Sixty years after the Nasa set the goal, and three years after the release of his Parker Solar spacecraft became the first to “touch the sun”.
A Parker Solar successfully flew through the solar corona, or upper atmosphere, to sample particles and the star’s magnetic fields.
“The Parker Solar spacecraft ‘touching the sun’ is a monumental moment for solar science and a truly remarkable achievement,” said Thomas Zurbuchen, associate administrator of NASA’s Scientific Mission Directorate, in a statement.
“This milestone not only provides us with deeper insights into the evolution of our sun and [seus] impacts our solar system, but everything we’ve learned about our own star also teaches us more about stars in the rest of the universe.”
The announcement was made during the 2021 edition of the Autumn Meeting of the American Geophysics Union in New Orleans on Tuesday (14), and the solar landmark research was published in Physical Review Letters.
The Parker Solar spacecraft was launched in 2018 and began circling closer and closer to the sun. Scientists, including the astrophysicist honored by the spacecraft’s name, Eugene Parker, want to answer fundamental questions about the solar wind emanating from the sun, hurling energetic particles throughout the solar system.
The solar corona is much hotter than the star’s actual surface, and the spacecraft can provide information about why. The corona is one million degrees Kelvin (999,726.85 degrees Celsius) at its hottest point, while the surface is about 6,000 Kelvin (5,726.85 degrees Celsius).
The spacecraft has already revealed surprising discoveries about the sun, including when in 2019 it revealed zigzag magnetic structures in the solar wind called “switchbacks”.
Now, thanks to Parker’s latest approximation of the sun, the spacecraft has helped scientists determine that these zigzags originate from the solar surface.
Before the Parker Solar probe’s mission is completed, it will have made 21 close-sun assaults over seven years. The probe will orbit within 3.9 million miles (6.2 million kilometers) of the sun’s surface in 2024, closer to the star than Mercury – the closest planet to the sun.
Although it seems far away, researchers liken this to the probe lying at the four-yard line of a football field and the sun being the end zone.
When closer to the sun, 4-inch-thick carbon-composite solar shields will have to withstand temperatures close to 2,500 degrees Fahrenheit (1,371 degrees Celsius). However, the interior of the spacecraft and its instruments will remain at a comfortable room temperature.
“Flying so close to the sun, Parker Solar now detects conditions in the magnetically dominated layer of the solar atmosphere – the corona – that we never could before,” said Nour Raouafi, Parker project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, in a statement.
“We see evidence of corona location in magnetic field data, solar wind data and visually in images. We can actually see the spacecraft flying through coronal structures that can be observed during a total solar eclipse.”
getting close to a star
In April, the Parker team realized that their spacecraft had crossed the border and entered the solar atmosphere for the first time.
It occurred when the spacecraft made its eighth overflight of the sun and recorded the specific magnetic and particle conditions for a boundary where the sun’s massive solar atmosphere ends and the solar wind begins – 8.1 million miles (13 million kilometers) above the surface of the sun.
“We were hoping that, sooner or later, we would enter the crown for at least a short period of time,” said Justin Kasper, lead author of the study, a professor at the University of Michigan and deputy chief technology officer at BWX Technologies, Inc. in an affirmation. “It’s very exciting that we’ve already achieved it.”
Parker moved in and out of the crown several times over a few hours during the April flyby, which helped researchers understand that the boundary, called the Alfvén critical surface, is not a smooth circle around the sun, but has peaks. and vouchers.
Understanding the presence of these features may allow scientists to compare them to the solar activity on the sun’s surface.
During the flyover, Parker had another intriguing encounter as he passed within 6.5 million miles (10.4 million kilometers) of the sun’s surface. He passed a place called a “pseudostreamer”, a large structure that rises above the sun’s surface and was observed from Earth during solar eclipses.
When the spacecraft flew through the pseudostreamer, everything went silent, like the eye of a storm.
Normally, Parker is bombarded with particles while flying on the solar wind. In this case, the particles moved more slowly and the zigzag switchbacks decreased.
The spacecraft will likely fly over the crown again in January, during its next flyover.
“I’m excited to see what Parker will find as it passes the crown several times over the next few years,” said Nicola Fox, division director for NASA’s Heliophysics Division, in a statement. “The opportunity for new discoveries is limitless.”
