Washington DC - NASA's Parker Solar Probe has become the first spacecraft to enter the solar atmosphere, the space agency announced on Tuesday.

The probe has flown through the Sun's corona, the star's upper atmosphere, sampling particles and magnetic fields there, NASA said, calling the milestone "one giant leap for solar science."

"Parker Solar Probe 'touching the Sun' is a monumental moment for solar science and a truly remarkable feat," said Thomas Zurbuchen of NASA's Science Mission Directorate.

"Not only does this milestone provide us with deeper insights into our Sun's evolution and its impacts on our solar system, but everything we learn about our own star also teaches us more about stars in the rest of the universe."

The space agency said that Parker found the right magnetic and particle conditions to enter the solar atmosphere at 18.8 solar radii – over 8 million miles – above the solar surface during its eighth flyby of the Sun on April 28, with the passage lasting a few hours.

"We were fully expecting that, sooner or later, we would encounter the corona for at least a short duration of time," said Justin Kasper, lead author on a new paper about the milestone published in Physical Review Letters.

"But it is very exciting that we've already reached it."

As the probe continues to spiral closer to the Sun, it will eventually get as close as 8.86 solar radii from the surface, NASA said. Its next flyby, set for January 2022, is likely to bring Parker through the corona again, it added.