This week, on Christmas Eve, NASA’s Parker Solar Probe made the closest recorded approach to the sun – 3.8 billion miles above the yellow dwarf star’s surface. Two days later, a beacon tone confirmed it made the trip safely.
“Operations teams have confirmed NASA’s mission to ‘touch’ the Sun survived its record-breaking closest approach,” the space agency revealed Friday. John Wirzburger, the Parker Solar Probe mission systems engineer at APL said getting this close to the sun “is a challenge the space science community has wanted to tackle since 1958 and had spent decades advancing the technology to make it possible.”
To manage the close approach, the Parker Solar Probe broke another record. It traveled through the solar atmosphere at 430,000 mph, faster than any human-made object has ever moved. Parker has broken speed records before.
NASA launched the probe into space in 2018 and it conducted seven flybys of Venus. Its last Venus flyby occurred this November and got the spacecraft to its optimal orbit. In this orbit, Parker reaches an ideal distance from the sun every three months.
That’s “close enough to study our Sun’s mysterious processes but not too close to become overwhelmed by the Sun’s heat and damaging radiation,” said NASA. Going forward, Parker is expected to pass the sun more times at the same distance.
“Flying this close to the Sun is a historic moment in humanity’s first mission to a star,” said Nicky Fox, leader of the Science Mission Directorate at NASA Headquarters in Washington. “By studying the Sun up close, we can better understand its impacts throughout our solar system, including on the technology we use daily on Earth and in space, as well as learn about the workings of stars across the universe to aid in our search for habitable worlds beyond our home planet.”
Here on Earth, we depend on the sun for our hospitable climate, the food we eat, and more. In fact, the star’s gravity is what holds our entire solar system together, keeping everything in orbit. Although it may seem far away at approximately 93 million miles from Earth, solar flares – giant explosions in the sun that send particles into space – can even impact ground-based technologies on our planet, such as power grids.
Right now, the sun is about 4.5 billion years old and it is halfway through its life cycle. At the sun’s core, its temperature can top 27 million degrees and in the upper atmosphere of the sun, called the corona, temperatures can still exceed 1 million degrees.
A carbon foam shield designed to reach 2,600 degrees – hot enough to melt steel – protects the Parker probe from the extreme heat and keeps its instruments shaded at a comfortable temperature. While it can withstand higher temperatures, Parker’s shield is expected to warm to 1,800 degrees in the low-density corona.
“Parker Solar Probe is braving one of the most extreme environments in space and exceeding all expectations,” said Nour Rawafi, the project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Laboratory (APL), which designed, built, and operates the spacecraft from its campus in Laurel, Md. “This mission is ushering a new golden era of space exploration, bringing us closer than ever to unlocking the Sun’s deepest and most enduring mysteries.”
When it flies through the sun’s corona, Parker can take measurements.
These measurements can help scientists understand how the sun gets so hot, trace the origin of a constant flow of material escaping the Sun called solar wind and discover how energetic particles are accelerated to half the speed of light.
“The data is so important for the science community because it gives us another vantage point,” Kelly Korreck, a program scientist at NASA Headquarters and heliophysicist who worked on one of the mission’s instruments, explained. “By getting firsthand accounts of what’s happening in the solar atmosphere, Parker Solar Probe has revolutionized our understanding of the Sun.”
Parker has actually already helped deepen our understanding of the star that anchors our solar system. Back in 2021, “scientists found signs of a wild ocean of currents and waves quite unlike the near-Earth space much closer to our planet,” in its first observations of the sun, according to NASA. Zig-zag features representing rapid magnetic flips in that ocean became known as switchbacks. It also “found the outer boundary of the corona is wrinkled with spikes and valleys, contrary to what was expected,” said NASA.
Furthermore, Parker made other discoveries across the inner solar system related to how giant solar explosions called coronal mass ejections vacuum up dust and about solar energetic particles.
Now, NASA is waiting for even more revelations that might come with Parker’s close passes by the sun. More passes are expected this March and this June.
“The data that will come down from the spacecraft will be fresh information about a place that we, as humanity, have never been,” said Joe Westlake, the director of the Heliophysics Division at NASA Headquarters.
“It’s an amazing accomplishment.”