Second helpings of Mercury

The ESA/JAXA BepiColombo mission has made its second gravity assist of planet Mercury, capturing new close-up images as it steers closer towards Mercury orbit in 2025.

"We have completed our second of six Mercury flybys and will be back this time next year for our third before arriving in Mercury orbit in 2025," says Emanuela Bordoni, ESA's BepiColombo Deputy Spacecraft Operations Manager.

Because BepiColombo's closest approach was on the planet's nightside, the first images in which Mercury is illuminated were taken at around five minutes after close approach, at a distance of about 800 km.

It hosts a rare example of a candidate volcano on Mercury, which will be an important target for BepiColombo's high resolution imaging suite once in orbit.

Just a few minutes after closest approach and with the Sun shining from above, Mercury's largest impact feature, the 1550 km-wide Caloris basin swung into view for the first time, its highly-reflective lavas on its floor making it stand out against the darker background.

"Mercury flyby 1 images were good, but flyby 2 images are even better," commented David Rothery of the Open University who leads ESA's Mercury Surface & Composition Working Group and who is also a member of the MCAM team.

BepiColombo will build on the data collected by NASA's Messenger mission that orbited Mercury 2011-2015.

BepiColombo's two science orbiters - ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter - will operate from complementary orbits to 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.

It is making use of nine planetary flybys in total: one at Earth, two at Venus, and six at Mercury, together with the spacecraft's solar electric propulsion system, to help steer into Mercury orbit.

Its next Mercury flyby will take place on 20 June 2023.