The ACM conference series occupies a unique position in planetary science. Unlike meetings devoted to a single mission or technique, it deliberately bridges communities that often work in parallel: dynamicists who model orbital evolution over millions of years, spectroscopists who infer composition from reflected sunlight, laboratory analysts who study meteorites in the clean room, and observers who track the fleeting trails of meteors burning in the upper atmosphere. The triennial cadence means each meeting functions as a census of the field, capturing which questions have matured into consensus and which remain open. The 2026 edition in Poznań continued that tradition, bringing together current and future generations of small body scientists, with a scientific programme assembled by an international Scientific Organizing Committee and local logistics managed by a committee based in the Wielkopolska region.

A recurring theme of the meeting was the flood of high-precision data now arriving from next-generation surveys and space telescopes. Work presented in the session literature includes studies of trans-Neptunian and Centaur populations informed by recent survey discoveries, analyses of the orbital structure of near-Earth asteroid populations, and characterizations of active asteroids and main-belt comets whose dust tails blur the classical boundary between asteroids and comets. The increasing sensitivity of ground-based facilities has pushed detections toward smaller and fainter objects, revealing populations that were statistically invisible a generation ago. For dynamicists, this means models of impact flux, delivery from the main belt and the Kuiper belt, and resonant transport can now be tested against observed size-frequency distributions rather than fitted to sparse catalogs.

Cometary science featured prominently, reflecting the maturation of remote sensing at unprecedented spatial resolution. Research discussed at the conference included observations of cometary activity captured with the James Webb Space Telescope, which has begun resolving the distributions of water, carbon dioxide and other volatiles within cometary comae, and studies of long-period comets making their first pass through the inner Solar System. These measurements bear directly on questions of where comets formed and how the primordial ice inventory of the outer disk was distributed during the giant planets’ migration. Compositional mapping of individual comets, combined with the in situ results from the Rosetta mission at comet 67P/Churyumov-Gerasimenko, is converging on a picture in which comets are heterogeneous aggregates assembled from material processed at different distances from the young Sun.

Planetary defence was another major strand of the programme, and one with particular urgency following the first deliberate alteration of an asteroid’s orbit. The Double Asteroid Redirection Test demonstrated that a kinetic impactor can measurably change the trajectory of a satellite asteroid, and follow-up work on the ejecta dynamics, momentum transfer efficiency and structural response of the target Dimorphos has reshaped how researchers model asteroid interiors. Presentations at ACM 2026 drew on this legacy as the European Space Agency’s Hera spacecraft travels toward the Didymos system to survey the impact outcome in detail. Related work on the physical properties of rubble-pile asteroids, their cohesion, porosity and rotational failure modes, informs both deflection planning and the broader understanding of how small bodies evolve through collisions and spin-up over Solar System history.

Meteor science, the third pillar of the conference’s remit, is undergoing its own quiet revolution driven by global camera networks and seismic monitoring. Modern fireball networks now triangulate meteoroid trajectories with sufficient precision to recover falls and compute pre-impact orbits, linking meteorites directly to their source regions in the main belt. Studies presented in the meeting literature include analyses of meteoroid fragmentation in the atmosphere, statistical treatments of fireball datasets, and the use of seismometers to detect and characterize bolide airbursts, a technique that extends monitoring to events too small or too remote for optical networks. Together these approaches constrain the flux of material reaching Earth and the physical structure of the parent bodies, connecting the meteorite record in laboratories to the asteroid populations observed telescopically.

Sample return missions have fundamentally changed the evidentiary basis of the field, and their results resonated through many sessions. Material returned from the carbonaceous asteroids Ryugu and Bennu has provided uncontaminated, space-weathered primitive material whose mineralogy, organic content and isotopic composition can be compared directly with meteorite classes. Work building on these samples, including studies of the volatile inventory and thermal history of primitive bodies, was among the research highlighted in the conference’s session literature. The comparison between returned samples and telescopic spectra of larger populations such as the D-type and P-type objects in the outer belt and Jupiter’s Trojan swarms remains a central challenge, and new infrared surveys of these populations are helping to close the gap between the few bodies visited by spacecraft and the hundreds of thousands catalogued from Earth.

The meeting also underscored the growing role of machine learning and large-scale computation in small body science. Automated classification of light curves, neural-network detection of moving objects in survey images, and large N-body simulations of asteroid family evolution are now standard tools, and several presentations examined how these methods perform on the data volumes expected from the Vera C. Rubin Observatory’s Legacy Survey of Space and Time. Orbit determination for potentially hazardous objects, impact probability computation and the propagation of uncertainties over decadal timescales all benefit from these advances, as do efforts to link meteorite falls to asteroid families through dynamical modeling. The methodological convergence across subfields, from comet photometry to meteoroid stream modeling, was one of the practical takeaways emphasized by attendees.

Beyond the science, the Poznań meeting made a deliberate effort to broaden participation. Support from the ESA Academy, the Europlanet Society, the NASA Planetary Data System Small Bodies Node, the UAE Space Agency, the Canadian Space Agency and industry partners enabled early-career researchers and scientists from underrepresented and underprivileged groups to attend, and the UAE Space Agency sponsored the conference’s Best Poster Award. Financial backing from Poland’s Ministry of Science and Higher Education through the Wektory Nauki programme, the Wielkopolska regional government and the Initiative of Excellence – Research University programme of Adam Mickiewicz University underwrote the meeting itself. Organizers noted that the resulting exchange helped foster new collaborations across the global small body community, a stated aim of a series that has historically rotated among host countries to keep the field international.

As the 15th edition closed, the field it surveyed looked markedly different from the one that gathered three years earlier. Spacecraft are en route to metallic and primitive asteroids, survey telescopes are cataloguing small bodies at rates that outpace manual analysis, and laboratory measurements of returned samples are rewriting textbooks on Solar System formation. The questions that will define the next ACM conference, expected in 2029, are already taking shape: how efficiently kinetic impactors transfer momentum to real rubble piles, how the isotopic diversity of meteorites maps onto asteroid spectral classes, and how the smallest members of the Solar System’s debris population record the giant planets’ early history. For the community that met in Poznań, the small bodies of the Solar System have never been a bigger subject.

Subject of Research: Asteroids, comets and meteors in the Solar System

Article Title: The 15th Asteroids Comets Meteors Conference

Article References: The 15th Asteroids Comets Meteors Conference. (n.d.). https://doi.org/10.1038/s41550-026-02995-3

Image Credits: AI Generated

DOI: 10.1038/s41550-026-02995-3

Keywords: asteroids, comets, meteors, planetary defence, DART, Hera, sample return, meteorites, Kuiper belt, near-Earth asteroids, space surveys, ACM 2026

Bennu is an unusually accessible target for science. The asteroid completes one orbit of the Sun every 1.2 years and passes within roughly 300,000 kilometres of Earth every six years, a close approach that made it an ideal destination for a sample-return mission. NASA seized this opportunity with its OSIRIS-REx probe, which in a spectacular operation touched down on the asteroid’s surface and collected material directly from it. In 2023, the sample container descended into the Utah desert carrying around 120 grams of Bennu’s rocky payload, the largest amount of asteroid material ever returned to Earth. From that haul, a small but extraordinarily precious portion made its way to Switzerland, where Maria Schönbächler, Professor of Isotope Geochemistry at ETH Zurich, received half a gram for analysis. Her laboratory began working on the samples immediately, and the completed investigations have now yielded results that reach far beyond Bennu itself, offering new insight into how the entire Solar System took shape.

The key to the discovery lies in isotopes, atoms of the same element that differ slightly in mass because their nuclei contain different numbers of neutrons. The ETH team measured isotopes of three elements: iron, titanium and chromium. Together, these isotopic ratios create a distinctive chemical fingerprint that allows researchers to determine where a body’s raw material originated and, to some extent, how old it is. Because isotopic ratios are inherited from the cloud of dust and gas that formed the Solar System and are altered only by specific nuclear and chemical processes, they act like immutable birth certificates written into the fabric of rocks. For Bennu, that fingerprint turned out to be unlike anything scientists expected.

The measurements revealed that titanium and iron are uniformly distributed throughout the Bennu material, a sign of a remarkably well-mixed source. More striking still, the analyses showed that Bennu has close relatives scattered across the Solar System. The asteroid Ryugu, sampled by Japan’s Hayabusa2 mission, and the so-called CI meteorites, a rare class of primitive, carbon-rich rocky bodies occasionally found on Earth, all share a similar isotopic fingerprint with Bennu. This shared signature indicates that all three bodies formed from the same reservoir of cosmic dust. At the same time, the group differs significantly in isotopic composition from other known asteroids, meteorite groups and the planets, marking Bennu and its siblings out as members of a chemically distinct family with a very specific place of origin.

That place of origin is precisely where the new study overturns long-held assumptions. Until now, scientists had assumed that asteroids such as Bennu formed in the outer regions of the Solar System, possibly in the same environment where comets formed, and that they accreted relatively late in the Solar System’s evolution. The new isotope data contradict both ideas. Instead, the most likely scenario is that the birthplace of Bennu, Ryugu and the CI meteorites lay close to the water-ice line, the boundary marking the point where water vapour freezes. Around 4.5 billion years ago, as the Solar System was still taking shape, this location was a dynamic mixing zone where material from the inner and outer regions met and mingled. The ice present there acted as a kind of glue, binding the finest dust particles together into larger aggregates that would eventually grow into asteroid-sized bodies.

Bennu, in other words, is a hybrid. As Schönbächler explains, the material does not clearly match either the inner or the outer Solar System; it bears characteristics of both regions, having formed in a specific zone where flows of matter from both sides converged. This hybrid character explains several long-standing puzzles about Bennu’s composition, including why its material is so rich in water. In the vicinity of the water-ice line, ice evaporated as temperatures fluctuated, and some of the resulting water vapour condensed again in exactly the region where Bennu’s parent body formed, soaking the accumulating dust with hydrated minerals. The result is an asteroid whose substance carries the chemical memory of a boundary environment that no longer exists in the modern Solar System.

The ETH researchers and their co-authors attribute a central role in this story to Jupiter. The gas giant formed remarkably early, within roughly one million years of the Sun’s birth from a collapsing cloud of dust and gas, driven by gravitational forces within the swirling disc of material that surrounded the young star. Because it grew so rapidly, Jupiter acted as a bridge pillar within that disc: its growing bulk blocked most coarse material from crossing its orbit, while fine dust from various regions of the disc flowed around the giant planet and mixed evenly in the transition zone near the water-ice boundary. The precursors of Bennu, Ryugu and the CI meteorites subsequently accreted in this sheltered region, built almost entirely from finely intermixed dust rather than from the larger pebbles and boulders that Jupiter filtered out.

This scenario elegantly accounts for another of Bennu’s defining traits: the extraordinary chemical similarity of its material to that of the Sun itself. Because Jupiter’s protective influence ensured that Bennu formed mainly from fine dust, and because fine dust orbiting in the disc around the young Sun was thoroughly mixed, the asteroid’s composition mirrors the average Solar System inventory of elements. Schönbächler compares it to fine dust at home, which simply ends up everywhere over time. That makes Bennu an extraordinarily valuable scientific resource. It is a very primordial asteroid, and its material dates back to the birth of the Solar System around 4.5 billion years ago, having hardly changed since. As Schönbächler notes, Bennu may offer our best glimpse of the original mix of chemical elements from which the terrestrial planets were ultimately built.

The implications extend to the deepest questions about our own origins. By performing precise geochemical analyses of Bennu’s samples, researchers are refining our understanding of how the Solar System arose and under what conditions planets formed. Because the asteroid is rich in water and organic material, it also provides important pieces of the puzzle regarding how the young Earth acquired the building blocks of life, the volatile compounds and carbon-based chemistry that may have been delivered to our planet by primitive bodies like Bennu during the chaotic early era of planetary formation.

Many questions remain open. The team is now wondering whether other asteroids share the same isotopic signature as Bennu and Ryugu, and it is still unclear to what extent the young Jupiter contributed to the fact that only fine dust particles clumped together in the transition zone. Further research will help clarify this picture. Meanwhile, Schönbächler is eagerly awaiting the Japanese sample-return mission to Mars’ moon Phobos, due to launch at the end of October this year, and intends to apply to the Japanese space agency JAXA for material to analyse in her laboratory. Patience will be required, however: the capsule containing the Phobos material is not expected to return to Earth until 2031. When it does, it may allow scientists to test whether the strange hybrid fingerprint of Bennu, forged beside a growing Jupiter at the edge of the ice, was shared more widely across the early Solar System than anyone had imagined.

Subject of Research: Isotopic analysis of OSIRIS-REx samples revealing the formation origin of asteroid Bennu near the Solar System's water-ice line

Article Title: Mystery surrounding the formation of asteroid Bennu solved

Article References: Mystery surrounding the formation of asteroid Bennu solved. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: asteroid Bennu, OSIRIS-REx, isotope geochemistry, water-ice line, Jupiter, Solar System formation, Ryugu, CI meteorites, ETH Zurich, sample return, Science Advances, planet formation

Sample acquisition has long been one of the most expensive and failure-prone elements of planetary missions. The Mars Curiosity rover, for example, relied on a sophisticated Sample Acquisition, Sample Processing and Handling system that required a choreographed series of robotic arm motions to move drilled or scooped material through a sieve and into pre-measured cups. The rover’s orientation, including its pitch, tilt, and yaw, dictated different arm commands, and sticky samples demanded a mechanical thwacker to dislodge material clinging to interior walls. The Mars Phoenix lander faced an even thornier problem: icy soil warmed by sunlight thawed and refroze inside the scoop, adhering to its walls so stubbornly that nothing fell into the Thermal and Evolved-Gas Analyzer when the arm attempted delivery. Engineers had to improvise on the fly, shielding the scoop from the Sun while preserving precious water ice for analysis.

Those experiences illustrate why Honeybee Robotics spent more than two decades developing an alternative. PlanetVac replaces complex articulation with a principle familiar from industrial powder handling on Earth: pneumatic transport. Gas jets pointed downward inside a sampling head loft regolith into a transfer hose, where it is swept along to a capture system that separates sample from gas flow. When high-pressure gas is released into vacuum and directed at a surface, it reaches supersonic velocities, efficiently lifting both fine and coarse particles. In sealed laboratory systems with minimal gas losses, the team measured lofting efficiencies of up to 5000, meaning a single gram of gas could move 5000 grams of regolith. The approach is gravity-agnostic, works with cohesive and non-cohesive materials alike, and completes a full sampling cycle within seconds using only a few watts of power, with no motors, closed-loop control, or elaborate avionics required.

The flight unit that rode to the Moon consisted of four subsystems: a machined aluminum sampling head with downward- and upward-pointing nozzles, a braided stainless steel transfer hose with a smooth PTFE core, a Sample Sorting System mounted in the lander’s temperature-controlled mid-deck, and avionics managing power and thermal control. The Sample Sorting System contained separate chambers for fine and coarse material divided by a 1-millimeter screen, a 0.38-millimeter exhaust sieve that let gas escape while retaining larger particles, and a camera to document the captured soil. Two infrared beam breaker sensors near the chamber entrance provided an inexpensive, camera-free method of verifying that material had arrived, a deliberate pathfinder for future missions. The entire payload weighed just 8.46 kilograms, a full 30 percent below its not-to-exceed mass, and drew between 3.5 and 24.1 watts depending on the operating mode, comfortably inside its power allocations.

Operationally, the system was mounted on Firefly’s Surface Access Arm, a single-degree-of-freedom arm designed to press the sampling head flush against the lunar surface with about 100 newtons of downforce. That preload mattered because PlanetVac acts, in effect, as a cold gas thruster; without it, the arm would simply lift off the ground during firing. The gas tank held 126 grams of nitrogen at 5000 pounds per square inch, enough for more than 30 seconds of sampling at flow rates exceeding one gram per second. But when Blue Ghost settled onto uneven terrain near a small crater, the footpad closest to the arm failed to fully contact the ground, leaving the sampling head angled toe-down rather than flush. Telemetry and imagery from the lander’s SCALPSS payload and ARGUS camera confirmed the tilt, which produced an asymmetric excavation crater roughly 350 by 400 millimeters in size.

Despite the compromised geometry, the device performed. During the primary five-second operation, a solenoid valve opened and nitrogen surged through the nozzles, lofting regolith up the transport tube in under a second. The beam breaker pair, spaced 10 millimeters apart, recorded particle transit times indicating a velocity of about 3.3 meters per second, with the majority of the sample arriving within the first second. Correlating flight images with computer-aided design models and extensive pre-flight vacuum chamber testing, the team estimated that roughly 3.6 cubic centimeters of soil settled at the bottom of the collection chamber while about 3.4 cubic centimeters of dust coated interior surfaces, a layer estimated at 50 microns across 680 square centimeters. That first haul alone exceeded the mission’s minimum capture requirement of one cubic centimeter. Three auxiliary operations, including a 24-second purge fired on March 15 as lunar sunset approached, brought the cumulative total to approximately 11 cubic centimeters.

The exterior camera footage delivered some of the most striking imagery of the mission. Millimeter-scale particles were ejected horizontally at speeds up to 10 meters per second, and one 15-millimeter rock, affectionately nicknamed Dwayne, was propelled an estimated 61 centimeters high before the radial gas plume deflected it sideways on descent. More serendipitously, the pneumatic blast visibly cleaned the lens of the ARGUS camera mounted about 70 centimeters above the surface, and even cleared cameras on the far side of the lander. The team suggests that charge dissipation by gas-borne charge carriers, rather than direct momentum transfer, may explain the distant cleaning effect, a phenomenon that could prove genuinely useful for future landers that need clear exterior imagery after touchdown. Onboard, a sieving operation separated the sample into size fractions and simultaneously blew fine dust off the internal camera window and the mounted material coupons.

That dust mitigation was no accident. Attached to the back wall of the collection chamber were coupons of candidate lunar surface materials, including polyimide, titanium alloy, a chromium carbide nickel chromium coating applied by high-velocity oxygen fuel spraying, and a proprietary work-function matched inorganic coating, some surfaces patterned by picosecond laser ablation to test how topography influences dust adhesion. Because the imaging setup lacked a bright internal reference standard, the team could not quantify dust accumulation directly, but grayscale brightness analysis of regions of interest revealed measurable changes across sampling sequences, with accumulation patterns differing between the two chambers. The researchers note that a brighter LED and a redesigned coupon arrangement would strengthen the experiment on future flights, and that further image analysis and laboratory work may clarify how laser-ablated surfaces perform against the relentless lunar dust.

The broader significance of the demonstration extends well beyond Mare Crisium. Because gravitational effects are secondary in pneumatic mining operations, PlanetVac-style systems can function on Mars, on comets, and in the microgravity of small bodies. The technology has already been selected for JAXA’s Martian Moons eXploration mission, where a variant called the P-Sampler will capture Phobos surface material for return to Earth, and similar pneumatic approaches will fly on NASA’s Dragonfly rotorcraft bound for Titan. The successful lunar flight provides critical risk reduction for those missions while offering the Commercial Lunar Payload Services program the cheap, simple sampling architecture it was designed to encourage. As the team concludes, the combination of low mass, low power, fast operation, and freedom from gravity-dependent mechanics makes pneumatic sampling a foundational capability for the next era of planetary exploration, in situ resource utilization, and sample return.

Subject of Research: Pneumatic lunar regolith sampling demonstrated by Lunar PlanetVac on Blue Ghost Mission 1

Article Title: Results of Lunar PlanetVacTM, a pneumatic regolith sampling system deployed to the moon on Blue Ghost Mission 1

Article References: Zacny, K., Fitzgerald, Z., Vendiola, V., Carrington, K., Jung, H., Wang, A., Misra, R., Ngo, P., Sanasarian, L., Bailey, J., Ng, P., Seto, E., Paulsen, G., Chow, P., Chu, P., Naclerio, N., Hernandez, J., King, I., Sabahi, D., … Watts-Shepherd, S. (2026). Results of Lunar PlanetVacTM, a pneumatic regolith sampling system deployed to the moon on Blue Ghost Mission 1. Space and Planetary Resources, 2(1), Article 11. https://doi.org/10.1007/s44461-026-00012-z

Image Credits: AI Generated

DOI: 10.1007/s44461-026-00012-z

Keywords: Lunar PlanetVac, pneumatic sampling, lunar regolith, Blue Ghost Mission 1, Mare Crisium, Honeybee Robotics, Firefly Aerospace, sample acquisition, ISRU, Phobos, dust adhesion, sample return