NASA astronomers first investigated the hot flow anomaly near the first planet from the Sun.
The data that the scientists used were obtained over the past two to three years from the Messenger station. First of all, astronomers studied the magnetic field of Mercury. This made it possible to determine the direction of the electric field lines in the areas of the areas of the alleged anomaly. The next stage of work was the measurement of heat fluxes of particles.
Messenger is an American automatic interplanetary station designed to explore Mercury. It was launched on August 3, 2004, and reached the orbit of Mercury on March 18, 2011. Since this planet is one of the least studied objects in the solar system, NASA specialists organized the Messenger mission. Due to the proximity of Mercury to the Sun, and, accordingly, the intense solar radiation, which is 11 times stronger than in the orbit of our planet, the station is equipped with a special protective system that prevents the probe and equipment from overheating
Thus, as a result of the analysis of the data obtained, the specialists were able to determine the turbulent regions in the atmosphere of Mercury, which are associated with the hot flow anomaly, as well as the sources of thermal and convective radiation.
A similar anomaly of the hot stream, investigated by scientists, is also characteristic of Venus, Earth, Mars and Saturn. This phenomenon occurs at the front of a near-planetary shock wave, where the solar wind interacts with the heated particles of the wave. This interaction changes the motion of particles - it can throw them away from the shock wave, and lead to the occurrence of the so-called hot flow anomaly.
Hot flow anomaly phenomenon: the solar wind (white) collides with a shockwave from the planet (gray), resulting in a hot flow anomaly (red)
© NASA / Duberstein
To date, these anomalies have been found in cosmic bodies, the dimensions of which are approximately from a thousand to one hundred thousand kilometers. According to astronomers, the determining factor in the formation of the hot flow anomaly is the geometric properties of the shock wave and its dimensions, and not at all the dimensions of the celestial body.
I must say that such a phenomenon as a hot flow anomaly is typical for a number of planets, but for Mercury it has been studied for the first time, therefore, a study by NASA specialists helped to understand the nature of such processes more broadly.