Touching the Solar Sphere

"For centuries, humanity has only been able to observe this atmosphere from afar. Now ... we have finally arrived."

"Humanity has touched the sun."

Nicola Fox, director,Hheliophysics Division, NASA

"[The Parker Solar Probe's success in] touching the sun [was] a monumental moment for solar science and a truly remarkable feat."

"Not only does this milestone provide us with deeper insights into our Sun's evolution and [its] impacts on our solar system, but everything we learn about our own star also teaches us more about stars in the rest of the universe."

Thomas Zurbuchen, associate administrator, Science Mission Directorate, NASA

"Touching [the sun with a probe, a long-sought mission, was] very exciting."

"It feels like visiting a planet for the first time."

"That was the sense of excitement we got."

Justin Kasper, lead author, study, deputy chief technology officer, BWX Technologies. Professor, Climate and Space Sciences and Engineering, University of Michigan 

Since the Parker Solar Probe launched in 2018, it's been orbiting the sun and inching closer with every loop. NASA/Johns Hopkins APL/Steve Gribben

 

A close encounter with our solar life source. Ambitious beyond belief. But now a reality. Those present Tuesday at the American Geophysical Union Fall Meeting held in New Orleans, heard directly from NASA scientists that one of its spacecraft achieved their goal as the first to "touch the sun". Representing a long-anticipated milestone, potentially recognized as a giant leap in understanding that life-giving orb's influence on the solar system.

In April, the Parker Solar Probe succeeded in flying through the sun's corona (upper atmosphere) to sample particles and the corona's magnetic fields. The research was published in the journal Physical Review Letters. Launched three years earlier, the spacecraft represented an effort to study the sun and its dangers for the purpose of aiding scientists to reveal significant and unknown information about Earth's closest star.

One of the goals in this specific project is to discover how the flow of the sun's particles can influence the planet. The associate administrator for NASA's Science Mission Directorate examines how discoveries in one scientific discipline are connected to other study areas; so 'touching the sun' is a great advance toward full and deep understanding of the physics involved in nature's fundamental plans of creation.

The Earth's closest star is absent a solid surface, comprised, according to a description in a NASA video, as "a giant ball of hot plasma that's held together by its own gravity". The sun's material helps to form the atmosphere of the sun; the corona, an area significantly hotter than the sun's actual surface. While the surface of the sun is around 10,350 degrees Fahrenheit, the corona is about 1.8 million degrees Fahrenheit at its hottest point. Solar wind is comprised of some of those hot, fast particles from the corona.

It has long been a struggle to predict space weather events given the ferocious environment around the sun. The boundary, named the Alfven critical surface, marking the end of the solar atmosphere and the beginning of the solar wind has long been studied by scientists. And then, on April 28, the Parker Solar Probe crossed the Alfven critical surface for the first time, entering the solar atmosphere on its eighth flyby of the sun.

"My instinct is, as we go deeper into the mission and lower and closer to the sun, we're going to learn more about how magnetic funnels are connected to the switchbacks."

"And hopefully resolve the question of what process makes them."

Stuart Bale, study co-author, astrophysicist, University of California, Berkeley