2018 preview: Epic mission to Mercury will unravel its mysteries

Mercury probe

It should be signposted “Welcome to hell”. Mercury, the sun’s closest neighbour, sees blasts of radiation and extreme temperatures – and it’s where we’re headed next.

In October 2018, a probe called BepiColombo will set off on an epic seven-year voyage to orbit the scorched world. Provided it can withstand the unforgiving 350°C after it arrives in 2025, the craft will try to unravel some of the enigmas left after observations by two previous missions to the planet.

Mariner 10 swept past Mercury in 1974 and found, to everyone’s surprise, that it had a magnetic field, whereas Venus, Mars and the moon don’t. More mysteries arose when Messenger visited a few years ago. In 2009, it confirmed that Mercury has a tenuous upper atmosphere of charged particles too sparse to constitute a true atmosphere. In 2012, it spotted what appeared to be ice buried in deep craters at the poles.