An artist’s impression of NASA’s Voyager 2 probe, now 18 billion kilometres (11 billion miles) from Earth, in the early stages of passing out of the Sun’s influence and into interstellar space. Image: NASA/JPL-Caltech
One year ago, on Nov. 5, 2018, NASA’s Voyager 2 became only the second spacecraft in history to leave the heliosphere – the protective bubble of particles and magnetic fields created by our Sun. At a distance of about 11 billion miles (18 billion kilometres) from Earth – well beyond the orbit of Pluto – Voyager 2 had entered interstellar space, or the region between stars. On 4 November, five new research papers in the journal Nature Astronomy describe what scientists observed during and since Voyager 2’s historic crossing.
Each paper details the findings from one of Voyager 2’s five operating science instruments: a magnetic field sensor, two instruments to detect energetic particles in different energy ranges and two instruments for studying plasma (a gas composed of charged particles). Taken together, the findings help paint a picture of this cosmic shoreline, where the environment created by our Sun ends and the vast ocean of interstellar space begins.
The Sun’s heliosphere is like a ship sailing through ...