An illustration of the Parker Solar Probe approaching the Sun./Courtesy of NASA

The National Aeronautics and Space Administration (NASA) solar probe "Parker Solar Probe" has successfully completed its closest approach observation flight.

NASA noted on the 27th (local time) that Parker sent a signal to the ground control team just before midnight Eastern Time the previous night. This indicates that the probe is operating normally after completing its closest approach flight to the sun.

Previously, Parker lost communication with the ground control team while passing through the sun's corona on the 24th. The solar corona is the outermost region of the sun's atmosphere, composed of ionized gases known as "plasma."

NASA stated that during the communication blackout, the probe was flying at a speed of 430,000 miles per hour (691,018 kilometers) at a point just 3.8 million miles (6,115,507 kilometers) from the sun's surface. Assuming a 1-meter distance between the sun and Earth, the distance between the sun and Parker at that time was only 4 centimeters. This is the closest and fastest approach ever made by a human-made probe to the sun. The previous record for the closest approach to the sun was at a distance of 7.26 million kilometers from the sun's surface.

Niki Fox, deputy director of NASA's Science Mission Directorate, remarked that "approaching the sun this closely is a historic moment for humanity's first mission to a star" and added, "Studying and understanding the sun up close can help us learn about stars throughout the universe and find potentially habitable places beyond Earth."

The Parker Solar Probe is scheduled to send data about its current state on Jan. 1, 2025. NASA stated, "This close solar observation will provide data that will help track the heating process of solar atmospheric materials and the origins of solar wind" and noted, "Transfer observations have contributed to understanding the origins of structures within the solar wind and distinguishing the outer boundaries of the sun's atmosphere." Solar wind refers to the flow of tiny particles emitted from the corona.

Parker is the fastest spacecraft ever built and is designed to withstand temperatures of 1,370 degrees Celsius. After being launched in 2018 for solar exploration, it first succeeded in flying through the upper layers of the corona in April 2021. Since then, it has continuously set new records for close approaches. Parker is also expected to approach the sun again in March and June of next year, along with a predicted peak in solar activity around July.