Parker Solar Probe, the first space probe in history to come so close to the Sun!

This is the first time in history that a spacecraft “touches” the Sun: the Parker solar probe has just entered the solar corona (the outer part of his atmosphere) in order to study particles and magnetic fields solar.

Passages in the solar atmosphere rich in discoveries

The boundary between the solar atmosphere and interplanetary space is blurred, since the Sun does not have a surface. solid. It is called the Alfvén critical surface, and is characterized by the point where the gravity and the Sun’s magnetic field can no longer retain the particles constantly pushed outwards by the heat of the’star. The successive entries and exits of the Parker probe have moreover shown that the Alfvén limit did not follow a well-rounded ball shape, but rather presented the shapes of ridges and valleys, as if “wrinkling” its surface.

At this proximity to the Sun, the probe is able to measure the conditions in the solar atmosphere as never before possible, marking important progress in the understanding of our star. The probe had for example identified magnetic structures in “laces” in the solar wind, but still stumbles on the identification of their origin.

The probe will continue to approach closer and closer to the Sun with a next passage in the corona scheduled for January 2022, providing data on phenomena impossible to study from Earth.

8.5 million km from the Sun: the Parker Solar probe breaks the distance and speed record!

NASA’s Parker solar probe, launched in 2018, aims to study the solar corona, the outer part of the Sun’s atmosphere. After a gravitational assistance operation around Venus, she broke new records this Sunday in her tenth orbit, by reaching a speed of 163 kilometers per second (or 586,800 km / h), at a distance of about 8.5 million kilometers from the Sun.

Article by Gaspard Salomon, published on 23 November 2021

After a gravitational assistance operation around Venus, it broke new records this Sunday during its tenth orbit, reaching a speed of 163 kilometers per second (586,800 km / h), at a distance of about 8, 5 million kilometers from the Sun.

The solar corona has a temperature reaching a million degrees (more than a hundred times the temperature on the surface of the Sun). She is at the origin of solar wind (flow ofions and D’electrons which bombards the planets of our star system) and the mechanisms behind these phenomena are still poorly understood.

The main objective of the Parker solar probe is to determine the processes causing the heating of the solar corona and the acceleration of energetic particles. Throughout its measurements, it will circulate in an elliptical orbit whose perihelion (point closest to the center of the orbit) is near the Sun, and theaphelia (point furthest from the center of the orbit) at the orbit of Venus. The gravitational effect of the latter will be used to gradually reduce the perihelion and allow the probe to come closer and closer of the Sun.

An astonishing and unexpected discovery

Whereas the probe accelerates towards the Sun, the instruments on board made it possible to make an unexpected discovery: according to Nour Raouafi, researcher participating in the project Parker Solar Probe, ” we observe higher amounts of dust than expected near the Sun “.

The probe is not initially designed to detect grains of dust, but the impacts they generate along the trajectory of the probe form clouds plasma that produce electrical discharges captured by Fields instrument of the probe, initially designed to measure electric fields and magnetic of the Sun. These impacts highlight light the presence of a cloud of dust which swirls in the innermost region of the Solar system, still very poorly explored.

After two more flyovers of Venus, in 2023 and 2024, the Parker probe will reach a distance of only 6.2 million kilometers from the Sun, at a speed close to 700,000 km / h.