The mission team, based at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, confirmed the success of the flyby on Friday morning after receiving a signal from the spacecraft late Thursday night.
Although the team anticipated no communication during the probe's closest approach, they are now awaiting more detailed data about its status, expected to arrive by January 1.
The uncrewed spacecraft traveled at an astonishing 430,000 miles per hour (692,000 kilometers per hour), a speed fast enough to reach Tokyo from Washington, DC, in under a minute, as NASA pointed out. This incredible speed makes the Parker Solar Probe the fastest human-made object in history, a milestone revealed during a December 16 NASA Science Live event on YouTube.
The mission, which has been progressing since the spacecraft's launch on August 12, 2018, reached this historic moment with the support of Dr. Eugene Parker, an astrophysicist who pioneered the field of heliophysics and whose groundbreaking research transformed our understanding of the sun and interplanetary space. Parker, who passed away in March 2022 at the age of 94, witnessed how the spacecraft advanced the mission he envisioned over 65 years ago.
In December 2021, the Parker Solar Probe became the first spacecraft to "touch the sun" by flying through its corona, collecting data about solar particles and magnetic fields.
Over its seven-year mission, the Parker Solar Probe has been gathering valuable data that helps scientists unravel long-standing questions about the sun. Researchers are particularly interested in understanding the solar wind, which is a continuous stream of particles released by the sun, and why the sun's corona is significantly hotter than its surface. Another area of focus is the structure of coronal mass ejections (CMEs), large bursts of plasma and magnetic fields from the sun's outer atmosphere, which can cause geomagnetic storms on Earth that disrupt satellites and communication systems.
The spacecraft's upcoming final flybys promise to provide crucial answers to these questions and uncover new mysteries by venturing into previously unexplored solar territory.
"Parker Solar Probe is revolutionizing heliophysics," said Helene Winters, project manager of the Parker Solar Probe at Johns Hopkins University’s Applied Physics Laboratory. "After enduring the extreme conditions of the inner solar system, enduring intense solar radiation and energy that no spacecraft has ever experienced, Parker Solar Probe continues to thrive."
The historic flyby occurred around 6:53 a.m. ET on Christmas Eve, marking the first of the spacecraft’s final three closest approaches, with the next two expected on March 22 and June 19. During this approach, the spacecraft came so close to the sun that if the distance from Earth to the sun were represented as an American football field, the spacecraft would be about 4 yards from the end zone, according to NASA.
At this proximity, the probe is capable of flying through plasma plumes and even solar eruptions. Despite the extreme conditions, the spacecraft, equipped with a carbon foam shield 4.5 inches (11.4 centimeters) thick, has withstood temperatures up to 2,500 degrees Fahrenheit (nearly 1,400 degrees Celsius) on previous flybys. On Christmas Eve, the temperature likely reached 1,800 F (980 C), as confirmed by telemetry data expected in January.
To protect its instruments, the spacecraft’s interior is maintained at a comfortable room temperature, while its solar arrays are kept at a steady 320 F (160 C) by a specialized cooling system designed by the Applied Physics Laboratory.
Since Parker's proximity to the sun blocked communications with mission control, the spacecraft operated autonomously during its flyby. The collected data and images will only be transmitted after the spacecraft moves farther from the sun in its orbit, expected around mid-January.
As the sun enters its solar maximum phase, scientists have been able to observe the most active period of its 11-year cycle, which started just over a year after the Parker Solar Probe’s launch. This active period has already led to spectacular auroras on Earth, driven by coronal mass ejections directed at our planet.
Scientists are hopeful that the Parker Solar Probe’s data will help them better understand solar storms and improve their ability to predict these events. As Dr. C. Alex Young, Associate Director of Science at NASA’s Goddard Space Flight Center, noted, the sun is a unique laboratory that allows us to learn not only about our star but also about other stars across the universe.
Parker Solar Probe project scientist Nour Rawafi expressed hope that the sun would put on an extraordinary display during the spacecraft’s upcoming close approaches, providing valuable insights into solar activity. "Sun, please do your best," Rawafi said. "Give us the strongest event you can do, and the Parker Solar Probe can handle it."