EXPLORING THE PAST AND FUTURE OF THE SWIFT PLANET

Visiting Mercury is a dangerous and difficult task. Navigating a spacecraft here requires propulsion that will get it to Mercury but also counteract the gravity of the Sun so the craft doesn’t go falling into its surface and burn up. This is why only two spacecraft have ever visited the small planet. NASA has been the operator of both of these, the first being Mariner 10 in 1974, which conducted a series of flybys and gathered close-up images.

The mission that brought the most fascinating results is MESSENGER – the first and only spacecraft to orbit the planet. MESSENGER’s most important results included how volatile-rich the planet was – volatiles being chemical compounds with low boiling points – which has important implications for the planet’s formation. It also found ice deposits at the poles, the weird magnetic field offset and irregular depressions called ‘hollows’.

BepiColombo, a joint endeavour by the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) will arrive at Mercury in 2025, where it will separate into two orbiters and use its impressive instrumental suite to investigate the planet from all angles. This unique mission will have its two orbiters working simultaneously as scientists get up-close observations of the surface and more distant observations of the magnetic field.