arXiv subjects

Alex Ellery

Publications and source records attributed to Alex Ellery.

3 recordsLinked to original sources

arXiv2026

The Search for Technosignatures: a Review of Possibilities

This paper aims to review the diverse range of technosignatures that have been proposed in the literature. We organize the review by scales, starting carefully from Earth, then zooming out to Earth's orbit, the solar system, including the Moon, the Earth-Moon Lagrange points, the inner solar system, the asteroid belt, interstellar objects, the outer solar system, the Kuiper belt, the solar gravitational lens region, and the Oort cloud. We then introduce the Kardashev and Barrow scale before exploring exoplanetary technosignatures, from surface, atmospheric to orbital sources. We next consider stellar technosignatures that may involve massive energy utilization, stellar modification or stellar pollution, and end with a section about compact objects. We then review attempts to detect interstellar communication, and discuss many dimensions of the search space from first principles. Then we consider interstellar travel technosignatures, and end with galactic, extragalactic and universal signatures. We end with a discussion about synergies between biosignatures and technosignatures searches, anomaly detection, multimodal strategies, instruments for detecting technosignatures, how to evaluate and prioritize the search, as well as epistemological issues.

astro-ph.EP↗

arXiv2025

Technosignatures of Self-Replicating Probes in the Solar System

We explore a much-neglected area of SETI: solar system techno-signatures. As our cursory solar system exploration consolidates into commercial industrialisation, it is crucial that we determine what to look for and where. We first consider the rationale for interstellar self-replicating probes and their implications for the Fermi paradox. Whether for defensive or exploratory reasons, self-replicating probes are a rational strategy for Galactic investigation. We determine that self-replicating probes will systematically explore the Galaxy by tracking resources of sufficient metallicity. We focus on the resource requirements of a self-replicating interstellar probe that may have visited our solar system. After considering asteroid resources, we suggest that evidence of asteroidal processing will be difficult to discern from natural processes given the constraints imposed by self-replication. We further determine that the Moon is an ideal base of manufacturing operations. We suggest that nuclear reactors, such as the Magnox reactor model, can feasibly be constructed from lunar resources which will have left isotopic ratio signatures of Th-232/Nd-144 and/or Th-232/Ba-137. We further suggest that in anticipatory economic trade for resources, a self-replicating probe may have left artefacts buried with asteroidal resources on the Moon. Such gifts would be detectable and accessible only once a threshold of technological sophistication has been achieved. An obvious gift in trade for the resources utilised would be a universal constructor.

astro-ph.IM↗

arXiv2004

Space Robotics Part 2: Space-based Manipulators

In this second of three short papers, I introduce some of the basic concepts of space robotics with an emphasis on some specific challenging areas of research that are peculiar to the application of robotics to space infrastructure development. The style of these short papers is pedagogical and the concepts in this paper are developed from fundamental manipulator robotics. This second paper considers the application of space manipulators to on-orbit servicing (OOS), an application which has considerable commercial application. I provide some background to the notion of robotic on-orbit servicing and explore how manipulator control algorithms may be modified to accommodate space manipulators which operate in the micro-gravity of space.

cs.RO↗