An international team of scientists has identified a completely new type of rock from the red planet and, for the first time, discovered the mineral garnet in a Martian sample. The breakthrough offers a rare glimpse into Mars' ancient past and could help researchers piece together the planet's 4.5-billion-year geological history. The discovery was made by an international research team including James Darling, professor of Earth and planetary science, from the University of Portsmouth's School of the Environment and Life Sciences.