Latest news with #southernHemisphere
Yahoo
22-07-2025
- Science
- Yahoo
'Chaos' reigns beneath the ice of Jupiter moon Europa, James Webb Space Telescope reveals
When you buy through links on our articles, Future and its syndication partners may earn a commission. New observations from the James Webb Space Telescope (JWST) are painting a new picture of Jupiter's moon Europa and revealing the hidden chemistry of the icy moon's interior. For decades, scientists pictured Europa's frozen surface as a still, silent shell. But the new observations reveal that it's actually a dynamic world that's far from frozen in time. "We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly," Richard Cartwright, a spectroscopist at Johns Hopkins University's Applied Physics Laboratory and lead author of the new study, said in a statement. Perhaps even more exciting is what this surface activity reveals about Europa's subsurface ocean. The presence of geologic activity and ongoing cycling between the subsurface and surface make "chaos terrains" — highly disrupted regions where blocks of ice seem to have broken off, drifted and refrozen — especially valuable as potential windows into Europa's interior. The study focused on two regions in Europa's southern hemisphere: Tara Regio and Powys Regio. Tara Regio, in particular, stands out as one of the moon's most intriguing areas. Observations from JWST detected crystalline ice both at the surface and deeper below — challenging previous assumptions about how ice is distributed on Europa. Related: Explore Jupiter's icy ocean moon Europa in NASA virtual tour (photos) By measuring the spectral properties of these "chaos" regions using remotely sensed data, scientists could gain valuable insight about Europa's chemistry as well as its potential for habitability, they explained in the paper, which was published May 28 in The Planetary Science Journal. "Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean nearly 20 miles (30 kilometers) beneath Europa's thick icy shell," Ujjwal Raut, program manager at the Southwest Research Institute and co-author of the study, said in the statement. Hidden chemistry Raut and his team conducted laboratory experiments to study how water freezes on Europa, where the surface is constantly bombarded by charged particles from space. Unlike on Earth, where ice naturally forms a hexagonal crystal structure, the intense radiation on Europa disrupts the ice's structure, causing it to become what's known as amorphous ice — a disordered, noncrystalline form. The experiments played a crucial role in demonstrating how the ice changes over time. By studying how the ice transforms between different states, scientists can learn more about the moon's surface dynamics. When combined with fresh data from JWST, these findings add to a growing body of evidence showing that a vast, hidden liquid ocean lies beneath Europa's icy shell. "In this same region […] we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean," Cartwright said. "We also see some of the strongest evidence for CO2 and hydrogen peroxide on Europa. The chemistry in this location is really strange and exciting." These regions, marked by fractured surface features, may point to geologic activity pushing material up from beneath Europa's icy shell. JWST's NIRSpec instrument is especially well suited for studying Europa's surface because it can detect key chemical signatures across a wide range of infrared wavelengths. This includes features associated with crystalline water ice and a specific form of carbon dioxide called ¹³CO₂, which are important for understanding the moon's geologic and chemical processes. NIRSpec can measure these features all at once while also creating detailed maps that show how these materials are distributed across Europa's surface. Its high sensitivity and ability to collect both spectral and spatial data make it an ideal tool for uncovering clues about what lies beneath Europa's icy crust. The team detected higher levels of carbon dioxide in these areas than in surrounding regions. They concluded that it likely originates from the subsurface ocean rather than from external sources like meteorites, which would have resulted in a more even distribution. Moreover, carbon dioxide is unstable under Europa's intense radiation environment, suggesting that these deposits are relatively recent and tied to ongoing geological processes. "The evidence for a liquid ocean underneath Europa's icy shell is mounting, which makes this so exciting as we continue to learn more," Raut said. RELATED STORIES —NASA Juno spacecraft picks up hints of activity on Jupiter's icy moon Europa —Jupiter's ocean moon Europa may have less oxygen than we thought —What next for NASA's Europa Clipper? The long road to Jupiter and its moons Another intriguing finding was the presence of carbon-13, an isotope of carbon. "Where is this 13CO2 coming from? It's hard to explain, but every road leads back to an internal origin, which is in line with other hypotheses about the origin of 12CO2 detected in Tara Regio," Cartwright said. This study arrives as NASA's Europa Clipper mission is currently en route to the Jovian moon, with an expected arrival in April 2030. The spacecraft will perform dozens of flybys, with each one bringing it closer to Europa's surface to gather critical data about the ocean hidden beneath the moon's icy crust. 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Daily Mail
19-06-2025
- Climate
- Daily Mail
Australia braces for the darkest week of the year during the winter solstice
Millions of Australians will shiver through the darkest week of the year as the annual winter solstice approaches this weekend. The southern hemisphere's winter solstice on Saturday, June 21, marks the shortest day and longest night of the year based on the time between sunrise and sunset. The three days before and after the solstice will contribute to a seven-day period with the least amount of daylight for the year. Hobart will have the shortest day, while Darwin will have the longest. The sun will rise at 7.42am in the island state and set at 4.43pm, while in Darwin, the sun will come up at 3.36am and set at 6pm. Darwin's day length will be 11 hours and 24 minutes compare to just nine hours and one minute in Hobart. Each hemisphere has a winter solstice, spaced six months apart. The southern hemisphere marks the winter solstice when the sun appears to be at the lowest point in the sky when viewed from the equator. The days will slowly begin to get longer and the nights shorter in the next six months until the summer solstice arrives in Australia between December 21 and 22. The solstice is caused by Earth's tilt on its axis and its orbital motion around the sun. The Earth is tilted on its axis by 23.5degrees with the tilt allowing northern and southern hemispheres to trade places in receiving the sun's light and warmth. It's the Earth's tilt, not its distance from the sun, that causes winter and summer.
RNZ News
11-06-2025
- Business
- RNZ News
'We're quite excited': Fieldays farmer spending tipped to hit new highs
The southern hemisphere's largest agricultural event is a ritual for many farmers, but this year it's hoped there'll also be record spending. Huge numbers are rolling into Fieldays in Hamilton which kicked off today, with an estimated 100,000 people expected to attend between Wednesday and Saturday. With a farmgate milk price of $10, record beef prices and strong sheep meat returns - the rural sector is on the up. Combine that with the government's recent move to allow farmers to deduct 20 percent off new farm equipment from their taxable income , and the prediction is sales could reach new highs. The Minister of Agriculture also announced a $4 million boost to rural wellbeing, and Prime Minister Christopher Luxon said during his visit to Fieldays that he wanted farmers to know they were "deeply loved" by the government. That's certainly something that agricultural machinery companies are feeling, down at the Husqvarna stand there were plenty of smiles and national sales manager Steve Middleton told RNZ there had been a recent uptick in spending and mood amongst farmers. Steve Middleton says sales are on the upward curve. Photo: RNZ / Marika Khabazi "We're seeing an improvement, there's been a lot of signals in the market place in the rural sector that we're seeing signs of the times getting better and farmers are looking to spend some of the cash they've built up. "We're definitely seeing it come through particularly in robotic auto mowers and lawn tractors - it's positive and we are on the upward curve now," he said. Palmerston North dairy farmers Christian Allen and Anna Maley believe the 20 percent tax reduction will make a difference. "Farm owners I think will be more willing to spend a bit more money and upgrade some gear considering it's 20 percent off you can get back. Palmerston North dairy farmers Christian Allen and Anna Maley. Photo: RNZ / Marika Khabazi "Farmers with older tractors that have done seven or eight thousand hours, it'll be more appealing to trade it in and get a new one, less hassle," he said. A sentiment that has businesses feeling optimistic. CNH business manager John Gilbert told RNZ that sales of Case and New Holland tractors were likely to be high at this year's Fieldays. "We're quite excited, I think there's a sense of a mood shift. Last year we sold 40 tractors at Fieldays and this year we're hoping to eclipse that. "With the tax boost announced a few weeks ago by government that's really got people talking and we've seen evidence of that already in the market - people are buying tractors," Gilbert said. John Gilbert is expecting this year's sales to eclipse last year's. Photo: RNZ / Marika Khabazi However, that's not the case for all of the 1200 exhibitors at Fieldays. A few tents along at the All Trade Tools stand, key account manager Rodney Smith told RNZ their clients, many DIYers and tradies, were not doing as well as farmers at the moment. "It's been tough for us out there, we're down considerably year on year. We're finding the DIY market is non existent at the moment. "I think interest rates, mortgages - people don't have that money in their pocket to go out and spend a couple hundred dollars on something they really don't need," he said. A cautious approach the Jowsey family is taking, they farm sheep and beef in Raglan and mum Amber said even in the good seasons, they were always careful. "You've still got to stay within your limits but farmgate prices are pretty good so doesn't feel bad like last year... for sure," she said. The Jowsey family from Raglan on their annual trip to Fieldays. Photo: RNZ / Marika Khabazi Husband Clint Jowsey is eyeing up solar water pumps, and is relieved to see the rural economy doing well. "I reckon it's going pretty good at the moment, it's ticking over," he said. Whangārei farmers Julie and Bruce Paton are also looking for some Fieldays deals such as water tanks. "We certainly feel we can spend a bit more this year. Because we're in dairy and beef, and both are up, so why wouldn't we be positive about that," they said. Whangārei farmers Julie and Bruce Paton on their annual Fieldays trip. Photo: RNZ / Marika Khabazi Sign up for Ngā Pitopito Kōrero , a daily newsletter curated by our editors and delivered straight to your inbox every weekday.
Bloomberg
22-05-2025
- Science
- Bloomberg
Penguin Poop Could Limit Global Warming's Impact on Antarctica
Large colonies of penguins in Antarctica have an ability to influence the atmosphere and could be helping reduce the impact of climate change, according to a scientific study. Accumulated penguin excrement — or guano — emits ammonia, a gas that can contribute to the formation of clouds and which is likely generating a cooling effect by creating a buffer between the sun's heat and Antarctica's ice and water.
The Guardian
06-05-2025
- Science
- The Guardian
What is the best time to see the Eta Aquariids meteor shower? Where and how can I see it in Australia?
Stargazers and early risers are in for a stellar show this week, with one of the biggest meteor showers in the southern hemisphere due to light up the skies. The meteors — called the Eta Aquariids – pass through the atmosphere every year, but 2025 is due to be particularly luminous as the moon won't be visible when they arrive. Here's how to catch a view of the celestial delight. What is the best time to see the Eta Aquariids meteor shower? The good thing is this particular meteor shower not only happens every year, but spans multiple days. McElroy said Wednesday 7 May would be the 'best day' for stargazers, with around two dozen meteors expected to pass per hour. But if it happens to be cloudy that day, you won't blink and miss it. The shower will continue to have a strong showing on the days preceding and following 7 May, before tapering off at the end of the month. 'Often these things are quite short-lived … it'll peak this week but it will continue,' McElroy said. Unfortunately, though, the best viewing window is between 3am and 5am – 'not for the faint-hearted or those who feel the cold'. If you happen to find yourself awake in the early dawn, though, you're in luck. Where can I watch the Eta Aquarrids? The Eta Aquariids can be viewed anywhere in the world, but they are best seen from the southern hemisphere where the shower will rise in the pre-dawn, darkened sky. In Australia, every state and territory will be able to witness the display. But McElroy said areas with the lowest light pollution would have the greatest visibility – such as Uluru and remote parts of the Northern Territory. 'These things aren't enormously bright, so you want to get away from as much light pollution as you can,' McElroy said. 'If you're in the city, get into the suburbs and away from bright lights.' Australia is lucky. McElroy said the best skies she has seen have been in Australia and in Chile because they look towards the centre of the Milky Way. 'In the northern hemisphere, you spend most of the year looking to the outskirts, but our winter happens to have the Milky Way's centre up in sky, and parts of Australia are very dark with a lot of protected [areas], like national parks,' she said. What are the best stargazing tips for how to watch? After heading outside, McElroy said you should first 'check the weather … That's the most important part. If it's cloudy you're not going to see anything, which is the curse of astronomy.' Then, turn off any porch or external lights and look away from bright street lights or your phone – which resets our daytime vision. 'Our eyes have a high dynamic range, and it takes 10 to 20 minutes to adjust to the night sky,' McElroy said. 'Grab a blanket, have a lie down and stay out there for an hour.' The constellation of Aquarius, where the meteors will appear, are in the north-east of the sky. Apps such as Star Mapper or Stellarium can help display the correct spot – but make sure you keep your brightness down. Why does the meteor shower occur? The Eta Aquariids are caused by Earth passing through debris left behind by Halley's Comet hundreds of years ago. Dr Rebecca McElroy, an astrophysicist from the University of Southern Queensland, said Earth passes through the debris field every year. As the bits of rock and dust hit the atmosphere at high speeds, they burn up and create bright streaks – creating what we call meteors. 'Meteors tend to look like a bright streak going by, like a shooting star, but more,' McElroy said. 'Occasionally they happen just randomly – when something of a high density is in our path.' It is known as 'Eta Aquariids' because of the part of the sky in which the meteors appear – which is near the star Eta Aquarii in the constellation of Aquarius.
