Unprecedented images of the Sun shed light on the mysteries of space weather
The closest images ever taken of the Sun reveal plasma eruptions stacked on top of each other and details of the solar wind, a true treasure trove for scientists.
NASA last week revealed these images captured by the Parker Probe on December 24, 2024, which will improve understanding of space weather and help protect Earth from solar threats.
"We've been waiting for this moment since the late 1950s," Nour Rawafi, the scientist in charge of the Parker mission, told AFP.
Other space probes had already studied the Sun, but from a much greater distance.
The mission, launched in 2018, is named after American astrophysicist Eugene Parker, who first described the phenomenon of solar winds in 1958 – the name given to the continuous streams of particles coming from the Sun.
The Parker probe recently entered its final orbit, which took it approximately 6.1 million kilometers from the surface of the Sun.
A record of proximity reached for the first time at Christmas 2024 and repeated twice since then, in March and June, following an 88-day cycle.
It came very close to the Sun. To give you an idea: if the distance between Earth and the Sun were one kilometer, Parker would have been only about forty meters from the star.
The spacecraft's only camera, WISPR, captured images as Parker explored the outermost layer of the sun's atmosphere, called the corona.
Assembled into a short video lasting a few seconds, these new images reveal for the first time in high resolution coronal mass ejections (CME), that is, huge jets of ionized particles that play a role in the occurrence of space weather phenomena.
These eruptions are, among other things, the cause of the spectacular aurora borealis seen across much of the world last May.
"We have several CMEs stacked on top of each other, that's what makes them so unique," explains Nour Rawafi. "It's truly incredible to see this dynamic in action," he adds.
Another surprising detail: the solar wind, flowing from the left of the image, outlines a structure called the heliospheric current layer – an invisible boundary where the Sun's magnetic field oscillates from north to south.
It is very important because it plays an essential role in the propagation of solar flares and their potential impact on Earth.
Space weather can have serious consequences, such as overloading power grids, disrupting communications, and damaging satellites.
Avoiding collisions between the thousands of additional satellites expected to enter orbit in the coming years is increasingly complex, especially during solar disturbances, which can slightly deviate their trajectory.
The Sun is now heading towards the minimum of its activity cycle, expected in about five to six years.
Some of the most extreme solar storms have occurred during this descending phase, such as the famous "Halloween storms" of 2003, which forced astronauts on the International Space Station to take extra radiation precautions.
“Capturing one of these gigantic eruptions (…) would be a dream,” says Rawafi.
Parker still has much more fuel than initially anticipated and could continue operating for several decades, until its solar panels degrade to the point where they no longer provide enough power to maintain the probe's orientation.
When its mission finally ends, the probe will slowly disintegrate until it becomes, according to Rawafi, “part of the solar wind itself.”
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