{"id":2274,"date":"2026-08-27T02:45:16","date_gmt":"2026-08-26T23:45:16","guid":{"rendered":"https:\/\/planeta21vek.ru\/eng\/?p=2274"},"modified":"2026-08-27T02:48:07","modified_gmt":"2026-08-26T23:48:07","slug":"new-horizons-expanded-the-boundaries-of-the-kuiper-belt-discovered-snowmen-and-other-unusual-objects","status":"publish","type":"post","link":"https:\/\/planeta21vek.ru\/eng\/2026\/08\/27\/new-horizons-expanded-the-boundaries-of-the-kuiper-belt-discovered-snowmen-and-other-unusual-objects\/","title":{"rendered":"New Horizons expanded the boundaries of the Kuiper Belt, discovered “snowmen” and other unusual objects"},"content":{"rendered":"

The Kuiper Belt may extend billions of miles further than anyone imagined. NASA’s New Horizons spacecraft encountered Pluto in 2015, then spent an extended period in the deepest layers of the Kuiper Belt and encountered a cosmic dust storm, suggesting that the outer reaches of the Solar System may be even further away than we imagine.<\/span><\/p>\n

<\/p>\n

Space is filled with dust, composed of tiny particles measuring just microns\u2014millionths of a meter. Most of the dust in our solar system is leftover from the formation of planets, a violent process that saw numerous objects collide with one another. Today, this ancient dust is also joined by fresh dust ejected from the surfaces of asteroids and comets by micrometeorite impacts. This dust content, both fresh and ancient, produces the mysterious “zodiacal light.” This dust extends to the farthest reaches of the solar system. Astronomers are still uncertain about the composition of this final frontier. The results obtained using the SDC were published on February 1, 2024, in the journal Astrophysical Journal Letters.<\/span><\/p>\n

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\nIllustration of the Kuiper Belt. NASA\/SOFIA\/Lynette Cook<\/span><\/em><\/p>\n

The Kuiper Belt (or Kuiper-Edgeworth Belt, named after astronomers Gerard Kuiper and Kenneth Edgeworth, who independently proposed its existence) is so distant, and its icy inhabitants so small and dim, that the first Kuiper Belt Object (KBO) beyond Pluto was discovered only in 1992. This discovery was made by University of Hawaii astronomers Dave Jewitt and Jane Luu. Since then, however, thousands of Kuiper Belt Objects have been discovered, allowing astronomers to begin mapping the outer Solar System.<\/span><\/p>\n

Beyond the Kuiper Belt lies the Scattered Disk, populated by Kuiper Belt objects (KBOs) that were scattered from the Kuiper Belt by gravitational tides emanating from the Solar System’s outermost planet, Neptune. Objects in the Scattered Disk typically have highly elliptical orbits, steeply inclined to the plane of the Solar System, and can be hundreds of astronomical units (AU) from the Sun. One AU, or astronomical unit, is equal to the distance between Earth and the Sun.<\/span><\/p>\n

Far beyond the Kuiper Belt and the scattered disk lies the Oort Cloud\u2014a vast, spherical region of frozen objects extending more than a light-year from the Sun. Although the Oort Cloud has never been directly observed due to its distance, scientists know of its existence because the orbits of long-period comets can be traced to this location.<\/span><\/p>\n

However, new data obtained by the New Horizons spacecraft threatens to overturn much of our understanding of the outer solar system.<\/span><\/p>\n

“The New Horizons spacecraft is making the first direct measurements of interplanetary dust far beyond Neptune and Pluto, so every observation has the potential to lead to a discovery,” astronomer Alex Doner of the University of Colorado at Boulder said in a statement.<\/span><\/p>\n

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\nThe New Horizons spacecraft’s trajectory through the outer solar system. Arrokoth was discovered at a distance of 44.6 astronomical units. NASA\/Johns Hopkins APL\/SwRI<\/span><\/em><\/p>\n

The distance between the outer edge of the Kuiper Belt and the Sun was thought to be approximately 50 astronomical units (AU) (one AU is also equal to 149.5 million kilometers, or 93 million miles). On January 1, 2019, New Horizons encountered a Kuiper Belt object named Arrokoth, which is 44.5 AU from the Sun. In 2024, New Horizons was 58.25 AU from the Sun, passing the 50 AU mark in April 2021. Over the past five years, New Horizons should have passed beyond the edge of the Kuiper Belt. However, because Kuiper Belt objects are separated by millions of miles, New Horizons would not have visually detected its passage away from them. Instead, a decrease in interplanetary dust levels would have been the telltale sign.<\/span><\/p>\n

However, the Venetia Burney Student Dust Counter (SDC) space instrument, named after the girl who named Pluto in 1930, did not detect this decrease in dust. In fact, there is still as much dust in space as before, baffling astronomers.<\/span><\/p>\n

The SDC detector is mounted on the forward surface of the New Horizons spacecraft. It consists of 14 plastic film detectors, each measuring 14.2 x 6.5 centimeters (5.6 x 2.6 inches) and just 28 microns thick. Twelve of the detectors are exposed to the atmosphere, while the other two are shielded to act as reference detectors, recording any events not related to dust intrusion to eliminate false alarms. Whenever a dust particle strikes one of the detectors, the impact leaves a small pit in the plastic film, which slightly changes the electrical conductivity of their surfaces.<\/span><\/p>\n

One possible explanation is that the excess dust formed closer to the Sun and was ejected from the Kuiper Belt by the pressure of sunlight striking the particles. However, Doner’s team found this theory unlikely. Instead, they say they favor a more attractive theory.<\/span><\/p>\n

The lingering presence of dust indicates that New Horizons is still in the Kuiper Belt, and that the Kuiper Belt is much larger than anyone thought, extending billions of miles farther from the Sun than our current maps show.<\/span><\/p>\n

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\nAn artist’s rendering of NASA’s New Horizons spacecraft. This view shows the student dust collector on the underside of the spacecraft. NASA\/Johns Hopkins APL\/SwRI\/Steve Gribben<\/span><\/em><\/p>\n

This isn’t just evidenced by dust data. Astronomers are using machine learning algorithms to analyze observations from the 8.2-meter Subaru Telescope on Mauna Kea in Hawaii and the 4-meter Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile to find more icy objects that New Horizons could explore. So far, they’ve discovered 154 objects in the direction New Horizons is headed, including about 20 that the spacecraft will approach within a few million miles, close enough for rudimentary observations. However, some of these 154 objects appear to be located beyond the Kuiper Belt, and not in the eccentric orbit typical of the scattered disk, but in the plane of the ecliptic, which is also divided by the Kuiper Belt.<\/span><\/p>\n

“The idea that we may have discovered an extended Kuiper Belt\u2014with a whole new population of objects colliding and producing more dust\u2014provides another clue in unraveling the mysteries of the solar system’s most distant regions,” Doner said.<\/span><\/p>\n

New Horizons is navigating uncharted waters. Only four spacecraft have visited this region before\u2014Pioneer 10 and 11, as well as Voyager 1 and 2\u2014and none of them were equipped with a dust counter like New Horizons.<\/span><\/p>\n\n

While the Pioneer spacecraft have long been inactive and Voyager 1 is beginning to malfunction, New Horizons has enough fuel and energy to last until the 2040s, when it could reach a distance of more than 100 astronomical units from the Sun. By the time its energy reserves run out, it will likely have completely redrew the map of the outer Solar System.<\/span><\/p>\n

In the distant reaches of the solar system lie numerous icy objects resembling snowmen\u2014pairs of connected spheres. A new study reveals a simple way these mysterious objects form.<\/span><\/strong><\/span><\/p>\n

Beyond the orbit of Neptune lie icy building blocks left over from the birth of the solar system, known as planetesimals. Just as snowballs are composed of clusters of snowflakes, planetesimals likely formed within the dust disks that surrounded the newborn Sun, from clouds of pebble-sized objects gravitationally attracted to each other. Scientists detailed their findings on February 19, 2026, in the journal Monthly Notices of the Royal Astronomical Society.<\/span><\/p>\n

In 2019, NASA’s New Horizons spacecraft captured the first images of planetesimals shaped like two joined spheres\u2014snowman-like objects known as contact binaries. Other studies have suggested that between one-tenth and one-quarter of planetesimals may be contact binaries.<\/span><\/p>\n

But how these distant snowmen formed remained a mystery. Previous studies attempted to calculate the origin of contact binaries by modeling them as colliding spheres. However, until recently, these calculations included ideal mergers, which always resulted in spheres, not any other shapes.<\/span><\/p>\n

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\nA composite image of the Kuiper Belt object Arrokoth, photographed by NASA’s New Horizons spacecraft in 2019. NASA\/Johns Hopkins University Applied Physics Laboratory\/Southwest Research Institute<\/span><\/em><\/p>\n

In the study, the scientists modeled planetesimals as clouds of particles resting on each other’s surfaces.<\/span><\/p>\n

Modeling studies have found that sometimes, as these clouds rotated, instead of merging into a single planetesimal, they formed two separate planetesimals orbiting each other. Astronomers have observed numerous such binary planetesimals in the Kuiper Belt beyond Neptune.<\/span><\/p>\n

In new simulations, these binary planetesimals can move closer together under the influence of their mutual gravitational attraction until they touch and merge. The most remarkable thing about this model is that it can create planetesimals not only spherical, but also flat, cigar-shaped, and, yes, snowman-shaped. The speed of these planetesimals and the strength of their particles’ cohesion determine the shape of their eventual merger.<\/span><\/p>\n

The pairs of planetesimals that make up these distant snowmen could remain together for millions or even billions of years, as they are unlikely to collide with anything else. Without a collision, nothing could separate them.<\/span><\/p>\n

The study found that contact binaries accounted for only 4% of the modeled planetesimals, which is not quite consistent with the estimated 10-25%.<\/span><\/p>\n

Barnes noted that the team’s computer simulations were limited by the number and size of particles making up the pebble clouds that later formed planetesimals. He suggested that increasing the number and range of particle sizes in their simulations could help increase the number of contact binaries that could form. Rotating pebble clouds could also form three or more planetesimals orbiting each other.<\/span><\/p>\n

The ring surrounding the icy dwarf planet Quaoar in the Kuiper Belt is located much further from its parent body than scientists previously thought possible.<\/span><\/strong><\/span><\/p>\n

Astronomers have discovered a completely new ring system in the solar system, and it’s located so far from its parent dwarf planet that it should be impossible.<\/span><\/p>\n

The ring surrounds Quaoar, a planet roughly half the size of Pluto and located beyond Neptune. It is only the third ring discovered around a minor planet and the seventh ring system in the Solar System, with the best-known and best-studied rings surrounding the giant planets Saturn, Jupiter, Neptune, and Uranus.<\/span><\/p>\n

All six previously known planets with ring systems have rings located quite close to the planet’s surface. This truly challenges theories of ring formation.<\/span><\/p>\n

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\nImage of the dwarf planet Quaoar, located beyond Neptune. ESA, CC BY-SA 3.0 IGO<\/span><\/em><\/p>\n

The ring system is located at a distance of seven planetary radii from Quaoar (that is, seven times the radius of Quaoar), which is twice the theoretical maximum limit for a ring system, known as the Roche limit. By comparison, the bulk of Saturn’s rings are located just three planetary radii from the gas giant.<\/span><\/p>\n

It was previously thought that rings located beyond the Roche limit would not be able to persist at such a large distance from their parent body. Rings formed beyond the Roche limit should not be stable; they should quickly accrete into the craters, consuming all the ring material.<\/span><\/p>\n

Scientists believe the Quaoar ring formed similarly to other rings in the Solar System: collisions between moons orbiting their parent planet created debris that settled, forming a ring of rock, ice, and dust particles. According to the researchers, these particles cannot form a moon if they are close to the planet and within the Roche limit, as the tidal forces of the parent body constantly tear them apart and prevent them from sticking together. But this is not the case with the Quaoar ring.<\/span><\/p>\n

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\nAn illustration showing the ring arrangement of the dwarf planet Quaoar compared to the Roche limit, which was considered the maximum distance at which planetary rings could form. Paris Observatory<\/span><\/em><\/p>\n

Researchers discovered the ring system while studying the atmosphere of Quaoar. The team used the high-speed HiPERCAM instrument on the Gran Telescopio Canarias (Canary Islands), which is capable of detecting small changes in the illumination of background stars. The ring became visible when it caused a decrease in the illumination of the background star by approximately 5\u201310% both before and after Quaoar’s main body passed in front of the star. This event, known as an eclipse, lasted less than a minute.<\/span><\/p>\n\n

The Quaoar ring is too small and too faint to be seen directly, even with a powerful instrument like the Hubble Space Telescope. Aside from eclipses, the only way to detect these dwarf planet rings is to send a robotic probe to them.<\/span><\/p>\n

Furthermore, according to modeling based on data from the James Webb Space Telescope, five Earth-like worlds may be hidden in the Oort Cloud at the outskirts of the Solar System. The young Sun may have captured several Mars- or Mercury-sized exoplanets currently orbiting the outer reaches of the Solar System, but identifying them will be extremely challenging.<\/span><\/strong><\/span><\/p>\n

Most astronomers agree that there are only four terrestrial planets, or rocky planets, in our Solar System, all located close to the Sun. However, new research suggests that up to five more planets may be lurking in the outer reaches of the Solar System.<\/span><\/p>\n

Free-floating planets (FFPs) are planet-sized objects that do not orbit a star. Also called rogue planets, FFPs either form from gas clumps unbound by a star or originate around stars but are ejected from their orbits. The James Webb Space Telescope (JWST) has discovered hundreds of FFPs in the Milky Way and beyond, including Jupiter-sized pairs in the constellation Orion. Modeling suggests that most FFPs are likely Mars-sized.<\/span><\/p>\n

While some rogue planets are ejected by stars, stars can also attract these lonely wanderers with their gravity, turning planets into constantly rotating members of the Solar System. In a study published December 18, 2023, in the journal Astrophysical Journal Letters, the researcher suggests that our own Sun may have also attracted rocky rogue planets in its early stages.<\/span><\/p>\n

To determine the likelihood, study author Amir Siraj, a graduate student in astrophysics at Princeton University and director of the university’s Interstellar Object Program, used several previously developed models, or sets of equations, based on observations of rogue planets. Assuming our young star has a 1 in 50 chance of capturing a rogue planet\u2014which he noted is a conservative estimate\u2014Siraj ran 100 million simulations, adjusting for factors such as orbital shape to determine how many rocky worlds the Sun could have captured. Siraj also assumed the Sun’s early environment was sufficiently constricted to estimate the number of planets in a worst-case scenario, as planet capture becomes more difficult in such circumstances.<\/span><\/p>\n

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\nRocky planets captured by the Sun may reside in the outer solar system, orbiting the Sun for tens of thousands of years. da-kuk via Getty Images<\/span><\/em><\/p>\n

The study found that two planets with a mass similar to Mars, or three to five planets with a mass comparable to Mercury, could reside within approximately 1,400 astronomical units (AU) of the Sun. (One AU is the distance between Earth and the Sun.) This means the captured rogue planets reside in the Oort cloud\u2014a hypothetical giant bubble of billions of mountain-sized icy objects that surrounds the Solar System.<\/span><\/p>\n

The proposed new planets are independent of Planet X, a yet-to-be-discovered hypothetical Neptune-like world thought to orbit approximately 43 astronomical units from the Sun. Unlike the new study, which relies on theory, scientists predicted the existence of Planet X based on observations of the strange trajectories of objects in the Kuiper Belt, a ring-shaped region of icy bodies extending from Neptune to the Oort Cloud.<\/span><\/p>\n

While captured terrestrial worlds would likely be more Earth-like than Planet X, their habitability remains a matter of speculation. While water may exist in the form of ice sheets, sunlight would be “very weak\u2014comparable to the brightness of moonlight here on Earth,” Siraj said. But since the putative planets originate from other star systems and are therefore exoplanets, future space missions exploring exoplanets could target them.<\/span><\/p>\n

However, detecting these newly proposed planets will be even more challenging than identifying Planet X, as they are much smaller and farther from the suspected planet. Siraj believes that the Vera S. Rubin Observatory, currently under construction in Chile and scheduled for launch in 2025, could detect a former FFP-listed planet closer than 700 astronomical units\u2014but only if, as he noted, “it’s in the southern hemisphere of the sky and close enough to us, with a high enough albedo,” meaning the ability to reflect the light that illuminates it.<\/span><\/p>\n<\/i> Comment on Facebook* The owner of the Meta company is recognized as extremist in Russia and is banned.<\/span><\/a>\n\n","protected":false},"excerpt":{"rendered":"

The Kuiper Belt may extend billions of miles further than anyone imagined. NASA’s New Horizons spacecraft encountered Pluto in 2015, then spent an extended period in the deepest layers of the Kuiper Belt and encountered a cosmic dust storm, suggesting that the outer reaches of the Solar System may be even further away than we imagine.<\/p>\n","protected":false},"author":1,"featured_media":2275,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[543,40],"tags":[978,829],"class_list":{"0":"post-2274","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-solar-system","8":"category-kosmos","9":"tag-kuiper-belt","10":"tag-oort-cloud"},"_links":{"self":[{"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/posts\/2274","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/comments?post=2274"}],"version-history":[{"count":2,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/posts\/2274\/revisions"}],"predecessor-version":[{"id":2277,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/posts\/2274\/revisions\/2277"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/media\/2275"}],"wp:attachment":[{"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/media?parent=2274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/categories?post=2274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/planeta21vek.ru\/eng\/wp-json\/wp\/v2\/tags?post=2274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}