Europe and Japan await the launch of their joint mission to the little world nearest the Sun.
Europe and Japan are set to launch their joint mission to Mercury, the planet closest to the Sun.
The partners have each contributed a probe to be despatched on an Ariane rocket from French Guiana.
The duo, together known as BepiColombo, are bolted to one another for the seven-year cruise to their destination, and will separate once they arrive.
It’s hoped their parallel observations can finally resolve some of the many puzzles about the hot, oddball planet.
One of the key ones concerns the object’s outsized iron core, which represents 60% of its mass. Science cannot yet explain why the planet only has a thin veneer of rocks.
Bepi’s high-resolution data should bring us nearer to an answer.
“Mercury doesn’t really fit with our theories for how the Solar System formed, and we can’t understand our planet fully unless we’re able to explain Mercury as well,” said Prof Dave Rothery, a Bepi scientist from the UK’s Open University.
The probes’ 6.4m-long, 4-tonne “stack” of parts are ready and waiting atop the Ariane launcher. Lift-off from the Kourou spaceport is timed for 22:45 local time, Friday (02:45 BST; 03:45 CEST; 10:45 JST Saturday). How important is this mission?
It’s the first time the European and Japanese space agencies (Esa & Jaxa) have gone to Mercury. The Americans have already been there, briefly with the Mariner 10 probe in the 1970s, and with the Messenger orbiter earlier this decade.
The latter provided remarkable new insights that included the amazing discoveries that water-ice is held inside some of baking Mercury’s shadowed craters, and that its crust contains a lot of graphite (pencil lead) .
Bepi will build on Messengers’ investigations. The new mission carries twice as much instrumentation and will get closer for longer, giving scientists much more detailed information. What will the probes do?
Europe’s Mercury Planetary Orbiter (MPO) and Japan’s Mercury Magnetospheric Orbiter (MMO) have different roles.
The MMO will make as its priority the study of the planet’s magnetic field. It will investigate the field’s behaviour and its interaction with the “solar wind”, the billowing mass of particles that stream away from the Sun.
