Since its launch in 2018, NASA's Parker Solar Probe has been getting closer to the Sun with each passing year, shedding light on key solar processes. By the end of 2024, it will have set a new record by grazing our star from a distance of just over 6 million kilometers, delving deep into its scorching outer layers.
One of the most daring missions in the history of space exploration, the Parker Solar Probe is the first spacecraft to fly through the Sun's outer atmosphere, known to scientists as the corona. It is scheduled to open new horizons in late December by covering 96% of the distance that separates our planet from its fiery star.
In doing so, Parker will reach speeds of about 700,000 kilometers per hour (or 435,000 miles per hour), enough to travel from New York to Tokyo in one minute – making it the fastest man-made vehicle in history. It will achieve this speed by oscillating around Venus, using the planet's gravity to tighten its orbit around the Sun and gain additional speed.
“This will be a tremendous achievement for all of humanity. This is equivalent to landing on the moon in 1969,” said Dr. Nour Rawafi, a Parker project scientist from Johns Hopkins University, at a press conference. Interview with BBC. “We're basically about to land on a star.”
in the Oven
Parker's mission is to make repeated passes around the Sun, getting closer to the star as it travels through its outer atmosphere, which, paradoxically, is 300 times hotter than its actual surface. This means facing unimaginable conditions, including temperatures approaching 1,400 degrees Celsius and solar winds charged with high-energy particles.
Parker's trick is to quickly dive into this inferno, relying on his superior speed and thick carbon composite heat shield. The shield protects an array of instruments that measure charged particles and magnetic fluctuations, and capture images and sounds.
In 2020, recordings made near the star provided the first audio clips of the solar wind – a stream of high-energy particles that streams continuously from the Sun.
Predicting solar storms
The mission's goal is to gain a better understanding of solar activity and shed light on many of the mysteries surrounding the coronavirus, as temperatures can reach a million degrees Celsius and above – compared to only 6,000 degrees Celsius on the surface of the Sun. Scientists hope that the data collected by Parker will help understand why the sun's outer atmosphere is hotter than its surface.
The corona is also where solar wind is generated, which sometimes turns into solar “flares” and “storms,” which can disrupt our planet's magnetic field, degrade communications, and pose health risks to astronauts. Ultimately, Parker's findings could pave the way for a space weather service capable of predicting and tracking such events.
The probe's end-of-year flight will represent its best opportunity to gain a greater understanding of key solar processes. It will also be its last encounter: after December, the probe's orbit will no longer allow it to swing around Venus, effectively preventing it from getting closer to the Sun.
This article has been translated from the original in French.
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