When Leire Coloma and her colleagues at the University of the Basque Country peered into samples of Martian meteorites, they found something unexpected: traces of blue ink. The discovery wasn't a breakthrough about Mars—it was a breakthrough about how scientists study Mars, and it points to a problem that could quietly undermine years of planetary research.
The IBeA research group at EHU-University of the Basque Country, led by Professor Juan Manuel Madariaga, has been collaborating with NASA since 2014, analyzing meteorites through an agreement with the Johnson Space Center. Their work aims to determine the chemical and mineralogical composition of rocks from Mars and the Moon—pieces of other worlds that arrive on Earth as scorched masses, their outer layers transformed by the violent passage through the atmosphere. To study their interiors, researchers must cut and polish samples, a process that requires various tools, solvents, lubricants, and materials. And it turns out that process can leave traces behind.
Using Raman spectroscopy to examine Martian meteorites including MIL 090030 and MIL 090136, the team identified contaminants falling into two categories: residues from the preparation itself, such as diamond fragments used in cutting, and substances introduced through handling—including the blue ink. They also detected MoDTC, a common lubricant, in the samples. The finding, published in the journal Applied Geochemistry, reveals a troubling possibility: that minerals detected in meteorites might not be from Mars at all, but from the very instruments designed to study them.
"The introduction and use of certain external compounds during sample preparation could lead to incorrect characterization," Coloma explained, "as it would be unclear whether the minerals detected are the result of contamination or whether they are indeed original components of the meteorites."
But this discovery is not a cause for alarm—it's a cause for celebration of scientific vigilance. The IBeA group has already proposed remedial measures, including substituting specific solvents and materials to reduce contamination. These protocol improvements will be essential not just for meteorite studies, but for the future of space exploration itself. NASA's Perseverance rover is currently collecting samples on Mars that scientists hope will one day reach Earth, and the Basque Country team is among the laboratories being considered to receive them. Having clean protocols in place before those samples arrive is not a luxury—it's a necessity.
"Through our work, we are aiming to improve the protocols for preparing subsamples for analysis," Coloma said. "It is essential to work in the laboratory in such a way as to avoid introducing any kind of contaminant into the samples." In the careful, patient work of understanding other worlds, knowing what belongs to Earth—and what doesn't—is the first step.