�������t¶��

Several countries "have tried or succeeded in developing nuclear weapons under the guise of civilian nuclear weapons programs," Sovacool said, quoting Nobel-winning physicist Hannes Alfven's observation that "Atoms for peace and atoms for war are Siamese twins."

It took several months for mission scientists to download and analyse the data it collected, and to be sure that the spacecraft had indeed crossed the much-anticipated boundary, known as the �����ڱ�é�� surface.

It crossed the �����ڱ�é�� surface on the eighth of those flybys, and might have done so again during its ninth pass in November 2021—a manoeuvre for which the data have not yet been fully downloaded and analysed.

Swedish physicist Hannes �����ڱ�é�� proposed the underlying theory behind the boundary in a paper in Nature in 1942, and scientists have been looking for it ever since.

The spacecraft crossed the �����ڱ�é�� boundary when it was around 14 million kilometres, or just under 20 solar radii, from the Sun’s surface.