NASA’s groundbreaking Parker Solar Probe is set to achieve its closest approach to the Sun on Christmas Eve, coming within a record-breaking distance of 3.8 million miles (6.2 million kilometres) from its surface.
Launched in August 2018, the spacecraft is on a seven-year mission to enhance our understanding of the Sun and improve predictions of space weather that can impact life on Earth. The historic perihelion will occur on Tuesday, December 24, at 6:53am Eastern Time (11:53 GMT).
To illustrate its proximity, if the Sun-Earth distance were scaled to an American football field, Parker would be just four yards (3.65 meters) from the end zone.
“This is one example of Nasa’s bold missions, doing something that no one else has ever done before to answer longstanding questions about our universe,” said Arik Posner, the Parker solar probe programme scientist, in a statement. “We can’t wait to receive that first status update from the spacecraft and start receiving the science data in the coming weeks.”
During this closest approach, known as perihelion, direct communication with Parker will be temporarily lost, with mission teams relying on a "beacon tone" this Friday to confirm its status.
The probe’s heat shield will endure extreme temperatures of 1,600 to 1,700°F (870 to 930°C), while its internal instruments remain at a comfortable 85°F (29°C). Travelling at a staggering speed of 430,000 mph (690,000 km/h) – fast enough to journey from Washington DC to Tokyo in under a minute – Parker will explore the Sun’s outer atmosphere, the corona.
“No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory,” said Nick Pinkine, mission operations manager at Johns Hopkins University Applied Physics Laboratory. “We’re excited to hear back from the spacecraft when it swings back around the sun.”
Parker’s mission has already provided insights into some of the Sun’s most intriguing mysteries, such as the origins of the solar wind, the unusually high temperature of the corona compared to the Sun’s surface, and the formation of coronal mass ejections—vast plasma clouds that travel through space.
This flyby is the first of three record-breaking close encounters, with subsequent approaches scheduled for March 22, 2025, and June 19, 2025, bringing Parker back to similarly close distances to the Sun.