Latest news with #radioastronomy
The Sun
2 days ago
- Science
- The Sun
‘Mystery pulse' spotted 25 miles ABOVE Antarctica is ‘unknown to science' as baffled experts say they ‘don't understand'
STRANGE radio pulses detected roughly 25 miles (40km) above Antarctica could be the mark of a new cosmic particle, according to a new study. This rare signal was first detected by the Antarctic Impulsive Transient Antenna (ANITA) in 2006, a series of tools floating over icy continent carried by balloons. 3 The now-retired ANITA experiment aimed to detect ultra-high-energy (UHE) cosmic neutrinos - or "ghost particles" - and other cosmic rays as they rain down on Earth from space. While ANITA usually picks up cosmic signals that bounce off the ice, this new radio pulse came from beneath the horizon and under the ice sheet. Its orientation cannot currently be explained by particle physics, a study in the journal Physical Review Letters wrote. A similar event was recorded in 2014, and it has continued to baffle scientists. The mysterious radio waves were being emitted at a steep angle below the ice, suggesting they had to pass through thousands of miles of rock before reaching ANITA. All those obstacles would typically leave a radio pulse too faint to be detectable - but not this signal. "It's an interesting problem, because we still don't actually have an explanation for what those anomalies are," ANITA team member and Penn State University researcher Stephanie Wissel said in a statement. "What we do know is that they're most likely not representing neutrinos." Scientists have ruled out neutrinos, the most common particle in the universe. Neutrinos are unofficially known as "ghost particles" due to the fact that they don't have any mass or carry any charge. "You have a billion neutrinos passing through your thumbnail at any moment, but neutrinos don't really interact," added Wissel. "So, this is the double-edged sword problem. If we detect them, it means they have traveled all this way without interacting with anything else. "We could be detecting a neutrino coming from the edge of the observable Universe." Scientists suspected that a supernova erupting in space could have coughed a slew of neutrinos in Earth's direction. An international team of researchers attempting to solve the mystery conducted a series of simulations to see if the 2006 and 2014 events align with any significant cosmic events, with data from the the Pierre Auger Observatory in Argentina. There was a supernova that aligned with the signals captured in 2014, but not the 2006 event. So there is no clear indication that this cosmic event is what caused the bizarre radio waves. What scientists have done, however, is narrow down their set of explanations. "My guess is that some interesting radio propagation effect occurs near ice and also near the horizon that I don't fully understand, but we certainly explored several of those, and we haven't been able to find any of those yet either," said Wissel. "So, right now, it's one of these long-standing mysteries, and I'm excited that when we fly [Payload for Ultrahigh Energy Observations], we'll have better sensitivity. "In principle, we should pick up more anomalies, and maybe we'll actually understand what they are. "We also might detect neutrinos, which would in some ways be a lot more exciting." 3
Yahoo
3 days ago
- Science
- Yahoo
Mysterious radio pulses detected high above Antarctica may be evidence of an exotic new particle, scientists say
When you buy through links on our articles, Future and its syndication partners may earn a commission. A cosmic particle detector has spotted a burst of strange radio signals from the ice of Antarctica that currently defy explanation. The results could hint at the existence of new particles, or interactions between particles currently unknown to physics, scientists say. The mystery radio pulses were picked up about 25 miles (40 kilometers) above Earth by the Antarctic Impulsive Transient Antenna (ANITA) experiment. ANITA is a series of instruments that float over Antarctica, carried by balloons with the aim of detecting ultra-high-energy (UHE) cosmic neutrinos and other cosmic rays as they pelt Earth from space. ANITA usually picks up signals when they are reflected off the ice of Antarctica, but these pulses were different, coming from below the horizon at an orientation that currently can't be explained by particle physics. "It's an interesting problem, because we still don't actually have an explanation for what those anomalies are," ANITA team member and Penn State University researcher Stephanie Wissel said in a statement. "What we do know is that they're most likely not representing neutrinos." The radio waves detected by ANITA were oriented at very steep angles, 30 degrees below the surface of the ice. This means that the signal had to pass through thousands of miles of rock before reaching ANITA. This should have led to interactions that left the radio pulses too faint to be detectable, but clearly that didn't happen here. The immediately obvious suspect for this signal is neutrinos. After all, it is the signature of these particles that ANITA is designed to pick up. Neutrinos are unofficially known as "ghost particles" due to the fact that they carry no charge and are virtually massless. Thus, as neutrinos — also the most abundant particles in the universe — stream through the cosmos at near-light speeds after being launched by powerful cosmic events, they can "phase" through matter, barely interacting. That means they remain unchanged after traversing many light-years, making them incredible "messengers" that can teach scientists about the events that launched them. However, this ghostly nature also makes neutrinos incredibly tough to detect. "You have a billion neutrinos passing through your thumbnail at any moment, but neutrinos don't really interact," Wissel said. "So, this is the double-edged sword problem. If we detect them, it means they have traveled all this way without interacting with anything else. We could be detecting a neutrino coming from the edge of the observable universe." Fortunately, even catching one neutrino as it passes through Earth can reveal a wealth of information. So, designing sophisticated experiments and taking them to remote regions of Earth or placing them deep underground in the hope of busting a cosmic ghost is well worth the effort for scientists like Wissel. "We use radio detectors to try to build really, really large neutrino telescopes so that we can go after a pretty low expected event rate," Wissel said. Just such an instrument, ANITA floats 25 miles over the ice of Antarctica, away from the possibility of other interfering signals, hunting for so-called "ice showers." "We point our antennas down at the ice and look for neutrinos that interact in the ice, producing radio emissions that we can then sense on our detectors," Wissel continued. These ice showers are caused by a particular "flavor" of neutrino called tau neutrinos, which strike the ice and interact to create a daughter particle called a tau lepton. This rapidly decays into an "air shower" containing even smaller constituent particles. Distinguishing between air showers and ice showers reveals the characteristics of the initial interacting particle and the origin of this particle. Wissel compares the strategy to using the angle of a bounced ball to trace it back to its initial path. However, because the angle of these newly detected signals is sharper than current models of physics allow, the backtracking process isn't possible in this case. Even more confusingly, other neutrino detectors like the IceCube Experiment and the Pierre Auger Observatory didn't detect anything that could explain these signals and the upward-oriented air shower. Thus, the ANITA researchers have declared the signals as "anomalous," determining they weren't the result of neutrinos. The signals could therefore be indicative of something new, perhaps even a hint of dark matter, the mysterious cosmic "stuff" that accounts for around 85% of the universe's matter content. Related Stories: — Scientists detect highest-energy ghost particle ever seen — where did it come from? — Elusive neutrinos caught streaming from a black hole hidden in dust — The greatest astronomical discoveries of the past 25 years Further answers may have to wait for the "next big thing" in neutrino detection, the larger and more sensitive Payload for Ultrahigh Energy Observations (PUEO) instrument, currently being developed by Penn State. "My guess is that some interesting radio propagation effect occurs near ice and also near the horizon that I don't fully understand, but we certainly explored several of those, and we haven't been able to find any of those yet either,' Wissel said. "So, right now, it's one of these long-standing mysteries, and I'm excited that when we fly PUEO, we'll have better sensitivity. "In principle, we should pick up more anomalies, and maybe we'll actually understand what they are. We also might detect neutrinos, which would in some ways be a lot more exciting."The team's research was published online in March in the journal Physical Review Letters.
Yahoo
3 days ago
- Science
- Yahoo
Starlink Satellites Are 'Leaking' Radio Emissions
Specialists at Australia's Square Kilometer Array (SKA) released a report this week showing Starlink's unexpected impact on radio astronomy. Despite national and international protections against radio emissions in certain bands, Starlink is clogging the skies with electromagnetic pollution. Light pollution stretches far beyond the hazy glow of a city on the horizon. Down in the radio portion of the electromagnetic spectrum, governments barter sections of light. Large portions of bandwidth stay reserved for the military, while others get auctioned off (sometimes literally) to communications companies. Squeezed in between these chunks of spectrum lie bands for public broadcasting, HAM radio, and science. Governments, corporations, and private citizens are supposed to stay away from protected bands so that radio telescopes can observe in peace. When the Starlink satellites launched, SpaceX collaborated with key radio astronomy observatories to avoid broadcasting while transiting above telescopes. Strategies include turning off Starlink WiFi services completely in certain regions of the sky. The resulting disruptions to Starlink operations are not insignificant. Spectrum management, especially in the United States, involves give-and-take on both sides. But American observatories have the benefit of observing at mid- to high-frequencies, at least by radio standards. Those frequency bands are less polluted than low frequencies, because emitting at low frequencies takes less energy and so costs less. If corporations and the military ignored protected bands, it would cause serious problems for radio astronomy. But a new study by engineers at the SKA suggests unintended electromagnetic radiation, or UEMR, may be a bigger issue than intended radiation. The SKA is still under construction. When completed, it will be the most powerful radio telescope in the world. The low-frequency part of the telescope (SKA-Low) is designed to go after trace echoes from when matter began to coalesce 13 billion years ago. SKA-Low looks odd even by the standards of radio telescopes. A thick forest of metallic Christmas trees in the Australian desert maximizes sensitivity to faint signals. But the new era of radio telescopes is butting up against a new era of satellites. There are more satellites in orbit than ever before, including massive networks of related satellites called constellations. With 7,000 satellites in Low Earth Orbit, Starlink is the biggest constellation. As they transit above SKA-Low, Starlink satellites release radio emissions through multiple protected bands. In a pre-print of their study, the SKA-Low team reports 112,534 intrusions of Starlink satellites in their radio images. Their month-long study showed that 30% of all Starlink satellites in the sky at the time appear in their data. Most of this emission seems to be accidental. UEMR from Starlink interfering with radio astronomy isn't unprecedented. During the initial launch phase, radio astronomers found that the propulsion system on the satellites emitted at unexpectedly low frequencies, decreasing the quality of astronomical data in an already polluted band. But the satellites had all been launched at the time of this new study. So where is all this radio pollution coming from? We don't know the various origins of the UEMR the SKA-Low team observed, except for one feature at 99.7 MHz. If that sounds like an FM radio band, it's no coincidence. Starlink satellites bounce FM radio shows back down to the Earth. For telescopes carefully located in radio-quiet zones, that's not ideal. Fixing this issue is particularly crucial to the success of SKA-Low, which seeks to look further back in time than any telescopes in a similar radio band. Signals from the early universe are very faint, and Starlink satellites are not. Unfortunately, the codes governing spectrum use only ban intended radio emission in protected bands. Consider a hyperbolic analogy: Imagine if murder were illegal, but manslaughter wasn't. Spectrum experts and regulators are currently discussing how to address this issue. For now, though, as long as Starlink is here, so are the unintended radio emissions.
The Herald
03-06-2025
- Politics
- The Herald
Scientists want astronomy-linked conditions on Starlink's SA licence deal
Di Vruno said the SKA Observatory, where he is spectrum manager, and the South African Radio Astronomy Observatory (Sarao) were lobbying for licence requirements to reduce the impact on observations in certain frequency ranges, including some that SKA-Mid uses. This could direct Starlink to steer satellite beams away from SKA receivers or stop transmission for a few seconds to minimise interference, he said. South Africa's SKA antennae, in the remote Northern Cape town of Carnarvon, uses the 350 megahertz to 15.4 gigahertz bandwidth, a range also used by most satellite operators for downlinks. The Independent Communications Authority of South Africa regulator and Starlink did not immediately respond to questions from Reuters about the scientists' concerns. South Africa's MeerKAT radio telescope, a precursor to SKA-Mid which will be incorporated into the larger instrument, has already discovered a rare giant radio galaxy that is 32 times the size of the Milky Way. Last year it found 49 new galaxies in under three hours, according to Sarao. SKA Observatory, an international body, also campaigns for conditions on licensing agreements with other major satellite operators such as Amazon and Eutelsat's OneWeb to ensure quiet skies amid a boom in new satellite launches. 'We are trying to follow different technical and regulatory avenues to mitigate this issue on the global stage,' Di Vruno said. Reuters
ABC News
28-05-2025
- General
- ABC News
Strange flashing object discovered in deep space puzzles astronomers
In the past few years, astronomers have recorded a handful of very strange radio signals, mostly coming from towards the centre of the Milky Way. Armed with increasingly powerful telescopes, they've detected objects that emit powerful bursts of energy a few times an hour, like a chiming clock — and then fall silent. The source of these "long-period radio transients", or LPTs, hasn't been nailed down, but it was thought they were caused by dead stars. But a newly discovered LPT, reported in the journal Nature, could shift our view about the origin of these mysterious objects. Unlike previous discoveries, this LPT also sends out X-ray pulses, making it the strangest one yet. An international team, led by Curtin University astronomer Ziteng Andy Wang, first detected a radio signal in data captured by the Australian Square Kilometre Array Pathfinder telescope (ASKAP) in Western Australia. Dubbed ASKAP J1832-0911, the object sent out radio waves for two minutes every 44 minutes. By chance the signal was also spotted by NASA's Chandra X-ray Observatory on Valentine's Day last year. Dr Wang said he was "pretty surprised" when he saw pulses of X-rays happening at the same time as the radio waves. "That is a huge discovery," Dr Wang said. The X-ray and radio pulses were emitted for a few weeks, and then fell silent. Had Chandra not been observing that patch of sky, the X-ray bursts would never have been detected. Astronomers have known about flashing objects since the 1960s, but until a few years ago, each one that had been recorded flickered very quickly, switching on and off every few seconds or minutes. Then, in 2022, an Australian-led team discovered an LPT which emitted super-bright radio waves regularly over hours. A handful of other LPTs have been discovered since. Researchers have proposed different theories for the source of these LPTs. One is a super-dense star called a neutron star that spins, regularly hitting Earth with a beam of energy from its poles. But these stars were thought to only be detectable when they were spinning very quickly, becoming too faint to see as they slowed down to LPT-level speeds. Or they could be weaker dead stars — white dwarfs — in binary systems, interacting with other stars. Michael Cowley, an astronomer at Queensland University of Technology who wasn't involved with the new research, pointed out a pre-print study from last year which supported this second theory. "This seemed like a reasonable answer and a promising step toward solving the puzzle," Dr Cowley said. But he said the detection of X-rays coming from ASKAP J1832-0911 "throws a spanner in the works". "Pulsed X-rays are usually associated with rotating neutron stars," Dr Cowley said. He believed this meant that LPTs could be coming from several different sources. "My takeaway is that LPTs don't appear to be a single phenomenon. Instead, they may represent a new category of objects, defined not by a shared origin but by how they behave." Dr Wang said it wasn't clear whether the new observation could be a white dwarf or a neutron star. "Both are possible, but personally I would prefer an isolated neutron star," he said. Whichever it is, the object has an extremely strong magnetic field, several billion times that of the Earth. This makes them very difficult to learn more about, according Stuart Ryder, an astronomer at Macquarie University who also wasn't involved with the research. "They're such extreme states of matter, we don't really have a good understanding of them because we can't replicate that here on Earth," Dr Ryder said. But the sheer weirdness of the object presents other opportunities. As radio telescopes improve, and more LPTs are discovered, they may help physicists understand how matter works in strange environments. "If we can study extra-strong magnetic fields in objects and elsewhere in the Universe, then we can learn a lot about the physics of matter," Dr Ryder said. He believes that understanding this extreme magnetism could help nudge science closer to clean nuclear fusion energy on Earth. "At the end of the day, a star is basically just a natural form of a fusion reactor, and we're trying to replicate those conditions in a very controlled manner here on Earth."
