BepiColombo has completed its fifth flyby of Mercury, marking a significant milestone in the European-Japanese mission to explore the planet. During this encounter, it became the first spacecraft to observe Mercury in mid-infrared light, revealing differences in temperature and surface composition across the planet’s heavily cratered terrain.
The groundbreaking images were captured using the German-led Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS), which made its maiden voyage into space. The MERTIS instrument is capable of detecting minerals on Mercury’s surface with unprecedented accuracy, providing valuable insights into the planet’s composition and geological history.
The first image taken by MERTIS shows the BashÅ impact crater, a feature seen previously by Mariner 10 and Messenger. The image reveals that the crater contains both very dark and bright material, indicating variations in temperature and surface roughness. The MERTIS instrument is sensitive to mid-infrared light with wavelengths of 7-14 micrometers, allowing it to distinguish rock-forming minerals.
The data gathered by BepiColombo will help scientists better understand Mercury’s mysterious surface composition, which has relatively little iron despite having an unusually large iron-nickel core. The mission also revealed that some chemical elements easily found on Earth are scarce on Mercury, contributing to its dark appearance.
To prepare for in-orbit studies, the MERTIS team tested various materials and mineral mixtures in laboratory experiments, simulating what Mercury’s surface might be composed of. The results will help scientists interpret the measurements taken by MERTIS during its upcoming flybys around Mercury in 2026.
BepiColombo is a joint mission between ESA and JAXA, launched on October 20, 2018. The mission comprises two scientific orbiters: ESA’s Mercury Planetary Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (Mio). After arrival at Mercury in late 2026, the spacecraft will separate and maneuver to their dedicated polar orbits around the planet, starting science operations in early 2027.
Source: https://scitechdaily.com/bepicolombo-unmasks-mercurys-hidden-surface-with-infrared-breakthrough