Complete Guide To ‘Ammonite,' The Solar System's Latest Member
The solar system suddenly has a new member. A new object discovered in the solar system beyond Neptune and Pluto has astronomers rethinking the history of the solar system. Called 2023 KQ14 and nicknamed 'Ammonite,' the discovery of this unique so-called trans-Neptunian object is both unexpected and could reshape what we know about the solar system's past.
Here's everything you need to know about Ammonite, the solar system's newly found object.
Is Ammonite A Planet Or A Dwarf Planet?
Ammonite is not classed as a planet. It's not even called a dwarf planet, like Pluto (and Ceres, Haumea, Makemake and Eris). Ammonite is classed as a sednoid — an object similar to Sedna, a dwarf planet candidate in the outer solar system, which was found in 2003.
Like Sedna, Ammonite orbits beyond Neptune and has a highly eccentric orbit. Ammonite is only the fourth sednoid ever discovered (after Sedna, 2012 VP113 — nicknamed Biden — and Leleākūhonua).
How Big Is Ammonite?
Based solely on how much sunlight it reflects, Ammonite is thought to be between 137 and 236 miles (220 and 380 kilometers) in diameter, according to the paper announcing its discovery published this week in Nature Astronomy. That's large, but significantly smaller than Pluto's diameter of about 1,477 miles (2,377 kilometers) and Earth's diameter of 7,926 miles (about 12,756 kilometers).
How Far Away Is Ammonite?
The solar system is measured in Earth-sun distances, one of which is called an astronomical unit (au). When it was found, Ammonite was 71 au from the sun. That's about twice as far as Neptune (30 au) and Pluto (40 au). However, Ammonite's orbital path is highly elliptical, getting as far from the sun as 432 au. It takes about 4,000 Earth-years to complete one orbit of the sun.
'Ammonite was found in a region far away where Neptune's gravity has little influence,' said Dr. Fumi Yoshida of the University of Occupational and Environmental Health and the Chiba Institute of Technology, who leads the FOSSIL project that uncovered Ammonite. That implies that 'something extraordinary occurred during the ancient era when Ammonite formed,' said Yoshida.
How Does Ammonite Affect The 'Planet Nine' Thesis?
The discovery appears to make the existence of a ninth planet less likely. There is an unusual clustering of six minor bodies in the outer solar system (including the sednoids). All appear to have hugely elongated and elliptical orbits, suggesting that they may have been 'herded' by the gravitational influence of a planet.
However, Ammonite's orbit is oriented in the opposite direction to the three other sednoids, breaking their orbital clustering — and, therefore, challenging the 'Planet Nine' theory.
'The fact that Ammonite's current orbit does not align with those of the other three sednoids lowers the likelihood of the Planet Nine hypothesis,' said Dr. Yukun Huang at the Center for Computational Astrophysics (CfCA) of NAOJ, who conducted simulations of Ammonite's orbit. 'It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today.'
The orbit of Ammonite (red line) and the orbits of the other three sednoids (white lines). Ammonite ... More was discovered close to its perihelion, at a distance of 71 astronomical units (71 times the average distance between the Sun and Earth). The yellow point shows its position as of July 2025.
Could 'Planet Nine' Still Exist After Ammonite's Discovery?
The so-called 'Planet Nine' could still exist, but much farther out in the solar system. It could also be a 'ghost planet,' ejected long ago, with only its past gravitational influence remaining. The orbits of Ammonite and the other sednoids could also be explained by the gravitational influence of a star passing close to the solar system billions of years ago.
How Was Ammonite Found?
Ammonite was first observed using the Subaru Telescope's wide-field prime-focus camera, Hyper Suprime-Cam (HSC), in March 2023 as part of the survey project FOSSIL (Formation of the Outer Solar System: An Icy Legacy). That also explains why it's named after a fossil of a cephalopod. It was observed using Suburu again in May and August 2023.
The Canada-France-Hawaii Telescope's MegaCam was used in July 2024 to trace its orbit more precisely. However, its orbit was calculated by finding it in archive images going back 19 years, including images from 2014 and 2021 from the DECam instrument in Chile and in 2005 images taken by Kitt Peak National Observatory.
This animation shows the observations of comet 3I/ATLAS when it was discovered on July 1, 2025. The ... More NASA-funded ATLAS survey telescope in Chile first reported that the comet originated from interstellar space.
Why Is Ammonite Called A 'Fossil' Of The Solar System?
Ammonite's status as a 'fossil' of the early solar system comes from the finding that it's at least 4.5 billion years old — almost as old as the solar system itself. Numerical simulations using NAOJ's CfCA PC Cluster supercomputer indicate Ammonite's orbit has remained stable for that time. It also revealed that around 4.2 billion years ago, the orbits of all the sednoids were very similar.
Ammonite is part of the fossil record of the orbital configuration of the early solar system. That helps astronomers understand what the solar system looked like when it first formed.
Why The Discovery Of Ammonite Is So Significant
The discovery of Ammonite goes far beyond merely adding one more distant object to the solar system's population. 'Ammonite's orbit tells us that something sculpted the outer solar system very early on. Whether it was a passing star or a hidden planet, this discovery brings us closer to the truth,' said Dr. Shiang-Yu Wang, the study's corresponding author and a Research Fellow in ASIAA.
'Spacecraft have only explored limited regions of the Solar System [and] most of the vast solar system remains unexplored,' said Yoshida. 'Wide-field observations with the Subaru Telescope are steadily pushing back the frontier. '
Whether 2023 KQ14 is officially named Ammonite remains to be seen, with the International Astronomical Union set to assign a name at a later date.
Wishing you clear skies and wide eyes.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
a day ago
- Yahoo
NASA says a plane-sized asteroid will pass Earth next week. Here's what to know.
A plane-sized asteroid scheduled to pass Earth next week is making headlines, but NASA experts want the public to understand why this encounter is more routine than remarkable. The asteroid is named 2025 OW and measures approximately 210 feet in length, according to NASA. It is set to pass Earth on July 28 at a distance of approximately 393,000 miles -- about 1.6 times the average distance to the Moon, according to the space agency. While it's traveling at an impressive speed of 46,908 miles per hour, NASA scientists emphasize this is normal and nothing to lose sleep over. "This is very routine," Ian J. O'Neill, media relations specialist at NASA's Jet Propulsion Laboratory (JPL), told ABC News. "If there was a threat, you would hear from us. We would always put out alerts on our planetary defense blog." MORE: Axiom private space mission could be glimpse of the future as ISS retirement looms Davide Farnocchia, an asteroid expert at NASA's Center for Near-Earth Object Studies (CNEOS), explains that space rocks passing by Earth are just business as usual in our solar system. "Close approaches happen all the time -- it's just part of the fabric of the solar system," Farnocchia told ABC News. His team usually tracks several asteroids passing Earth each week -- as of Tuesday, they're watching five for next week alone. While 2025 OW is large enough to be of interest to NASA scientists, its well-understood orbit means it poses no danger. "We know exactly where it's going to be. We'll probably know where it's going to be for the next 100 years," O'Neill said. MORE: Chance of asteroid striking Earth in the next decade rises to 3.1%, NASA says For space enthusiasts hoping to catch a glimpse of 2025 OW, Farnocchia indicates it won't be visible with binoculars. However, he points to a more exciting upcoming event: the 2029 approach of asteroid Apophis. "Apophis will come within 38,000 kilometers of Earth in April 2029 -- closer than our geostationary satellites," Farnocchia said. Approximately 1,115 feet in length, and due to its exceptionally close approach, Apophis will be visible to the naked eye, offering a rare opportunity for public observation of an asteroid. Both Farnocchia and O'Neill emphasize that while Earth is struck by roughly 100 tons of space material daily, most of this is harmless dust. Larger, potentially hazardous impacts are extremely rare. "For an object the size of 2025 OW, while close approaches might happen yearly, an actual Earth impact would only occur roughly every 10,000 years," Farnocchia notes. NASA continues to monitor near-Earth objects through its planetary defense programs, maintaining public transparency about any potential risks while emphasizing that most asteroid headlines are more sensational than concerning.
Gizmodo
2 days ago
- Gizmodo
The ‘Hail Mary' That Saved NASA's Juno Camera From Jupiter's Radiation Hell
NASA's Juno spacecraft, which launched in 2011 to investigate Jupiter's origin and evolution, travels through the solar system's most intense planetary radiation fields. When the spacecraft's JunoCam—a color, visible-light camera—began to suffer the consequences in December 2023, the mission team back on Earth had to think of a remote fix before they lost their chance to photograph the Jovian moon, Io. A relatively simple process was ultimately what enabled the long-distance save: heating the instrument before slowly cooling it down (I trust they tried turning it off and on again). The experience has provided insightful lessons on spacecraft radiation tolerance for mission scientists beyond the Juno team, according to a Jet Propulsion Laboratory statement published yesterday. Scientists estimated that JunoCam, whose optical unit is located outside of a protective radiation vault, could resist radiation for the spacecraft's first eight orbits around Jupiter. It wasn't until Juno's 47th orbit, however, that the scientists began to observe radiation damage. The team identified evidence suggesting that the radiation had damaged the voltage regulator, which is crucial to JunoCam's power supply. From hundreds of millions of miles away, their options were limited. As such, they decided to try a lesser-known process called annealing, which consists of heating a material for a given amount of time to reduce its defects before slowly cooling it down. 'We knew annealing can sometimes alter a material like silicon at a microscopic level but didn't know if this would fix the damage,' Jacob Schaffner, a JunoCam imaging engineer from Malin Space Science Systems, said in the statement. 'We commanded JunoCam's one heater to raise the camera's temperature to 77 degrees Fahrenheit [25 degrees Celsius]—much warmer than typical for JunoCam—and waited with bated breath to see the results.' While their approach successfully enabled JunoCam to capture clear photographs for several orbits, the spacecraft continued to barrel into Jupiter's radiation fields, and the damage was soon apparent again. 'After orbit 55, our images were full of streaks and noise,' explained JunoCam instrument lead Michael Ravine, also from Malin Space Science Systems. 'We tried different schemes for processing the images to improve the quality, but nothing worked. With the close encounter of Io bearing down on us in a few weeks, it was Hail Mary time: The only thing left we hadn't tried was to crank JunoCam's heater all the way up and see if more extreme annealing would save us.' At first, the more extreme annealing didn't seem to produce any improvements, but as the Io approach got nearer, and with just days to go, the images suddenly improved significantly. On December 30, 2023, JunoCam successfully captured detailed photographs of Io's north polar region, including previously undocumented volcanoes. Scientists presented the accomplishment at the Institute of Electrical and Electronics Engineers Nuclear & Space Radiation Effects Conference in Nashville on July 16. Jupiter's 'Tortured Moon': Astronomers Uncover Surprising Source of Io's Intense Volcanic Fury Despite the fact that the image corruption returned during its recent 74th orbit, 'Juno is teaching us how to create and maintain spacecraft tolerant to radiation, providing insights that will benefit satellites in orbit around Earth,' explained Scott Bolton, Juno's principal investigator from the Southwest Research Institute. 'I expect the lessons learned from Juno will be applicable to both defense and commercial satellites as well as other NASA missions.'
Yahoo
2 days ago
- Yahoo
Everyone's talking about the Perseid meteor shower – but don't bother trying to see it in Australia or NZ
In recent days, you may have seen articles claiming the 'best meteor shower of the year' is about to start. Unfortunately, the hype is overblown – particularly for observers in Australia and New Zealand. The shower in question is the Perseids, one of the 'big three' – the strongest annual meteor showers. Peaking in the middle of the northern summer, the Perseids are an annual highlight for observers in the northern hemisphere. As a result, every year social media around the world runs rife with stories about how we can enjoy the show. For an astronomer in Australia, this is endlessly frustrating – the Perseids are impossible to see for the great majority of Australians and Kiwis. Fortunately, there are a few other meteor showers to fill the void, including a pair that will reach their peak in the next seven days. What are the Perseids? Every year, Earth runs into a stream of debris laid down over thousands of years by comet 109P/Swift–Tuttle. The comet swings around the Sun every 133 years or so, shedding dust and debris each time. Over the millenia, that material has spread to create a vast stream. Earth starts to run into debris from Swift–Tuttle in mid-July, and takes six weeks to pass through the stream. When the dust and debris hit Earth's atmosphere, the resulting meteors create bright streaks in the sky – a meteor shower. For most of that time, the dust we encounter is very widely spread, and so few meteors are seen. Around August 12, Earth reaches the densest part of the Perseid stream and the shower reaches its peak. The Perseids aren't even the 'best' meteor shower Comet Swift–Tuttle last passed through the inner Solar System in 1992. With the comet nearby, Earth encountered more dust and debris, making the Perseids the best meteor shower of the year. In the decades since, the comet has receded to the icy depths of the Solar System, and the peak rates for the Perseids have fallen off. The 'best' (most abundant) meteor shower of the year is now the Geminids. However, for people in the northern hemisphere, the Perseids are still well worth looking out for. The curse of the spherical Earth All meteor showers have a 'radiant"– the point at which meteors seem to originate in the sky. This is because, for a given shower, all the debris hitting Earth comes from the same direction in space. The debris from comet Swift–Tuttle crashes towards Earth from above the north pole, and at an angle. As a result, for people at a latitude of 58 degrees north, the Perseid radiant would be directly overhead in the early hours of the morning. If a meteor shower's radiant is below the horizon, you won't see any meteors – Earth is in the way, and all the dust and debris is hitting the other side of the planet. It's exactly the same reason you can't see the Sun at nighttime. Given the location of the Perseid radiant, it will never rise for observers south of 32 degrees. This means anyone below that line will never see any Perseids. In theory, anyone north of 32 degrees south latitude can see the Perseids – but there are other complications. The higher a shower's radiant is in the sky, the more meteors you will see. This is why the Perseids can't put on a great show for people in Australia. Even in the far north of Australia, the Perseid radiant remains low in the sky at its highest. For most Australians, the Perseids will be a spectacular disappointment. Look for these meteor showers instead If you're keen to see a meteor shower from Australia or New Zealand, it's best to cross the Perseids off your list. Fortunately, there are other options. Every May, Earth passes through debris left behind by comet 1P/Halley, creating the Eta Aquariid meteor shower – only visible in the hours before dawn. For Australian observers, that's the second best shower of the year. At the end of July each year, two minor meteor showers reach their peaks: the Southern Delta Aquariids and Alpha Capricornids. This year, they peak on 29 and 30 July, with the best views coming in the hours around midnight. It's a perfect time to head out to a dark sky site and relax under the stars – the centre of the Milky Way is high overhead in the evening sky, and these two showers provide some added fireworks to make the sky extra special. Then, in December, comes the true "best shower of the year' – the Geminids. Reaching a peak on 14 and 15 December, the Geminids always put on a spectacular show. Unlike the Perseids, it can be seen from all across our island continent and in Aotearoa. If you really want to see a great meteor shower, skip the Perseids and plan to head somewhere dark this summer, to spend a couple of nights relaxing under the stars. This article is republished from The Conversation. It was written by: Jonti Horner, University of Southern Queensland Read more: Astronomers have spied an interstellar object zooming through the Solar System Astronomers have discovered another puzzling interstellar object − this third one is big, bright and fast After 50 successful years, the European Space Agency has some big challenges ahead Jonti Horner does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
