Planetary Science Institute scientists have converged in the lab, trying to decipher the mineral composition of dust. Not just any dust, but rather a simulated sample of Mercury’s surface, created as a test run for the spectral observations from the BepiColombo mission to Mercury, which is expected to arrive in November 2026.
When the previous mission to Mercury, MESSENGER, arrived over 10 years ago, one of its goals was to decipher the mineral composition of the planet’s surface. But, while the spacecraft’s instruments were able to map the elemental surface composition, determination of the mineral composition remained enigmatic. The alteration of the surface by space weathering processes – such as impacts from micrometeorites, radiation from the Sun and thermal heating and cooling – are thought to be the cause.
The BepiColombo mission, a joint endeavor with the European Space Agency and the Japan Aerospace Exploration Agency, will explore Mercury with a new suite of instruments to help decipher the mineral makeup of the surface. To practice mission science in advance and prepare for interpreting the data collected, the German Aerospace Center, Deutsches Zentrum für Luft- und Ramfahrt or DLR for short, hosted a workshop focused on what laboratory work could be done to support this up-and-coming mission. A plan emerged called the Mercury Y project.
The Mercury Y project is a consortium of laboratories that have agreed to examine a mocked-up sample from Mercury, called a “mystery Mercury surface simulant,” said PSI Senior Scientist Deborah Domingue. “The scientists at DLR constructed a simulant that displays the spectroscopic properties observed by MESSENGER’s instruments, but didn’t tell anyone the mineral composition. The participating laboratories have to figure that out. PSI’s spectroscopic laboratory was invited to participate in solving this mystery.”
These observations are being led by Domingue and PSI Lab technician Neil Pearson as part of a project with Columbia University, led by Daniel Wolf Savin.
PSI’s laboratory is measuring the Mercury Y mystery sample at wavelengths spanning the ultraviolet to the mid-infrared and conducting X-ray diffraction and X-ray fluorescence measurements. These will overlap with the wavelengths observed by the SIMBIO-SYS camera system and the MERTIS mid-infrared spectrometer on board the BepiColombo spacecraft.
“The results will be shared and compared to the measurements obtained by the other consortium participants,” Domingue said. “Can we help solve this mystery? Will this provide insight into the interpretation of the new observations anticipated from BepiColombo? Stay tuned!”
