Latest news with #Icarus
NDTV
2 days ago
- Science
- NDTV
Earth May Have At Least Six "Minimoons" At Any Given Time: Study
Scientists estimate that Earth may have at least six "minimoons" at any given time. Notably, this number is uncertain, and the researchers have called for further observations to confirm. As per the study published in the journal Icarus, the minimoon is a colloquial term for natural objects that complete an orbit around the Earth within a geocentric distance of three Earth Hill radii while being temporarily bound in the Earth-Moon system (EMS). Scientists said minimoons are small, rocky fragments that temporarily orbit Earth before eventually moving on to circle the sun. They're usually less than 6.5 feet (2 metres) in size and can originate from various areas in the solar system, the study revealed. Robert Jedicke, a researcher at the University of Hawaii and lead author of the study, told that it's "kind of like a square dance, where partners change regularly and sometimes leave the dance floor for a while." The research suggests that minimoons may come from the Moon rather than the asteroid belt, as previously thought. This theory is supported by the discovery of minimoons with lunar-like compositions, such as 2024 PT5. It's difficult to detect minimoons because of their small size and high speeds. As per the research, they can complete one rotation in under an hour and may showcase unique orbital patterns. "Detecting objects in that size range means they have to be close so they are bright, but if they are close, it means they also appear to be moving quickly across the sky," Jedicke said. "It is incredible that modern telescopic surveys have the ability to detect such small objects up to millions of kilometres away." Studying minimoons can provide insights into the Moon's history and crater formation process. They could also have commercial applications, such as resource extraction. Minimoons "may help reveal how the solar system formed and continues to evolve," Jedicke said
CNN
6 days ago
- Science
- CNN
Two meteorites found in the Sahara could be from the solar system's least studied rocky planet, scientists say
Researchers suspect that two meteorites found in the Sahara Desert in 2023 may originally have come from Mercury, which would make them the first identified fragments of the solar system's innermost planet. The least studied and most mysterious of the solar system's rocky planets, Mercury is so close to the sun that exploring it is difficult even for probes. Only two uncrewed spacecraft have visited it to date — Mariner 10, launched in 1973, and MESSENGER, launched in 2004. A third, BepiColombo, is en route and due to enter orbit around the planet in late 2026. Scientists know little about Mercury's geology and composition, and they have never been able to study a fragment of the planet that landed on Earth as a meteorite. In contrast, there are more than 1,100 known samples from the moon and Mars in the database of the Meteoritical Society, an organization that catalogs all known meteorites. These 1,100 meteorites originated as fragments flung from the surfaces of the moon and Mars during asteroid impacts before making their way to Earth after a journey through space. Not every planet is likely to eject fragments of itself Earth-ward during collisions. Though Venus is closer to us than Mars is, its greater gravitational pull and thick atmosphere may prevent the launch of impact debris. But some astronomers believe that Mercury should be capable of generating meteors. 'Based on the amount of lunar and Martian meteorites, we should have around 10 Mercury meteorites, according to dynamical modeling,' said Ben Rider-Stokes, a postdoctoral researcher in achondrite meteorites at the UK's Open University and lead author of a study on the Sahara meteorites, published in June in the journal Icarus. 'However, Mercury is a lot closer to the sun, so anything that's ejected off Mercury also has to escape the sun's gravity to get to us. It is dynamically possible, just a lot harder. No one has confidently identified a meteorite from Mercury as of yet,' he said, adding that no mission thus far has been capable of bringing back physical samples from the planet either. If the two meteorites found in 2023 — named Northwest Africa 15915 (NWA 15915) and Ksar Ghilane 022 (KG 022) — were confirmed to be from Mercury, they would greatly advance scientists' understanding of the planet, according to Rider-Stokes. But he and his coauthors are the first to warn of some inconsistencies in matching those space rocks to what scientists know about Mercury. The biggest is that the fragments appear to have formed about 500 million years earlier than the surface of Mercury itself. However, according to Rider-Stokes, this finding could be based on inaccurate estimates, making a conclusive assessment unlikely. 'Until we return material from Mercury or visit the surface,' he said, 'it will be very difficult to confidently prove, and disprove, a Mercurian origin for these samples.' But there are some compositional clues that suggest the meteorites might have a link to the planet closest to the sun. It's not the first time that known meteorites have been associated with Mercury. The previous best candidate, based on the level of interest it piqued in astronomers, was a fragment called Northwest Africa (NWA) 7325, which was reportedly found in southern Morocco in early 2012. Rider-Stokes said that was the first meteorite to be potentially associated with Mercury: 'It got a lot of attention. A lot of people got very excited about it.' Further analysis, however, showed a richness in chrome at odds with Mercury's predicted surface composition. More recently, astronomers have suggested that a class of meteorites called aubrites — from a small meteorite that landed in 1836 in Aubres, France — might come from Mercury's mantle, the layer below the surface. However, these meteorites lack a chemical compatibility with what astronomers know about the planet's surface, Rider-Stokes said. 'That's what's so exciting about the samples that we studied — they have sort of the perfect chemistry to be representative of Mercury,' he said. Most of what is known about Mercury's surface and composition comes from NASA's MESSENGER probe, which assessed the makeup of the planet's crust from orbit. Both meteorites from the study, which Rider-Stokes analyzed with several instruments including an electron microscope, contain olivine and pyroxene, two iron-poor minerals confirmed by MESSENGER to be present on Mercury. The new analysis also revealed a complete lack of iron in the space rock samples, which is consistent with scientists' assumptions about the planet's surface. However, the meteorites contained only trace amounts of plagioclase, a mineral believed to dominate Mercury's surface. The biggest point of uncertainty, though, is still the meteorites' age. 'They are about 4.5 billion years old,' Rider-Stokes said, 'and most of Mercury's surface is only about 4 billion years old, so there's a 500 million-year difference.' However, he said he thinks this discrepancy is not sufficient to rule out a Mercurian origin, due to the limited reliability of MESSENGER's data, which has been also used to estimate the age of Mercury's surface layer. 'These estimates are based on impact cratering models and not absolute age dating, and therefore may not be entirely accurate,' Rider-Stokes said. 'It doesn't mean that these samples aren't good analogs for regional areas on the surface of Mercury, or the early Mercurian crust that is not visible on the modern surface of Mercury.' With more modern instruments now available, BepiColombo, the European Space Agency probe that will start studying Mercury in early 2027, may be able to answer long-standing questions about the planet, such as where it formed and whether it has any water. Having material confirmed to have come from other planetary bodies helps astronomers understand the nature of early solar system's building blocks, Rider-Stokes said, and identifying fragments of Mercury would be especially crucial since a mission to gather samples from the planet closest to the sun and bring them back would be extremely challenging and expensive. Sean Solomon, principal investigator for NASA's MESSENGER mission to Mercury, said in an email that he believes the two meteorites described in the recent paper likely did not originate from Mercury. Solomon, an adjunct senior research scientist at Columbia University in New York City, was not involved with the study. The primary reason Solomon cited for his doubts is that the meteorites formed much earlier than the best estimates for the ages of rocks now on Mercury's surface. But he said he thinks the samples still hold research value. 'Nonetheless, the two meteorites share many geochemical characteristics with Mercury surface materials, including little to no iron … and the presence of sulfur-rich minerals,' he added. 'These chemical traits have been interpreted to indicate that Mercury formed from precursor materials much more chemically reduced than those that formed Earth and the other inner planets. It may be that remnants of Mercury precursor materials still remain among meteorite parent bodies somewhere in the inner solar system, so the possibility that these two meteorites sample such materials warrants additional study.' Solomon also noted that it was difficult to persuade the planetary science community that there were samples from Mars in meteorite collections, and that it took precise matching of their chemistry with data about the surface of Mars taken by the Viking probes to convince researchers to take a closer look. Lunar meteorites were also not broadly acknowledged to be in meteorite collections until after the existence of Martian meteorites had been demonstrated in the 1980s, he added, even though the Apollo and Luna missions had returned abundant samples of lunar materials more than a decade earlier. Once samples are confirmed to be from a planetary body, Solomon said, they can provide crucial information not available from remote sensing by an orbiting spacecraft on the timing of key geological processes, the history of internal melting of the body, and clues to planet formation and early solar system processes. Rider-Stokes plans to continue the discussion around these meteorites at the annual meeting of the Meteoritical Society, which takes place in Perth this week. 'I'm going to discuss my findings with other academics across the world,' he said. 'At the moment, we can't definitively prove that these aren't from Mercury, so until that can be done, I think these samples will remain a major topic of debate across the planetary science community.'
Belfast Telegraph
7 days ago
- Entertainment
- Belfast Telegraph
Five of the best sports documentaries of all time (and where to watch them)
The great thing about sports documentaries is that they can cover a huge, HUGE amount of events. Obviously, the stuff that immediately comes to mind are the huge sporting events from around the world, but if you think smaller, think more niche, there is very likely a fantastic documentary dealing with that event too. Fascinated by deep-sea diving? A must-watch for you is The Deepest Breath. A lover of e-sports? Then you have to check out The King Of Kong. Looking for something completely left field but still super competitive? Spellbound is the one for you, set in the world of spelling bees. Sports fans tend to follow more than just the games—news, stats, even things like betting offers often come up in the mix. These documentaries tap into that same wide interest, showing how deep the love for competition can go. See what we mean? There is quite literally something for everyone. Whittling down that list to five of the best is tough, but these picks are tremendous, and some of the best movies ever made, not just under the banner of sports documentaries. So on with our five picks, and where to watch them* right now: Free Solo – Disney+ From the description alone, you would be forgiven for thinking this isn't going to be THAT interesting a watch, as the documentary profiles rock climber Alex Honnold on his quest to perform the first-ever free solo climb of a route on El Capitan, a vertical rock formation found in Yosemite National Park in California. So you'll have to trust us when we tell you this is one of the most edge-of-your-seat movies you'll ever see, and it proved to be so impressive that it went on to win the Best Documentary Oscar back in 2019. Murderball – rent on Apple TV This documentary focuses on the intense rivalry between the American and Canadian wheelchair rugby teams in the run-up to the 2004 Paralympic Games taking place in Athens, Greece. We get to know the players and their families, who all talk openly and frankly about their injuries, personal lives, and the love of the game that has them all vying for the gold. This movie was nominated for Best Documentary at the 2006 Oscars, but lost out to March of the Penguins. Icarus – Netflix Some of the best documentaries are those that begin filming with something specific in mind – in this case, director Bryan Fogel wanted to expose the inadequacy of the procedures to catch athletes using performance-enhancing substances – but become something else over the course of the movie being made – here, the World Anti-Doping Agency's investigation of doping in Russia led to the head of the Moscow Anti-Doping Laboratory to flee his country and become a whistleblower. Icarus went on to win the 2018 Best Documentary Feature Oscar. Senna – Netflix Arguably one of the best and most impactful documentaries not to even be nominated for an Oscar, this film tells the story of much-loved Brazilian motor-racing champion Ayrton Senna. Directed by Asif Kapadia (who went on to win an Oscar in 2016 for his Amy Winehouse documentary), it tells us about Senna's life, death, and intimate rivalry with fellow driver Alain Prost through archival race footage and home video recorded by Senna's friends and family. When We Were Kings – Sky/NOW Another Best Documentary Picture winner, focusing on the night of The Rumble in the Jungle in 1974. Betting offers on underdog Muhammad Ali were 4-1 against the then-unbeaten, heavy-hitting George Forman. It took director Leon Gast over 22 years to edit and finance before it could be released in 2006, when it was met with immediate critical acclaim, and the movie is still considered to be one of the best sports documentaries ever made.
Yahoo
15-07-2025
- Science
- Yahoo
Earth may have at least 6 'minimoons' at any given time. Where do they come from?
When you buy through links on our articles, Future and its syndication partners may earn a commission. Half a dozen fragments of the moon may briefly orbit Earth at any given time, before moving on to circle the sun, new research suggests — but the minimoons' small size and quick pace make them challenging to spot. When objects collide with the moon, they send up a shower of material, some of which manages to escape into space. Although there may be an occasional large chunk, most are fast-moving and smaller than 6.5 feet (2 meters) in diameter. The bulk of the lunar material falls into orbit around the more gravitationally attractive sun. But some of the debris may occasionally be pulled into an orbit around Earth before returning to circle the sun, researchers explained in a study published in the journal Icarus. It's "kind of like a square dance, where partners change regularly and sometimes leave the dance floor for a while," Robert Jedicke, a researcher at the University of Hawaii and lead author of the study, told by email. Although the International Astronomical Union doesn't have an official definition, previous research suggested that a minimoon could be an object that is at least temporarily bound to Earth, makes at least one revolution of the planet, and is closer than about four times the Earth-moon distance at some point in its orbit. Minimoons can come from anywhere in the solar system, but a 2018 study suggested most come from the region of the asteroid belt, between the orbits of Mars and Jupiter. The recent appearance of minimoons from the moon, however, is calling that finding into question. In 2016, the Pan-STARRS1 asteroid survey telescope in Hawaii spotted a 131- to 328-foot-wide (40 to 100 meters) near-Earth object identified as Kamo'oalewa, or "469219 Kamo'oalewa," orbiting the sun in sync with Earth. Later studies revealed that Kamo'oalewa was a slice of the moon excavated between 1 million and 10 million years ago in the crash that formed the Giordano Bruno crater. Earlier this year, astronomers announced that a second temporary terrestrial satellite appeared to have a lunar origin. Discovered last year, the object — called 2024 PT5 — looks more like the moon than an asteroid. Together, these two objects suggest that the moon could be birthing its own tiny moons. So Jedicke and his colleagues decided to calculate just how many lunar minimoons might exist. Relying on simulations of how particles blown from the moon might behave, they found that many of the particles blasted into space could be captured at least temporarily by Earth, and about a fifth of them were likely to become minimoons. The new findings nominally predict that 6.5 lunar-born satellites may be circling Earth at a time. The individual objects are changeable; if they could be counted today, and then again in a year, some would be new objects. A typical minimoon dances around Earth for an average of about nine months, Jedicke said, and these minimoons are constantly replenished from the material traveling in an Earth-like orbit. But when it comes to nailing down the predicted number of minimoons, Jedicke cautioned that the uncertainty is "ginormous — many orders of magnitude." That's due to many unknowns, including the size of a crater formed by an impact and the size and speed distribution of the ejected material. "If there were that many [temporarily bound objects], the telescopic surveys would probably detect more of them," Jedicke said. "So the nominal prediction is almost certainly wrong. That's science." Because science builds on new information, identifications of more lunar minimoons and a better understanding of their size distribution will help to refine that prediction and provide new insight into the crater formation process. Due to their size, the tiny, temporary moons are challenging to spot. The problem relates to both their size and their speed. With most of the fragments ranging from 3 to 7 feet (1 to 2 m) in diameter, even the most seasoned instruments can struggle to detect them. Jedicke compares them to a car or an SUV. "Detecting objects in that size range means they have to be close so they are bright, but if they are close, it means they also appear to be moving quickly across the sky," Jedicke said. "It is incredible that modern telescopic surveys have the ability to detect such small objects up to millions of kilometers away." In massive sky surveys, computers usually work to pull out motion. When minimoons are close enough to be seen, their rapid motion may leave trails, rather than spots, on images of the sky. "Trails are more difficult for computer algorithms to identify," Jedicke said. RELATED STORIES —Newborn moon may have had many mini-siblings in Earth orbit long ago —Earth's mini-moon has finally departed. Will it ever return as a 'second moon?' —NASA raises the odds that an asteroid could hit the moon in 2032 But all is not lost. The new research suggests that 2020 CD3 was visible to the Catalina Sky Survey on only two of the roughly 1,000 nights the object was in range. The successful detection bodes well for future observations. Once the objects have been identified, tracking becomes easier because astronomers know where and when to look for the minimoons. These brief visitors could also have intriguing commercial applications, since they would require the least amount of fuel to visit, Jedicke said. Instead of flying to the asteroid belt to extract water, minerals and other commercially desirable elements, companies could find ways to snag the transients as they briefly orbit Earth. From a scientific perspective, minimoons and their kin "may help reveal how the solar system formed and continues to evolve," Jedicke said. Understanding how lunar debris was flung off of the moon during an impact can help researchers better understand and estimate damage due to asteroid impacts on Earth.
Yahoo
14-07-2025
- Science
- Yahoo
Researchers may have solved mystery of Mercury's missing meteorites, but doubts remain
Researchers suspect that two meteorites found in the Sahara Desert in 2023 may originally have come from Mercury, which would make them the first identified fragments of the solar system's innermost planet. The least studied and most mysterious of the solar system's rocky planets, Mercury is so close to the sun that exploring it is difficult even for probes. Only two uncrewed spacecraft have visited it to date — Mariner 10, launched in 1973, and MESSENGER, launched in 2004. A third, BepiColombo, is en route and due to enter orbit around the planet in late 2026. Scientists know little about Mercury's geology and composition, and they have never been able to study a fragment of the planet that landed on Earth as a meteorite. In contrast, there are more than 1,100 known samples from the moon and Mars in the database of the Meteoritical Society, an organization that catalogs all known meteorites. These 1,100 meteorites originated as fragments flung from the surfaces of the moon and Mars during asteroid impacts before making their way to Earth after a journey through space. Not every planet is likely to eject fragments of itself Earth-ward during collisions. Though Venus is closer to us than Mars is, its greater gravitational pull and thick atmosphere may prevent the launch of impact debris. But some astronomers believe that Mercury should be capable of generating meteors. 'Based on the amount of lunar and Martian meteorites, we should have around 10 Mercury meteorites, according to dynamical modeling,' said Ben Rider-Stokes, a postdoctoral researcher in achondrite meteorites at the UK's Open University and lead author of a study on the Sahara meteorites, published in June in the journal Icarus. 'However, Mercury is a lot closer to the sun, so anything that's ejected off Mercury also has to escape the sun's gravity to get to us. It is dynamically possible, just a lot harder. No one has confidently identified a meteorite from Mercury as of yet,' he said, adding that no mission thus far has been capable of bringing back physical samples from the planet either. If the two meteorites found in 2023 — named Northwest Africa 15915 (NWA 15915) and Ksar Ghilane 022 (KG 022) — were confirmed to be from Mercury, they would greatly advance scientists' understanding of the planet, according to Rider-Stokes. But he and his coauthors are the first to warn of some inconsistencies in matching those space rocks to what scientists know about Mercury. The biggest is that the fragments appear to have formed about 500 million years earlier than the surface of Mercury itself. However, according to Rider-Stokes, this finding could be based on inaccurate estimates, making a conclusive assessment unlikely. 'Until we return material from Mercury or visit the surface,' he said, 'it will be very difficult to confidently prove, and disprove, a Mercurian origin for these samples.' But there are some compositional clues that suggest the meteorites might have a link to the planet closest to the sun. It's not the first time that known meteorites have been associated with Mercury. The previous best candidate, based on the level of interest it piqued in astronomers, was a fragment called Northwest Africa (NWA) 7325, which was reportedly found in southern Morocco in early 2012. Rider-Stokes said that was the first meteorite to be potentially associated with Mercury: 'It got a lot of attention. A lot of people got very excited about it.' Further analysis, however, showed a richness in chrome at odds with Mercury's predicted surface composition. More recently, astronomers have suggested that a class of meteorites called aubrites — from a small meteorite that landed in 1836 in Aubres, France — might come from Mercury's mantle, the layer below the surface. However, these meteorites lack a chemical compatibility with what astronomers know about the planet's surface, Rider-Stokes said. 'That's what's so exciting about the samples that we studied — they have sort of the perfect chemistry to be representative of Mercury,' he said. Most of what is known about Mercury's surface and composition comes from NASA's MESSENGER probe, which assessed the makeup of the planet's crust from orbit. Both meteorites from the study, which Rider-Stokes analyzed with several instruments including an electron microscope, contain olivine and pyroxene, two iron-poor minerals confirmed by MESSENGER to be present on Mercury. The new analysis also revealed a complete lack of iron in the space rock samples, which is consistent with scientists' assumptions about the planet's surface. However, the meteorites contained only trace amounts of plagioclase, a mineral believed to dominate Mercury's surface. The biggest point of uncertainty, though, is still the meteorites' age. 'They are about 4.5 billion years old,' Rider-Stokes said, 'and most of Mercury's surface is only about 4 billion years old, so there's a 500 million-year difference.' However, he said he thinks this discrepancy is not sufficient to rule out a Mercurian origin, due to the limited reliability of MESSENGER's data, which has been also used to estimate the age of Mercury's surface layer. 'These estimates are based on impact cratering models and not absolute age dating, and therefore may not be entirely accurate,' Rider-Stokes said. 'It doesn't mean that these samples aren't good analogs for regional areas on the surface of Mercury, or the early Mercurian crust that is not visible on the modern surface of Mercury.' With more modern instruments now available, BepiColombo, the European Space Agency probe that will start studying Mercury in early 2027, may be able to answer long-standing questions about the planet, such as where it formed and whether it has any water. Having material confirmed to have come from other planetary bodies helps astronomers understand the nature of early solar system's building blocks, Rider-Stokes said, and identifying fragments of Mercury would be especially crucial since a mission to gather samples from the planet closest to the sun and bring them back would be extremely challenging and expensive. Sean Solomon, principal investigator for NASA's MESSENGER mission to Mercury, said in an email that he believes the two meteorites described in the recent paper likely did not originate from Mercury. Solomon, an adjunct senior research scientist at Columbia University in New York City, was not involved with the study. The primary reason Solomon cited for his doubts is that the meteorites formed much earlier than the best estimates for the ages of rocks now on Mercury's surface. But he said he thinks the samples still hold research value. 'Nonetheless, the two meteorites share many geochemical characteristics with Mercury surface materials, including little to no iron … and the presence of sulfur-rich minerals,' he added. 'These chemical traits have been interpreted to indicate that Mercury formed from precursor materials much more chemically reduced than those that formed Earth and the other inner planets. It may be that remnants of Mercury precursor materials still remain among meteorite parent bodies somewhere in the inner solar system, so the possibility that these two meteorites sample such materials warrants additional study.' Solomon also noted that it was difficult to persuade the planetary science community that there were samples from Mars in meteorite collections, and that it took precise matching of their chemistry with data about the surface of Mars taken by the Viking probes to convince researchers to take a closer look. Lunar meteorites were also not broadly acknowledged to be in meteorite collections until after the existence of Martian meteorites had been demonstrated in the 1980s, he added, even though the Apollo and Luna missions had returned abundant samples of lunar materials more than a decade earlier. Once samples are confirmed to be from a planetary body, Solomon said, they can provide crucial information not available from remote sensing by an orbiting spacecraft on the timing of key geological processes, the history of internal melting of the body, and clues to planet formation and early solar system processes. Rider-Stokes plans to continue the discussion around these meteorites at the annual meeting of the Meteoritical Society, which takes place in Perth this week. 'I'm going to discuss my findings with other academics across the world,' he said. 'At the moment, we can't definitively prove that these aren't from Mercury, so until that can be done, I think these samples will remain a major topic of debate across the planetary science community.'
