On December 1, , the BepiColombo mission flew past Mercury for the fifth time and, as the first spacecraft ever, observed the planet in the mid-infrared. The new data reveals differences in surface temperature and the composition of its crater-rich surface.
Mercury is the innermost and smallest of the eight planets. Outwardly, it bears a strong resemblance to Earth's Moon, but the planet differs considerably from it in terms of its structure and composition. Planetary researchers therefore still have many unanswered questions about the formation, development and structure of the planet. The spacecraft will enter into orbit around Mercury in November The fifth of six close Mercury flybys has now taken place, bringing the mission closer to its final orbit around the rocky planet.
At exactly CET on 1 December , BepiColombo reached its closest point to Mercury in this fifth orbit, 37, kilometres above the planet's surface, resulting in a slight change in its trajectory. The flyby, or 'gravitational assist', occurred at a significantly greater distance than the previous four flybys — the previous taking place in September at an altitude of just kilometres.
At these high temperatures, the spectral signals of minerals differ from those measured at moderate temperatures. By measuring the heat radiation, BepiColombo is carrying out pioneering work. It is simply fantastic! The planetary geologist, Hiesinger, looks to the future and adds: "It is a real pleasure to work with such a fantastic team to analyse this data.
We are breaking new ground and will be much better able to understand the composition, mineralogy and temperatures on Mercury". As project lead, she has played a key role in planning the current flyby.
