Lina Hadid, a former ESA Research Fellow now at the Laboratoire de Physique des Plasmas at Paris Observatory, used the Mercury Plasma Particle Experiment (MPPE) suite of instruments active on Mio during the 19 June 2023 flyby, BepiColombo’s third of six Mercury gravity assists, to build up an impressive picture of the planet’s magnetic landscape in a very short period of time.

“These flybys are fast; 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,” she describes. “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.”

“We saw expected structures like the ‘shock’ boundary between the free-flowing solar wind and the magnetosphere, and we also passed through the ‘horns’ flanking the plasma sheet, a region of hotter, denser electrically charged gas that streams out like a tail in the direction away from the Sun. But we also had some surprises.