Surprise Spiral Shape Revealed in The Darkness Surrounding The Solar System
We have a rough idea of the size and shape of this field, but the fine particulars elude our understanding. Now, a new computational study has revealed a surprising structure – a spiral generated by the tidal forces exerted by the Milky Way galaxy itself.
The finding, in press at The Astrophysical Journal, is currently available on preprint server arXiv.
"As the galactic tide acts to decouple bodies from the scattered disk it creates a spiral structure in physical space that is roughly 15,000 astronomical units in length," writes a team led by astronomer David Nesvorný of the Southwest Research Institute in the US. "The spiral is long-lived and persists in the inner Oort Cloud to the present time."
The outer Solar System is a frontier that is difficult to probe. We know there are lots of small, icy objects out there in the Kuiper Belt out past the orbit of Neptune; and, beyond that, from 1,000 astronomical units to 100,000 astronomical units, spins the Oort Cloud, the far reaches of the Sun's gravitational influence.
It's from here that the Solar System's long-period comets originate, bumped from their orbits and sent careening toward the Sun, releasing streams of gas as their ices sublime.
We know, also, that the Oort Cloud is roughly divided into two parts. The outer portion is huge, a spherical cloud that extends out from around 10,000 astronomical units from the Sun. Interior to that is the inner Oort Cloud. According to simulations, this portion is more of a torus, or donut shape, extending from 1,000 to 10,000 astronomical units.
Most of the long-period comets in the Solar System come from the outer Oort Cloud. The inner region is much more stable. It's closer to the Sun, which means it's more strongly bound by the Sun's gravity; and it's not as prone to disruption by the passing stars that stir up the outer cloud and knock the icy objects out of their normal orbits.
Because of this long-term stability, the inner Oort Cloud is usually modeled as a more-or-less flat disk aligned with the ecliptic plane of the Solar System.
Nesvorný and his colleagues have been studying the inner Oort Cloud for years. In their latest research, they used NASA's Pleiades Supercomputer to simulate the debris field, applying the gravitational effects of the Sun, as well as the external gravitational effects exerted by the Milky Way galaxy itself, and the orbits of the comets.
They simulated the 4.6 billion-year lifespan of the Solar System, from the formation of the Sun from a dense knot of material in a huge molecular cloud of gas and dust. As the Sun formed, the leftover material in that cloud formed the planets, asteroids, comets, and everything else in the Solar System, including the outer Oort Cloud.
But the simulations suggest that the inner Oort Cloud is not a nice, even, toroidal disk at all. Rather, it mirrors the shape of the Milky Way galaxy, with a spiral structure, and a warp to the disk similar to the warp in the galactic disk. The entire disk measures around 15,000 astronomical units in diameter – and it's inclined 30 degrees from the ecliptic plane.
From a distance, it would appear as a spiral, with two twisted arms.
This structure, according to the simulations, emerged early in the Solar System's history, within the first few hundred years after the formation of the Solar System. It's also remarkably stable – it persists to this day. And, even when stars pass closely by the Solar System, it remains intact, which means that it's not related to the gravitational perturbations induced by passing stars.
To confirm what they were looking at, the researchers went back over the previous studies. All their previous work suggested that the inner Oort Cloud has a spiral shape that persisted through various parameter tweaks to their simulations.
Directly observing, and therefore confirming, this spiral is going to be very difficult, if it's possible at all. But it fits observation data, and its presence in previous studies that weren't even looking for it is interesting.
Unraveling the mysteries of the Oort Cloud means peering back into the Solar System's distant past, and observing the influences at play over the course of its formation and evolution. Sometimes, the difficult thing is worth doing.
The team's research will be published in The Astrophysical Journal, and is available on arXiv.
Ancient Beaches Found on Mars Reveal The Red Planet Once Had Oceans
A Rare Alignment of 7 Planets Is Taking Place in The Sky This Week
Rock Fragments Reveal The Moment The Moon Turned Solid
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
41 minutes ago
- Yahoo
Mysterious Object Hurtling Toward Us From Beyond Solar System Appears to Be Emitting Its Own Light, Scientists Say
Last month, astronomers made an exciting discovery, observing an interstellar object — only the third ever observed — hurtling toward the center of the solar system. The object, dubbed 3I/ATLAS, has caught the attention of Harvard astronomer Avi Loeb, who has a long track record of making controversial predictions about previous interstellar objects being relics from an extraterrestrial civilization. While there's been a growing consensus among astronomers that the latest object is a comet, Loeb has continued to entertain the idea that it may have been sent to us by an intelligent species from outside of the solar system — and he's far from backing down. In a blog post over the weekend, Loeb pointed to observations by NASA's Hubble Space Telescope, which showed a "glow of light, likely from a coma, ahead of the motion of 3I/ATLAS towards the Sun." A coma is the hazy and luminous cloud that surrounds the nucleus of a comet. However, there's "no evidence for a bright cometary tail in the opposite direction," he wrote, with scientists suggesting it was evidence that dust was evaporating from the object's Sun-facing side. The observations led Loeb and his colleagues to an intriguing, albeit far-fetched possibility: is the mysterious space object generating "its own light?" After deliberations with his colleague and Harvard astrophysicist Eric Keto, Loeb suggested that the "simplest interpretation" of 3I/ATLAS' observed "steep brightness profile" is that its nucleus "produces most of the light." That would also mean that its actual size is much smaller than currently thought, roughly in line with the size of the first two interstellar objects we've observed, 'Oumuamua and 2I/Borisov. The Harvard astronomer suggested two possibilities: either 3I/ATLAS is naturally emitting radiation because its a "rare fragment from the core of a nearby supernova that is rich in radioactive material" — or it's a "spacecraft powered by nuclear energy, and the dust emitted from its frontal surface might be from dirt that accumulated on its surface during its interstellar travel." Loeb deemed the former explanation "highly unlikely," and the latter as requiring "better evidence to be viable." Loeb previously argued that the object's unusual trajectory — which includes suspiciously close flybys of both Earth and Jupiter — and its lack of a visible tail both undermine the theory that it's a comet. Intriguingly, 3I/ATLAS will come within spitting distance — at least in astronomical terms — of Mars this fall, giving us a tantalizing opportunity to have a first-hand look. Loeb suggested using NASA's Mars Reconnaissance Orbiter to point its scientific instruments at the rare visitor. Best of all, scientists at the space agency appear to be game. "This morning, I encouraged the HiRISE team to use their camera during the first week of October 2025 in order to gather new data on 3I/ATLAS," Loeb wrote. "They responded favorably." More on the object: Astronomer Suggests New Interstellar Object Could be Advanced Aliens Testing Our Intelligence Solve the daily Crossword
Engadget
an hour ago
- Engadget
YouTuber Mark Rober is bringing his experiments to Netflix
Mark Rober will bring his scientific talents to Netflix with two upcoming projects. Rober is a former NASA engineer who parlayed his skills into an entertaining and educational YouTube career. In past years, we've seen him develop not just one , but two stinky glitter bombs to fend off porch package thieves, as well as leading work on a Guinness World Record-holding robot called the Dominator . According to an announcement from Netflix, Rober "will bring some of his most beloved, ambitious, and informative experiments" to the streaming platform later this year. Then in 2026, he'll also host a competition series aimed at kids and family viewers. Rober's CrunchLabs business and Kimmelot, late night host Jimmy Kimmel's production company, will be producing.
Yahoo
3 hours ago
- Yahoo
Crew-10 astronauts to depart ISS: How the Florida launch helped Starliner crew return
In mid-March, four spacefarers arrived at the International Space Station on a mission that at any other time would have been relatively routine and unremarkable. NASA astronauts Nichole Ayers and Anne McClain were joined by Japanese astronaut Takuya Onishi and Russian cosmonaut Kirill Peskov on a mission known as Crew-10 that took on far more significance than most of the regular ventures jointly carried out by NASA and SpaceX. As expected, awaiting the Crew-10 contingent at the orbital outpost were months of scientific experiments tailored to be conducted in microgravity. Crucially, though, the mission also attracted plenty of headlines and fanfare as it cemented its place in spaceflight history for its role in ending the infamous Starliner saga. The Crew-9 team may have arrived in September on a spacecraft with room for the two astronauts who crewed the doomed Boeing Starliner to hitch a ride home. But it was the arrival of the Crew-10 astronauts at the space station that set the stage for Butch Wilmore and Suni Williams to make their long-awaited homecoming. Now that the Crew-10 astronaut are soon due to depart the space station more than four months later, here's everything to know about the mission and why it made headlines during the Starliner debacle. Remembering the Boeing Starliner: Look back at mission's biggest moments What was the Crew-10 mission? Astronauts relieve 'stuck' Starliner crew The March 15 arrival of Crew-10 astronauts at the International Space Station made it possible for NASA astronauts Butch Wilmore and Suni Williams, who arrived in June on the doomed Starliner, to finally depart. The mission got off the ground the day prior from NASA's Kennedy Space Center. The U.S. space agency had originally been working toward a February liftoff before announcing in December 2024 that the mission had been pushed to late-March to give SpaceX more time to prepare a new Dragon capsule. The launch date was then moved back up to mid-March – most likely due to pressure from President Donald Trump and SpaceX founder Elon Musk – when NASA decided to instead use a "previously flown" Dragon. The Dragon spacecraft docked at the orbital outpost following a 28-hour journey, allowing the crew to exit the vehicle and enter the space station through its Harmony module. Once aboard, the four Crew-10 spacefarers officially greeted the Expedition 72 crew members, including the astronauts who flew aboard the Starliner. What happened with the Boeing Starliner after launch from Florida? Selected for the inaugural crewed flight of the Boeing Starliner, Wilmore and Williams became fixtures of the news cycle when the vehicle they flew to the space station in June 2024 encountered a series of technical issues. NASA and Boeing ultimately decided that the troubled Starliner capsule wasn't safe enough to crew, and would instead undock and return to Earth with them. On Sept. 28, 2024, NASA launched the SpaceX Crew-9 mission as planned, but with one crucial change: Just two astronauts – Nick Hague of NASA and Russian cosmonaut Aleksandr Gorbunov – headed to the space station on a Dragon instead of four to leave two empty seats on their vehicle reserved for Wilmore and Williams. NASA opted to keep Williams and Wilmore at the station a few extra months rather than launch an emergency mission to return them to Earth to avoid having the station be understaffed. Williams and Wilmore eventually departed the space station with the Crew-9 team and safely landed March 17 off the Florida coast following the arrival of the Crew-10 mission. When will SpaceX launch Crew-11 astronauts from Kennedy Space Center? Now, the astronauts of the Crew-10 mission are due to return to Earth themselves following the impending arrival of their own replacements. The Crew-11 mission is due to get off the ground no earlier than 12:09 p.m. ET Thursday, July 31, from near Cape Canaveral, Florida, according to NASA. As the name suggests, Crew-11 is NASA and SpaceX's 11th science expedition to the International Space Station. The missions, most of which last about six months, are contracted under NASA's commercial crew program. The program allows the U.S. space agency to pay SpaceX to launch and transport astronauts and cargo to orbit aboard the company's own vehicles, freeing up NASA to focus on its Artemis lunar program and other spaceflight missions, including future crewed voyages to Mars. Selected for the mission are NASA astronauts Zena Cardman and Mike Fincke, Japanese astronaut Kimiya Yui with the Japan Aerospace Exploration Agency (JAXA) and Russian Oleg Platonov, a Roscosmos cosmonaut. SpaceX uses its Falcon 9 rocket – one of the most active in the world – to launch the crew missions from Launch Complex 39A at NASA's Kennedy Space Center. The astronauts themselves ride a Dragon crew capsule – the only U.S. spacecraft capable of carrying astronauts to and from the space station – which separates from the rocket in orbit. Ahead of the planned launch, the Dragon has been stacked atop the Falcon 9 rocket, which was rolled out Sunday, July 27 to the launch pad before being raised to a vertical position, according to NASA. When will the Crew-10 astronauts depart ISS, return to Earth? The arrival of Cardman, Fincke, Yui and Platonov will ultimately pave the way for their predecessors, the Crew-10 contingent, to depart the space station and head back to Earth. But the Crew-10 astronauts won't leave right away. What follows upon the arrival of any astronauts is a brief handover period in which the new crew members are familiarized with the orbital laboratory and station operations. McClain, Ayers, Onishi and Peskov will then depart a few days later on the same Dragon capsule that transported them to the space station. Mission teams will also have to review weather conditions off the coast of California, where the Dragon will eventually make a water landing. Who else is at the International Space Station? Another three spacefarers are also living and working about the International Space Station as members of Expedition 73. That includes NASA astronaut Jonny Kim, who reached the outpost in April 2025 with cosmonauts Sergey Ryzhikov and Alexey Zubritsky. Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at elagatta@ This article originally appeared on Florida Today: SpaceX launched Crew-10 from Florida to relieve 'stuck' astronauts Solve the daily Crossword
