Space travel Space probe "Bepicolombo" has come closer to Mercury than ever before

SDA

8.1.2025 - 12:09

Swiss instruments are also on board the "Bepicolombo" space probe. (archive picture)
Swiss instruments are also on board the "Bepicolombo" space probe. (archive picture)
Keystone

More than six years after its launch, the "Bepicolombo" space probe flew past the planet Mercury for the last time on Wednesday. The probe, equipped with Swiss instruments, thus completed the last milestone before entering Mercury's orbit.

Keystone-SDA

The European-Japanese space probe has thus come closer to Mercury than ever before, the European Space Agency (Esa) announced on X on Wednesday. At 06:58 Swiss time, it was only 295 kilometers away from the surface of the planet.

The flyby was intended to give the probe the necessary gravitational boost to enter an orbit around the innermost planet in our solar system in 2026.

During the flyby, Bepicolombo passed the night side of Mercury and then switched to the sunlit side, as Esa explained in a statement before the flyby. According to the researchers involved in the mission, including scientists from the University of Bern, this offers a unique opportunity to study the permanently shadowed craters at Mercury's north pole.

Long without the sun

According to Esa, one of the biggest challenges during this flyby was the long time that the sun-powered probe spent in the shadow of Mercury. For more than 23 minutes, "Bepicolombo" had to get by without direct sunlight and had to rely solely on its batteries.

"Bepicolombo" was launched on October 20, 2018 on its journey to the smallest and least explored planet in our solar system. The University of Bern is the project leader for two instruments on board the Esa orbiter: a mass spectrometer called "Strofio", which will analyze Mercury's atmosphere, and a laser altimeter called "Bela" (Bepicolombo Laser Altimeter), which will create a 3D image of Mercury's surface.