Venus may be grabbing all of the headlines, but the craters of Mercury’s north pole region star in the latest stunning images from the $1.8 billion BepiColumbo mission.
Flying just 183 miles (295 kilometers) above Mercury’s surface on Jan. 8, 2025, the spacecraft — which was built in the U.K. — imaged craters on the planet’s vast sunlit northern plains. It also imaged polar craters suspected of hosting ice and whose floors may be in permanent shadow.
Despite Mercury being about 39% as far from the sun as Earth is, its surface temperature can range from -290 degrees Fahrenheit (-180 degrees Celsius) at night to 800 degrees Fahrenheit (430 degrees Celsius).
Shadowed Craters
The flyby images, all black-and-white 1024×1024 pixel snapshots, come from two M-CAM monitoring cameras on BepiColombo that are mostly there to monitor the spacecraft’s solar panels, antenna and magnetometer boom.
The above image shows shadowed craters at the north pole, including Prokofiev and Kandinsky. These frigid, unlit craters may contain frozen water—a key mystery for future study. Nearby, the vast volcanic plains of Borealis Planitia showcase ancient lava flows and surface wrinkles.
Craters And Basins
BepiColombo’s second image reveals Mercury’s expansive Borealis Planitia, with lava-flooded craters like Mendelssohn and Rustaveli, their rims barely visible. Dominating the bottom left is the massive Caloris basin, spanning 1,500 km, surrounded by radiating troughs from its ancient impact. A bright lava flow near a deep trough hints at volcanic mysteries yet to be solved.
BepiColombo is named after the late Professor Giuseppe (Bepi) Colombo, an Italian mathematician and engineer who discovered a resonance that makes Mercury rotate on its axis three times every two years.
Volcanic Explosion
BepiColombo’s third flyby image showcases the Nathair Facula near Mercury’s upper edge, the site of the planet’s largest volcanic explosion. A 40 km-wide vent sits at its center, surrounded by a 300 km-wide deposit from at least three eruptions. To the left lies the Fonteyn crater, just 300 million years old, its bright impact debris radiating outward.
BepiColombo follows in the footsteps of NASA’s Mariner 10, which photographed Mercury in 1974-75, and NASA’s MESSENGER, which mapped it from 2008-2015.
BepiColumbo’s Journey
BepiColumbo is on a seven-year journey from Earth to Mercury, most of which is necessary for spacecraft to slow down enough to enter orbit safely. Having left Earth in 2018, it will reach the closest planet to the sun in November 2026. That’s a delay of 11 months on the original date, caused by a technical issue with its solar panels identified in April that means BepiColumbo’s thrusters from operating at full power. This was the final of six gravity assist maneuvers to steer it into orbit.
Joint Mission
The joint mission from the European Space Agency and the Japanese Space Agency—about as tall as a giraffe—is two spacecraft, ESA’s Mercury Planetary Orbiter and JAXA’s Mercury Magnetospheric Orbiter. They will separate from the chassis before they enter different orbits around Mercury.
The two orbiters will collaborate to investigate Mercury’s origin and evolution and its internal structure, geological features, composition, and craters. They will also study its atmosphere, magnetosphere, and the effect of the solar wind, explore the origin of Mercury’s magnetic field, and analyze deposits at its poles. They’ll also map the planet across various wavelengths.
Wishing you clear skies and wide eyes.
