Revealing the Secrets: Breathtaking New Views of Mercury’s North Pole Illuminate Its Enigmatic Permanent Shadows

The BepiColombo spacecraft—a collaborative project between the European and Japanese space agencies—has recently captured breathtaking images of Mercury’s north pole during its latest flyby of the nearest planet.

The photos, showcasing the depths of Mercury’s notable polar craters, were taken by the spacecraft’s monitoring cameras (M-CAMs) on January 8. European Space Agency (ESA) Director General Josef Aschbacher unveiled the first image during a press briefing the following day.

“It required waking up at 5:30 a.m., but when the close-up photos began appearing in our shared folder, it was absolutely rewarding,” David Rothery, a planetary science expert at the Open University, states to New Scientist’s Alex Wilkins. “We had previously examined some simulated perspectives and used those to formulate our imaging tactics; nonetheless, what we witnessed exceeded our expectations.”

M-CAM 1, the inaugural monitoring camera, recorded a picture of the shadowy north pole (above) from an altitude of 489 miles above Mercury’s surface. The white apparatus seen on the right side of the image constitutes BepiColombo’s solar panel, and a part of the spacecraft’s Mercury Transfer Module is visible in the lower left. The image highlights Mercury’s terminator—the demarcation between day and night—at the center, almost parallel to the Prokofiev, Kandinsky, Tolkien, and Gordimer craters.

Due to Mercury’s rotation on an axis with a minimal inclination of only 0.01 degrees—practically vertical to its orbit around the sun—the edges of all four of these polar craters cast everlasting shadows within them. These perpetually dark regions are some of the coldest in the solar system, even considering that Mercury is the closest planet to the sun.

Earlier observations indicated that these perpetual shadows might contain frozen water, a thrilling theory that the BepiColombo mission seeks to explore further. The project and the spacecraft are named in tribute to Giuseppe (Bepi) Colombo, a 20th-century Italian mathematician who aided prior space missions, according to the Associated Press’ Marcia Dunn, including NASA’s Mariner 10, the first spacecraft dispatched to Mercury.

The region located left of the craters and terminator is the Borealis Planitia, which is Mercury’s largest area of smooth volcanic terrain, formed by significant volcanic eruptions 3.7 billion years ago. The resulting lava inundated pre-existing craters, such as the Henri and Lismer craters identified in the image. The wrinkled characteristics on the left side of the image likely emerged after the lava plains solidified and as the planet’s interior cooled and contracted, as per an ESA announcement.

Another M-CAM 1 image (above) showcases the Mendelssohn and Rustaveli craters, both ancient depressions in the Borealis Planitia that were flooded with lava billions of years in the past. The Caloris basin can also be seen in the lower left of the photograph; spanning over 932 miles in width, it is the largest impact crater on the planet and features linear troughs radiating from the point of impact.

Roughly positioned in the center, Mercury’s surface displays a relatively bright, boomerang-shaped lava streak. According to the announcement, this represents yet another cosmic inquiry the BepiColombo mission plans to investigate: the orientation of the lava flow. Did the lava proceed “into the Caloris basin, or out of it?”

BepiColombo captured this second image just five minutes following the first.

In conclusion,the third image, taken by M-CAM 2, illustrates the comparatively young Fonteyn crater (aged 300 million years) alongside the Nathair Facula, a characteristic formed from the most significant volcanic eruption in Mercury’s past. It contains a volcanic opening with a width of roughly 25 miles.

“[Nathair Facula] represents a crucial scientific target for several of BepiColombo’s instruments once we achieve orbit, as it provides our best opportunity to understand what aspects of Mercury’s makeup have permitted explosive volcanic activity to persist throughout much of the planet’s timeline,” Rothery states to New Scientist.

BepiColombo’s sixth flyby served as the final gravity assist maneuver required to advance the spacecraft before it enters orbit around Mercury in late 2026, as noted by BBC News’ Danny Fullbrook. Constructed by Airbus and launched in 2018, the spacecraft has traversed past Earth, Venus, and Mercury to achieve its intended velocity and path.

With its recent north pole flyby being the final one, these images are also the M-CAMs’ last close-range photographs of Mercury. The module to which they are linked will detach from the craft’s two orbiters when they commence their loop around the planet.

“Although BepiColombo’s principal mission phase may commence only in two years, all six of its Mercury flybys have provided us with priceless new insights regarding the inadequately studied planet,” remarks Geraint Jones, BepiColombo’s project scientist at the ESA, in a statement from the agency. “In the coming weeks, the BepiColombo team will diligently work to decipher as many of Mercury’s enigmas using the data from this flyby.”