NASA's Parker Solar Probe, launched in August 2018, is about to make history this Christmas Eve by flying closer to the Sun than any human-made object has ever dared before. On December 24, at 6:53 AM EST, the probe will skim within 3.8 million miles (6.1 million kilometers) above our star's surface. This remarkable venture is not just another tick on the box; it's poised to deliver unprecedented insights about our stellar neighbor and possibly answer some of the most enduring mysteries about solar behavior.
This flyby marks the probe's 22nd close approach—referred to as perihelion—out of 24 planned for its mission. With each swing around the Sun, the Parker Solar Probe has gradually edged closer to the heart of solar phenomena. The spacecraft is set to travel at record-speeds, reaching approximately 430,000 miles per hour (692,000 kilometers per hour), shattering its previous records for speed among human-made objects.
Parker Solar Probe's mission, which focuses on studying the Sun's atmosphere—the corona—will explore why the corona is significantly hotter than the solar surface, which is somewhat baffling to scientists. It is expected to pass through solar plasma and gather invaluable data, which will contribute to our knowledge of solar winds and the influences they wield over space weather.
“On Christmas Eve of this year, Parker Solar Probe will be the closest human-made object ever to a star,” said Nour Rawafi, project scientist for the mission at the Johns Hopkins University Applied Physics Laboratory. This monumental achievement holds great promise not just for researchers, but for the field of heliophysics as a whole.
The probe's advanced thermal protection system, which enables it to survive extreme temperatures—up to 2,500°F (about 1,370°C)—is made up of materials expected to withstand the intense conditions encountered during these close stellar visits. Betsy Congdon, lead engineer for the thermal protection system, expressed confidence, stating, “We expect lower temperatures than we originally planned for,” emphasizing how the heat shield has exceeded initial expectations.
According to Nick Pinkine, the Parker Solar Probe mission operations manager, “No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory.” This unprecedented close approach presents unique opportunities to observe solar phenomena at their source, offering direct insights not available from afar.
The Parker Solar Probe had to utilise multiple gravity-assist maneuvers around Venus which helped it slingshot toward its upcoming perihelion. The probe's adeptness at speed adjustments and orbital changes showcases NASA's engineering prowess and the data-rich anticipated outcomes from this position.
After this Christmas flyby, the Parker Solar Probe will remain out of contact with Earth for the duration of the maneuver but is expected to send back telemetry data shortly after—potentially as soon as December 27. The projections suggest the probe will begin transmitting scientific data back to Earth by early January, allowing scientists to analyze the findings almost immediately.
The data the Parker Solar Probe collects will prove invaluable during this current solar maximum phase—when solar activity is at its peak, and sunspots and solar flares are more prevalent. Kelly Korreck noted, “If you can image, it's like going 96% of the way there to the Sun's surface,” underlining the significance of proximity for data collection.
NASA’s Heliophysics team will be working synchronously with ground-based telescopes to gather as much information as possible during Parker’s perihelion pass, reinforcing the collaborative spirit of space exploration. This coordinated effort will enable scientists to validate Parker’s observations against terrestrial and orbital data.
Science gained from the Parker Solar Probe's missions could also lead to improved predictive models for space weather, which has direct effects on satellite operations, GPS technology, and even power grids on Earth. The missions not only aim to shed light on solar wind origins and high-energy solar particles but present opportunities for future work extending beyond the current primary mission ending around June 2025.
“The system is very healthy, and it can go much farther than we planned for,” Rawafi remarked, hinting at potential mission extensions beyond 2025. With Parker already providing insight about phenomena traditional observatories cannot, the expectation is for even greater discoveries as it continues to collect data closely.
The scientific community eagerly awaits the awards of this daring endeavor, and as the Parker Solar Probe sails through the Sun’s inhospitable embrace, it presents humanity with the opportunity to decode the secrets of the Sun, deepening our quest for knowledge about our immediate celestial surroundings.
