https://phys.org/ en-us Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. The Gaia mission has allowed researchers to understand the motions of stars like never before, even revealing possible interactions between our solar system and nearby stars. Planetary Science Institute Senior Scientist Nathan Kaib and collaborator Sean Raymond (Universite de Bordeaux) have found that a recent stellar passage likely triggered a huge increase in comet formation as the star's gravity altered Oort cloud objects' orbits, sending them cascading into the inner solar system. We may even still be feeling the effects of this passage today. This work is being presented at the American Astronomical Society Division on Dynamical Astronomy. https://phys.org/news/2026-06-ancient-stellar-flyby-period-comets.html Astronomy Thu, 25 Jun 2026 19:40:04 EDT news701625061 Astronomers have long sought evidence to explain why comets at the outskirts of our own solar system contain crystalline silicates, since crystals require intense heat to form and these "dirty snowballs" spend most of their time in the ultracold Kuiper Belt and Oort Cloud. Now, looking outside our solar system, NASA's James Webb Space Telescope has returned the first conclusive evidence that links how those conditions are possible. https://phys.org/news/2026-01-webb-young-sun-star-forging.html Astronomy Wed, 21 Jan 2026 14:55:41 EST news688229701 Two bright green comets are streaming through the skies and are visible to skygazers in the Northern Hemisphere. https://phys.org/news/2025-10-green-comets-bright-night-sky.html Space Exploration Thu, 16 Oct 2025 12:41:41 EDT news679837287 The interstellar object 3I/ATLAS has been something of a mystery ever since it graced our solar system. From all outward appearances, the object appears to be a comet that originated in another star system and was ejected by gravitational perturbations. This was evident from the way it has been actively releasing water vapor as it draws closer to the sun, forming a coma and a tail. Nevertheless, it has exhibited some anomalous behavior, fueling speculation that it may be an interstellar visitor of another kind. https://phys.org/news/2025-10-esa-mars-exomars-orbiters-glimpse.html Astronomy Mon, 13 Oct 2025 10:39:04 EDT news679570741 Comet 3I/ATLAS is the third ISO ever detected. It was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) station on 1 July 2025. It's traveling through the inner solar system at about 220,000 km/h and will make its closest approach to the sun in late October. https://phys.org/news/2025-09-interstellar-comet-3iatlas.html Planetary Sciences Fri, 12 Sep 2025 10:10:07 EDT news676890602 In the outer reaches of our solar system, far beyond the orbit of Pluto, lies Sedna, one of the most mysterious objects ever discovered. This reddish dwarf planet follows such an extreme orbit that it takes more than 11,000 years to complete a single journey around the sun. Now, scientists are proposing a new mission to reach this distant world using a revolutionary propulsion technology. https://phys.org/news/2025-06-propulsion-enable-mission-sedna.html Space Exploration Fri, 27 Jun 2025 12:08:04 EDT news670244881 If our solar system seems stable, it's because our short lifespans make it seem that way. Earth revolves, night follows day, the moon moves through light and shadow, and the sun hangs in the sky. But in reality, everything is moving and influencing everything else, and the fine balance we observe can easily be disrupted. Could passing stars have disrupted Earth's orbit and ushered in dramatic climatic changes in our planet's past? https://phys.org/news/2025-06-stellar-flybys-earth-climate-million.html Planetary Sciences Wed, 18 Jun 2025 16:32:04 EDT news669483121 A team of astronomers has made a groundbreaking discovery by detecting molecular activity in comet C/2014 UN271 (Bernardinelli-Bernstein)—the largest and second most distantly active comet ever observed from the Oort Cloud. https://phys.org/news/2025-06-largest-oort-cloud-comet-reveals.html Astronomy Tue, 17 Jun 2025 11:13:03 EDT news669377581 Scientists have unlocked one of the solar system's many secrets from an unexpected source: a planetarium show opening to the public on Monday. https://phys.org/news/2025-06-planetarium-scientists-cosmic-secret.html Astronomy Tue, 03 Jun 2025 11:05:34 EDT news668167529 Asteroids are the ancient remnants of our solar system's birth, rocky fragments that never formed into planets. Most of these celestial wanderers inhabit the asteroid belt between Mars and Jupiter, where Jupiter's immense gravitational influence prevents them from assembling into a single world. Ranging from house-sized boulders to Ceres, a dwarf planet nearly 1,000 kilometers across, asteroids preserve pristine records of the early solar system's composition and conditions. https://phys.org/news/2025-05-china-tianwen-asteroid-sample.html Planetary Sciences Thu, 29 May 2025 10:30:05 EDT news667732622 It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. https://phys.org/news/2025-05-mysterious-planet.html Planetary Sciences Thu, 29 May 2025 05:01:31 EDT news667713684 A small team led by Sihao Cheng, Martin A. and Helen Chooljian Member in the Institute for Advanced Study's School of Natural Sciences, has discovered an extraordinary trans-Neptunian object (TNO), named 2017 OF201, at the edge of our solar system. https://phys.org/news/2025-05-extreme-cousin-pluto-dwarf-planet.html Astronomy Thu, 22 May 2025 10:37:10 EDT news667129026 A newly discovered green comet tracked by telescopes has likely broken apart as it swung by the sun, dashing hopes of a naked-eye spectacle. https://phys.org/news/2025-04-green-comet-wont-visible-naked.html Planetary Sciences Mon, 21 Apr 2025 12:33:27 EDT news664457604 Interstellar material has been discovered in our solar system, but researchers continue to hunt for where it came from and how it got here. A new study led by Western astrophysicists Cole Gregg and Paul Wiegert recommends Alpha Centauri—the next closest solar system to ours—is a great place to start, highlighting how and why it's a prime target. https://phys.org/news/2025-03-astrophysicists-unexpected-space-solar-alpha.html Planetary Sciences Thu, 06 Mar 2025 13:10:30 EST news660489024 We typically think of the Oort cloud as scattered ice balls floating far from the sun, yet still tied to it gravitationally. Occasionally, some wayward gravitational perturbation will knock one of them a weird way and create a long-period comet, which might briefly delight us lowly humans by providing something interesting in the sky to look at. https://phys.org/news/2025-02-spiral-oort-cloud.html Astronomy Wed, 19 Feb 2025 12:31:56 EST news659190708 When astronomers detected the first known interstellar object, 'Oumuamua, in 2017, it sparked a host of new studies trying to understand the origin and trajectory of the galactic sojourner. https://phys.org/news/2025-02-stars-oumuamua.html Planetary Sciences Mon, 17 Feb 2025 10:35:04 EST news659010902 The appearance of the interstellar objects (ISOs) 'Oumuamua and Comet Borisov in 2017 and 2019, respectively, created a surge of interest. What were they? Where did they come from? Unfortunately, they didn't stick around and wouldn't cooperate with our efforts to study them in detail. Regardless, they showed us something: Milky Way objects are moving around the galaxy. https://phys.org/news/2025-02-interstellar-visitors-material-alpha-centauri.html Planetary Sciences Wed, 12 Feb 2025 15:35:04 EST news658596901 What "may" be the best anticipated comet of 2025 is coming right up. Right now, there's only one comet with real potential to reach naked eye visibility in 2025: Comet C/2024 G3 ATLAS. This comet reaches perihelion at 0.094 Astronomical Units (AU, 8.7 million miles or 14 million kilometers, interior to the orbit of Mercury) from the sun on January 13th, and "may" top -1st magnitude or brighter. https://phys.org/news/2025-01-comet-g3-atlas-perihelion.html Astronomy Tue, 07 Jan 2025 16:16:03 EST news655488961 New studies led by researchers at the University of Central Florida offer for the first time a clearer picture of how the outer solar system formed and evolved based on analyses of trans-Neptunian objects (TNOs) and centaurs. https://phys.org/news/2024-12-webb-glimpse-icy-planetesimals-early.html Astronomy Thu, 19 Dec 2024 10:22:30 EST news653826143 In 2017, NASA discovered and later confirmed the first interstellar object to enter our solar system. https://phys.org/news/2024-12-dark-comet-quick-kids-solar.html Astronomy Mon, 16 Dec 2024 12:00:01 EST news653569714 We know that interstellar objects occasionally visit our solar system. So far, we have only discovered two interstellar objects (ISOs), but that's mainly because we can only distinguish them from solar system bodies by their orbital motion, and that takes a series of observations over time. https://phys.org/news/2024-12-tidal-streams-interstellar-milky-braided.html Astronomy Thu, 12 Dec 2024 14:01:35 EST news653234489 When 'Oumuamua traversed our solar system in 2017 it was the first confirmed Interstellar Object (ISO) to do so. Then in 2019, Comet 2l/Borisov did the same thing. These are the only two confirmed ISOs to visit our solar system. Many more ISOs must have visited in our solar system's long history, and many more will visit in the future. There are obviously more of these objects out there, and the upcoming Vera Rubin Observatory is expected to discover many more. https://phys.org/news/2024-12-interstellar-rogue-planets-solar.html Planetary Sciences Thu, 05 Dec 2024 15:09:04 EST news652633741 Trying to understand the makeup and evolution of the solar system's Kuiper belt has kept researchers busy since it was hypothesized soon after the discovery of Pluto in 1930. In particular, binary pairs of objects there are useful as indicators since their existence today paints a picture of how energetic or violent the evolution of the solar system was in its early days four billion years ago. https://phys.org/news/2024-11-ultrawide-binary-kuiper-belt-earliest.html Astronomy Tue, 26 Nov 2024 07:25:11 EST news651756713 Identifying asteroids on a potential collision course with Earth could be made easier thanks to an advancement in how to track their orbits more precisely. https://phys.org/news/2024-11-earth-bound-asteroids-tracked-precisely.html Planetary Sciences Mon, 25 Nov 2024 12:05:15 EST news651758709 Comets have long been seen as omens and portents, and it's easy to understand why. They first appear as faint smudges of light in the sky, sometimes fading soon after and sometimes becoming brighter than the planets, with a long, glowing tail. They have been observed throughout human history, but it wasn't until the eighteenth century that astronomers began to predict the return of some comets. https://phys.org/news/2024-10-astronomers-orbits-potentially-hazardous-comets.html Astronomy Thu, 31 Oct 2024 14:38:10 EDT news649604285 The human mind may find it difficult to conceptualize: a cosmic cloud so colossal it surrounds the sun and eight planets as it extends trillions of miles into deep space. https://phys.org/news/2024-10-comet-tsuchinshan-atlas-oort-cloud.html Astronomy Mon, 14 Oct 2024 12:50:01 EDT news648128414 Prepare to spot a rare, bright comet. The space rock is slinging toward Earth from the outer reaches of the solar system and will make its closest pass on Saturday. It should be visible through the end of October, clear skies permitting. https://phys.org/news/2024-10-tsuchinshan-atlas-comet-visible-naked.html Space Exploration Wed, 09 Oct 2024 12:20:46 EDT news647695236 Stargazers will have the chance to spot what could be the most impressive comet of the year over the coming weeks. https://phys.org/news/2024-09-comet-a3-tsuchinshan-atlas.html Astronomy Mon, 30 Sep 2024 09:15:07 EDT news646906500 A comet is expected to risk having its tail clipped on Friday by flying perilously close to the sun, promising fireworks next month should it survive the fraught flypast. https://phys.org/news/2024-09-fireworks-comet-survives-risky-sun.html Space Exploration Sat, 28 Sep 2024 05:28:05 EDT news646720065 Throughout Earth's history, the planet's surface has been regularly impacted by comets, meteors, and the occasional large asteroid. While these events were often destructive, sometimes to the point of triggering a mass extinction, they may have also played an important role in the emergence of life on Earth. This is especially true of the Hadean Era (ca. 4.1 to 3.8 billion years ago) and the Late Heavy Bombardment, when Earth and other planets in the inner solar system were impacted by a disproportionately high number of asteroids and comets. https://phys.org/news/2024-09-comets-blocks-life-ocean-worlds.html Astrobiology Mon, 09 Sep 2024 12:46:05 EDT news645104761