NASA's Parker Solar Probe sets out on closest flyby of the Sun on Christmas Eve

NASA’s Parker Solar Probe achieved a groundbreaking milestone on Christmas Eve, making its closest approach to the sun at just 3.8 million miles from its surface.

The record-setting flyby, known as a perihelion, occurred at 6:53 a.m. EST (11:53 GMT), marking a significant step in humanity’s exploration of the solar system's central star.

The spacecraft, launched in August 2018, is on a seven-year mission to deepen scientific knowledge of the sun’s behavior and improve predictions of space weather that can impact Earth. Named after Eugene Parker, a pioneer in solar science who passed away in 2022, the probe is venturing into uncharted territory, offering a closer look at the sun’s outer atmosphere, known as the corona.

At its closest point, the probe was effectively within 4 meters on a scaled 100-meter model of the Earth-sun distance. Despite the extreme proximity, the spacecraft's advanced carbon-composite heat shield, 4.5 inches (11.43 cm) thick, protects its instruments from temperatures reaching 1,600–1,700°F (870–930°C), keeping them near room temperature.

The Parker Solar Probe travels at an unprecedented speed of 430,000 mph (690,000 km/h), enabling it to complete the Washington DC-to-Tokyo journey in less than a minute. NASA’s Dr. Nicola Fox highlighted the mission’s importance in understanding solar mechanics, which in turn aids the search for habitable exoplanets.

Parker has already provided valuable insights into the sun’s mysteries, including the origins of solar wind, the mechanisms behind coronal mass ejections, and why the corona is significantly hotter than the sun’s surface.

The spacecraft uses gravitational assists from Venus to adjust its orbit closer to the sun. A recent flyby on November 6 yielded unprecedented data on Venus, capturing visible and near-infrared light and revealing new ways to observe the planet’s surface through its thick clouds.

Though contact with the probe was temporarily lost after its December 20 transmission, NASA expects to receive updates by December 27, thanks to the Deep Space Network in Canberra, Australia. Mission operations manager Nick Pinkine expressed excitement about the data that Parker will return after this historic journey.

This Christmas Eve flyby is the first of three record-setting approaches planned. The subsequent ones, scheduled for March 22, 2025, and June 19, 2025, will bring the probe back to similarly close distances.

Arik Posner, Parker’s program scientist at NASA headquarters, emphasized the mission’s bold ambition, stating, “This is one example of NASA’s daring efforts to answer enduring questions about our universe, going where no one else has ventured before.”