While NASA's rovers have looked for signs of life outside of our world, they haven't searched for life directly. But Melissa Floyd, a scientist at NASA's Goddard Space Flight Center, is working on a device that might change that. She wants to build an instrument that could look through soil and rock samples for evidence of bacteria or another type of single-celled microorganism called archaea. These organisms are thought to have been the first to appear on Earth and Floyd began to wonder if maybe life on nearby planets evolved like it did on our own. "I had this idea, actually a major assumption on my part: what if life evolved on Mars the same way it did here on Earth? Certainly, Mars was bombarded with the same soup of chemistry as Earth," Floyd said in a statement.