Latest Search for Alien Life Taking Place on Earth

NASA's latest partner in the search for alien life: a group of about 50 geologists who are hunting for evidence of ancient life here on Earth. The University of Wisconsin's Astrobiology Research Consortium last month started a five-year, $7 million project funded by a NASA grant. It'll examine Earth rocks up to 3.5 billion years old in the hopes of understanding how life might have arisen elsewhere in the universe. "There's a story always hidden in rocks," says the lead investigator.

As the AP explains, the consortium has been tasked with finding biosignatures (elements or isotopes that show evidence of ancient life) and microscopic signs of life like microbes and other tiny and adaptable one-celled organisms. Among the team's findings so far: microbial life some 2 billion to 3 billion years old relied more on iron than sunlight for energy. Their work will ultimately be used to interpret data collected by Curiosity on Mars. (More Mars stories.)