Latest news with #astronomers
Daily Mail
4 hours ago
- Science
- Daily Mail
Dead NASA satellite inexplicably comes back to life to fire huge pulse that lit up the sky
A NASA satellite that had remained inactive in orbit for nearly six decades suddenly emitted a powerful radio signal, leaving astronomers around the world stunned. The brief but intense signal, detected by radio telescopes in Western Australia, lasted only a fraction of a second yet became the brightest object in the sky, momentarily outshining entire galaxies and stars. The source of this unexpected burst was Relay 2, a communications satellite launched by NASA in 1964. After both of its transmitters failed in 1967, the satellite had been silent and declared defunct until now. Experts believe the signal wasn't deliberately transmitted by the satellite, but was triggered by an external event. One possibility is an electrostatic discharge: a sudden release of electrical energy, similar to a spark, caused by the satellite building up charge as it orbits through Earth's magnetic field. Another theory is that a micrometeoroid, a tiny piece of rock traveling at high speed, struck Relay 2, causing a burst of heat and charged particles that emitted the brief but intense signal. The burst briefly emitted about 400 watts of power, similar to a small microwave oven. The fact that this signal remained that powerful after traveling from space to Earth makes it especially rare. Australian scientists, who were scanning the sky for fast radio bursts (FRBs)—short, high-energy flashes typically originating from deep space—made the startling discovery. According to NASA, FRBs can briefly outshine entire galaxies, a phenomenon that occurs in the blink of an eye. However, this signal was unique: it originated not from a distant galaxy but from within Earth's orbit, just about 2,800 miles above the planet's surface. 'We thought we might've found a new pulsar or a never-before-seen object,' Dr. Clancy James, lead researcher and associate professor at Curtin Institute of Radio Astronomy, told New Scientist. 'Instead, we saw an incredibly powerful radio pulse that eclipsed everything else in the sky for a split second.' The burst was detected by the Australian Square Kilometer Array Pathfinder (ASKAP), a network of 36 radio telescopes. Researchers quickly traced the source to Relay 2, which happened to be passing overhead at that exact moment. Despite lasting only nanoseconds, the radio burst was extraordinarily strong. Scientists estimated its strength at more than three million janskys, a unit used to measure radio wave intensity. That's roughly 100 billion times stronger than the radio signals from your typical smartphone. The shape of the signal was clean and well-defined, allowing scientists to analyze it in detail. Relay 2 was originally launched to improve satellite communication and conduct studies on Earth's radiation belts, areas filled with charged particles trapped by the planet's magnetic field. It carried two transmitters and was designed to spin for stability. But by mid-1967, both transmitters had failed, and the satellite became just another piece of space junk orbiting Earth. At first, researchers thought the detected signal came from a distant cosmic object. But a closer look confirmed it aligned exactly with Relay 2's position in the sky. 'This must have been caused by an external trigger, like an electrostatic discharge or a micrometeorite hit,' Dr. James explained. The burst lasted 1,000 times faster than previous electrostatic signals detected from satellites, which typically last a microsecond (one-millionth of a second). This makes it the fastest and most powerful signal of its kind ever recorded near Earth. While the signal caused a stir in the astronomy world, it also raised concerns. Many telescopes scan the sky for signals from far-off galaxies, and an unexpected burst from a nearby defunct satellite could cause confusion or lead to false discoveries. Still, some scientists see a silver lining. Dr Karen Aplin, a space weather expert at the University of Bristol, said this surprise detection could lead to new tools for studying electrical activity in space. 'It may ultimately offer a new technique to evaluate electrostatic discharges in orbit,' she said.
The Independent
7 hours ago
- Science
- The Independent
Astronomer reveals the exact time of this year's summer solstice
The summer solstice marks the official start of summer. It brings the longest day and shortest night of the year for the 88 per cent of Earth 's people who live in the Northern Hemisphere. People around the world traditionally observe the change of seasons with bonfires and festivals, and Fête de la Musique celebrations. Astronomers can calculate an exact moment for the solstice, when Earth reaches the point in its orbit where the North Pole is angled closest to the Sun. That moment will be at 10.42pm Eastern Time on June 20 this year - or 3.42am on June 21 in the United Kingdom. In Europe, Africa and points eastward, the moment of the equinox falls on June 21 locally, making that the day of the solstice. From Earth, the Sun will appear farthest north relative to the stars. People living on the Tropic of Cancer, 23.5 degrees north of the Equator, will see the Sun pass straight overhead at noon. Six months from now, the Sun will reach its southern extreme and pass overhead for people on the Tropic of Capricorn, and northerners will experience their shortest days of the year at the winter solstice. The Sun's angle relative to Earth's equator changes so gradually close to the solstices that, without instruments, the shift is difficult to perceive for about 10 days. This is the origin of the word solstice, which means 'solar standstill.' This slow shift means that daylight on June 20 is only about 2 seconds longer than on June 21, at mid-northern latitudes in the United States. It will be about a week before there's more than a minute change to the calculated amount of daylight. Even that's an approximation — Earth's atmosphere bends light over the horizon by different amounts depending on weather, which can introduce changes of more than a minute to sunrise and sunset times. Monuments at Stonehenge in England, Karnak in Egypt, and Chankillo in Peru reveal that people around the world have taken note of the Sun's northern and southern travels for more than 5,000 years. From Stonehenge's circle of standing stones, the Sun will rise directly over an ancient avenue leading away to the northeast on the solstice. We know little about the people who built Stonehenge, or why they went to such great effort to construct it, moving multi-ton stones from rock outcrops as far as 140 miles away. All this to mark the spot on the horizon where the Sun returns each year to rest for a while before moving south again. Perhaps they, like us, celebrated this signal of the coming change of seasons. Stephen Schneider is a Professor of Astronomy at UMass Amherst.
Yahoo
a day ago
- Science
- Yahoo
Astronomers Suggest That Entire Stars Are Being Obscured by Giant "Lampshades" of Dark Matter
Hunting for dark matter, the invisible substance thought to account for 85 percent of all mass in the cosmos, isn't easy. If it interacts with light at all, it does so incredibly weakly. Still, we can see its handiwork everywhere, with its gravitational pull determining the formation of everything from whole galaxies to individual stars. Now a team of astronomers is proposing a new technique for searching for dark matter — and it runs counter to its reputation as a completely invisible, light-inert presence haunting the universe. In a recent study published in the journal Physical Review Letters, the astronomers raise the possibility that clumps of the mysterious stuff could actually be acting as "lampshades" around stars, dimming their light just enough to be detectable by our present-day telescopes. "While we usually say dark matter does not interact with light at all, making it totally transparent and invisible, the truth is, it is allowed to interact with light a tiny bit," coauthor Melissa Diamond at Queen's University in Ontario, Canada, told "Dark matter might form large clumps or clouds, often called MACHOs," she continued. "There may be enough dark matter in these MACHOs that their weak interactions with light collectively block light from passing through the cloud, like how a lampshade blocks some but not all light from getting through." What dark matter actually is remains a mystery despite being a cornerstone of modern cosmology, but there are several strong candidates. The prevailing theory is that it's made of a hypothetical class of particles called weakly interacting massive particles, or WIMPs, which neither emit nor absorb light, don't interact with standard baryonic matter, and are slow and heavy enough to exert a powerful gravitational influence while clumping together. So far, experiments to detect WIMPs have been unsuccessful. For this latest study, the researchers explore another dark matter suspect called massive astrophysical compact halo objects, or MACHOs. Unlike other candidates, MACHOs are hypothesized, rather conveniently, to comprise ordinary matter. They aren't a substance hitherto unknown to science, but a hodgepodge of well-studied cosmic objects like ultra-dense neutron stars or black holes. Since these objects typically give off little to no light, that would explain why they go undetected by our telescopes, especially if they're isolated in the outskirts of their galaxy. Another key point is that MACHOs don't have to be the only type of dark matter out there — maybe it's a mix of WIMPs and other candidates. Astronomers have reported detections of MACHOs using a technique called gravitational microlensing. When the light from a background source is warped by the gravity of a massive object — like a MACHO — it gets bent in such a way that it acts like a natural lens, brightening the light. But this has its drawbacks. If the intervening object isn't massive enough, or if its matter is spread too thinly, then its lensing effect may be too slight to notice, Diamond explained. "This is where the lampshade effect can make a big difference," she told "While the clump might be too puffy to make for a good lens, it can still block some starlight, causing the star to dim instead of brightening." "The advantage of this technique is that it works for dark matter objects that are difficult or impossible to search for using available techniques," she added. And we can actually start looking for these lampshades now using surveys already available to us, like the Optical Gravitational Lensing Experiment — no new telescopes required. "This technique lets us get new use out of existing data, and lets us look for new types of MACHOs that microlensing surveys might not otherwise be sensitive to," Diamond told What makes this so exciting is that if these lampshade detections are borne out by the evidence, we'd gain a stronger idea of dark matter is, Diamond said. And if they aren't made, then we've narrowed down the list of dark matter candidates. As it stands, MACHO skeptics argue we haven't seen enough of these objects out there to account for all of dark matter. More on space: James Webb Peers Into Mysterious Haze Covering Pluto
Yahoo
a day ago
- Science
- Yahoo
'The models were right!' Astronomers locate universe's 'missing' matter in the largest cosmic structures
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have discovered a vast tendril of hot gas linking four galaxy clusters and stretching out for 23 million light-years, 230 times the length of our galaxy. With 10 times the mass of the Milky Way, this filamentary structure accounts for much of the universe's "missing matter," the search for which has baffled scientists for "missing matter" doesn't refer to dark matter, the mysterious stuff that remains effectively invisible because it doesn't interact with light (sadly, that remains an ongoing puzzle). Instead, it is "ordinary matter" made up of atoms, composed of electrons, protons, and neutrons (collectively called baryons) which make up stars, planets, moons, and our bodies. For decades, our best models of the universe have suggested that a third of the baryonic matter that should be out there in the cosmos is missing. This discovery of that missing matter suggests our best models of the universe were right all along. It could also reveal more about the "Cosmic Web," the vast structure along which entire galaxies grew and gathered during the earlier epochs of our 13.8 billion-year-old universe. The aforementioned models of the cosmos, including the standard model of cosmology, have long posited the idea that the missing baryonic matter of the universe is locked up in vast filaments of gas stretching between the densest pockets of space. Though astronomers have seen these filaments before, the fact that they are faint has meant that their light has been washed out by other sources like galaxies and supermassive black hole-powered quasars. That means the characteristics of these filaments have remained elusive. But now, a team of astronomers has for the first time been able to determine the properties of one of these filaments, which links four galactic clusters in the local universe. These four clusters are all part of the Shapley Supercluster, a gathering of over 8,000 galaxies forming one of the most massive structures in the nearby cosmos. "For the first time, our results closely match what we see in our leading model of the cosmos – something that's not happened before," team leader Konstantinos Migkas of Leiden Observatory in the Netherlands said in a statement. "It seems that the simulations were right all along." The newly observed filament isn't just extraordinary in terms of its mass and size; it also has a temperature of a staggering 18 million degrees Fahrenheit (10 million degrees Celsius). That's around 1,800 times hotter than the surface of the sun. The filament stretches diagonally through the Shapely Supercluster. Vital to the characterization of this filament was X-ray data from XMM-Newton and Suzaku, which made a great tag-team of telescopes. While Suzaku, a Japan Aerospace Exploration Agency (JAXA) satellite, mapped X-ray light over a vast region of space, the European Space Agency (ESA) operated XMM-Newton zoomed in of X-ray points from supermassive black holes studded within the filament, "contaminating" it."Thanks to XMM-Newton, we could identify and remove these cosmic contaminants, so we knew we were looking at the gas in the filament and nothing else," team member and University of Bonn researcher Florian Pacaud said. "Our approach was really successful, and reveals that the filament is exactly as we'd expect from our best large-scale simulations of the universe." The team then combined these X-ray observations with optical data from a plethora of other telescopes. Revealing this hitherto undiscovered tendril of hot matter connecting galaxy clusters has the potential to aid scientists' understanding of these extreme structures and how they are connected across vast cosmic distances. This could, in turn, aid our understanding of the Cosmic Web, filaments of matter that acted as a cosmic scaffold helping the universe to assemble in its current form. Related Stories: — Scientist image 3-million-light-year-long 'cosmic web' ensnaring 2 galaxies for 1st time — 'Superhighways' connecting the cosmic web could unlock secrets about dark matter — How does the Cosmic Web connect Taylor Swift and the last line of your 'celestial address?'years "This research is a great example of collaboration between telescopes, and creates a new benchmark for how to spot the light coming from the faint filaments of the cosmic web," XMM-Newton Project Scientist Norbert Schartel explained. "More fundamentally, it reinforces our standard model of the cosmos and validates decades of simulations: it seems that the 'missing' matter may truly be lurking in hard-to-see threads woven across the universe."The team's research was published on Thursday (June 19) in the journal Astronomy & Astrophysics.
Daily Mail
2 days ago
- Science
- Daily Mail
City-killer asteroid on a collision course with the moon could shower Earth with SHRAPNEL – causing 10-years of damage to satellites in just a few days, experts warn
The world breathed a sigh of relief when NASA confirmed the city-killer asteroid 2024 YR4 was no longer likely to hit Earth. But scientists now warn that the threat posed by this deadly space rock is far from over. Astronomers say that the 60-metre asteroid still has a 4.3 per cent chance of slamming into the moon on December 22, 2032. This collision would shower Earth with a wave of shrapnel that could wreak havoc on satellites in orbit. According to simulations created by Dr Paul Wiegert, of the University of Western Ontario, the asteroid could hit the moon at over 29,000mph (46,800 kmph), carving out a 0.6 mile-wide crater in the biggest lunar impact in the last 5,000 years. If the asteroid hits in the right place, Earth's gravity might funnel between 10 and 30 per cent of the ejected material directly towards our planet. And this could have devastating consequences for the thousands of satelites in low-Earth orbit. Dr Wiegert's calculations show that the shrapnel could cause up to a decade's worth of damage in just days. 2024 YR4 was first discovered in December 2024 and quickly caused concern among astronomers as the chances of an impact with Earth rose. At its peak, astronomers predicted that the asteroid had a 3.1 per cent chance of hitting Earth in 2032. While emergency observations from the James Webb Space Telescope (JWST) soon confirmed that the asteroid would miss Earth, it also revealed a surprisingly high probability of a lunar impact. At around 60 metres wide, the city-killer's impact would unleash a blast 500 times larger than the atomic bomb dropped on Hiroshima. On the moon, the absence of an atmosphere to slow the space rock's approach could mean an even bigger impact. By simulating 10,000 possible impact scenarios, Dr Wiegert found that this would eject around 10,000 tonnes of material between 0.1 to 10 millimetres in size. How much of this material travels towards us depends on where the asteroid lands, but the simulations suggest a scenario in which up to 10 per cent is delivered. This would lead to the Earth experiencing rates of particle impacts between 10 and 1,000 times higher than normal. Dr Wiergert told the New Scientist: 'We were a little bit surprised at the possibility of there being a substantial amount of material at the Earth. 'Intuitively, the Earth is actually quite a small target when seen from the moon, and so your intuition is that not very much material would actually hit the Earth, but it turns out that the Earth's gravity can focus that material under certain conditions.' None of this material is likely to make it through Earth's atmosphere, but it would create a severe problem for satellites in low-Earth orbit and other spacecraft. Dr Wiegert points out that this debris could even affect the operations of lunar-orbiting spacecraft such as NASA's planned Lunar Gateway. Any debris that doesn't escape orbit would rain back down on the moon, damaging landers, rovers, and even threatening the lives of astronauts in the Artemis program. However, this would be particularly dangerous for the large satellite constellations, such as SpaceX's Starlink satellites, currently in orbit. In a preprint paper, submitted to the American Astronomy Society Journals, Dr Wiegert predicts that a lunar impact could lead to 'hundreds to thousands of impacts from mm-sized debris'. If lots of satellites are hit at once, these impacts can easily combine to cause more widespread disruption. Professor Burchell, a space scientist from the University of Kent, told MailOnline: 'A lot of satellites failing at once is worse than occasional failures spread over a decade, as the latter can be more readily managed without stretching resources. 'If all at once, it would risk temporarily overwhelming the response with short-term loss of provision.' The impact from lunar debris would typically be small, but could cause problems that cannot easily be repaired. Research conducted by Professor Mark Burchell suggests that debris just one millimetre across is large enough to damage solar cells, sever cables, and even penetrate astronaut space suits. Pieces up to 10 millimetres in diameter are large enough to break into the interior of spacecraft and cause 'increasing damage'. Professor Burchell told MailOnline: 'If a sensor is damaged, or a piece of cabling, the satellite as a whole is still there, but may lose performance or some essential capability. 'Think of this as the difference between a car crash which wrecks your car and getting a chip on the windscreen. The former is clearly bad, but a chip? It is liveable in most cases, but may fail.' POTENTIAL METHODS FOR ELIMINATING THE THREAT OF AN ASTEROID DART is one of many concepts of how to negate the threat of an asteroid that have been suggested over the years. Multiple bumps Scientists in California have been firing projectiles at meteorites to simulate the best methods of altering the course of an asteroid so that it wouldn't hit Earth. According to the results so far, an asteroid like Bennu that is rich in carbon could need several small bumps to charge its course. 'These results indicate multiple successive impacts may be required to deflect rather than disrupt asteroids, particularly carbonaceous asteroids,' researchers said. Nuke Another idea, known simply as 'nuke', involves blowing up a nuclear explosive close to the asteroid. However, this could create smaller but still potentially dangerous fragments of rock that could spin off in all directions, potentially towards Earth. Ion Beam Deflection With Ion Beam Deflection, plumes from a space probe's thrusters would be directed towards the asteroid to gently push on its surface over a wide area. A thruster firing in the opposite direction would be needed to keep the spacecraft at a constant distance from the asteroid. Gravity tractor And yet another concept, gravity tractor, would deflect the asteroid without physically contacting it, but instead by using only its gravitational field to transmit a required impulse. Professor Colin Snodgrass, an astronomer at the University of Edinburgh said: 'There have been a few concepts suggested, such as a 'gravity tractor' to slowly tow an asteroid away instead of pushing it with a kinetic impactor.
