Japan's Mio probe will attempt its first photographs of Mercury as early as March, with preparations under way for the attempt, people involved in the project said on the 4th. The spacecraft is due to arrive at Mercury late this month.
Mio is the Japanese half of BepiColombo, a joint mission with Europe that left Earth in 2018. It is expected to capture the thin sodium atmosphere that drifts around Mercury, and to record the planet's terrain as well. The arrival follows roughly eight years of travel covering about 10 billion kilometers.
Mercury sits closest to the sun of any planet in the solar system, and the sun's gravity makes it hard to reach. Exploration of the planet has therefore lagged. BepiColombo is the first mission to put two probes into orbit around Mercury, one from the Japan Aerospace Exploration Agency and one from the European Space Agency.
Two spacecraft, two orbits
Both craft are built to withstand the heat and will observe simultaneously from different orbits, studying Mercury's magnetic field, magnetosphere, surface and interior. The aim is to explain how the planet formed.
Mio traveled attached to the European probe, MPO, and launched from French Guiana in South America in October 2018. Its only imaging device is a sodium atmosphere camera, which has been unable to observe anything since launch because MPO has blocked its view.
The two craft separate in early December. Mio will then photograph Mercury and its surroundings and transmit the images through its own antenna.