Discover these stunning recent images of Mercury.

On January 8, at 06:59 Central European Time, the BepiColombo spacecraft successfully completed its sixth flyby of Mercury, the closest planet to the sun. This encounter was part of a "gravity assist" maneuver, using Mercury's gravitational pull to modify the spacecraft's trajectory, which aims to enter orbit around the planet by the end of 2026.

BepiColombo is a collaboration between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), designed to investigate the composition of Mercury. The mission includes two spacecraft: the ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter, launched in the fall of 2018 and currently orbiting the sun. As they approach Mercury again, the two spacecraft will separate to head toward their respective polar orbits, where scientific work will begin in early 2027. This work will focus on the planet's formation and the possible presence of water in the form of ice in some of its craters.

Meanwhile, three images captured during this latest flyby have been released. The first image, taken from approximately 490 miles above Mercury’s surface, shows the terminator zone, which is the boundary between the sunlit side of the planet and its shadowed side. Since Mercury’s rotational axis is almost perpendicular to its orbital plane, some areas, particularly the interiors of certain craters near the poles, remain in darkness. These craters are believed to be some of the coldest places in the solar system. The image identifies the Prokofiev, Kandinsky, Tolkien, and Gordimer craters, and the BepiColombo mission aims to determine whether there is frozen water within them.

Another image, captured from about 900 miles in height, shows large regions of Mercury's crater that have been smoothened by lava, indicating significant volcanic activity in the planet's past. This phenomenon is particularly observable in the 180-mile-wide crater called Mendelssohn. The crater rim is still visible, highlighted with an orange circle in the image, and has largely been filled in by smooth volcanic material that also makes up the surrounding plains. In the lower left of the image, the Caloris Basin can be seen, the largest impact structure known in the solar system, measuring more than 900 miles in diameter.

Finally, although the images may suggest otherwise, it is noted that Mercury is a dark planet. Indeed, to the naked eye, it may appear similar to our moon; however, its surface reflects only two-thirds of the light reflected by the moon. The younger formations on its surface tend to be lighter, but the material that emerges from the planet's interior darkens over time. For example, the light observed at the top of an image taken from 1,300 miles above Mercury corresponds to Nathair Facula, a result of a significant volcanic eruption on the planet. This particular site will become the focus of several mission instruments, which will attempt to study the composition of the erupted material to deepen the understanding of Mercury's composition. Just below Nathair Facula, the image shows the 125-mile-wide Rustaveli crater, whose inner mountains barely protrude from the surface due to the lava fill.