Latest news with #Satur
Yahoo
25-04-2025
- Science
- Yahoo
Why are meteor showers so unpredictable? The sun may be to blame
When you buy through links on our articles, Future and its syndication partners may earn a commission. Our sun is wobbling, and this has a huge impact upon the regularity of many of Earth's meteor showers, according to new research that discovers why streams of comet dust bob and weave in and out of Earth's orbit. Stargazers are familiar with half a dozen or so bright meteor showers that return with unerring regularity every year — April's Lyrids, August's Perseids, Decembers's Geminids and others. What most people don't realize is that Earth has approximately 500 distinct meteor showers. Many of these are seemingly unpredictable. But now astronomers think they know why. When comets come close enough to the sun, they begin to warm up, which causes ices to vaporize and pockets of gas beneath the surface to expand and burst out, carrying dust into space. Although we're familiar with dusty comet tails close to the sun, tail formation can begin while a comet is still beyond the orbit of Saturn. The streams of material they leave behind linger long after their parent comet has headed back out of the solar system on orbits lasting centuries or even millennia. Related: Meteor showers 2025: When, where and how to see the best 'shooting stars' of the year Stuart Pilorz and Peter Jenniskens of the SETI (Search for Extraterrestrial Intelligence) Institute in California wanted to track some of these meteoroid streams back to their parent comet. Meteoroids are how we refer to these small dust particles and pebbles when they are in space; once they enter the atmosphere as a shooting star we call them meteors, and if they manage to reach the ground, they are called meteorites. However, tracking the streams back to their parents is not easy, because the streams move, weaving in and out of Earth's orbit and spreading out over time. The regular meteor showers that we are most familiar with come from meteoroid streams that have dispersed quite widely; some of these familiar periodic meteor showers can last weeks as Earth moves through the wide stream. However, when a meteoroid stream is still relatively young, it is quite narrow and, as it moves around, sometimes the Earth will pass through it, sparking a meteor shower. Other times, Earth will miss it. Computer simulations were having trouble explaining this movement of the streams. Then Pilorz and Jenniskens realized something that in hindsight might seem obvious. "Contrary to popular conception, everything in the solar system does not orbit the sun," said Pilorz in a statement. "Rather, the sun and planets all orbit their common center of mass, known to scientists as the solar system barycenter." The sun appears to wobble as it moves around this barycenter, which is located just outside the sun — pretty close to it, because the sun contains the vast majority of mass in the solar system. The position of this barycenter shifts, matching the orbits of the planets, particularly the two most massive, Jupiter and Saturn. It's the same principle that allows astronomers to use radial velocity measurements to discover exoplanets based on how a star wobbles about the center of mass in its system. When Pilorz and Jenniskens introduced this fact to their simulations, they found it accurately described the movement and dispersal of the meteoroid streams as they loop around the sun. The meteoroids in a cometary dust stream gain a gravitational boost, or are braked, by interactions with the wobbling sun as they pass close to it. Pilorz compares it to the way spacecraft can be sped up in a gravitational slingshot effect, or slowed down, during planetary flybys. The duo also noticed that, while beyond the orbit of Jupiter, meteoroids in a stream orbit the solar system's barycenter. Their orbit is therefore referred to as barycentric. However, inside the orbit of Jupiter, the sun's gravity is great enough to make the meteoroids orbit the sun rather than the barycenter, hence they become heliocentric. "Long-period comets spend most of their lives so far away from the solar system that they feel the tug from the barycenter," said Pilorz. "But every few hundred years, they swoop inside Jupiter's orbit and come under the sun's influence." This subtle difference results in a step-change in the motion of the streams. "We found that the two jumps in the plane of motion, when the sun takes control as the comet approaches and then again when it hands control back to the barycenter as the comet heads away, kicked the inclination and node of the orbit by a small amount," said Pilorz. "Again, if we considered the sun fixed at the center, the reason for this change is not obvious." Related: Comets: Everything you need to know about the 'dirty snowballs' of space Related stories: — Lyrid meteor shower 2025 delights stargazers with the help of a dramatic fireball display (photos) — Meteor showers and shooting stars: Formation and history — Solar system planets, order and formation: The ultimate guide To test this model, Jenniskens made a prediction that one particular meteor shower would return when Jupiter and Saturn were in certain locations in their respective orbits, their gravity pulling the barycenter and the wobbling sun in a certain direction to nudge the stream so that it cut across Earth's path. "We traveled to Spain in an attempt to record one of these showers and saw what was described in the past as 'stars fall at midnight,'" said Jenniskens. "The whole shower lasted only 40 minutes, but there was a bright meteor every minute at the peak." The motion of Jupiter and Saturn in their orbits — which last 12 and 29 years, respectively — results in this particular meteor shower returning every 60 years, Jenniskens and Pilorz found. Over millennia or longer, these meteoroid streams will disperse like the others, becoming wider. This occurs because the meteoroid stream is long as it wraps around the sun, and different meteoroids receive a gravitational kick at different times, increasing the range of orbital motions within the stream, widening it. The research was published online April 13 in the journal Icarus.
Straits Times
25-04-2025
- Science
- Straits Times
A ‘sad face' in the sky: Singaporeans catch rare ‘smiley' celestial alignment
While many parts of the world would be glimpsing a cheerful celestial smiley face, observers in Singapore instead saw a 'sad face' lighting up the pre-dawn sky. PHOTO: TAN SHARON/FACEBOOK SINGAPORE - Those in Singapore who looked up at the sky in the early hours of April 25 were treated to a charming – albeit melancholic – astronomical sight. While many parts of the world would be glimpsing a cheerful celestial smiley face, observers in Singapore instead saw a 'sad face' lighting up the pre-dawn sky. The phenomenon occurs when the waning crescent moon aligns with V enus and Satur n in the night sky. In many regions, especially across the western hemisphere, the conjunction is expected to resemble a smiling face, with the moon forming the curve of a grin and the two planets positioned like eyes above it. However, in Singapore, the view told a different story. Due to the timing and positioning of the alignment relative to this part of the world, the crescent moon appeared inverted – forming the arc of a frown instead of a smile. Venus and Saturn hovered above the moon, acting as the eyes of what many described as a wistful or even winking expression. Skywatchers also noted that Saturn appeared significantly brighter and larger than Venus, adding to the quirkiness of the scene. This specific event is a conjunction between Venus and Saturn and is classified as a conjunction between an inferior and a superior planet. According to popular astronomy app Star Walk, su ch alignments o ccur roughly once every 10 years, typically when the inferior planet is in its retrograde phase and the superior planet is near opposition. Skywatchers across Singapore took to social media to share photos and musings of the unexpected sight. Ms Tan Sharon shared a photo on Facebook of what she called 'Singapore's version of the rare smiley moon', set against a soft purplish dawn sky. Ms Anita YK's Facebook photo featured the image of the crescent moon and the two planets forming an upside down frowning face. 'I was told I would see a (smiley face), but I saw a (sad face) instead this morning,' wrote Facebook user Goh Ngaileng on April 25. Mr Javier Yong-En Lee posted photos of the celestial face and remarked, 'I could see the greyed part of the moon with my naked eyes.' Heart Panopio, a member of the Cloudspotting and Skyspotting Singapore Facebook group, said she had set an alarm for 5am in anticipation of a smile-like crescent, only to be greeted by a sad face instead. According to The Weather Network, the cel estial smile is expected to be visible from parts of the US from 5.30pm SGT. Astronomy enthusiasts can also look forward to the Super New Moon, expected to occur at 3.31am on April 28. Although new moons are typically invisible to the naked eye, this one will be the sec ond-clos est to earth in 2025, marking a notable moment in the lunar calendar. Join ST's WhatsApp Channel and get the latest news and must-reads.
Yahoo
26-02-2025
- Business
- Yahoo
Court Dismisses Novartis Challenge To Medicare Drug Price Negotiation Program
A federal court rejected Novartis Pharmaceuticals', a unit of Novartis AG (NYSE:NVS) legal challenge to the Medicare Drug Price Negotiation Program, ruling that the program does not violate constitutional protections against excessive fines, unlawful takings, or compelled speech. The court determined that pharmaceutical manufacturers are not legally required to participate in the program, and those that do must adhere to its terms. Also Read: For over 30 years, Congress has imposed price ceilings on prescription drugs purchased by federal agencies, including the Departments of Defense and Veterans Affairs. These agencies also have the authority to negotiate prices below these limits. The Inflation Reduction Act of 2022 expanded this model by granting the Department of Health and Human Services (HHS) similar authority to negotiate prices for Medicare-covered drugs that lack generic competition and constitute a significant portion of Medicare spending. Under the law, the Centers for Medicare & Medicaid Services (CMS) can negotiate prices for high-expenditure drugs. Manufacturers who disagree with the program's terms or the proposed pricing are not legally obligated to participate. Novartis, however, argued that the program imposed unconstitutional burdens, challenging it on three grounds: that it violated the Eighth Amendment's prohibition on excessive fines, the Fifth Amendment's protection against takings without just compensation, and the First Amendment's ban on compelled speech. The court dismissed Novartis' Eighth Amendment claim, citing the Anti-Injunction Act, which prevents lawsuits challenging the constitutionality of a tax before it is enforced. Additionally, the court ruled that the program does not amount to a government taking under the Fifth Amendment, as it does not forcibly seize or mandate the sale of the company's drugs. Instead, the government offers to purchase medications under specific terms, which Novartis can choose to accept or decline. If a company finds the negotiated price unfavorable but still opts to sell, it does not constitute an unlawful taking. Price Action: NVS stock is down 1.64% at $107.83 at the last check on Wednesday. Read Next:Photo: Courtesy of Satur via Shutterstock UNLOCKED: 5 NEW TRADES EVERY WEEK. Click now to get top trade ideas daily, plus unlimited access to cutting-edge tools and strategies to gain an edge in the markets. Get the latest stock analysis from Benzinga? NOVARTIS (NVS): Free Stock Analysis Report This article Court Dismisses Novartis Challenge To Medicare Drug Price Negotiation Program originally appeared on © 2025 Benzinga does not provide investment advice. All rights reserved. Sign in to access your portfolio
Yahoo
07-02-2025
- Entertainment
- Yahoo
Everything we know so far about Britain's Got Talent 2025
If you've noticed Britain's Got Talent adverts popping up on your TV recently, sadly it doesn't mean that winter has passed more quickly than expected - for the first time, the ITV talent show will get a February launch date. The Saturday night entertainment favourite is set to introduce its 2025 series early following a schedule shake-up at ITV and has also announced a big-name guest to join the judging panel. Here's everything we know so far about the changes at Britain's Got Talent for 2025. Read more: Who won Britain's Got Talent 2024? Should Britain's Got Talent be axed? Britain's Got Talent: The 10 biggest scandals The great news for BGT fans is that there's less time to wait for the start of the 2025 series than you might be expecting. Last year, it was reported that the schedule for the ITV talent show had changed and was due to start in February this time, running through to a final in May. The series usually launches in mid-April and runs until early June, but it's now expected that we'll see the first episode of the 2025 series much earlier on Saturday, 22 February. Hosts Ant and Dec have also been teasing a big Royal announcement, which is set to be revealed on 8 February. Can the boys keep our big #BGT secret? 🤐👑 — BGT (@BGT) February 6, 2025 Long-time viewers of Britain's Got Talent will know that the show usually begins with weeks of pre-recorded auditions and heats that take place around the UK and air on Saturday nights. It then moves to a nightly schedule for the last week, with Monday to Friday as live semi-finals, a day off on Saturday, and then a last live show for the grand final on the Sunday. However, this year it's thought that rather than condensing the semis and final into a week, the live shows will be strung out across the usual Saturday night weekly schedule, meaning that the whole supersized series could run for around three months. It's thought that the earlier start date and longer run could fill a gap left in the ITV1 schedule by BGT hosts Ant and Dec, whose long-running series Saturday Night Takeaway which would usually air from February to April has gone on indefinite hiatus. The duo were keen to take a break from so much live TV work while they concentrate on their young families. Addressing reports of a supersize 2025 series with Good Morning Britain at the end of last year's series, judge Amanda Holden said: "I think it would be amazing if it was true and if we did it every single Saturday rather than strip it in a week like we have done for 17 years. Because it is a Saturday night show." Fellow judge Alesha Dixon also backed the idea, saying: "Yeah and it is such an event when it comes around. And it is so warm and it brings so much joy - why not have it last a little bit longer? We need that in the world right now... escapism." Auditions began early for the new series, launching at The Oval in London on 14 and 15 September. Despite Ant and Dec wanting to take time away from Saturday Night Takeaway, their fans will be pleased to know they aren't quitting BGT any time soon. The lads have been confirmed for the new series and have appeared in a teaser ad hinting at a special Royal announcement this weekend. Ant and Dec have been with the show since it began in 2007. In 2018 when Ant McPartlin took time away from TV, he only appeared in some of the pre-recorded auditions and Dec Donnelly hosted the live shows alone. However, he returned the following series. For the third year running, we'll see the same judging line-up behind the desk for most of the series. Show boss Simon Cowell is back to give his unflinching judgment on contestants, alongside Amanda Holden who has also been with BGT since it began. They'll be joined by Alesha Dixon who is entering her 13th season as a judge on the show, as well as former Strictly Come Dancing judge Bruno Tonioli who is back for a third year. However, Tonioli had to miss some of the auditions in Blackpool as he had commitments with Dancing with the Stars in the US, where he still serves on the panel. Replacing him for the episodes he had to miss is influencer, boxer and musician KSI, who makes his debut as a judge. Britain's Got Talent is expected to return to ITV1 on Saturday, 22 February.
