In the JCMT-Venus project, we conducted three multi-week disc-integrated observations of Venus’ atmosphere using the JCMT ‘Ū‘ū receiver. This paper focuses on the HDO 2(2,0)-3(1,3) transition line at 266.1611 GHz, employed as a proxy for water abundance under the assumption of a constant D/H ratio. Based on the HDO line depth, we observed significant and rapid short-term variations, and have tentatively identified potential long-term effects. Water vapor abundance values were retrieved daily, and their variations will be displayed and discussed in our forthcoming publications.

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.

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.

Optical observation is used to track objects in orbit, but it’s challenging for objects in Low-Earth Orbit (LEOs) due to high-speed satellites leaving long trails. We present a study that uses a multilayer neural network software called Source-Extractor (SExtractor) to accurately determine the position of stars and orbital objects. By modifying input parameters, we can draw ellipses around star trails, including very long ones. Using images from the TFRM telescope and Fabra Observatory, we accurately determine the position of objects in all types of orbits, including of 6000 km-high 1U CubeSats and up to magnitude 18.0 on 10-second exposure images following the object showing star trails over 400 pixels long. This technique can recognise all types of objects, including other satellites or debris, if bright enough. This technique can help study the negative impact on astronomical observations caused by megaconstellations of satellites like Starlink or OneWeb, for professional and amateur observatories.

The characterisation of stellar magnetism of planetary host stars has increased momentum, especially for transmission spectroscopy investigations of exoplanets. Indeed, the magnetic field regulates how irradiated planets are, and the presence of inhomogeneities on the stellar surface hinder the precise extraction of the planetary atmospheric absorption signal. We are conducting a spectropolarimetric campaign to unveil the magnetic field properties of known exoplanet hosting stars included in the current list of Ariel targets. Here, we will focus on two of them: GJ 436 and HD 63433. The former hosts a warm-Neptune experiencing substantial atmospheric loss, modelled as a comet-like trail of hydrogen atoms. The latter hosts two sub-Neptunes and an Earth-sized planet that have likely experienced different atmospheric evolution paths. We reconstructed the stellar large-scale magnetic field via Zeeman-Doppler imaging, and used it as boundary condition to simulate the stellar magnetised wind and environment at the planetary orbits. For GJ 436, the planet motion is sub-Alfvénic, meaning that star-planet magnetic connections can occur. We derived the power released by star-planet interactions to be 1022 − 1023 erg/s, consistent with the upper limit of 1026 erg/s measured from ultraviolet lines. For HD63433, we identified 10% of the innermost planetary orbit as sub-Alfvénic, while the outer planets are outside the Alfvén surface, and a bow shock between the stellar wind and the planetary magnetosphere could form.

Surprisingly large numbers of post-mission satellites will be decaying towards re- entry at any time, after the mega-constellations are highly populated and one mission lifetime has expired. This study shows calculations that there will be many thousands at one time. And these post-mission satellites will have substantial additional issues for astronomers. Mitigation methods to be considered include a larger satellite in each orbital ring, to service or de-orbit Internet satellites that have failed or depleted their propellant, as well as joint research projects to develop and mature subsystems to deploy drag balloons, drag tethers, or other methods to de- orbit more rapidly. Proposals include the potential for a joint research facility at an appropriate existing space research centre.

The title of the Kavli–IAU Symposium (Toward) Discovery of Life Beyond Earth and its Impact invites us to speculate upon the consequences for humanity of the detection of biological processes out there in the cosmos. The discovery of any form of life beyond Earth would be a momentous event for science, but for many people it is the discovery of intelligent life that would have the most profound impact—not just on science, but on philosophy, religion, and society in general. Equally profound, however, might be the impact of a continuing non-discovery of extraterrestrial intelligence. In this paper I outline some personal thoughts regarding the implications of continuing non-discovery.

In this study, we examine the social media response statistics to a recent astrobiology headline about the discovery of phosphorus on Venus, which led to a media outbreak of ‘Life on Venus?’ claims. We estimate its impact scale by comparing it with other events.

It was found that the cluster NGC 1977, located in the region of Orion’s Sword, in past epochs approached in space the star TOI-2796, which has a planetary system. It should be noted that in the vicinity of NGC 1977, the James Webb Space Telescope observed more than 500 free planets and free binary planets. Numerical calculations of the orbit around the Galactic Center were carried out. It is shown that these objects approached at a distance of ∼7.8 pc about ∼4.4 million years ago. This approach could have a gravitational effect on the Oort cloud analogue TOI-2796, leading to a change in the orbital elements of small bodies. It is important to note that the observed effect could be the loss of objects from the TOI-2796 planetary system into interstellar space.

As the commercial space industry advances, the number of artificial objects orbiting the Earth rises exponentially. To categorize the reflectivity of bright Low Earth Orbit (LEO) objects, a number of spectroscopic observations of such objects was performed in collaboration with the Astronomical Institute of the University in Bern, Switzerland. Supported by laboratory measurements of various aerospace materials, spectra of space objects were analyzed to search for correlations with material samples. On top of that, near-Earth object 2020 SO originally discovered as asteroid was later identified as Surveyor 2 rocket debris. Spectroscopic observation of this object was conducted with the OSIRIS camera-spectrograph at the 10.4m Gran Telescopio Canarias (GTC) located in La Palma (Spain). Spectrum of this object is compared with spectra of upper stage rockets observed by the ZimMain telescope to investigate correlations within their material properties and search for signs of space weathering.

This work provides a detailed walk through the design, construction, and operation of a DIY monitoring station, emphasising its affordability, accessibility, and ease of use. The station leverages readily available components, including software defined radio (SDR) receivers and a Raspberry Pi. These tools allow for constant 24/7 monitoring and automatic storage of band usage and the detection of Doppler-shifts in the satellite beacons, providing valuable data for analysis.

Using this DIY setup can lead to indications of power levels and beam shapes of the Starlink satellites and user link strategy. Additionally, an experimental interferometer mode is being implemented, further expanding the capabilities of this home-based monitoring station with direct positional information.

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.

This study examines the potential impact of the discovery of extraterrestrial intelligent life (ETI) on Catholic theology. The investigation addresses whether the existence of ETIs would challenge core theological principles, particularly the doctrine of Redemption. The study concludes that the discovery of ETIs would not disrupt the foundational tenets of Catholic faith, which is centered on Jesus Christ. The Church has not made any official statements regarding the theological implications of ETIs, reflecting the current speculative nature of their existence. However, the Vatican Observatory is actively involved in research related to potential life-hosting stars, indicating a scientific interest in the topic.

For several decades we have been performing photometric monitoring of some of the star formation regions using the telescopes in Rozhen Observatory. We consider that the study of photometric variability of pre-main sequence (PMS) stars is of great importance in understanding stellar evolution. A number of young stellar objects show brightness variability with large amplitudes that can be registered with small and medium-sized telescopes. But in recent years, bright traces of satellites have increasingly appeared in our CCD images. So far they are not much of a problem since most of our objects and the standard stars around them are point sources of small apparent size. But in the future, the possible increase in the number and brightness of satellite tracks may affect the quality of the photometric data we receive.

Bright satellite streaks present challenges for astronomy. No streak detection is prefect and the profile of the streak flux varies along the streak. Using Rubin Observatory’s LSST as an example, we undertake full simulations and outline the challenges and the impact on science.

The Pampilhosa da Serra Space Observatory (PASO) is located in the centre of the continental Portuguese territory, in the heart of a dark-sky destination certified by the Starlight Foundation (Aldeias do Xisto) and has been an instrumental asset to advance science, education and astrotourism certifications. PASO hosts astronomy and Space Situational Awareness (SSA) activities including a node of the Portuguese Space Surveillance & Tracking (SST) infrastructure network, such as a space radar currently in the test phase using the GEM radiotelescope, a double Wide Field of View (WFOV) Telescope system, and a European Union SST optical sensor telescope. These instruments allow surveillance of satellite and space debris in LEO, MEO and GEO orbits. The WFOV telescope offers spectroscopy capabilities enabling light curve analysis and cosmic sources monitoring. Instruments for space weather are being considered for installation to monitor solar activities and expand the range of SSA services.

The search for extraterrestrial life, especially intelligent life, is among the most profound scientific endeavors. Although the international community achieved consensus within a few years of the launch of Sputnik on legal principles fundamental to the peaceful exploration of outer space, including the Moon and other celestial bodies, those principles did not directly address the subject of SETI. Nevertheless, principles relevant to SETI are expressed in the law of outer space, including treaties in force as well as non-binding forms of international instruments. As the search for extraterrestrial intelligent beings has developed and a myriad of issues has arisen, the relevance of many of these legal principles has become apparent.

I examine the applicability of ecological concepts in discussing issues related to space environmentalism. Terms such as “ecosystem”, “carrying capacity”, and “tipping point” are either ambiguous or well defined but not applicable to orbital space and its contents; using such terms uncritically may cause more confusion than enlightenment. On the other hand, it may well be fruitful to adopt the approach of the Planetary Boundaries Framework, defining trackable metrics that capture the damage to the space environment. I argue that the key metric is simply the number of Anthropogenic Space Objects, rather than for example their reflectivity, which is currently doubling every 1.7 years; we are heading towards degree scale separation. Overcrowding of the sky is a problem astronomers and satellite operators have in common.