Mercurys Mystical Magnetosphere: Mio Space Shuttle and X-Ray Aurora

Image of the formation of echo waves on mercury. Credit: Image of Mercury: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington

Exploration of Mercury by the Mio spacecraft revealed echoes localized in its magnetic field. International research has used advanced theories and simulations to understand these waves, emphasizing the important role of tocophers in protecting the planet from metallic radiation.

Since Mercury is the closest planet to the sun among the planets of the solar system, it is strongly influenced by solar wind, which is a fast-moving stream (hundreds of kilometers per hour). Plasma Blow from the sun.

The exploration of Mercury was first carried out by the Mariner 10 spacecraft in 1974 and 1975, showing that Mercury has a magnetic field and therefore a magnetic field similar to Earth.

In the 2000s, the MESSENGER spacecraft provided detailed images of Mercury’s magnetic and magnetic fields and showed that the center of Mercury’s magnetic field was moved north from the center of the planet by about 0.2 RM (RM is 2,439.7 km of Mercurys). M).

A third exploration of Mercury is currently being developed by the BepiColombo International Mercury Exploration Project.^[1] Thanks to the Mio spacecraft (Project Scientist, Dr. Murakami) and the Mercury Planetary Orbiter (MPO). In particular, unlike the Mariner 10 and MESSENGER, the Mio spacecraft is equipped with a complete plasma waveguide (PWI, Principal Investigator Prof. Kasaba) designed specifically for the first time to investigate the electromagnetic environment around mercury. Electromagnetic waves can effectively accelerate the speed of plasma particles (heavier electrons, protons, ions); Thus they play an important role in the magnetic dynamics of mercury.

Current study results

The current study was carried out by a joint international research team consisting of scientists from the University of Kanazawa, Tohoku University, Kyoto University, MagneDesign Corporation, Laboratoire de Physique des Plasmas, France, with support from CNES (French Space Agency). And the Japan Aerospace Exploration and Space Science Institute.Zaza)

The Mio spacecraft, which was launched on October 20, 2018, is currently traveling to Mercury with the final launch into orbit around the planet, scheduled for December 2025. Although getting Mio into Mercury’s orbit is technically difficult due to the strong gravity. The Sun, compared to Mercury, is scheduled to enter orbit around Mercury in 2025 after several flights.^[2] Of the earth, VenusAnd Mercury for gravity-assisted drills.

During the Mercury flight, which took place on October 1, 2021 and June 23, 2022, the Mio spacecraft approached Earth at an altitude of about 200 km. The configuration of the spacecraft during the journey to Mercury is not optimal for measuring electromagnetic waves due to the noise coming from the spacecraft itself. However, the Mio spacecraft is designed to minimize its electromagnetic noise level as much as possible and is therefore certified as a clean electromagnetic spacecraft through EMC testing.^[3]

Alternating current magnetic field sensors that can withstand the hot atmosphere of Mercury were developed by Japan and France and allowed the first observation of electromagnetic waves around Mercury without noise pollution from Live spacecraft. This suggests a generation of local echo waves, such as those often found in the Earth’s magnetic field.

The existence of echoes in the magnetic field of Mercury, which has now been confirmed, has been predicted (frequency range, intensity, etc.) since the 2000s, when the Mio spacecraft’s plasma waveguide (PWI) device was designed. Up. What surprised most of the joint international research team, including Dr. Ozaki of Kanazawa University, was the location of the eclipse, which was found only in the most limited region in the early morning part of the Mercurys magnet in During both flights. This means that there is a physical mechanism that tends to generate echo waves only in the early morning part of the magnetic field of mercury.

To investigate the causes of eclipses in the dawn, a joint international research team used the theory of nonlinear growth of echo waves developed by Professor Omura of Kyoto University to evaluate the effect of the curvature of the distorted magnetic field of mercury. Strongly formed by solar wind. The magnetic field lines in the nocturnal field are stretched by solar wind pressure, while the magnetic field lines in the morning field have less impact, resulting in smaller curves.

Based on the characteristics of the magnetic field line and the nonlinear growth theory, it is shown that in the dawn field, energy is efficiently transferred from the electron to the electromagnetic wave along the magnetic field line, creating conditions that favor the formation of echo waves. The effect was also demonstrated in numerical simulations of the Mercury atmosphere using high-performance computers.

In this study, the team demonstrated the importance of the planet’s magnetic field, which is strongly affected by solar wind, on the basis of echo waves, due to the strong combination of theoretical observations and simulations. Of spacecraft.

The future

In observing the Mercury flyby, the team prepared for a comprehensive electromagnetic environment survey using the Mio spacecraft planned in orbit around Mercury. The echo waves that are expected to be detected during planning are observed locally, i.e., in the unpredictable morning part of Mercury, and the results show that Variations in the magnetic field of mercury.

The data show the existence of energetic electrons on mercury that can generate echo waves, the possibility of active electron generation accelerated by echo waves, and X-ray generation by precipitation electrons forcibly moving from a mercury magnet to a mercury surface. Driven by accompanying waves. These observations will have a broad impact on the scientific understanding of the mercury environment.

The Mio spacecraft is on its way to conduct a comprehensive exploration of Mercury. Based on flyby observations, we found that the distortion of the magnetic field is responsible for the formation of local echoes (e.g., extensive exploration of the electromagnetic environment by the Mio spacecraft in Mercury orbit). Not only an understanding of the plasma atmosphere of the entire Mercurys magnet, but also an in-depth understanding of the magnetic potential in general.

The magnetic field acts as a shield against life-threatening metallic radiation on the planets of the solar system. Comparing data from Mercury and Earth will strengthen our understanding of this vital natural protection of our planet.

Glossary

1. BepiColombo International Mercury Mining Project: Comprehensive exploration project for Mercury using two spacecraft (Mio and MPO) by Japan-Europe Cooperation. In particular, Japan is in charge of the Mio mercury probe, which is equipped with electromagnetic wave detectors, etc.
2. Flyby: With the probe of a spacecraft traveling closer to a planet. The orbit of the spacecraft probe changes in the desired direction using gravity.
3. EMC (Electromagnetic Compatibility) Testing: Evaluation tests to check whether unnecessary electromagnetic noise is emitted and whether the device is designed and manufactured in such a way that it will not malfunction even if it receives unwanted electromagnetic noise.

Evaluation tests to check whether unnecessary electromagnetic noise is emitted and whether the device is designed and manufactured in such a way that it will not malfunction even if it receives unwanted electromagnetic noise.

References: Whistler-mode waves in the Mercurys magnet observed by BepiColombo / Mio by Mitsunori Ozaki, Satoshi Yagitani, Yasumasa Kasaba, Yoshiya Kasahara, Shoya Matsuda, Yoshiharu Omura, Mitsuru Hikishima, Fouad Sahraoui, Laurent Chankazawion, Laurent Chankazawai, Laurent September 14, 2023Natural astronomy.
DOI: 10.1038 / s41550-023-02055-0