By John Ikani
Since its debut in 2018, NASA’s Parker Solar Probe has steadily closed in on the sun, unravelling crucial solar intricacies year after year.
By the close of 2024, it is poised to establish a groundbreaking milestone, skimming within a little over 6 million kilometres of our blazing star, delving deep into its fiery outer layers.
The Parker Solar Probe stands as a daring venture in space exploration history, being the inaugural spacecraft to navigate the sun’s outer atmosphere, scientifically termed the corona.
In late December, it is set to chart unexplored territory, covering a staggering 96% of the distance separating Earth from its radiant celestial body.
During this odyssey, Parker will reach speeds of approximately 700,000 km/h (or 435,000 mph), fast enough to traverse from New York to Tokyo in just one minute, securing its position as the swiftest human-made craft ever.
The remarkable velocity will be attained through strategic orbits around Venus, utilizing the planet’s gravitational force to tighten its trajectory around the sun and gain additional speed.
“This will be a monumental achievement for all humanity. This is equivalent to the Moon landing of 1969,” expressed Parker project scientist Dr. Nour Raouafi of Johns Hopkins University in an interview with the BBC. “We are basically almost landing on a star.”
Into the inferno
Parker’s mission unfolds with successive approaches to the sun, venturing closer to the star as it navigates its outer atmosphere—a region paradoxically 300 times hotter than its actual surface.
Enduring extreme conditions, including temperatures nearing 1,400 degrees Celsius and solar winds laden with high-energy particles, is the challenge for Parker.
The probe executes rapid descents into this inferno, relying on its tremendous speed and a robust heat shield crafted from carbon composite.
This shield safeguards an array of instruments, measuring charged particles and magnetic fluctuations, capturing both visual images and audio recordings.
In 2020, recordings obtained in proximity to the star yielded the initial sound snippets of the solar wind—a continuous stream of high-energy particles emanating from the sun.
Predicting solar storms
The mission’s primary objective is to enhance comprehension of solar activity and unveil the mysteries surrounding the corona, where temperatures can soar to a million degrees Celsius and beyond—significantly higher than the sun’s surface temperature of 6,000C.
Researchers anticipate that Parker’s data will offer insights into why the sun’s outer atmosphere is substantially hotter than its surface.
The corona is the birthplace of the solar wind, sometimes escalating into solar “flares” and “storms,” which could potentially disrupt Earth’s magnetic field, impair communications, and pose risks to astronauts’ health.
Ultimately, Parker’s discoveries may pave the way for a space weather service capable of predicting and monitoring such celestial occurrences.
The probe’s year-end journey stands as its prime opportunity to amass a deeper understanding of pivotal solar processes. However, it also signifies the mission’s conclusion; post-December, the probe’s orbit will no longer permit it to loop around Venus, effectively ruling out a closer encounter with the sun.