Guelph physicists Ralf Gellert and Iain Campbell are among authors of a new paper about Martian geology published last week in the journal Science. The paper discusses soil samples collected by the Mars Science Laboratory rover Curiosity, which landed on Mars in 2012, and compares those results to samples taken by earlier rovers. An instrument on the robotic rovers for studying elements in Martian soil and rock was developed by an international group of scientists led by Gellert. Curiosity is seeking evidence that Mars might have supported life.