The joint European-Japanese BepiColombo mission captured this view of Mercury on 1 October 2021 as the spacecraft flew past the planet for a gravity assist manoeuvre.
The image was taken at 23:44:12 UTC by the Mercury Transfer Module’s Monitoring Camera 2, when the spacecraft was about 2418 km from Mercury. Closest approach of about 199 km took place shortly before, at 23:34 UTC. In this view, north is towards the lower left. The cameras provide black-and-white snapshots in 1024 x 1024 pixel resolution.
The region shown is part of Mercury’s northern hemisphere including Sihtu Planitia that has been flooded by lavas. A round area smoother and brighter than its surroundings characterizes the plains around the Calvino crater, which are called the Rudaki Plains.The 166 km-wide Lermontov crater is also seen, which looks bright because it contains features unique to Mercury called ‘hollows’ where volatile elements are escaping to space. It also contains a vent where volcanic explosions have occurred. BepiColombo will study these types of features once in orbit around the planet.
The gravity assist manoeuvre was the first at Mercury and the fourth of nine flybys overall. During its seven-year cruise to the smallest and innermost planet of the Solar System, BepiColombo makes one flyby at Earth, two at Venus and six at Mercury to help steer on course for Mercury orbit in 2025. The Mercury Transfer Module carries two science orbiters: ESA’s Mercury Planetary Orbiter and JAXA’s Mercury Magnetospheric Orbiter, which from complementary orbits will study all aspects of mysterious Mercury from its core to surface processes, magnetic field and exosphere, to better understand the origin and evolution of a planet close to its parent star.
Image & info via ESA