From one perspective, the Sun is a benevolent orb of plasma and its warmth makes Earth habitable and has kept if habitable for billions of years, allowing complex things like human beings to evolve.
From another perspective, it's a malevolent orb that sends deadly UV radiation our way, and sometimes erupts and hurls massive blobs of plasma toward Earth. The truth is somewhere in the middle, and NASA launched the Parker Solar Probe to flesh out that truth.
NASA launched the Parker Solar Probe (PSP) in 2018 and its mission is to examine the Sun's coronal plasma and its magnetic field. To do this, it has to get close. NASA describes it as a mission to "touch the Sun," and that's pretty accurate.
Related: Parker Probe Repeats Record Brush With The Sun in Daredevil Dive
Throughout its mission it has gotten progressively closer, setting a new record each time for closest approach to the Sun. On Dec. 24, 2024, the spacecraft flew just 6.1 million km (3.8 million miles) from the solar surface.
That is incredibly close, but luckily, the spacecraft has several layers of protection. The PSP is also the fastest-moving spacecraft ever built. It was travelling at 692,000 km/h (430,000 mph) during its 2024 flyby, and didn't spend much time that close to the star.
The result of this daring piece of coronal navigation is the closest images yet of our star.
The PSP carries four main instruments, and one of them is WISPR, the Wide-field Imager for Solar Probe. WISPR has two radiation-hardened cameras that can withstand the Sun's power. Its job is to image the corona, the solar wind, and other phenomena near the Sun. On the last flyby, WISPR showed us the solar corona and the solar wind in a way we've never seen before.
"Parker Solar Probe has once again transported us into the dynamic atmosphere of our closest star," said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington.
"We are witnessing where space weather threats to Earth begin, with our eyes, not just with models. This new data will help us vastly improve our space weather predictions to ensure the safety of our astronauts and the protection of our technology here on Earth and throughout the solar system."
There are important implications for understanding or misunderstanding the solar wind and coronal mass ejections (CME). They're ever present forces in the Solar System. The wind is a stream of charged particles that constantly flows outward from the Sun.
It's responsible for the gorgeous aurorae that we love to gaze it, but it's also responsible for damaging power grids and satellites. As we expand into cislunar space and crowd more satellites into Low-Earth Orbit, it's important that we understand not only the solar wind, but everything that flows from the Sun, including coronal mass ejections (CME).
While the solar wind is a continuous phenomenon, coronal mass ejections are episodic. They're ejections of plasma that can reach Earth. CMEs can contain billions of tons of plasma moving at high speeds. Only a small number of them reach Earth, but when they do, they can also cause geomagnetic storms that can damage power grids and other equipment.
The Parker Solar Probe is named after the American heliophysicist Eugene Parker, who coined the term 'solar wind' in 1958. His theories, though they faced stiff resistance at the time, revolutionized our scientific understanding of the Sun. Multiple spacecraft have been launched to study the Sun and the solar wind, but the Parker Solar Probe has outdone them all.
Each mission has revealed more about the Sun and the solar wind, but none have come as close to the star as the PSP. It also has the advantage of the most modern technologies and instruments. One of the things its revealed is the nature of so-called switchbacks.
When measured near Earth, the solar wind is pretty much constant. But closer to the Sun, things are more chaotic. The Sun has extremely powerful magnetic fields, and when the PSP came within 14.7 million miles of the Sun, it showed us that some of those fields zig-zag.
These zig-zagging fields are called switchbacks. The PSP also showed us that these switchbacks are more common than thought, and that they come in clumps.
As the PSP got progressively closer and travelled through the Sun's corona, it noticed that the corona's boundary was uneven and complex. Getting even closer in subsequent flybys, it was able to pinpoint the source of the switchbacks. The source is patches on the Sun where magnetic funnels form and images showed that the switchbacks are partly responsible for the fast solar wind, one of the wind's two components.
"The big unknown has been: how is the solar wind generated, and how does it manage to escape the Sun's immense gravitational pull?" said Nour Rawafi, the project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Laboratory.
"Understanding this continuous flow of particles, particularly the slow solar wind, is a major challenge, especially given the diversity in the properties of these streams — but with Parker Solar Probe, we're closer than ever to uncovering their origins and how they evolve."
The slow solar wind is twice as dense as the fast solar wind, and interplay between the two seems to create moderately strong conditions on Earth that can rival conditions generated by CMEs. The slow solar wind appears to originate from the Sun's equatorial regions, but scientists are still debating what structures they originate in and how the material is released.
"We don't have a final consensus yet, but we have a whole lot of new intriguing data," said Adam Szabo, Parker Solar Probe mission scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
We've learned a lot about the Sun in recent decades, and the PSP is poised to show us more and hopefully provide answers to our most probing questions. It's next perihelion will be in September, 2025, when it will again fly through the solar corona. That approach will gather even more data on the slow solar wind and other facets of the Sun.
It will also give us more stunning images.
This article was originally published by Universe Today. Read the original article.