The Parker Solar Probe made history with a record-breaking encounter with our star, soaring within 3.8 million miles (6.1 million kilometers) of the sun's surface, marking the closest approach to a star ever achieved by humankind.

The mission operations team, based at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, confirmed the successful flyby on Friday morning after receiving a signal from the spacecraft just before midnight on Thursday. Although the team was unable to communicate with the spacecraft during its closest pass to the sun, they are now anticipating more detailed data on the spacecraft’s status, expected to arrive on Earth on January 1.

This uncrewed spacecraft traveled at an astonishing speed of 430,000 miles per hour (692,000 kilometers per hour), fast enough to travel from Washington, DC, to Tokyo in less than a minute, according to NASA. This speed has earned the probe the title of the fastest human-made object in history, as shared by the agency on December 16 during a NASA Science Live presentation on YouTube.

The mission, which launched on August 12, 2018, has been leading up to this historic milestone, and it was attended by the probe’s namesake, Dr. Eugene Parker, an astrophysicist who pioneered the field of heliophysics. Dr. Parker was the first living person to have a spacecraft named after him and, although he passed away in March 2022, he was able to witness the probe's contributions to solar research.

The probe made history again in December 2021 by being the first to "touch the sun" by flying through the sun’s corona, or upper atmosphere, to sample particles and the star’s magnetic fields. Over the course of its seven-year mission, the Parker Solar Probe has collected data that has shed light on some of the sun’s greatest mysteries.

Heliophyicists have long been puzzled by the generation of the solar wind, a constant stream of particles released by the sun, and the significant temperature difference between the sun’s corona and its surface. Additionally, scientists are eager to understand the structure of coronal mass ejections, large plasma clouds carrying ion gas and magnetic field, it erupts from the outer atmosphere of the sunWhen these ejections are directed at Earth, they can cause geomagnetic storms, which can disrupt satellites and power and communication infrastructure on our planet.

Now, with Parker’s closest and final flybys, scientists hope to unlock the answers to these enduring questions and uncover new mysteries by venturing into uncharted solar territory. "Parker Solar Probe is changing the field of heliophysics," said Helene Winters, the project manager from Johns Hopkins University’s Applied Physics Laboratory. "After years of braving the heat and dust of the inner solar system, taking blasts of solar energy and radiation that no spacecraft has ever seen, Parker Solar Probe continues to thrive."

The flyby on Christmas Eve was the first of the spacecraft’s final three closest approaches, with the other two expected to occur on March 22 and June 19. The spacecraft came so close to our star that, if the distance between Earth and the sun were the length of an American football field, the spacecraft would be about 4 yards from the end zone, according to NASA. At this proximity, the probe is able to fly through plumes of plasma and within a solar eruption if one releases from the sun.

The spacecraft was built to withstand the extremes of the sun and has flown through coronal mass ejections in the past with no impact on the vehicle, said Parker Solar Probe project scientist Nour Rawafi. Equipped with a carbon foam shield that is 4.5 inches (11.4 centimeters) thick and 8 feet (2.4 meters) wide, the shield was tested on Earth to withstand temperatures near 2,500 degrees Fahrenheit (nearly 1,400 degrees Celsius).

On Christmas Eve, the shield likely faced temperatures up to 1,800 F (980 degrees C), which the telemetry data expected in January will confirm. Meanwhile, the spacecraft’s interior is maintained at a comfortable room temperature to ensure the electronics systems and science instruments can operate as expected. A unique cooling system designed by the Applied Physics Laboratory pumps water through the craft’s solar arrays to keep them at a steady temperature of 320 F (160 C), even during close approaches to the sun.

The spacecraft carried out its flyby autonomously because mission control was out of contact with the probe due to its proximity to the sun. The immense set of data and images gathered during the flyby won’t become available to mission control until Parker has moved away from the sun in its orbit, which will occur about three weeks later in mid-January, Rawafi said.

Just over a year after the Parker Solar Probe first launched, the sun entered a new solar cycle. Now, the sun is experiencing solar maximum, meaning that the mission has had a chance to witness most of a solar cycle and the transitions between its highs and lows, 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 solar maximum, or the peak of activity within its 11-year cycle.

At the peak of the solar cycle, the sun’s magnetic poles flip, causing the sun to transition from calm to active. Experts track increasing solar activity by counting how many sunspots appear on the sun’s surface. And the sun is expected to remain active for the next year or so. The sun’s increasing activity became obvious this year during two major displays of auroras on Earth in May and October, when coronal mass ejections released by the sun were directed at our planet. The solar storms are also responsible for generating auroras that dance around Earth’s poles, known as the northern lights, or aurora borealis, and southern lights, or aurora australis.

When the energized particles from coronal mass ejections reach Earth’s magnetic field, they interact with gases in the atmosphere to create different colored light in the sky. “Both of those storms caused auroras to be visible down to the very bottom of the United States,” Young said. “But the May storm was an especially strong storm. In fact, we think it could be a 100- to possibly 500-year event, and that caused auroras very close to the equator, which is extremely unheard of. It was a worldwide event that millions and, hopefully billions, of people, were able to see, and it may not happen again.”

The data gathered by Parker Solar Probe could enable scientists to better understand solar storms and even how to predict them, Young said. “The sun is the only star that we can see in detail, but we can actually go to and measure it directly,” Young said. “It’s a laboratory in our solar system that allows us to learn about all the other stars in the universe and how all those stars interact with the billions and billions of other planets that may or may not be like our own planets in our solar system.”

With that in mind, Rawafi expressed his hope that the sun puts on a spectacular show during the probe’s close approaches, enabling scientists to gain insights into the sun’s activity. “Sun, please do your best,” Rawafi said. “Give us the strongest event you can do, and the Parker Solar Probe can deal with it.”