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<\/p>\nThe European Space Agency\u2019s BepiColombo spacecraft recently performed its fifth flyby of Mercury on Dec. 1, becoming the first spacecraft ever to observe the planet in mid-infrared light. BepiColombo\u2019s observations from the flyby have revealed interesting new details on the Mercury\u2019s surface, including temperature and composition variations.<\/p>\n
BepiColombo is only the third mission to visit the smallest planet in our solar system, making Mercury the least-explored rocky planet in the solar system. In 2026, BepiColombo will enter orbit around Mercury and begin its primary mission, becoming the first spacecraft to orbit Mercury since NASA\u2019s Messenger from 2011 to 2015.<\/p>\n<\/p>\n
BepiColombo\u2019s long journey to Mercury began on Oct. 20, 2018, when the mission launched from French Guiana atop an Ariane 5 rocket. The mission was initially planned to arrive at the planet in December 2025. However, thruster issues discovered in September 2024 forced a one-year extension of the coast phase, bringing the arrival date to November 2024.<\/p>\n
The mission\u2019s coast phase has involved several flybys of Earth, Venus, and Mercury, using the gravitational pull from each planet to alter BepiColombo\u2019s orbital trajectory around the Sun and bring the spacecraft closer to Mercury. BepiColombo\u2019s recent Dec. 1 flyby saw the spacecraft fly within 38,000 km of the planet\u2019s surface. The primary objective of this flyby was to gather additional data on Mercury\u2019s surface and surrounding environment.<\/p>\n
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Infographic highlighting BepiColombo\u2019s fifth flybys. (Credit: ESA)<\/p>\n
The spacecraft measured particles and electromagnetic fields while in the planet\u2019s vicinity and, for the first time, imaged the cratered surface in mid-infrared wavelengths with the Mercury Radiometer and Thermal Infrared Spectrometer (MERTIS) instrument.<\/p>\n<\/p>\n
\u201cWith MERTIS, we are breaking new ground and will be able to understand the composition, mineralogy, and temperatures on Mercury much better,\u201d said MERTIS principal investigator Harald Hiesinger of the University of M\u00fcnster in Germany.<\/p>\n
NASA mission patches (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n \u201cAfter about two decades of development, laboratory measurements of hot rocks similar to those on Mercury, and countless tests of the entire sequence of events for the mission duration, the first MERTIS data from Mercury is now available. It is simply fantastic!\u201d added MERTIS co-principal investigator J\u00f6rn Helbert of the German Aerospace Center (DLR) in Berlin.<\/p>\n The first observations from MERTIS revealed that certain areas of Mercury\u2019s surface shine brighter in the mid-infrared than others. More specifically, the Caloris Basin and parts of a large volcanic plain in Mercury\u2019s northern hemisphere emit more mid-infrared light.<\/p>\n Mid-infrared light increases in these regions due to surface temperature, roughness, and composition. MERTIS\u2019 imaging spectrometer is sensitive to mid-infrared light with wavelength between 7 and 14 nm. This wavelength range is known to be particularly suitable for observing and distinguishing rock-forming minerals in surface features.<\/p>\n MERTIS\u2019s mid-infrared measurements of Mercury\u2019s surface from the Dec. 1 flyby. (Credit: MERTIS\/DLR\/University of M\u00fcnster\/NASA\/Johns Hopkins University Applied Physics Laboratory\/Carnegie Institution of Washington)<\/p>\n \u201cThe moment when we first looked at the MERTIS flyby data and could immediately distinguish impact craters was breathtaking. There is so much to be discovered in this dataset \u2014 surface features that have never been observed in this way before are waiting for us. We have never been this close to understanding the global surface mineralogy of Mercury with MERTIS ready for the orbital phase of BepiColombo,\u201d said project lead Solmaz Adeli of the DLR.<\/p>\n Mercury\u2019s surface composition has long been a mystery in planetary science, and Messenger\u2019s data on the planet\u2019s surface and composition has proven lackluster in providing definitive results. When MERTIS and other BepiColombo instruments arrive in orbit around the planet in 2026, they will provide planetary scientists with better surface imaging resolution and elemental composition accuracy.<\/p>\n Messenger\u2019s data has led scientists to believe that Mercury\u2019s surface contains low amounts of iron \u2014 an interesting discovery given the planet\u2019s large iron-nickel core. Messenger also showed that some chemical elements that easily evaporate are present in high concentrations on Mercury\u2019s surface despite the planet\u2019s tight orbit around the Sun.<\/p>\n Another mystery surrounding Mercury is its dark appearance. While the planet\u2019s cratered surface may look similar to that of the Moon at first glance, it only reflects around two-thirds as much light as the Moon\u2019s surface \u2014 a fascinating characteristic for a planet that orbits extremely close to our Sun.<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2024\/12\/Mercury_in_mid-infrared_light.png\")
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