Latest news with #UC)Berkeley
Yahoo
19-04-2025
- Science
- Yahoo
Hailstorms on Jupiter Pelt Giant Slushee Balls of Ammonia And Water
Weather on Jupiter may have some surprising similarities to Earth phenomena, but some things it does defy easy explanation. Now, scientists have come up with one to explain the strange compositional properties of its wild clouds: during giant storms of thunder and lightning, Jupiter rains a hail of "mushballs", huge clumps of mushy ice consisting of ammonia and water, with a consistency like wet snow or a convenience store slushee. It's the best scenario astronomers have come up with to explain why Jupiter's atmosphere – and those of Saturn, Uranus, and Neptune – have such a patchy distribution of ammonia. "Imke [de Pater] and I both were like, 'There's no way in the world this is true,'" says planetary scientist Chris Moeckel of the University of California (UC) Berkeley, who led the research. "So many things have to come together to actually explain this, it seems so exotic. I basically spent three years trying to prove this wrong. And I couldn't prove it wrong." The hypothesis first emerged in 2020, when scientists studying data from Jupiter probe Juno suggested a peculiar mechanism for the extraction of ammonia and water from the planet's upper atmosphere. Jupiter's massive storms, they proposed, eject water high above the planet's water clouds, where they encounter ammonia vapor that melts the ice. Then, the water and ammonia freeze together in the extreme cold. "At these altitudes, the ammonia acts like an antifreeze, lowering the melting point of water ice and allowing the formation of a cloud with ammonia-water liquid," planetary scientist Heidi Becker of NASA' s Jet Propulsion Laboratory explained at the time. "In this new state, falling droplets of ammonia-water liquid can collide with the upgoing water-ice crystals and electrify the clouds. This was a big surprise, as ammonia-water clouds do not exist on Earth." To investigate whether this is even possible, Moeckel and his colleagues, Imke de Pater of UC Berkeley and Huazhi Ge of Caltech, pored over data collected by Juno and the Hubble Space Telescope in July 2017, as the probe flew over a giant lightning storm that is still raging to this day. Juno took recordings in six different radio frequencies with its microwave radiometer instrument, while Hubble made observations across ultraviolet, optical, and near-infrared wavelengths. Jupiter's atmosphere is pretty wild, with multiple storms unlike anything on Earth raging at any given time. Most of the weather, however, is relatively shallow. In a preprint currently undergoing peer review, Moeckel, de Pater, and a separate team describe the 3D structure of the upper atmosphere, revealing that most of the weather systems only extend 10 to 20 kilometers (6.2 to 12.4 miles) below the visible cloud tops. Some weather systems, however, plunge much deeper into the troposphere, such as cyclonic vortices, ammonia-rich cloud bands, and the violent lightning storms in which the mushballs emerge. "Every time you look at Jupiter, it's mostly just surface level. It's shallow, but a few things – vortices and these big storms – can punch through," Moeckel says. "We're basically showing that the top of the atmosphere is actually a pretty bad representative of what is inside the planet." These mushball storms effectively unmix the upper atmosphere. The mushballs form and they fall, depleting the atmosphere of ammonia down to about 150 kilometers, but transporting it deeper into the planetary interior. Previously, scientists had no idea what had removed the ammonia. Mushballs explain it perfectly. Water starts its journey deep in the clouds before being flung upwards, meeting with ammonia, and mixing in a ratio of around three parts water to one ammonia. The mixed blobs freeze and fall deep into Jupiter, where they evaporate and deposit their contents. This requires really specific conditions, such as extremely strong updrafts to carry the water, and extremely rapid mixing so that the mushballs can form and grow large enough to survive raining back down into Jupiter's atmosphere. The smoking gun was one signal in the Juno radio data. "There was a small spot under the cloud that either looked like cooling, that is, melting ice, or an ammonia enhancement, that is, melting and release of ammonia," Moeckel says. "It was the fact that either explanation was only possible with mushballs that eventually convinced me." This transport mechanism is unlikely to be unique to Jupiter. Scientists have hypothesized that similar mechanisms might be at play on all the giant planets in the Solar System, and beyond. Let's hope future observations can find them. The research has been published in Science Advances. Half The Universe's Matter Was Missing. Astronomers Just Found It. Curiosity Finds First In Situ Evidence of Carbon Cycle on Ancient Mars There's A Sky Full of Meteors in April! Here's What's on This Easter Weekend
Yahoo
26-02-2025
- Health
- Yahoo
There's a Critical Thing We Can All Do to Keep Alzheimer's Symptoms at Bay
Deep sleep could be key to forestalling slow declines in brain health that may one day lead to Alzheimer's disease, the most common form of dementia. In their 2023 study of 62 older, cognitively healthy adults, researchers from the University of California (UC) Berkeley, Stanford University, and UC Irvine in the US found individuals with brain changes associated with Alzheimer's performed better on memory function tests as they got more deep sleep. This was irrespective of education and physical activity, two factors along with social connection known to contribute to cognitive resilience in older age. Those with similar Alzheimer's-linked changes who failed to get as much deep sleep didn't fare quite as well on the same tests. By comparison, sleep made little difference to those individuals with few deposits. Taken together, the results, which were published in May 2023, imply having a generous amount of solid shut-eye could help support the decline in memory that sets in as dementia begins to take hold. "Think of deep sleep almost like a life raft that keeps memory afloat, rather than memory getting dragged down by the weight of Alzheimer's disease pathology," said University of California (UC) Berkeley neuroscientist Matthew Walker. "This is especially exciting because we can do something about it. There are ways we can improve sleep, even in older adults." The study echoes previous research which has found a build-up of amyloid-beta proteins in the brains of people with disrupted sleep. But poor sleep is both a risk factor for and a symptom of Alzheimer's disease, making it tricky to tease apart cause and effect. Likewise, clumpy amyloid-beta proteins might only be a sign of Alzheimer's disease, not its root cause. Even so, levels of amyloid-beta proteins are commonly used as a marker of Alzheimer's disease, as research suggests they – and another protein called tau – can start clogging up brain cells decades before symptoms of the disease arise. Past research from Walker's group found significant levels of amyloid-beta aggregating in the brains of older adults can disrupt deep sleep – also known as non-rapid eye movement slow wave sleep – and impair memory function. But some folk appear to stave off the decline that comes with Alzheimer's disease, even when levels of amyloid-beta proteins are relatively high. To find out why, Walker and colleagues monitored participants' brain waves as they slept, and then asked them to complete a memory test the next day. Among those whose brain scans revealed similarly high levels of beta-amyloid deposits, getting a good night's sleep seemed to make a critical difference in cognitive function. This effect was only seen when the researchers looked specifically at non-rapid eye movement slow wave sleep, and not at other sleep wave frequencies or sleep stages. Longer-term studies in older adults are needed to test whether increasing deep sleep over a number of years can actually help preserve a person's cognitive function in that time, even as levels of amyloid-beta increase. This research adds to scores of studies suggesting that sleep could be a modifiable risk factor for Alzheimer's disease, one that could potentially forestall molecular changes by giving the brain time to clean up waste products that accumulate during the day. It also points to sleep quality being important. "With a certain level of brain pathology, you're not destined for cognitive symptoms or memory issues," UC Berkeley neuroscientist and lead author Zsófia Zavecz said of the study findings in 2023. Although people may display molecular changes indicating a progression toward Alzheimer's disease, Zavecz says their findings suggest lifestyle factors can help buffer against those effects. "One of those factors is sleep and, specifically, deep sleep," she said. The study, though small, also hints at why getting good sleep naturally might be a better option than taking sleeping pills to get some shut-eye. Other research shows users of sleeping pills appear to have lower levels of amyloid proteins in their cerebrospinal fluid, which washes the brain clean at night. But these medications come with side effects; they may also lull people into shallow bouts of sleep rather than deep sleep phases. Instead, to set yourself up for a good night's sleep, Zavecz suggests cutting out coffee late in the day, doing some exercise, avoiding screen time, and taking a hot shower before bed. While you snooze, rest assured scientists are working hard to figure out the knotty problems of Alzheimer's disease, which affects millions of people worldwide. The study has been published in BMC Medicine. A version of this article was first published in May 2023. Traces of a Nutrient in Brazil Nuts Could Fight Cancer, But Dosage Is Crucial Tardigrade Protein Could Soon Make Cancer Patients More Radiation Proof X-Rays of Viking-Age Skulls Reveal a Shocking Level of Disease
