At Christmas, NASA will see its Parker Solar Probe challenge the Sun at 690,000 km/h!
Illustration of the Parker Solar Probe during a very close flyby of the Sun. © Steve Gribben / Johns Hopkins APL / NASA via AP, File
Ah, Christmas by the fire! A beautiful image of Epinal which represents for many of us the memories of holidays with the smell of pine… This is a bit of what NASA will offer to Parker Solar Probe. This kamikaze probe will warm up, not in the corner of the chimney, but in the fire of the star of the Solar System, melting towards it at practically 700,000 km/h to get closer to its surface at a distance of 6 million kilometers. , which has never happened before. The 22nd scientific study flyby of the Sun will therefore take place on December 24, 2024 at 6:53 a.m. GMT.
The speed achieved by the Parker Solar Probe exceeds anything that humans have designed. © NASA / Goddard Space Flight Center
192 km/s, all instruments pointed towards the Sun
If we compare it with those of the Voyager 1 and 2 probes, of approximately 17 km/s, the speed of 192 km/s reached by the Parker Solar Probe is truly dizzying. The probe reached such a peak by relying on two parameters. The first is thegravity assist (or gravitational slingshot effect) of the planet Venus, whose seven flybys in November gave it a great acceleration. The second element is obviously the very great gravity of the Sun. As long as the space probe plunges into the gravitational well of our star, it accelerates; and as it gets closer than ever to our star, it also accelerates like never before!
Why make this poor NASA space probe suffer so much?
It goes without saying that the temperature increases near the Sun which, remember, is a gigantic ball of thermonuclear fusion gas. This is why the Parker Solar Probe, with a launch mass of 685 kg, has a thermal shield which allows it to withstand around 1400°C. In fact, one of the major missions of the NASA probe is to discover why and by what mechanism the crown of our star, a region of gas surrounding the surface, happens to be several million degrees hotter than its surface. A bit as if your hand “blistered” less in contact with the logs than in the surroundings of the fireplace…
Scientists believe that the activity of the Sun is to blame, in particular its magnetic field and its so-called “lacing” structures. Following the movements of these structures, magnetic field reversals occur, which release large quantities of matter and energy, thus heating the corona.
When the magnetic field suddenly folds back on itself, large ejections of material can take place. © SD Bale et al. 2019
The solar corona, clearly visible in this photo, was discovered during an eclipse. © L. Laveder
