Satellites provide important data and services, such as communications, internet access, Earth observation, and technologies like GPS that provide positioning, navigation, and timing. However, the launch, operation, and disposal of an increasing number of satellites could cause or increase several potential effects, such as hindering optical and radio astronomy, creating additional space debris, and affecting the upper atmosphere through launch and reentry emissions. To help policymakers address the challenges presented by the ongoing increase of satellites in orbit, the U.S. Government Accountability Office (GAO) issued a report: Large Constellations of Satellites: Mitigating Environmental and Other Effects (GAO-22-105166). This keynote address discussed the report findings, including policy options directed to a range of policymakers that may include legislative bodies, government agencies, researchers, standards-setting organizations, industry, and other groups.

The advent of innovative new radio telescopes and instruments around the world has enabled HI observations of galaxies that are sharper, deeper, fainter and farther than ever before. This paper provides an overview of the extragalactic HI landscape today, with a focus on large surveys with SKA pathfinder facilities. Ongoing work to measure structural properties of HI disks from the WALLABY survey on the ASKAP telescope is also summarised, with an emphasis on the challenges of building statistical samples of the marginally detected and resolved systems that are characteristic of widefield untargetted surveys. This work paves the way to map HI disks across cosmic time with the SKA.

Saturn’s magnetism and diamagnetism of ice can help explain the emergence of visible dense rings by transformation of the protoplanetary cloud containing ice bodies into a disk-shaped system of stable visible dense rings with extreme flatness at Saturn’s equator. It can also explain the thin structure of the rings as a whole, the sharp edges of dense rings, the existence and specific features of B-rings, and the stability of the entire dense ring system around Saturn. Additionally, it allows calculation of equilibrium separation of ice bodies, as predicted by J.C. Maxwell, with the magnetic repulsion of the ice bodies compensating for their gravitational attraction.

Strong solar flares and coronal mass ejections (CMEs) are prone to originate within and near active regions (ARs) with a high magnetic complexity. Therefore, to better understand the generation mechanism of flares and the resultant CME eruption and to gain insight into their stellar counterparts, it is crucial to reveal how solar flare-productive ARs are generated and developed. In this review, first, we summarize some general aspects of solar flares and key observational characteristics of such ARs. Then, we discuss a series of flux emergence simulations that were performed to elucidate the subsurface origins of their complexity and introduce state-of-the-art models that consider the effect of turbulent thermal convection. Future flare observations using SOLAR-C, a next-generation high-throughput extreme ultraviolet spectroscopy mission, are also discussed.

Cultural Astronomy is loosely defined as the study of humans and their relationship to the sky. With the movement to decolonize the curriculum and decolonize the academy happening in various parts of the world, academics along with students are co-creating new ways of being and learning. Inclusive astronomy can be seen as part of or adjacent to this movement, with its goals to transform astronomy to better attract and retain people embodying all types of diversity. This transformation has been framed largely as cultural with some efforts to augment rather than to transform the curriculum entirely. As a cultural astronomer, my research engages the transformation of astronomy both culturally and pedagogically. I will share how my research weaves and threads its way into creating a more inclusive astronomy (yes, I’m using intentionally gendered imagery!).

Astrobiology and SETI search for life-not-as-we-know-it (yet). Researchers aspire to an understanding not yet found. With that in mind, knowledge about three types of context can inform and improve the search. Observational context: knowing our location as humans (anthropism) can mitigate biases introduced by our desire to over-value humanity (anthropocentrism). Historical context: knowing the history of the search, not just the last 10–30 years, can clarify concepts and significance. Disciplinary context: understanding the rules by which different disciplines operate can reveal the limitations of a single perspective (astronomy, biology, ecology, sociology, law, medicine, philosophy, theology…). Astrobiology and SETI tell epic stories about the place of life in the cosmos. They locate humans morally as well as physically. We should ask why we tell them and how our context shapes the telling, because the stories shape human interactions with the world.

We are in the age of the direct and indirect search for extraterrestrial life. The major question is: what are we looking for and to what extent can life on Earth provide an analogy for extraterrestrial life. We will address these questions by examining the emergence of life and its evolution through geological time, based on consideration of the Earth as an exoplanet. We conclude that, with the exception of a couple of hundred million years during the Great Oxydation Event 2.3-2.1 Ga, it would not have been possible for an extraterrestrial observer to detect traces of terrestrial life until the advent of planktonic eukaryotic algae after the Neoproterozoic Oxydation Event about 800 Ma. Thus, for most of the history of life on Earth, there would be no externally observable evidence of its existence. We address the implications of this for the search for extraterrestrial life.

Atomic hydrogen (HI) gas is a key fuel reservoir for star formation in galaxies and provides an excellent tracer of their dynamical masses. The Square Kilometre Array (SKA) precursor observatories are already hinting at the incredible HI observations that we can expect from the SKA. We are also undergoing a quieter but equally exciting revolution in simulations of HI in galaxies. Up to now, we have had to resort to labelling HI in cosmological galaxy formation simulations in post-processing, subject to uncertain calibration and assumptions. New simulations are implementing cooling to 10 K and non-equilibrium ionization and chemistry, enabling on-the-fly calculation of HI fractions. We will soon have for the first time fully self-consistent, spatially-resolved predictions for the atomic hydrogen content, structure and kinematics of galaxies across cosmic history. I give an overview of the state of the art in simulation-based predictions for HI including recent breakthroughs and current challenges.

As the number and variety of communications satellites proliferate in the rapidly accelerating New Space Age, specialists and lay observers alike have weighed the implications of a crowded orbital environment for astronomical research. Although so-called “megaconstellations” may be a relatively new development, conflict over the anticipated effects of space technology on astronomy has a much longer history, going back to the very first experimental communications satellites. Astronomers have long acted as environmental watchdogs for outer space even as the power landscape in the international aerospace industry shifted during the half century since Sputnik. What lessons might current astronomers take from past conflicts over the integrity of the night sky to address contemporary and future risk?

This study analyzes the motion of bodies ejected from the Earth or the Moon. We studied the ejection of bodies from several points on the Earth’s surface, as well as from the most far point of the Moon from the Sun. Different velocities and angles of ejection of bodies were considered. The dynamical lifetimes of bodies reached a few hundred million years. Over the entire considered time interval, the values of the probability of a collision of a body ejected from the Earth with the Earth were approximately 0.3, 0.2, and 0.15–0.2 at an ejection velocity υej equaled to 11.5, 12, and 14 km/s, respectively. At υej≤11.3 km/s, most of the ejected bodies fell back onto the Earth. The total number of bodies delivered to the Earth and Venus probably did not differ much. The probabilities of collisions of bodies with Mercury and Mars usually did not exceed 0.1 and 0.02, respectively. At υej ≥11.5 km/s, the probability of a collision of a body ejected from the Earth with the Moon was about 15–35 times less than that with the Earth, and it was about 0.01. The probability of a collision with the Earth for a body ejected from the Moon moving in its present orbit was about 0.3–0.32, 0.2–0.22, and 0.1–0.14 at υej =2.5 km/s, υej =5 km/s, and at 12≤ υej ≤16.4 km/s, respectively.

Modern societies have an increasing number of technological developments which are shaping the structure and execution of daily duties. Communities with disabilities have historically experienced restricted access to many opportunities of study, work and leisure, but now the emergence of new resources and appliances is likely to increase the inequity gap unless actions against this are reinforced at different levels in the society. Every person, regardless of any aspect should have an equal right and opportunity to access, engage with and contribute to knowledge, participating actively in the decisions, institutions and processed, and making use of new technologies. Unfortunately, in many cases, access to this is not feasible because the frameworks for inclusive involvement and engagement are not being implemented or are not implemented in an appropriate way. This work highlights the importance to ensure inclusive participation in astronomy education, research and outreach, identifying the barriers preventing people with disabilities to engage and progress in all the aspects that are natural of our scientific field and underpinning the crucial actions that can foster equality, accessibility and inclusivity.

Despite the proliferation of solar and heliospheric observations, many questions regarding the nature and evolution of coronal mass ejections (CMEs) persist. We focus on exploring relationships between the three-dimensional characteristics of CMEs and their source region properties. We analyze the sources of a set of CMEs having polar position angles as seen from Earth, for which their morphological characteristics can be estimated with less uncertainties than typically possible. We rely on observations of different solar atmospheric regimes, provided by the STEREO, SOHO, and SDO missions. In the low corona and chromosphere, we characterize associated filaments and eruptive phenomena; while in the photosphere we investigate polarity inversion lines. The joint analysis of source regions and CMEs enables studying how the attributes of source regions impact the morphological and dynamical characteristics of CMEs, with implications for space weather forecasting and for the understanding of processes involved in the initiation and early evolution of CMEs.

This abstract explores the application of quantitative information theory measures and linguistic features to analyze animal communication systems and extends this methodology to contemplate the possibilities of interstellar communication as a part of CETI practice. We will assess some early findings by using information theory on social species with sophisticated acoustic communication abilities, such as bottlenose dolphins and humpback whales (Hanser, Sean F., et al.) as well as birds, as examples of how the complex interplay between notions, data, and misinterpretations can become established as reliable knowledge and cognition about and understanding of an ETI civilization and culture. The study also looks into the potential implications of extraterrestrial contact. Given the diversity of language instances in Earth’s evolutionary history, we discuss the choice of syntactic complexity of an “intelligent message” for potential alien civilizations. The central point of this paper is to examine the advantages and limitations of acoustic and visual communication, considering linguistical and mathematical constraints that may apply universally.

The increasing addition of meteor showers to the International Astronomical Union (IAU) list underscores the need for more accurate identification of new parent bodies, especially with the growing availability of video meteor data. Current methods using a high-threshold single-linking Dsh criterion often lack accuracy, prompting our study to explore advanced techniques for linking meteors to their parent bodies. Using the Moroccan meteor observation network as a foundation, we applied and compared several methods on the SonotaCo and EDMOND databases to detect new parent bodies. We further applied rigorous statistical tests to avoid random associations. This presentation highlights the network’s innovative methodology, its success in accurately tracing meteoroid origins, and its potential to predict impact zones on Earth (Guennoun et al.(2019)). Through collaborative efforts, this network provides a significant contribution in the study of meteor dynamics.

Using sound to represent data (data sonification) and exploiting the unique characteristics of sound and human hearing can provide a powerful means to enhance scientific discovery in large datasets, rapid real-time data analyses, high dimensional analyses, and to filter signals from noise. Data sonification can be used to expand, accelerate, and validate discovery for sighted, blind and visually-impaired researchers and provides capabilities to improve the quality of everyday life. We describe improvements to StarSound for 1D and multi-dimensional analyses, introduce VoxMagellan for 2D image, plot and graph analyses, discuss applications in astronomy and for low signal-to-noise ratio data, often present at the leading-edge of science. We find that data sonification can successfully push scientific research forward and expand research accessibility to the blind and visually-impaired community, while promoting STEM careers.

As part of the mission of the International Astronomical Union Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (IAU-CPS) Policy Hub to consider national and international regulations about the usage and sustainability in outer space, we also included discussion specific to the rights of Indigenous peoples with respect to outer space under the context of the United Nations Declaration for the Rights of Indigenous Peoples (UNDRIP). In this work, we review how some of the articles of UNDRIP require various actors in the use and exploitation of outer space including satellite companies, nation states, and professional/academic astronomy to consult and support Indigenous peoples/nations and respect Indigenous sovereignties. This work is concluded with recommendations for consulting and collaborating with Indigenous peoples and recommendations for moving from the traditional colonial exploitation of outer space and building an anti-colonial future in relationship with outer space.

The Wide-field ASKAP L-band Legacy All-sky Blind Survey (WALLABY) is a large H<sc>i</sc> survey being carried out with the Australian SKA Pathfinder (ASKAP). WALLABY will image about 14,000 square degrees of the sky in the 21-cm line of neutral hydrogen and is expected to detect approximately 200,000 galaxies out to a redshift of about 0.1. What makes WALLABY unique is the combination of a large galaxy sample with sufficiently high angular resolution (30″ FWHM) to spatially resolve a significant fraction of those galaxies. This enables entirely new scientific studies, such as the search for H<sc>i</sc> polar ring galaxy candidates or the extraction of resolved galaxy H<sc>i</sc> scaling relations for statistical samples. While the full survey is still underway, catalogues, images and spectra of nearly 2400 galaxies detected during the pilot phase have already been publicly released. More data releases are anticipated over the next few years as the survey progresses.

We study the relationship between the speed of coronal mass ejections (CMEs) and the height profile of the ambient magnetic field, quantified by its decay index, n(h). Our sample is composed of 15 very fast CMEs (VCME ≥ 1500 kms–1; all halo CMEs) and 22 halo CMEs below this speed limit from Solar Cycle 23. The very fast CMEs yield a high correlation of 0.81 between VCME and the slope of n(h) in a height range above the onset height of the torus instability if one extremely fast outlier, which closely followed another very fast CME, is excluded. This is consistent with the hypothesis that the torus instability plays a decisive role in CME acceleration. The whole sample yields a weaker correlation, which is still significant if events with a broad torus-stable dip in n(h) are excluded. A parametric simulation study of flux-rope eruptions from quadrupolar and two-scale bipolar source regions confirms the decelerating effect of such dips. Very fast, moderate-velocity, and confined eruptions are found.

The discovery of phosphine in Venus’s atmosphere provides lessons for the search for life. The detection has survived all challenges and has acquired independent support from archival data from PVP. The presence of phosphine in Venus’ oxidising environment is perplexing, and comprehensive studies rule out all known abiotic sources. More data is needed to understand the origin of phosphine, leading to JCMT-Venus, a long term atmospheric monitoring programme. This can find how phosphine varies in relation to other species providing clues to its origin. We present the latest JCMT-Venus results. The discovery and subsequent papers were explicit that they did not constitute evidence for life, only of phosphine. Media and public reaction to the discovery and its implications provide lessons for future life searches, as does the reaction of the scientific community. How this was handled by the team, media, and general public will be reviewed.

There have been marked advances in astronomy in the last 100 years towards gender equality and the empowerment of women researchers. However, progress has been slow, and disparities still persist around the world. Women represent only about 18% of astronomers worldwide (2019) and are not immune to inequalities such as gender-based discrimination and a lack of equal opportunities. Bullying and harassment are the obstacles that not only women but also men face in their professional careers. We need to pay due attention, too, to LGBTQ requirements. Here, we will share our experiences of problems that exist in Japan and elsewhere and the ways of overcoming them. This report was in part made in collaboration with the former IAU President, Norio Kaifu, R.I.P., and his advice to overcome these problems is involved.