On the baggy Mercury | TIME ONLINE

For the first time, Europe and Japan are flying to Mercury. This is the third mission to the tiny of the solar systemWhy do you want to go back? What does the little planet have to offer both probes to travel together in space for seven years? Neither rings like Saturn nor gigantic storms like Jupiter. Not even an impressive color. It's safe. Moreover, the Americans were already there!

In fact, Mercury is still considered one of the least explored planets in the inner solar system. As the planet closest to the sun, it rotates the fastest around the central star. It looks like the rocky land, with temperatures between minus 180 and over 430 degrees Celsius, a world of extremes. The sun shines relentlessly for days and weeks.
In addition, he is able to betray here an unknown on the first period of our solar system. And the planetary messenger of the gods can, if you allow the very big questions, help to clarify: where do we come from? Why is the Earth special? Why is there no life here and the next planetary?

Forty years ago, NASA first visited Wandelstern. Mariner 10 was the name of the mission, arrived safely in 1974, but covered about 50% of the surface of the planet in three flyovers. Only successful messaging probe between 2011 and 2015, from an orbit to exhaustively decipher the mysteries of Mercury – and with almost every discovery, raises new questions.

BepiColombo is better thanks to the competition

Messenger photographed strange wells. There can be no impact craters or volcanic structures – but what exactly? Also documented on probe Irregularities in the magnetic field – but are they temporal, local? Discovery of volcanic activity – but what processes are going on? In the shadow of the poles near the poles, there were exceptionally bright deposits – perhaps ice? And the evidence found that graphitic carbon provides the dark color of the planet – does it come only from space or from a global ocean of molten magma from the planet's earlier history?

"In fact, we wanted to be launched in the year of messaging," says Ulrich Christensen, director of the Max Planck Institute for Solar Systems Research. His institute is involved in several instruments of the BepiColombo mission. "Before the Americans thought of flying to Mercury, we had already considered that," he continues. In 1993, there were the first ideas, in 2000, the project was decided, then discussed, planned, designed, rejected and the beginning thus postponed several times. "Americans are sometimes faster than Europeans."

This is also due to American pragmatism. Messenger was part of the Discovery program, which includes Mars Pathfinder, the Kepler Telescope or Stardust; the latter collected particles from the tail of a comet. Faster, better, cheaper Their motto was these missions – not too ambitious, they were quick and inexpensive, says Christensen. But nevertheless insightful. Fortunately.

Because without Messenger, BepiColombo would be unimaginable. The missions are in the spirit as closely related as the two probes BepiColombo physically with their transport module: From 2026, the Japanese MMO and the European DFO will explore the Mercury together. Their goal: to know as much as possible about the internal structure, the surface, the extremely thin atmosphere and the magnetic fields. After all, you will not be back soon.

"When Messenger started, we probably wondered," Is it still worth it? "" Christensen declares. The answer was unanimously "yes". It has adapted the objectives of the expedition and not only the advantage of being able to exploit the current data to answer the questions mentioned above, but also the possibility of filling the gaps of Messenger. If the US spacecraft is looking in particular at northern latitudes, BepiColombo should also pay meticulous attention to the southern hemisphere.