NASA's New Horizons spacecraft, being at a distance over 8,8 billion kilometers from Earth in the Kuiper belt, became a participant in a unique experiment — the world's first demonstration of star navigation in deep space.
Research results, which have already been accepted for publication in The Astronomical Journal, available as a preprint on the arXiv server.
During the test, a team of international astronomers took advantage of the unique location of the device, heading for interstellar space, and took pictures of the two closest stars to us - Proxima Centauri (4,2 light years from Earth) and the Wolf 359 (7,86 light years).
From New Horizons' point of view, these stars have shifted in the sky compared to that, how they look from Earth is a phenomenon known as stellar parallax. By measuring the change in the position of the stars and comparing it with a three-dimensional model of the surrounding star space, the researchers were able to calculate the position of the device with an accuracy of approx 6,6 million kilometers. For comparison, this is equivalent to an error in 66 centimeters when measuring the distance from New York to Los Angeles.
Despite them, that this is only a demonstration experiment and did not lead to scientifically significant results, researchers note, that the observation of great parallax from two extremely distant points gives a vivid insight into the principles of astronomical measurement.
The main goal of the New Horizons mission was to study the dwarf planet Pluto and its largest moon, Charon. After 9,5 years of flying and overcoming more than 5 billions of kilometers, the device transmitted the first ever detailed images of these distant bodies of the Solar System.
During the extended mission phase, New Horizons continues to study the heliosphere and, according to forecasts, in the coming years, the so-called "shock front" will cross the border between the solar system and interstellar space.
Source: https://phys.org/news/2025-07-horizons-successful-deep-space-stellar.amp