The Parker Space Probe was launched in 2018 with the intent of observing the Sun more closely than any other spacecraft.
The boundary between solar atmosphere and outgoing solar wind is known as the Alfvén critical surface. Researchers aimed to discover where this surface lay, using data collected by the spacecraft. In April, during its eighth close approach to the Sun, the probe encountered the tell-tale magnetic and particle conditions that marked this surface, 8.1 million miles from the centre of the Sun. However, it has taken several months to return the data and confirm the encounter. The plunge was announced this week during a meeting of the American Geophysical Union.
“Parker Solar Probe 'touching the Sun' is a monumental moment for solar science and a truly remarkable feat,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at Nasa’s Washington headquarters. “Not only does this milestone provide us with deeper...