times
'Unprecedented' changes around Antarctic
By Eloise Gibson of RNZ Researchers have found evidence of a major shift in the circulation of the Southern Ocean which could accelerate climate change for the whole planet. They say the finding has caught them off-guard and that the sea ice around Antarctica could be in "terminal decline". The study, led by the University of Southampton in the United Kingdom and helped by Spanish and other European researchers, found evidence of a change which has shocked other researchers, and which could explain the region's rapid loss of sea ice. The authors say the circulation of the Southern Ocean has reversed. Typically, as global heating melts the ice around Antarctica, climate scientists would expect saltier water at the surface of the ocean to be replaced by fresh water, because melting ice typically makes the ocean fresher. But new satellite data shows the opposite is happening. Because salt water draws up heat from the deep ocean and makes it harder for sea ice to regrow - as well as bringing up carbon dioxide from the depths - a reversal could accelerate ice loss and global heating. The authors - who published their findings in the peer-reviewed journal PNAS - say their salt content measurements "can now provide a coherent explanation for the rapid Antarctic sea ice loss that had puzzled the scientific community". However, the consequences are potentially disruptive for the planet. They say the Southern Ocean plays an essential role in regulating the Earth's heat and carbon and its disruption could trigger cascading effects on other ocean circulation systems, with potential consequences as far away as Europe. "We are witnessing a true change in ocean properties in the Southern Hemisphere - something we've never seen before," said Antonio Turiel, co-author of the study, published by the Spanish marine research institute Institut de Ciències del Mar. "While the world is debating the potential collapse of the AMOC (Atlantic Meridional Overturning Circulation) in the North Atlantic, we're seeing that the Southern Ocean is drastically changing, as sea ice coverage declines and the upper ocean is becoming saltier. This could have unprecedented global climate impacts." "What we found was astonishing," said co-author Alessandro Silvano, an oceanographer at University of Southampton in a piece for The Conversation. "By combining satellite observations with data from underwater robots, we built a 15-year picture of changes in ocean salinity, temperature and sea ice," he said. "Around 2015, surface salinity in the Southern Ocean began rising sharply - just as sea ice extent started to crash. This reversal was completely unexpected." The fleet of underwater robots used in the study are Argo floats, many of them deployed by New Zealand scientists, which drift with ocean currents and return data that any scientist can use. More work urgently needed: NZ researchers The new paper does not explain why the reversal is happening, and New Zealand scientists say more work is urgently needed to complete the puzzle. For decades, the surface of the Southern Ocean was getting fresher and colder, helping sea ice expand - seemingly in defiance of global heating. At the same time, sea ice in the Arctic at the opposite pole was in freefall. Now Antarctic sea ice is also shrinking, contributing to a feedback loop where larger areas of darker open ocean reflect less of the sun's heat back than ice would have - further increasing the heating and melting. Professor Wolfgang Rack, a glaciologist at University of Canterbury and Director of Gateway Antarctica, said the growth of sea ice in the Southern Ocean was seen as climate paradox until it stopped around 2015. "Many scientists expected the trend to reverse at some point, but the rate of the current retreat is completely unexpected and mind boggling," he said. He said the ocean south of Wellington was the "most under-surveyed region globally" and more and urgent work was needed. Associate Professor Inga Smith, a sea ice physicist at the University of Otago, said the new results were "shocking" for those researching Antarctic sea ice. "In a warming world, fresher water from melting of land-based ice sheets and floating ice shelves would be expected to dominate at the ocean surface." Instead, the ocean surface was getting warmer and more salty right at the time the extent of the sea ice shrank. She said although the paper didn't explore why, "the authors will no doubt explore this in a longer paper sometime soon". Dr Ken Hughes, a senior lecturer in coastal processes at the University of Waikato, says when he first began research in 2012 scientists assumed that the ocean and big ice shelves buffered the Antarctic system in some way so that the warming climate was not wrecking havoc on the ice extent in the same way it was for the Arctic. That security could no longer be taken for granted, he said, and the most difficult question was whether the decline would continue. Professor James Renwick, a climate scientist at Victoria University of Wellington, said other research had shown how upper-ocean heat content and westerly winds were changing in the Southern Ocean. The new paper provided more evidence that climate change was causing a "major change" in the way the ocean was working, he said. "The implications are very worrying. "Antarctic sea ice extent will likely continue to trend downwards from here (with ups and downs from year to year). That will accelerate the melting of ice shelves and land-based ice, increasing the rate of sea level rise and pushing us closer to the irreversible loss of the West Antarctic ice sheet. It will also reduce the reflectivity of the planet, bringing more warming." Natalie Robinson, a marine physicist at Earth Sciences New Zealand (formerly NIWA) and associate professor at Victoria University, said despite covering only 17% of the planet, the Southern Ocean was a critical player in the global climate. The annual cycle of sea ice forming and shrinking was a major player in stabilising the climate, especially for New Zealand. "We are moving into uncharted climate territory," she said. "What happens in Antarctica has implications for the entire globe, but here in New Zealand we are impacted by changes to Antarctic sea ice more directly than most. "Early indications are that a warmer Southern Ocean, exacerbated by retreat of the sea ice edge, contributes to increased storminess for New Zealand. "When combined with the steadily warming waters of New Zealand's Exclusive Economic Zone, we should expect to see more of the intense rainfall events we've experienced recently, since warmer air can hold more moisture. "In order to secure a liveable future for ourselves and our children, it is imperative that we drastically reduce our reliance on fossil fuels."
