Longtime Slashdot reader fahrbot-bot shares a report from NewScientist: According to quantum chromodynamics (QCD) -- widely considered to be our best theory for describing the strong force, which binds quarks inside protons and neutrons -- even a perfect vacuum isn't truly empty. Instead, it is filled with short-lived disturbances in the underlying energy of space that flicker in and out of existence, known as virtual particles. Among them are quark-antiquark pairs. Under normal conditions, these fleeting pairs vanish almost as soon as they appear. But if enough energy is injected into a vacuum, QCD predicts they can be promoted into real, detectable particles with measurable mass. Now, the STAR collaboration -- an international team of physicists working at the Relativistic Heavy Ion Collider in Brookhaven National Laboratory in New York state -- has observed this process for the first time. The team smashed together high-energy protons in a vacuum, producing a spray of particles. Some of these particles should be quark-antiquark pairs pulled directly from the vacuum itself, but quarks can never exist alone and immediately combine into composite particles. Quarks and antiquarks are born with their spins correlated -- a shared quantum alignment inherited from the vacuum. The researchers found that this link persists even after the quarks and antiquarks become part of larger particles called hyperons, which decay in less than a tenth of a billionth of a second. Spotting these spin-aligned hyperons in the aftermath of the proton collisions allowed the researchers to confirm that the quarks within them came from the vacuum. The findings have been published in the journal Nature.

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The Artemis II crew has passed 100,000 miles from Earth and is now on a "free-return" path around the moon after a successful "translunar" injection burn. "Ladies and gentlemen, I am so, so excited to be able to tell you that for the first time since 1972 during Apollo 17, human beings have left Earth orbit," NASA's Dr Lori Glaze told a news conference. The Guardian reports: The astronauts -- the Americans Reid Wiseman, Victor Glover and Christina Koch, and a Canadian, Jeremy Hansen -- spent their first day in space performing checks on the spacecraft, which had never carried humans before. Later they had time to speak to US TV networks. "I've got to tell you, there is nothing normal about this," Wiseman told ABC News from the cramped interior of the capsule. "Sending four humans 250,000 miles away is a herculean effort, and we are now just realising the gravity of that." Orion will travel about 4,000 miles (6,400km) beyond the moon before turning back, providing unprecedented and illuminated views of the lunar far side. If all proceeds smoothly, the astronauts will set a record by venturing farther from Earth than any human before -- more than 250,000 miles. The mission is part of a longer-term plan to repeatedly return to the moon, with the aim of establishing a permanent base that will offer a platform for further exploration. After the final engine burn, NASA said Wiseman took two "spectacular" images of Earth. The first photo, called Hello, World, "shows the vast expanse of blue that is the Atlantic Ocean, framed by a thin glow of the atmosphere as the Earth eclipses the Sun and green auroras at either pole," reports the BBC. Another photo shows the view of Earth from inside the Orion spacecraft.

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"It is the talk of the town today — the loud boom, the flash of light in the sky experienced by a lot of folks across the Houston area this afternoon," says a local Texas newscaster. "And then there was this — a home in northwest Harris county hit by something that crashed through their roof." Travelling at very high speed, the six-pound meteorite crashed through their roof and through their attic, crashing again through the ceiling of the floor below. It then bounced off the floor, hit the ceiling again — and then fell onto the bed. CBS News reports: NASA said in a social media post that the meteor became visible at 49 miles above Stagecoach, northwest of Houston, at 4:40 p.m. local time. The meteor moved southeast at 35,000 miles per hour, breaking apart 29 miles above Bammel, just west of Cypress Station, NASA said. "The fragmentation of the meteor — which weighed about a ton with a diameter of 3 feet — created a pressure wave that caused booms heard by some in the area," NASA said in the post. Across the Houston area, residents described hearing a low, rumbling sound that many compared to thunder, even though the skies were clear, according to CBS affiliate KHOU. Earlier this week, an asteroid weighing about 7 tons and traveling at 45,000 mph traveled over multiple states. And last June, a bright meteor was seen across the southeastern U.S. and exploded over Georgia, creating similar booms heard by residents in the area.

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NASA's Hubble Space Telescope unexpectedly captured a rare, early-stage breakup of comet C/2025 K1 (ATLAS) just days after it first began disintegrating. Phys.org reports: "Sometimes the best science happens by accident," said co-investigator John Noonan, a research professor in the Department of Physics at Auburn University in Alabama. "This comet got observed because our original comet was not viewable due to some new technical constraints after we won our proposal. We had to find a new target -- and right when we observed it, it happened to break apart, which is the slimmest of slim chances." Noonan didn't know K1 was fragmenting until he viewed the images the day after Hubble took them. "While I was taking an initial look at the data, I saw that there were four comets in those images when we only proposed to look at one," said Noonan. "So we knew this was something really, really special." Hubble caught K1 fragmenting into at least four pieces, each with a distinct coma, the fuzzy envelope of gas and dust that surrounds a comet's icy nucleus. Hubble cleanly resolved the fragments, but to ground-based telescopes, at the time they only appeared as barely distinguishable, bright blobs. [...] "Never before has Hubble caught a fragmenting comet this close to when it actually fell apart. Most of the time, it's a few weeks to a month later. And in this case, we were able to see it just days after," said Noonan. "This is telling us something very important about the physics of what's happening at the comet's surface. We may be seeing the timescale it takes to form a substantial dust layer that can then be ejected by the gas." The findings have been published in the journal Icarus.

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