The dark side of Mercury: ESA's spacecraft will soon reveal sights on the planet that have never been seen before (video).

On Wednesday, January 8, 2025, the BepiColombo spacecraft (a joint project of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency) will perform a close flyby of Mercury at a distance of just 295 km. The spacecraft's instruments will measure the planet's environment, allowing scientists to calibrate them for operation during the main phase of the mission. This marks the sixth gravity assist maneuver around Mercury, which will help BepiColombo slow down and enter orbit around the smallest and least explored planet in the Solar System by the end of 2026, reports ESA.

BepiColombo was launched to study Mercury in October 2018. To achieve orbit around the small planet, the spacecraft has already utilized gravity assists from Earth, Venus, and Mercury itself. During the final gravity assist maneuver, BepiColombo's instruments will examine the vicinity of the innermost planet from the Sun, as well as the characteristics of its surface. Scientists will also perform calibration of the instruments in preparation for the start of its main mission in 2026.

The spacecraft will approach the dark side of Mercury, which will not be illuminated by the Sun at that time. Following this, the spacecraft will move toward the sunlit side of the planet. Scientists expect to receive the first images of Mercury's surface as early as January 9.

When BepiColombo nears Mercury, its solar panels will not receive sunlight for charging the batteries for 23 minutes. This will be the longest a spacecraft has ever gone without recharging. Scientists have ensured that BepiColombo will continue to function normally during this time.

BepiColombo will fly directly over Mercury's northern pole. This flight path will allow the spacecraft's cameras to observe the interiors of craters that have not been seen before. While temperatures on the sunlit side of Mercury can reach up to 450 degrees Celsius, some craters are so cold that they contain water ice. However, this is merely a hypothesis, and new data will reveal whether ice is present or not.

According to scientists, the spacecraft's cameras are expected to capture images of several of the most famous craters on Mercury, including the largest one – the Caloris Basin, which has a diameter of over 1500 km. BepiColombo will also pass through Mercury's magnetosphere, providing insights into the charged particles present there and the planet's magnetic field.

It is worth noting that BepiColombo consists of two orbiters: the Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter. Once it enters orbit around Mercury, the spacecraft will separate, and the two orbiters will orbit the planet on polar orbits. For a year, the orbiters will study Mercury, which still holds many secrets. There is a possibility that this mission could be extended for another year.