On Christmas Eve 2024, NASA’s Parker Solar Probe achieved a historic milestone, flying closer to the sun than any spacecraft in history. The probe approached within 3.8 million miles of the sun’s surface, venturing into the sun’s corona—its outer atmosphere—where powerful solar storms originate.
The Parker Solar Probe, which has been orbiting the sun since its launch in 2018, is designed to withstand the intense conditions of this region. Its heat shield, measuring eight feet in diameter and 4.5 inches thick, can endure temperatures of up to 2,500 degrees Fahrenheit. Behind the shield, the spacecraft’s instruments operate at room temperature, enabling it to collect critical data safely.
During this record-breaking approach, the probe reached a speed of 430,000 miles per hour. “It’s the fastest human-made object ever,” said Nour Raouafi, an astrophysicist at the Johns Hopkins Applied Physics Laboratory and project scientist for the mission. To illustrate the speed, Raouafi explained, “That’s like going from Philadelphia to Washington, D.C., in one second.”
The mission’s goal is to study the sun’s corona and better understand solar phenomena such as coronal mass ejections (CMEs), which are eruptions of superheated gas that can affect Earth’s power grids, communications systems, and satellites. In 1989, for instance, a CME caused a 12-hour blackout in Québec, Canada, highlighting the importance of this research.
Raouafi emphasized the significance of the mission: “When the sun unleashes an explosion of energy and particles, the corona accelerates these particles. We want to understand how the acceleration is done.” Such insights could improve space weather forecasting and help protect critical infrastructure on Earth.
The Parker Solar Probe has made 22 orbits around the sun, each bringing it closer to its target. This close approach is part of a series of planned flybys, with two more scheduled for March and June 2025. As the spacecraft continues its journey, researchers hope to uncover new insights about the sun’s behavior.
“Hopefully, we’ll see something that surprises us quite a bit,” Raouafi said.
The spacecraft is expected to send a signal confirming its status on December 27, marking another milestone in its unprecedented mission.
