Mercury's magnetic field explored by BepiColombo flyby

Written by Copernical Team Sunday, 06 October 2024 09:52

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Paris, France (SPX) Oct 04, 2024

During its June 2023 flyby of Mercury, ESA's BepiColombo spacecraft gathered critical data on the planet's magnetic field, offering insights into its dynamic magnetosphere. This brief encounter hints at the deeper mysteries BepiColombo will uncover when it enters orbit in 2026. Mercury, like Earth, has a magnetic field, though it is about 100 times weaker. Despite this, the planet's magnet

Mercury's magnetic field explored by BepiColombo flyby
by Erica Marchand
Paris, France (SPX) Oct 04, 2024

During its June 2023 flyby of Mercury, ESA's BepiColombo spacecraft gathered critical data on the planet's magnetic field, offering insights into its dynamic magnetosphere. This brief encounter hints at the deeper mysteries BepiColombo will uncover when it enters orbit in 2026.

Mercury, like Earth, has a magnetic field, though it is about 100 times weaker. Despite this, the planet's magnetosphere acts as a buffer, protecting it from the intense solar wind that constantly bombards it due to its proximity to the Sun. Studying this interaction is a primary goal for BepiColombo, which aims to understand how the solar wind shapes Mercury's environment.

BepiColombo will arrive at Mercury using a series of gravity assists, and once in orbit, two orbiters-ESA's Mercury Planetary Orbiter (MPO) and JAXA's Mercury Magnetospheric Orbiter (Mio)-will be deployed to capture a complete picture of the planet's magnetic and plasma environment.

During its June flyby, BepiColombo sped across Mercury's magnetosphere in just 30 minutes, gathering data that previewed the mission's larger goals. "We crossed Mercury's magnetosphere in about 30 minutes, moving from dusk to dawn and at a closest approach of just 235 km above the planet's surface," explained Lina Hadid, a former ESA Research Fellow, who now works at the Paris Observatory.

The mission's instruments, including Mio's Mercury Plasma Particle Experiment (MPPE), detected various features of Mercury's magnetosphere, including the 'shock' boundary where solar wind meets the magnetic field and the plasma sheet, which extends like a tail away from the Sun. "We sampled the type of particles, how hot they are, and how they move, enabling us to clearly plot the magnetic landscape during this brief period," added Lina.

One key observation was the detection of a low-latitude boundary layer with a broader range of particle energies than seen before at Mercury. This discovery was made possible by the Mass Spectrum Analyser, which was designed specifically to analyze Mercury's unique environment. The instrument detected ions of oxygen, sodium, and potassium likely ejected from the surface due to micro-meteorite impacts or solar wind interactions.

Lead researcher Dominique Delcourt highlighted how these findings hint at deeper connections between the surface and magnetosphere. "It's like we're suddenly seeing the surface composition 'exploded' in 3D through the planet's very thin atmosphere, known as its exosphere," he explained.

As the mission continues, researchers are eagerly anticipating data from the remaining two flybys scheduled for December 2024 and January 2025, and the eventual deployment of MPO and Mio. "We can't wait to see how BepiColombo will impact our broader understanding of planetary magnetospheres," said ESA project scientist Geraint Jones.

Meanwhile, the science team is already analyzing the wealth of information gathered from the latest Mercury flyby.

Research Report:Mercury's plasma environment after BepiColombo's third flyby