NASA’s Parker Solar Probe has made history by surviving humanity’s closest-ever approach to the Sun.

Just before midnight EST on Thursday (05:00 GMT on Friday), scientists received a signal from the spacecraft after days of silence during its scorching flyby. NASA confirmed that Parker was “safe” and operating normally after passing just 3.8 million miles (6.1 million km) from the Sun’s surface.

On Christmas Eve, the probe plunged into the Sun’s outer atmosphere, enduring intense radiation and the almost unmeasurable temperatures of the solar atmosphere to deepen our understanding of our star. NASA had been waiting for the return signal, expected at 05:00 GMT on December 28. Moving at speeds up to 430,000 mph (692,000 kph) and facing temperatures of 1,800°F (980°C), Parker emerged unscathed thanks to its 4.5-inch (11.5 cm) thick carbon-composite heat shield and a strategy of speed and precision.

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“This close-up study allows Parker Solar Probe to take measurements that help scientists understand how material in this region is heated to millions of degrees, trace the solar wind’s origins, and explore how energetic particles are accelerated to near light-speed,” NASA explained.

Dr. Nicola Fox, head of science at NASA, previously described the significance of the mission: “For centuries, people have studied the Sun, but you can’t truly experience its atmosphere unless you fly through it.”

Launched in 2018, Parker has now completed 21 passes around the Sun, each closer than the last, but its Christmas Eve encounter broke records. At just 3.8 million miles from the Sun, the probe was dramatically close. Dr. Fox illustrated this scale: “If the Sun and Earth were one meter apart, Parker would be just 4 cm away.”

The probe’s speed, driven by the Sun’s immense gravitational pull, made it the fastest human-made object in history. Its velocity—430,000 mph—could cover the distance from New York to London in under 30 seconds.

Unlocking Solar Mysteries

Why go through such extreme measures to “touch” the Sun? Scientists hope Parker’s journey through the corona—its tenuous outer atmosphere—will answer a longstanding puzzle: why is the corona millions of degrees hotter than the Sun’s surface?

“The surface of the Sun is about 6,000°C, yet the corona—further out—is millions of degrees hotter. We still don’t understand why,” explained Dr. Jenifer Millard, an astronomer at Fifth Star Labs in Wales.

Additionally, Parker aims to shed light on the solar wind, the continuous flow of charged particles escaping from the corona. These particles interact with Earth’s magnetic field, causing stunning auroras but also posing risks to power grids and communication systems.

A Tense Wait

NASA scientists spent an anxious Christmas waiting for the probe’s signal. Dr. Fox anticipated a simple text—a green heart emoji—to confirm Parker’s safety. Despite her nerves, she expressed confidence in the probe: “I worry about the spacecraft, but it’s built to withstand these brutal conditions. It’s a tough little spacecraft.”

[As published on SCIFI.radio]