Since its launch in 2018, NASA's Parker Solar Probe has come closer to the Sun each year, shedding light on key solar processes. By the end of 2024, it will graze our star from just 6 million kilometers away, probing deeper into its fiery outer layers and setting a new record.
One of the most daring missions in the history of space exploration, the Parker Solar Probe was the first spacecraft to fly through the Sun's outer atmosphere, which scientists call the corona. It is set to break new ground in late December by passing 96% of the distance separating our planet from its fiery star.
In doing so, Parker will reach speeds of about 700,000 km/h (or 435,000 mph), enough to fly from New York to Tokyo in one minute — making it the fastest man-made craft in history. It will achieve such speed by oscillating around Venus, using the planet's gravity to tighten its orbit around the Sun to gain additional speed.
“This will be a monumental achievement for all of humanity. It will be the equivalent of the moon landing in 1969,” said Parker Project Scientist Dr. Noor Rouwafi of Johns Hopkins University. Interview with the BBC. “We're basically almost landing on a star.”
into the furnace
Parker's mission is to fly past the Sun repeatedly, getting closer to the star as it travels through its outer atmosphere — which, ironically, is 300 times hotter than its actual surface. That means facing unimaginable climates, including temperatures of 1,400 degrees Celsius and solar wind charged with high-energy particles.
Parker's trick is to dive quickly into this hellish scene, relying on its blistering speed and thick heat shield made of carbon composite. The shield protects an array of instruments that measure charged particles and magnetic fluctuations, capturing both images and sounds.
In 2020, recordings made close to the star provided the first sound clips of the solar wind — the stream of high-energy particles that constantly flow from the Sun.
Forecasting solar storms
The mission aims to gain a better understanding of solar activity and shed light on many of the mysteries surrounding the corona – compared to temperatures of just 6,000C on the surface of the Sun. Scientists hope the data Parker collected will help them understand why the Sun's outer atmosphere is so much hotter than its surface.
The corona is also where the solar wind forms, sometimes fueled into solar “heats” and “storms,” that can disrupt our planet's magnetic field, disrupt communications, and pose health risks to astronauts. Ultimately, Parker's findings could pave the way for a space weather service capable of predicting and monitoring such events.
The expedition's final year of exploration will represent an excellent opportunity to gain a greater understanding of key solar processes. It will also be its last: beyond December, the probe's orbit will no longer allow it to orbit Venus, preventing it from ever closer encounters with the Sun.
This article has been translated from French.