A Demonstration of Interstellar Navigation Using New Horizons
Abstract
As NASA's New Horizons spacecraft exits the Solar System bound for interstellar space, it has traveled so far that the nearest stars have shifted markedly from their positions seen from Earth. We demonstrated this by imaging the Proxima Centauri and Wolf 359 fields from Earth and New Horizons on 2020 April 23, when the spacecraft was 47.1 au distant. The observed parallaxes for Proxima Centauri and Wolf 359 are and respectively. These measurements are not of research grade, but directly seeing large stellar parallaxes between two widely separated simultaneous observers is vividly educational. Using the New Horizons positions of the two stars alone, referenced to the three-dimensional model of the solar neighborhood constructed from Gaia DR3 astrometry, further provides the spacecraft spatial position relative to nearby stars with 0.44 au accuracy. The range to New Horizons from the Solar System barycenter is recovered to 0.27 au accuracy, and its angular direction to accuracy, when compared to the precise values from NASA Deep Space Network tracking. This is the first time optical stellar astrometry has been used to determine the three-dimensional location of a spacecraft with respect to nearby stars, and the first time any method of interstellar navigation has been demonstrated for a spacecraft on an interstellar trajectory. We conclude that the best astrometric approach to navigating spacecraft on their departures to interstellar space is to use a single pair of the closest stars as references, rather than a large sample of more distant stars.
Cite
@article{arxiv.2506.21666,
title = {A Demonstration of Interstellar Navigation Using New Horizons},
author = {Tod R. Lauer and David H. Munro and John R. Spencer and Marc W. Buie and Edward L. Gomez and Gregory S. Hennessy and Todd J. Henry and George H. Kaplan and John F. Kielkopf and Brian H. May and Joel W. Parker and Simon B. Porter and Eliot Halley Vrijmoet and Harold A. Weaver and Pontus Brandt and Kelsi N. Singer and S. Alan Stern and Anne. J. Verbiscer and Pedro Acosta and Nicolás Ariel Arias and Sergio Babino and Gustavo Enrique Ballan and Víctor Ángel Buso and Steven J. Conard and Daniel Das Airas and Giorgio Di Scala and César Fornari and Jossiel Fraire and Brian Nicolás Gerard and Federico González and Gerardo Goytea and Emilio Mora Guzmán and William Hanna and William C. Keel and Aldo Kleiman and Anselmo López and Jorge Gerardo Machuca and Leonardo Málaga and Claudio Martínez and Denis Martinez and Raúl Meliá and Marcelo Monópoli and Marc A. Murison and Leandro Emiliano Fernandez Pohle and Mariano Ribas and José Luis Ramón Sánchez and Sergio Scauso and Dirk Terrell and Thomas Traub and Pedro Oscar Valenti and Ángel Valenzuela and Ted von Hippel and Wen Ping Chen and Dennis Zambelis},
journal= {arXiv preprint arXiv:2506.21666},
year = {2025}
}
Comments
Accepted for publication in the Astronomical Journal. The introduction includes a link to the Jupyter notebook and images used in the analysis