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The Parker Solar Probe is set to fly past the sun on Tuesday in a record-breaking close approach, reaching within 3.8 million miles (6.1 million kilometers) of the solar surface in humanity’s nearest encounter with a star.
The unmanned spacecraft will travel at a speed of 430,000 miles per hour (692,000 kilometers per hour), which is quick enough to travel from Washington, DC, to Tokyo in less than a minute, as noted by NASA. This rapid pass will make the probe the swiftest human-made object to date, as reported by the agency on December 16 during a NASA Science Live event on YouTube.
This mission has been reaching this landmark moment since its launch on August 12, 2018 — a occasion attended by the probe’s namesake, Dr. Eugene Parker, an astrophysicist who was a trailblazer in the field of heliophysics.
Parker was the first living individual to have a spacecraft named in his honor. The astrophysicist, whose pioneering research transformed humanity’s comprehension of the sun and interplanetary space, passed away at 94 years old in March 2022. Nevertheless, he was able to observe how the spacecraft could unravel mysteries about the sun more than 65 years after the mission’s initial concept.
The probe achieved the milestone of being the first spacecraft to “touch the sun” by successfully navigating through the sun’s corona, or upper atmosphere, to collect samples of particles and our star’s magnetic fields in December 2021.
Throughout the last six years of its seven-year mission, the Parker Solar Probe has gathered data that can illuminate scientists on some of the sun’s greatest enigmas.
Heliophysicists have long puzzled over how the solar wind, a persistent stream of particles emitted by the sun, is produced and why the sun’s corona is significantly hotter than its surface.
Researchers are also eager to comprehend the structure of coronal mass ejections, or large clouds of ionized gas known as plasma and magnetic fields that burst from the sun’s outer atmosphere.
When these ejections target Earth, they can trigger geomagnetic storms, significant interruptions of the planet’s magnetic field, affecting satellites along with power and communication systems on Earth.
Now arrives the time for Parker’s nearest and final flybys, which could pave the way toward resolving these persistent questions and uncover new mysteries by investigating uncharted solar territory.
“Parker Solar Probe is transforming the domain of heliophysics,” stated Helene Winters, project manager of Parker Solar Probe from Johns Hopkins University’s Applied Physics Laboratory, in a declaration. “After years of enduring the heat and dust of the inner solar system, facing solar energy and radiation blasts that no spacecraft has ever experienced, Parker Solar Probe continues to thrive.”
Parker’s flyby, expected at around 6:53 a.m. ET on Christmas Eve, will be the initial of the spacecraft’s final three closest approaches, with the subsequent two anticipated on March 22 and June 19.
The spacecraft will come so near that if the space between Earth and the sun were the
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At a distance comparable to the length of an American football field, the spacecraft would be approximately 4 yards from the end zone, as per NASA.
In this vicinity, the probe will have the capability to navigate through jets of plasma and also within a solar flare if one erupts from the sun.
The spacecraft was designed to endure the sun’s harsh conditions and has previously traversed coronal mass ejections without affecting the vehicle, noted Parker Solar Probe project scientist Nour Rawafi.
The spacecraft features a carbon foam insulation that measures 4.5 inches (11.4 centimeters) in thickness and 8 feet (2.4 meters) in width. Prior to launch, the shield underwent testing on Earth and demonstrated its ability to tolerate temperatures approaching 2,500 degrees Fahrenheit (nearly 1,400 degrees Celsius). On Christmas Eve, the shield may encounter temperatures as high as 1,800 F (980 degrees C).
Simultaneously, the interior of the spacecraft will maintain a pleasant room temperature to ensure that electronic systems and scientific instruments function properly. A specialized cooling system developed by the Applied Physics Laboratory circulates water through the craft’s solar panels, maintaining a constant temperature of 320 F (160 C), even during close encounters with the sun.
The spacecraft will perform its flyby independently since mission control will be out of reach due to its nearness to the sun.
Following the closest approach, around midnight between Thursday and Friday, Parker will transmit a signal known as a beacon tone back to mission control to verify the success of the flyby, Rawafi mentioned.
The beacon tone is a limited data signal that conveys the overall status of the spacecraft, he added.
The vast amount of data and images collected during the flyby will not be accessible to mission control until Parker has distanced itself from the sun in its orbit, which is expected to happen about three weeks later in mid-January, Rawafi stated.
Just over a year after the launch of the Parker Solar Probe, the sun transitioned into a new solar cycle. As Parker gets closer, the sun is at solar maximum, indicating that the mission has observed nearly the entire solar cycle and its fluctuations between high and low activity, said Dr. C. Alex Young, associate director for science in the Heliophysics Science Division at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Scientists from NASA, the National Oceanic and Atmospheric Administration, and the international Solar Cycle Prediction Panel announced in October that the sun has reached its solar maximum, marking the zenith of activity during its 11-year cycle.
At the summit of the solar cycle, the sun’s magnetic poles interchange, prompting the sun to shift from a passive state to an active one. Specialists monitor escalating solar activity by tallying the number of sunspots that appear on the sun’s surface. The sun is anticipated to remain active for the upcoming year or so.
The sun’s escalating activity became apparent this year during two significant aurora displays on Earth in May and October, when coronal mass ejections launched by the sun were directed towards our planet. These solar storms also contribute to the formation of auroras that illuminate Earth’s polar regions, referred to as the northern lights, or aurora borealis, and southern lights, or aurora australis. When energized particles from coronal mass ejections encounters Earth’s magnetic field, they interact with atmospheric gases to generate various colors of light in the sky.
“Both of those storms caused auroras to be visible down to the very bottom of the United States,” Young said. “However, the May storm was particularly intense. In fact, we believe it could be a 100- to possibly 500-year occurrence, and that resulted in auroras appearing remarkably close to the equator, which is extremely unusual. It was a global phenomenon that millions, and hopefully billions, of individuals were able to witness, and it may not occur again.”
The information collected by the Parker Solar Probe could provide scientists with a deeper understanding of solar storms and even enhance predictions about them, Young mentioned.
“The sun is the lone star that we can observe in detail, yet we can actually approach and measure it directly,” Young remarked. “It serves as a laboratory within our solar system that enables us to learn about all the other stars in the universe and how these stars interact with the countless other planets that may or may not resemble our planets in our solar system.”
With this perspective, Rawafi expressed hope that the sun will provide a magnificent performance during the probe’s close encounters, allowing scientists to glean valuable insights into the sun’s behavior.
“Sun, please showcase your best,” Rawafi urged. “Deliver us the most intense event possible, and the Parker Solar Probe is ready for it.”