NASA and the European Space Agency, aka ESA, have signed a statement of intent in order to explore ways to undertake an ambitious joint project -- one under which Martian rocks can be gathered and brought back to Earth. Astronomers have witnessed signs of water on Mars and believe sometime in the distant past the planet may have hosted necessary conditions to support life. But, in order to prove this possibility and better understand our neighboring planet, comprehensive studies of Martian rocks are needed. Current Mars missions like the Curiosity Rover are doing a pretty good job at analyzing surface samples, but they can neither conduct lab-grade chemical and organic analysis nor scientists can verify the outcomes of those basic experiments. Prompted by these limitations, NASA and ESA agreed to work in conjunction with each other and signed the statement outlining the potential roles each of them could play in retrieving Martian rock samples. "There is no question that for a planetary scientist, the chance to bring pristine, carefully chosen samples of the Red Planet back to Earth for examination using the best facilities is a mouth-watering prospect," David Parker, ESA's director of human and robotic exploration, said in a statement.