Mercury has a tenuous atmosphere containing alkali metals. In particular, the neutral sodium emission is bright and suitable for ground-based observation.

We use Tohoku University’s 60 cm telescope (T60) in Hawaii to perform 2D observations of Mercury’s exosphere.

In coordination with the BepiColombo spacecraft, which will enter Mercury’s orbit in 2027, we aim to observe Mercury both from the ground and in situ. Mercury’s magnetosphere is much smaller than Earth’s and varies on a timescale of just a few minutes.

By observing these rapid variations, we hope to better understand the interaction between Mercury’s atmosphere and its magnetic environment.