Related papers: Is the Interstellar Object 3I/ATLAS Alien Technolo…

If the signals that are being sought in SETI programs do exist but are very brief, for example because they are produced intermittently to conserve energy, then it is essential to know when these signals will arrive at the Earth. Different…

Interstellar objects (ISOs), particularly those with cometary activity, provide unique insight into the primordial physical and chemical conditions present during the formation of the planetary system in which they originated. Observations…

The main purpose of this article is to make Astronomers aware that Searches for Extraterrestrial Intelligence can be carried out by analyzing standard astronomical spectra, including those they already have taken. Simplicity is the…

The ELTI concept capitalizes on recent breakthroughs in large-format SPAD (Single-Photon Avalanche Diode) imaging sensors, combining them with the unprecedented collecting area and segmented architecture of the ELT to deliver a…

We examine the funding disparity in astronomical research priorities: the Habitable Worlds Observatory is planned to receive over $10 billion over the next two decades whereas extraterrestrial intelligence research receives nearly zero…

1I/'Oumuamua (or 1I) and 2I/Borisov (or 2I), the first InterStellar Objects (ISOs) discovered passing through the solar system, have opened up entirely new areas of exobody research. Finding additional ISOs and planning missions to…

The Search for Extraterrestrial Intelligence (ETI) is, historically, a search for aliens like us, inspired by human centric ideas of intelligence and technology. However, humans are not the only instance of an intelligent, communicating…

Arnold (2005), Forgan (2013), and Korpela et al. (2015) noted that planet-sized artificial structures could be discovered with Kepler as they transit their host star. We present a general discussion of transiting megastructures, and…

In this work we will create the Secular Light Curve (SLC) of exocomet 3I/ATLAS, using the SLC-Methodology (Ferrin 2010-2023). The SLCs give a throve of new information and allow the comparison of exo-comets with comets of our own solar…

The Earth will pass approximately downstream of the previous position of comet C/2023 A3 (Tsuchinshan-ATLAS) during 2024 October 10-13. We predict that spacecraft at the Sun-Earth Lagrange Point 1, L1, have a significant likelihood to…

Extraterrestrial technology may exist in the Solar System without our knowledge. This is because the vastness of space, combined with our limited searches to date, implies that any remote unpiloted exploratory probes of extraterrestrial…

We present a detailed analysis of the trajectory of the interstellar comet 3I/ATLAS, focusing on its non-gravitational acceleration (NGA) parameters and their uncertainties. Orbital solutions are computed with models that implement…

The Extremely Large Telescope (ELT) will transform our knowledge of the outer planets and their satellite systems; however the visibility of unique targets of opportunity with high scientific value will be reduced for northern objects.…

The first definitely interstellar object 1I/'Oumuamua (previously A/2017 U1) observed in our solar system provides the opportunity to directly study material from other star systems. Can such objects be intercepted? The challenge of…

We present high-resolution optical spectroscopy of interstellar comet 3I/ATLAS (C/2025 N1) obtained with the High Dispersion Spectrograph mounted on the Subaru Telescope on UT 2026 January 7, when the comet was on its outbound trajectory at…

Comets are the most pristine planetesimals left from the formation of the Solar System. They carry unique information on the materials and the physical processes which led to the presence of planets and moons. Many important questions about…

It is known that the shape of a planet (oblateness, rings, etc.) slightly modifies the shape of the transit light curve. The forthcoming space missions (Corot, Kepler), able to detect the transit of Earth-like planets, could a fortiori also…

Deliberate and unintentional radio transmissions from Earth propagate into space. These transmissions could be detected by extraterrestrial watchers over interstellar distances. Here, we analyze the harms and benefits of deliberate and…

Nearly 1/3 of the sources listed in the Third Fermi Large Area Telescope (LAT) catalog (3FGL) remain unassociated. It is possible that predicted and even unanticipated gamma-ray source classes are present in these data waiting to be…

Comet Interceptor (Comet-I) was selected in June 2019 as the first ESA F-Class mission. In 2029+, Comet-I will hitch a ride to a Sun-Earth L2 quasi-halo orbit, as a co-passenger of ESA's M4 ARIEL mission. It will then remain idle at the L2…