This study focuses on the impact of satellite trails on spectroscopic observations in the visible and near-infrared, which represent a large fraction of the observing time on large professional telescopes. We simulate the number of observations affected using an hypothetical large set of low Earth orbit satellite constellations. We evaluate the effect of this contamination on various spectrographs. We also measure the contamination on actual data from the ESO archive for a set of representative objects, after adding a scaled solar analogue spectrum to represent the satellite.

Even with a satellite population much larger than today’s, the fraction of contaminated spectra will remain low, essentially thanks to the typically small field of view of these instruments. Furthermore, high-resolution spectrographs, and medium-resolution ones on smaller telescopes, are essentially blind to satellites. However, for a range of instruments the contamination will be at a level comparable to that of the science signal, making its identification difficult, and potentially affecting the astrophysical measurements derived from the data.

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.

The increasing amount of space debris and the number of mega-constellations are creating a serious problems for terrestrial astronomy. Light trails caused by these objects contaminate astronomical images, rendering them ultimately worthless. Knowing where in the sky these objects will be and how bright they will be are essential to optimising observation planning and avoiding such contamination. Photometric phase functions are a powerful tool for understanding asteroids and resident space objects (RSOs) such as satellites, upper stages, and space debris. However, they also provide a means of predicting how these objects will reflect sunlight toward the observer. We consider a model that assumes a spherical object with diffuse and specular components. We defined the phase functions of more than 600 rotating RSOs using more than one million photometric measurements of more than 10 000 objects from the Mini-MegaTORTORA (MMT) light curve catalogue. We discuss in detail the photometric properties of space debris and satellites extracted from the MMT photometric catalogue using the model. We introduce our freely available online service that predicts the brightness of RSOs, including space debris and mega-constellations, for the purpose of supporting astronomers’ decision-making.

Astrobiology is generally considered to be a promising gateway into science, and storytelling techniques have been getting increasingly more traction lately in education and outreach because of their potential benefits for learning. At the European Astrobiology Institute, we combined these two pathways by creating two anthologies of astrobiology-inspired science fiction stories accompanied by science fact essays, Strangest of All and Life Beyond Us. Furthermore, we created educational materials that build on the anthology project and acquaint students with the issue of planetary protection. Here we introduce the project and planned future directions in story-driven astrobiology outreach and education.

This paper presents an overview of the attitudes and awareness within the amateur astronomical community regarding modern satellite megaconstellation projects. A series of interviews and polls to assess the perspectives of this large community was conducted, aiming to uncover their concerns and issues. Additionally, the potential to involve respondents in community-driven projects focused on satellite data acquisition and processing was investigated. The objective is to enhance data quality for astronomical imagery protection and improve existing tools for scientific research, including satellite tracking, trajectory prediction, and the detection of space debris and orbital objects.

Traditionally the search for extraterrestrial intelligence (SETI) has been mostly a kind of engineering task, based on two assumptions: the existence of other technological culture somewhere in our Galaxy and that this culture is using radiotechnology that can be detected with our receivers. However, SETI endeavors could benefit more by expanding its scope into two-folded interdisciplinary research program, one exploring the nature of human, other animals, and artificial cognition, and the another exploring all possible and hypothetical ways and channels that potential ETI could use to manifest itself. This kind of new research program could be named cognitive astrobiology in order to better describe its research areas.

The predicted impact of large satellite constellations on optical astronomy has been worked out, from the beginning, using Montecarlo methods: individual satellite orbits inside each shell are randomly initialised and satellite tracks are computed one by one to check whether or not they hit the field of view, and under what conditions. However, it is known that the density of satellites inside each shell follows the analytic double-sine probability density distribution, which offers new ways to get similar results at a much lower computational cost. We compare results obtained applying the two approaches and we derive some conclusions on the advantages and drawbacks of each method. The original FORTRAN code of the software is available at https://galadi.net/satsim/.

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.