Latest news with #Astrophysics
Gizmodo
2 days ago
- General
- Gizmodo
Scientists Are Creeping Closer to Colorized Black Hole Images
Black holes are infamous for being invisible. But thanks to a new technique from the Event Horizon Telescope (EHT) team, we're about to start seeing them in color. Astronomers have figured out a way to observe the radio sky in multiple frequencies at once, allowing them to create full-color images of supermassive black holes. The breakthrough is built on a technique called frequency phase transfer, which lets scientists correct for atmospheric interference in real time across multiple radio bands. In plain English: They've basically figured out how to give radio telescopes a multi-color vision upgrade. Sara Issaoun, a researcher at the Center for Astrophysics | Harvard & Smithsonian, led the team, whose research was recently published in The Astronomical Journal. The Event Horizon Telescope (EHT) stunned the world in 2019 with the first image of a black hole—M87*, followed in 2022 by Sagittarius A*, the supermassive black hole at our galaxy's center. Now, scientists are planning a $300 million space-based successor mission, the Event Horizon Explorer, designed to sharpen those images tenfold and reveal the elusive photon rings that may confirm black hole spin and push the limits of general relativity. Meanwhile, some researchers have challenged aspects of the original Sgr A* image, proposing that its accretion disk may be more elongated than ring-like—an open question future observations may resolve. Similar to how our eyes take in visible light's various wavelengths and interpret them as a range of colors, radio telescopes capture slices of invisible radio light in specific frequency bands. Stitch enough of those slices together and you get something like a color image—just not in the visible spectrum. But until now, most radio telescopes could only observe one frequency band at a time. That's fine when astronomers' target is a distant galaxy that appears sedentary against the cosmos. But if scientists are trying to image a rapidly spinning black hole spewing relativistic jets, or wobbling from gravitational forces, the radio data can't be captured in a single image. The object simply moves so fast that multiple exposures can't be layered in a coherent way. Enter frequency phase transfer. As reported in Universe Today, the team was able to track atmospheric distortions in their observations at one wavelength and sharpen the image in a different wavelength. (Correcting for atmospheric distortion is a regular problem for Earth-based observatories, but new technologies are allowing telescopes to overcome this longstanding hurdle in ground-based astronomy). The team's new black hole imaging method is still experimental, but the proof-of-concept means we're on the cusp of getting sharper, truer images of the most extreme objects in the universe. Next-gen observatories like the EHT and Black Hole Explorer (BHEX) are already gearing up to use this method, bringing us one step closer to seeing a black hole in all its violent and vivid brilliance.
The Sun
4 days ago
- General
- The Sun
Sun hiding ‘invisible asteroid threat' as scientists warn Earth risks ‘collision' with ‘highly chaotic' Venus space rock
A FIELD of at least 20 asteroids has been found lurking near Venus, having previously been hidden by the Sun's glare, experts have revealed. The belt of asteroids is currently co-orbiting Venus, swinging around Earth's closest planetary neighbour with differing proximities to our planet. 3 Scientists from Brazil have warned that there could be more asteroids hiding near Venus, and that they may even pose a risk to Earth. "Twenty co-orbital asteroids of Venus are currently known," the authors wrote in their study, published in the journal Astronomy & Astrophysics. "Co-orbital status protects these asteroids from close approaches to Venus, but it does not protect them from encountering Earth." Asteroids are considered potentially hazardous asteroids (PHA) if they have a diameter of at least 140 metres and come within 0.05 astronomical units of Earth's orbit, according to experts. "We aim to assess the possible threat that the yet undetected population of Venus co-orbiters may pose to Earth, and to investigate their detectability from Earth and space observatories," the authors wrote. 3 Only one of the 20 known asteroids has an orbital eccentricity below 0.38 - with 0 being a perfectly circular orbit and 1 meaning an elliptical or oval-shaped orbit. This means some asteroids with wider orbits will be easier to spot, but those with minor orbital eccentricities may be difficult to detect. However, Venus asteroids with an orbital eccentricity higher than 0.38 could "pose a collisional hazard to Earth," the researchers warned. Co-orbital asteroids - ones that share an orbit with their nearby planet - are also known for having unpredictable orbits. This makes it harder to figure out how dangerous they are. Cold War era Soviet spaceship that was meant to reach Venus to FINALLY crash back to Earth at 17,000mph "The co-orbital asteroids of Venus are highly chaotic, with Lyapunov times of the order of 150 years," the authors explained. The Lyapunov time refers to how long an object's orbit takes to become unpredictable because of chaotic dynamics. So scientists have no idea how the orbit of an asteroid will evolve over the next 150 years, and if it could collide with Earth in the future. It's unclear how big the Venus asteroids are. But even a relatively small asteroid of 150 meters in diameter could strike Earth with a force equal to hundreds of megatons of TNT, Universe Today reported. For context, that is thousands of times more potent than the atomic bombs dropped in World War 2. The researchers said that more research is required to determine just how many asteroids are hiding near Venus. But since they are only observable periodically due to the Sun's glare, research from Earth's perspective might be difficult - even with powerful telescopes. The researchers suggest, therefore, that the best way to learn more about these hidden asteroids is to get a closer look. "Observations conducted from Venus' orbit, positioned facing away from the Sun, may enhance the detection of these bodies," the researchers explained.
New York Times
08-05-2025
- Science
- New York Times
Quote of the Day: Spacecraft Lost in 1972 Is Coming Back to Earth
'It's going to get its moment in atmospheric entry — albeit on the wrong planet.' JONATHAN MCDOWELL, an astronomer at the Harvard & Smithsonian Center for Astrophysics who maintains a catalog of space objects, on the Kosmos-482, a half-ton Soviet-era craft which never made it to its planned destination of Venus and was expected to re-enter Earth's atmosphere this weekend.
The Independent
06-05-2025
- Science
- The Independent
Soviet spacecraft expected to crash land on Earth in just days. Here's what to know
A piece of Soviet-era space debris is expected to crash land down to Earth this weekend. The Russian Kosmos 482 spacecraft launched in 1972 could come plunging down some time between Friday and Sunday, according to NASA – but exactly when and where is currently a mystery. As of Tuesday, the lander probe could strike between 52 degrees north latitude and 52 degrees south latitude, including all of Africa, South America, Australia, New Zealand, most of Europe and Asia, and the continental U.S. Experts say people shouldn't be 'too worried,' but that they cannot exclude the chance of the spacecraft actually hitting someone or something. "There's a not-trivial chance that it could hit somewhere where it damages property, and there's a small chance — but it's like one in thousands — that it could hurt someone,' Dr. Jonathan McDowell, an astronomer at the Center for Astrophysics at Harvard & Smithsonian, told NPR. A more accurate location and timeline should be known over the coming days, but NASA said the uncertainty 'will be fairly significant right up to reentry.' For now, here's what to know. It can take the heat 'Because the probe was designed to withstand entry into the Venus atmosphere, it's possible the probe (or parts of it) will survive reentry at Earth and reach the surface,' the space agency warned. Although Venus isn't the closest planet to the sun, it is the hottest. The average surface temperature of the planet is a blistering 870 degrees Fahrenheit. Comparatively, when the future Orion spacecraft comes back from the moon, it will experience temperatures around 5,000 degrees Fahrenheit as it screams back into Earth's atmosphere at 25,000 miles per hour. The extreme temperatures are why most falling debris burn up upon re-entry. It was once larger Hundreds of objects enter Earth's atmosphere every year. At least three old satellites or rocket bodies come down every day. Most objects that don't burn up and disintegrate fall into the ocean, which covers 70 percent of Earth's surface. It is rare for this debris to cause damage, but it does happen. With an increasing number of satellites in low-Earth orbit, the situation has become more precarious. Over time, the atmospheric drag slowly lowers the orbit of space debris like Kosmos 482. The Venus probe failed to escape low-Earth orbit after its launch in 1972. Instead, the spherical, 1,000-pound object broke into four pieces after its rocket malfunctioned. Two of them decayed, and the lander probe — which has a parachute that may be visible right now — and another piece went higher. 'It is thought that a malfunction resulted in an engine burn which did not achieve sufficient velocity for the Venus transfer, and left the payload in this elliptical Earth orbit,' NASA said. Scientists are still working to study Venus The 1972 launch came toward the end of the space race. The Soviet Union had been launching Kosmos spacecraft ten years before Kosmos 482. Kosmos 482 was a sister probe to the successful Venera . Since then, dozens of other missions have been launched to explore Venus.
Morocco World
18-03-2025
- Climate
- Morocco World
5.1 Magnitude Earthquake Hits Algeria
Rabat – Algeria felt an earthquake of 5.1 magnitude, which struck the northwestern region of Mihoub in the Medea province today. The earthquake struck the country at 10:50 a.m. this morning, Algerie360 reported citing the Research Center in Astronomy, Astrophysics, and Geophysics. The news report said Algerians based in the capital and surrounding provinces felt the tremor, causing panic. 'Residents of Algiers, as well as neighboring provinces such as Blida, Medea, Bouira, Boumerdes, and Tizi-Ouzou, reported feeling the vibrations,' the news outlet said, noting that the tremor caused no material or human damage. The report further said that teams have been deployed to inspect infrastructure and ensure citizens' safety. Algeria's Civil Protection stated that their units are carrying out 'reconnaissance operations in the provinces that felt the earthquake, such as Algiers, Tizi Ouzou, Bouira, Medea, Boumerdes, and Blida,' also noting that no injuries have been reported. Tags: 4.2 magnitude earthquakeAlgeria
