BepiColombo Spacecraft’s Captured Images During Its Third Flyby Reveal Geologic Features on the Surface of Mercury

Mercury is the fastest planet in the Solar System, named after the Roman messenger god. Although it is the smallest planet in our star system, it is also one of the five classical planets visible to the naked eye. Just recently, Mercury took the attention of astronomers who sent space probes to investigate its environment.

Up-Close View of Mercury's Topography

On June 19, 2023, the BepiColombo spacecraft made its third close flyby of Mercury. Scientists behind the mission used this to investigate the planet's topography and capture images of its hot surface. The flyby carried the spacecraft within 240 kilometers above the surface of its target planet.

The new images released by the European Space Agency (ESA) the following day revealed the geology bounty of Mercury. Its surface contains excessive amounts of ancient volcanic ridges, craters, and lava flows. A particularly large crater becomes one of the most curious features of the images sent by the probe. It was given the name Edna Manley, a visual artist who contributed to the history of Jamaican art.

According to Professor David Rothery of Planetary Geosciences at the UK's Open University, the large crater could get the attention of astronomers in the future because it exposes dark low-reflectance material. This material is thought to be remnants of early carbon-rich crust on the surface of Mercury. Moreover, its interior has a basin floor flooded by smooth lava, suggesting prolonged volcanic activity.

Another feature spotted by BepiColombo is the Beagle Rupes escarpment, a 600-km cliff discovered during NASA's Messenger mission on Mercury between 2011 and 2015. Scientists believe that the cliff was formed when Mercury was young and was at the stage of cooling and contraction.

BepiColombo's Space Mission

BepiColombo is an international space mission that resulted from the collaboration between the ESA and the Japan Aerospace Exploration Agency (JAXA). It was named after Italian professor Giuseppe (Bepi) Colombo, who significantly contributed to celestial mechanics and space science.

Launched on October 20, 2018, its seven-year voyage aims to explore the inner Solar System. It relies on the gravitational force of Earth, Venus, and Mercury to slow itself down and move from the sun's orbit to that of its target planet. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (Mio).

Because of its proximity to the Sun, Mercury is least explored due to its hot surface temperature. Aside from it, orbiters find it more difficult to reach Mercury than to get Saturn. Despite these challenges, ESA claims that BepiColombo is the most advanced space probe ever to visit the least traveled planet in the inner Solar System. It made its first two flybys on October 1, 2021, and June 23, 2022.

Upon arriving at Mercury by December 2025, it is expected to begin its routine science operations. During this process, it has to endure extreme temperatures of over 350 degrees Celsius and gather helpful information during its nominal mission that will last one year.