9 June, 2024 – Professor Edward C Stone, Shaw Laureate in Astronomy 2019, David Morrisroe Professor of Physics, Emeritus, at Caltech, USA, passed away at the age of 88.

Professor Stone was honoured for his leadership in the Voyager project, which has, over the past four decades, transformed our understanding of the four giant planets and the outer solar system, and is still on a journey to explore interstellar space.
The Voyager project consists of two spacecraft launched by NASA in August and September 1977 to explore the outer solar system. Both spacecraft flew past Jupiter and Saturn in the period 1979-1981 and Voyager 2 also visited Uranus in 1986 and Neptune in 1989. These unique data are particularly important for the study of exoplanets, since Uranus and Neptune now appear to be more representative of the bulk of the exoplanet population than the other solar-system planets.

Voyager 1 and 2 crossed the heliopause, often considered the ‘boundary’ of the solar system, in 2012 and late 2018, respectively, and returned data on the velocity, density, temperature and other properties of the ambient plasma as the spacecraft crossed into interstellar space. This was the final major milestone of the Voyager mission.

Professor Stone served as the sole project scientist for the Voyager project from 1972 until his retirement in 2022, and was also in charge of one of the spacecraft’s 11 instruments.

At the 2019 Shaw Prize Award Presentation Ceremony, Professor Stone said, “Little could I have predicted that 42 years after the twin Voyager probes were launched from Cape Canaveral, Florida, that it would remain my privilege to helm this remarkable project – and to work alongside a most extraordinary team of scientists and engineers – on what has been a truly unprecedented journey. But then, Voyager has always exceeded expectations, reminding us that no matter what we think we know, we will know much more tomorrow.”

Professor Stone’s pioneering spirit extended beyond scientific achievements. During the planetary flybys, he became internationally known as the public spokesman for Voyager and explained Voyager’s scientific discoveries to the public with remarkable lucidity and scientific authority.

The Shaw Prize Foundation extends its heartfelt condolences to Professor Stone’s family, friends, colleagues, and the entire scientific community. May his remarkable legacy continue to inspire and guide future generations of astronomers and space explorers.

12 June, 2024