The Parker Solar Probe: The Spacecraft That “Touched” the Sun

The Sun is the center of our solar system and the source of the light and heat that make life on Earth possible. Even though it is the star we know best, many questions about it remain unanswered. Why is the Sun’s outer atmosphere, called the corona, much hotter than its visible surface? How is the solar wind accelerated? And how do solar eruptions affect Earth and the rest of the solar system? To help answer questions like these, NASA launched the Parker Solar Probe on August 12, 2018.

The mission is named after astrophysicist Eugene Parker, whose work helped explain the existence of the solar wind. At the time, his ideas were considered controversial and initially rejected by his peers, but they later became a major part of modern solar physics, which makes it especially fitting that the spacecraft exploring the Sun was named after him.

(The New York Times)

One reason the Parker Solar Probe became so well known is because NASA said it had “touched the Sun.” However, it is important to note that this does not mean the spacecraft reached the Sun’s visible surface, which is called the photosphere. Instead, it entered the Sun’s outer atmosphere, the corona. Since the corona is still considered part of the Sun, scientists described this as the first time a spacecraft had technically entered the Sun itself.

Layers of Atmosphere in the Earth vs. Sun

The spacecraft has also broken records for speed and distance. During its historic close approach on December 24, 2024, Parker Solar Probe flew just 3.8 million miles, or about 6.2 million kilometers, above the Sun’s surface. At this point, it was moving at about 430,000 miles per hour, or roughly 692,000 kilometers per hour, making it the fastest human-made object ever built. As of March 11, 2026, it had completed its 27th close approach to the Sun.

(NASA Science)

Getting that close to the Sun is an enormous engineering challenge. To survive the intense heat, the spacecraft is protected by a carbon-composite heat shield about 11.4 centimeters thick. This shield allows its scientific instruments to operate while the spacecraft passes through one of the harshest environments in the solar system. Parker Solar Probe uses repeated flybys of Venus to gradually shrink its orbit and move closer to the Sun over time.

The mission is important because it helps scientists study the corona, the solar wind, and powerful solar events such as coronal mass ejections. These events are part of what is known as space weather, which can interfere with satellites, communications, and even power systems on Earth. By studying the Sun up close, Parker Solar Probe is helping scientists better understand the star that shapes our solar system every day.