Science & Exploration
First taste of Mercury’s exosphere
The BepiColombo PHEBUS spectrometer made its first measurements of Mercury’s tenuous atmosphere (exosphere) during the 1-2 October 2021 close flyby of the planet. The two brightest detections are shown in this uncalibrated quick-look data plot, highlighting the presence of calcium and hydrogen. The emission is seen as a function of time, which peaked once BepiColombo exited the shadow of Mercury (dotted region), shortly after closest approach.
The green line represents the distance from Mercury.
