On December 14, 2021, NASA officials revealed that the Parker Solar Probe had successfully pierced through the Sun's outer atmosphere — the corona — and "touched" the star. The historical feat was achieved on April 28, 2021, during the spacecraft's eighth flyby, when it was about 8.1 million miles away from the star. The space probe spent five hours collecting magnetic and solar particle data from the Alfvén critical surface — the point that marks the end of the Sun's atmosphere.