Jupiter was once twice as large as it is today
One of Jupiter's most recognizable attributes is its sheer size. With a diameter over 88,800 miles, our solar system's largest planet is 11 times as wide as Earth and twice as massive as all its sibling planets combined. But according to recent calculations based on some of the gas giant's tiniest moons, astronomers now believe Jupiter was once more than double its current size, with a magnetic field 50 times as strong. These gargantuan dimensions aren't only impressive—they played a major role in shaping our solar system as it exists today. The new findings are detailed in a study published on May 20 in the journal Nature Astronomy.
To better understand Jupiter's primordial stages, researchers turned to the tiniest of the planet's 92 known moons. Almathea and Thebe respectively circle Jupiter at slightly tilted orbits roughly 112,400 and 138,000 miles above the planet's cloudtops.
By analyzing the dynamics of these orbital discrepancies along with the planet's conservation of angular momentum, the team could estimate its radius and interior state at about 3.8 million years after the solar system formed its first solids. At that time, the sun was surrounded by a disk of material known as a protoplanetary nebula that was gradually dissipating as it coalesced into the planets we know and love. Based on their calculations, researchers believe early Jupiter was 2 to 2.5 times larger than it is today with a much more powerful magnetic field.
'It's astonishing that even after 4.5 billion years, enough clues remain to let us reconstruct Jupiter's physical state at the dawn of its existence,' said Fred Adams, one of the study's co-authors and a University of Michigan professor of physics and astronomy.
By focusing on the directly measurable information from Jupiter's moons and the conservation of its angular momentum, the team was able to sidestep many of the common uncertainties that plague planetary formation models. These often require astronomers to make assumptions about variables like gas opacity, accretion rate, and heavy element core mass.
According to the team, their new calculations enhance more than experts' understanding of Jupiter. These factors can be applied to the evolution of other giant planets as they circle stars. They also suggest that gas giants generally form through core accretion–or when a gas rapidly gathers around a core of ice and rock.
'Our ultimate goal is to understand where we come from, and pinning down the early phases of planet formation is essential to solving the puzzle,' said Konstantin Batygin, a Caltech planetary science professor and study co-author. 'This brings us closer to understanding how not only Jupiter but the entire solar system took shape.'
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
a day ago
- Yahoo
Experts doubt FBI's claim that crop fungus smuggled by Chinese students is a threat
By Heather Schlitz CHICAGO (Reuters) -A biological sample that a Chinese researcher was accused of smuggling into the United States and that prosecutors cast as a "dangerous biological pathogen" is a common type of fungus already widespread in U.S. crop fields that likely poses little risk to food safety, experts said. On Tuesday, U.S. federal prosecutors accused two Chinese researchers of smuggling samples of the fungus Fusarium graminearum into the U.S., describing it as a potential agricultural terrorism weapon. Yunqing Jian, 33, a researcher at the University of Michigan's Department of Molecular, Cellular and Developmental Biology has been charged in connection with allegations that she helped her boyfriend, Zunyong Liu, 34, smuggle the pathogen into the U.S. However, agriculture experts interviewed by Reuters this week said the fungus has been in the U.S. for more than a century, can be prevented by spraying pesticides, and is only dangerous if ingested regularly and in large quantities. "As a weapon, it would be a pretty ineffective one," said Jessica Rutkoski, a crop sciences professor, wheat breeder and geneticist at the University of Illinois at Urbana-Champaign. Rutkoski and other researchers said extensive testing for the fungus' toxin, widespread use of fungicides and the difficulty of intentionally creating an infection with the pathogen would make it a clumsy weapon. The U.S. Attorney's Office and the FBI declined Reuters' request for comment. Since the 1900s, U.S. farmers have been battling the fungus, which causes Fusarium head blight, usually known as "scab," which often infects wheat, barley and other grains on farms during rainy years. The telltale pink streaks on the grain heads contain a toxic byproduct called vomitoxin, which is tested for and tightly controlled by grain elevators where farmers sell their crops. Constant testing and monitoring means that only negligible amounts of vomitoxin ever make it into the bread, pasta and cookies Americans eat, far below levels that would sicken a human, experts said. "We have a long history of managing epidemics of scab," said Andrew Friskop, professor and plant pathologist at North Dakota State University, noting that farmers have access to many tools to prevent and control the disease. Farmers began regularly spraying their fields with fungicide as early as the 1990s, and researchers have since developed multiple strains of fungus-resistant wheat. Plant experts said that it would be difficult to fully assess the risks posed by the samples without more information on the particular strain. But Rutkoski, whose research involves intentionally contaminating wheat with the fungus, said that she isn't always successful at infecting her test field's wheat with scab. She said the pathogen is difficult to control, and her lab has to strike the right balance of temperature and humidity to create an infection. In federal court in Detroit on Tuesday, Jian was charged with conspiracy to commit offense or to defraud the U.S., smuggling goods into the U.S., false statements and visa fraud. Jian did not comment on the charges, and the lawyer who represented her in court was not immediately available for comment. Liu could not be immediately reached for comment. The court scheduled Jian's bail hearing for June 13.
The Hill
a day ago
- The Hill
Milky Way has 50-50 chance of colliding with neighbor galaxy
The collision of the Milky Way and Andromeda galaxies that scientists believed was inevitable has a much lower probability than previously thought. The Associated Press reported Monday that astronomers in Finland have determined that our galaxy has a 50-50 chance of colliding with the neighboring Andromeda within the next 10 billion years. The previous theory suggested that the two galaxies had a high probability of colliding within the next five billion years. 'Based on the best available data, the fate of our galaxy is still completely open,' the team wrote in the study, which appeared in Nature Astronomy. A team led by University of Helsinki researcher Till Sawala simulated all possible scenarios using the latest data from NASA's Hubble Space Telescope and the European Space Agency's Gaia star-tracking mission. According to the simulation yielded some surprising results. 'A head-on collision is very unlikely, we found a less than 2 percent chance for that,' Sawala said. 'In most of the cases that lead to a merger, the two galaxies will indeed fly past each other at first, which will lead to a loss of orbital energy, and subsequently to a merger. 'How close they come on their first passage is very uncertain, however, and if they don't come very close, meaning if their distance is more than around 500,000 light-years, they might not merge at all,' the researcher added. Sawala said he was not prepared for what his team found. 'In short, the probability went from near-certainty to a coin flip,' Sawala noted. The study relied on newer and more precise information, and the team took into consideration a 'more complete system,' including the potential effects of the Large Magellanic Cloud. The dwarf galaxy is the Milky Way's largest satellite galaxy, reported. Ultimately, the astronomers found that the Milky Way and Andromeda would inevitably collide if the two galaxies' orbits come close enough to affect a gravitational pull on one another. If they stay well separated, the merger won't happen. While the scenarios indicated a less likely merger between the two, they found that the Milky Way is far more likely to cannibalize the Large Magellanic Cloud. The research indicates that this newly theorized merger is likely to happen over the next two billion years.
Yahoo
2 days ago
- Yahoo
James Webb telescope spots 'groundbreaking' molecule in scorching clouds of giant 'hell planet'
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers using NASA's James Webb Space Telescope (JWST) have identified several surprising molecules in the scorching clouds of a "hellish" alien world. One of the compounds has never been seen in any planetary atmosphere before. The exoplanet, dubbed WASP-121b, is a gas giant, around 1.2 times more massive than Jupiter and roughly 1.8 times as wide, that was first discovered in 2016. It is located approximately 880 light-years from the solar system and orbits extremely close to its home star, circling the alien sun every 30.5 hours. Its extreme proximity to the star means that it is "tidally locked," similar to how the moon is trapped around Earth, where one side of the planet constantly faces the star while the other is always pointed away. If it were to get any closer to the star, the planet would likely be ripped apart. The hell planet's eternal "day side" reaches temperatures of around 5,500 degrees Fahrenheit (3,000 degrees Celsius), classifying the exoplanet as "ultra hot," while its dark "night side" is a slightly milder 2,750 F (1,500 C). Recent studies have also revealed that the alien world likely has molten iron rain and extreme hurricanes that make the solar system's biggest storms seem calm in comparison. Researchers recently turned JWST's Near-Infrared Spectrograph (NIRSpec) instrument toward WASP-121b — also known as "Tylos" (meaning Bahrain in ancient Greek), after the Gulf state won the right to name it in 2022 — to get a better look at its superhot atmosphere. The team took observations from across the exoplanet's brief orbit around its sun, allowing them to capture clear pictures of both its day and night sides. The team's observations, described in two papers published June 2 in the journal Nature Astronomy and The Astronomical Journal, revealed silicon monoxide (SiO) gas in the exoplanet's never-ending day side atmosphere, which has not been detected in the atmospheres of any of the more than 5,000 exoplanets discovered so far. Related: Did the James Webb telescope really find evidence of alien life? Here's the truth about exoplanet K2-18b. "Detecting SiO in WASP-121b's atmosphere is groundbreaking," Anjali Piette, an astronomer at the University of Birmingham in the U.K. and co-author of the Nature Astronomy study, said in a statement. "[It is] the first conclusive identification of this molecule in any planetary atmosphere." SiO is sometimes found in stars, but is fairly rare elsewhere. It can be synthetically produced on Earth and is used to make solar panels, optical devices and some batteries. However, it is always a solid because its gaseous form is too unstable to exist in most planetary atmospheres. Unlike other first-of-their-kind molecules spotted by JWST, such as the controversial "signature of life" dimethyl sulfide on K2-18b, the presence of SiO on the exoplanet is not an indication of potential extraterrestrial life — even though silicon-based lifeforms may be possible. Instead, the molecule likely originates from silicate-rich materials, such as quartz, inside asteroids that have burned up in WASP-121b's atmosphere. The compound has remained in a gaseous state due to the incredibly high temperatures on the day side. RELATED STORIES —James Webb telescope reveals rare, 'rotten egg' atmosphere around nearby hell planet —'Utterly cataclysmic': James Webb telescope spots 2 alien planets disintegrating before our eyes —James Webb telescope spots 'rogue' planet with a cake-like atmosphere barrelling through space without a star The researchers note that the new findings are proof of JWST's extraordinary resolution, which will allow us to learn more about how "hell planets" and other gas giants form. "Studying the chemistry of ultra hot planets like WASP-121b helps us to understand how gas giant atmospheres work under extreme temperature conditions," Joanna Barstow, a planetary scientist at the Open University in the U.K. who co-authored both new studies, said in a statement.
