Technosignature searches with VLBI

Acta Astronautica, vol. 248, pp. 1002–1007

Abstract

Radio searches for extra-terrestrial intelligence (SETI) are increasingly hindered by radio frequency interference (RFI). Very Long Baseline Interferometry (VLBI) not only mitigates RFI but also enables precise localization of candidate signals, offering clear advantages over conventional single-dish or beam-formed array surveys. We present a preparatory study on the potential of VLBI for SETI. As a proof of concept, we observed Voyager-2 with the Long Baseline Array (LBA) and created synthetic VLBI datasets simulating exoplanetary signals at a distance of 20 pc, with different orbital parameters. The analysis demonstrates that spacecraft transmissions and exoplanetary signals present clearly distinguishable signatures in the visibility domain, especially on long baselines. These findings highlight the diagnostic advantages of interferometry for SETI and lay the groundwork for dedicated VLBI SETI programs that will advance current search efforts.

Authors 5

1. Dong-Jin Kim corresponding

   Commonwealth Scientific and Industrial Research Organisation · Australia Telescope National Facility

   Affiliation as printed

   Australia Telescope National Facility, CSIRO, Space and Astronomy, PO Box 76, Epping, NSW 1710, Australia

2. Chris J. Phillips

   Commonwealth Scientific and Industrial Research Organisation · Australia Telescope National Facility

   Affiliation as printed

   Australia Telescope National Facility, CSIRO, Space and Astronomy, PO Box 76, Epping, NSW 1710, Australia

3. Cormac Reynolds

   Commonwealth Scientific and Industrial Research Organisation

   Affiliation as printed

   CSIRO Astronomy and Space Science, P.O. Box 1130, Bentley, WA 6102, Australia

4. Danny C. Price

   SKA Telescope, Australia

   Affiliation as printed

   SKA Observatory (SKAO), 26 Dick Perry Ave, Kensington, WA 6151, Australia

5. M. A. Garrett Aachen Leiden Observatory

   Leiden University · University of Manchester · Leiden Observatory

   Affiliation as printed

   Jodrell Bank Centre for Astrophysics (JBCA), School of Physics & Astronomy, The University of Manchester, Oxford Road, M13 9PL, UK

   Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA, Leiden, The Netherlands