22-03-2025
NASA spacecraft set for second close encounter with the sun—what it hopes to learn
The Brief
NASA's Parker Solar Probe is making its second of three planned close passes through the sun's outer atmosphere.
The spacecraft will reach speeds of 430,000 mph, making it the fastest human-made object.
Scientists hope the mission will help explain why the sun's outer atmosphere is far hotter than its surface.
LOS ANGELES - NASA's Parker Solar Probe is set to make another daring plunge through the sun's outer atmosphere, continuing its mission to unlock the secrets of our star. This will be the probe's second of three planned passes through the solar corona, the superheated outer layer of the sun that remains one of astronomy's biggest mysteries.
The spacecraft, launched in 2018, is expected to reach record speeds of 430,000 mph (690,000 kph) during its closest approach, making it the fastest human-made object ever built. Since the flyby occurs in an area where real-time communication is impossible, NASA won't receive data from Parker until Tuesday afternoon.
The backstory
The Parker Solar Probe was designed to get closer to the sun than any spacecraft in history. Its mission is to study the solar wind, the continuous stream of charged particles that flows from the sun and affects space weather throughout the solar system.
One of the biggest puzzles Parker hopes to solve is why the sun's corona is hundreds of times hotter than its surface—a phenomenon that defies conventional physics. By flying directly through this intense region, Parker is gathering data that could help scientists better predict solar storms, which can impact satellites, communication networks, and power grids on Earth.
By the numbers
To withstand this extreme environment, Parker is equipped with a 4.5-inch-thick (11.4 cm) carbon-composite heat shield, which keeps its instruments at a safe operating temperature despite the intense heat outside.
The spacecraft will fly within 3.8 million miles (6 million kilometers) of the sun, much closer than any previous mission.
It will reach speeds of 430,000 mph (690,000 kph), fast enough to travel from Los Angeles to New York in about 20 seconds.
The sun's corona, where Parker is flying, can reach temperatures of several million degrees Fahrenheit.
What we know
Previous flybys have already provided unprecedented insights into how solar wind is generated and how the sun's magnetic field behaves. The latest close encounter will build on that data, potentially offering new clues about:
Why the corona is so much hotter than the sun's surface.
How solar wind is accelerated to supersonic speeds.
What triggers powerful solar storms that can impact Earth.
What we don't know
Despite decades of research, scientists still don't fully understand the mechanisms behind these phenomena. The more Parker Solar Probe can observe, the better researchers can predict and mitigate space weather effects on Earth.
What's next
After this flyby, Parker will make one more close pass through the corona in the coming months before continuing its long-term mission. NASA plans to gradually bring the probe even closer to the sun over time, eventually reaching within 3.83 million miles (6.16 million kilometers) by 2025.
With each encounter, Parker is expected to deliver even more groundbreaking data, helping scientists unravel the mysteries of the sun and improve our ability to predict space weather events.
The Source
This report is based on NASA's official mission updates and previous findings from the Parker Solar Probe. Additional information has been sourced from NASA's Goddard Space Flight Center and mission scientists.
